Mount Sutro Forest Isn’t Diseased or Dying – It’s Natural

This post is reproduced, with permission and minor changes, from SutroForest.com

sutro forest canopy June 2014 sm

CRYING WOLF WITH BEETLES

In the Sutro Stewards blog last month, Craig Dawson (who is its Executive Director) wrote a post claiming that the forest was in dire straits, infected with funguses and beetles: specifically, Anthracnose, armillaria, phytopthora, wood decay fungi, the snout beetle and the tortoise beetle. It concluded: “The bottom line is that we cannot expect much of the declining forest to recover from the condition it is currently found in, rather we can expect further widespread die-off. The dying trees will quickly pose a significant hazard within a year or two as we have already witnessed.”

It sounded alarming.

We sent the link to the article to a number of experts. None of them thought it was particularly serious. (One academic ecologist called it “…pure twaddle…” ) Nor did they agree with its conclusion that the forest would therefore decline.

  • “The diseases and insects mentioned in the Sutro report could be found in any forest…” (from a certified arborist and plant pathologist)
  • “The description of common conditions of eucalypt trees on the part of Mr Dawson’s piece seems to me solid as such—a description—but unconvincing as an argument that pretends to show some state of pathological emergency in Sutro…” (from an environmental science professor)
  • “This is amateur plant pathology at its best….” (from an urban forester)
  • “…faith-based botany…” (from an urban forester)
  • “This is certainly not the first time I have seen someone want to use a disease threat as a roundabout way to get some politically inconvenient trees removed.” (from an academic plant pathologist)

THE SPECIFICS

Some commented specifically on the individual fungi/ beetles. We also investigated ourselves, using the UC Davis website.

  • Anthracnose: “anthracnose is found on the leaves of many plants…” [In San Francisco] “sycamore leaves are filled with anthracnose…” (We would also note the UC Davis website says, “In California, anthracnose rarely causes permanent damage to plants except for elm trees.”)
  • Armillaria: “…definitely all over the place in the coast ranges and is even rampant in Golden Gate Park.” (This does not indicate a dire disease requiring intervention, especially tree-felling.)
  • Phytopthora: We could find no references to phytophthora in eucalyptus in California.
  • Wood decay fungi: “..these are mostly associated with older trees. The pictures represent Trametes versicolor – mostly found on dead wood, very rarely on living trees; Laetiporus gilbertsolnii – common on living Eucalyptus and oaks…” (Again, there’s no indication that these are reason for alarm.)
  • Eucalyptus snout beetle: These beetles feed on eucalyptus leaves. According to UC Davis’s website, “Eucalyptus snout beetle is controlled biologically by Anaphes nitens, an introduced parasitic wasp. No further control is necessary.”
  • Eucalyptus tortoise beetle: Also a leaf feeder, these beetles don’t usually kill trees. From the UC Davis website: “Unsightly, tattered leaves are usually just an annoyance that does not appear to threaten eucalyptus survival or health.” Since some tattered leaves in a forest setting are quite natural, we don’t think this is a problem.

Following a recent walk through Sutro Forest, Dr McBride (Professor Emeritus, UC Berkeley) noted that the forest looked healthy and thriving, with no evidence of the feared decline. He pointed out that in a naturalized setting like this one, we should expect some number of trees to do poorly or even die, as the forest “self-thins.” Furthermore, he said, without fungi and other creatures as part of the forest ecosystem, we’d be up to our eyeballs in dead logs.

fungus on a stump - sutro forest - june 2014

We have to say that in our years of frequent walks in the forest, in all weather and at all times of the year, most of these fungi and beetles are rare. Rare enough, in fact, that when we see fungi or mushrooms (the fruiting body of some fungi) we take pictures. We found a few leaves with evidence of tortoise beetles (semi-circular “bites” from the leaves), but they were few and far between. So far, we have not been able to find leaves showing the elongated perforations made by snout beetles.

few leaves have beetle holes

We asked about hollow trees. Dr McBride said that unless the remaining wood is less than 30% of the diameter, hollows in trees did not weaken them. “A tube is structurally one of the strongest forms,” he said. The life of a tree is in its outer layers. The center of a tree essentially provides structure. (And – hollow trees are great wildlife habitat.)

WHAT ABOUT THAT CANOPY?

The Sutro Stewards article also includes a picture of a stand of trees with a defoliated canopy, implying that is typical of the forest. It is not. This picture at the start of this article, taken in June 2014, is actually much more representative of the conditions in Sutro Forest. (Here’s a picture of the forest taken from Twin Peaks.)

sutro forest from twin peaks - June 2014

The stand portrayed in the article does exist. It is on the lower part of the East Ridge – right above an area where UCSF has removed a lot of trees and understory as part of their “fire hazard” action in August 2013. This has made the forest there much drier and less able to retain moisture – particularly since this is on a steep slope near the edge of the forest. Dr McBride considers that the trees’ intergrafted root system may also have been damaged during the work, making the stand much more vulnerable. However, the trees do seem to be recovering, currently with epicormic growth.

gradually recovering defoliated eucalyptus on east ridge of sutro forest

CAUTION: DON’T MESS WITH THE FOREST

But rather than indicating that the forest is diseased and trees should be removed, it suggests much more caution. The removal of smaller trees and understory and damage to root systems can stress trees, reducing the moisture available and increasing wind damage. Instead of making the remaining trees more healthy by “releasing” them, it can make them less healthy – as we see on the lower part of the East Ridge. Similar impacts are visible in Glen Canyon, where a lot of clearing has been going on – exacerbated by pesticide use.

Furthermore, with the normal fungi present, and with the usual damp conditions in this cloud forest environment, chopping down trees doesn’t help reduce fungi, it only spreads it around.

Bees in Glen Canyon – Update

 We’ve reported here before about the bee tree that was cut down as part of the “improvements” to Glen Canyon Park – and the one that was killed by mistake when someone thought it was a nest of yellow-jackets, not bees. This meant that only one of the three wild bee trees was still a living hive. We recently had both good news and bad news. There’s still only one bee tree, but the bees have proved resilient.

Karen Peteros wrote this note, which is published with permission. [This was originally published at Save the Trees of Glen Canyon Park.]

BEE TREES IN GLEN CANYON by Karen Peteros

Scott Mattoon and I have been working with RPD [San Francisco Recreation and Parks Department] Capital Improvements since 2011 to minimize adverse impacts Glen Canyon Park improvements could have on our feral honey bee colonies.

exposed hive with bees (Photo- Scott Mattoon)

Exposed hive with bees (Photo – Scott Mattoon)

One bee tree was lost on the hill above the Rec Center. Despite many many meetings with RPD, and a negotiated agreement to cut that bee tree at 25′ and otherwise leave it alone, the subcontractor failed to get that instruction and cut the tree at 5′. The trunk split and the colony exposed, but I was able to save the remaining bees and queen and install them in a Langstroth hive.

The bee tree that Scott discovered to have had its hive opening spray-foamed shut a few years back (above where Islais Creek goes underground) due to mistaken identification as a culprit of a nearby sting incident, seems to have reopened and a swarm moved in last year. That colony has done well, and recently swarmed (I understand Philip Gerrie retrieved the swarm).

revived hive

Revived hive – Photo (c) Janet Kessler

the bee tree that was killed has bees again

The bee tree that was killed has bees again. Photo (c) Janet Kessler

After many discussions, emails and meetings with RPD, Scott and I have convinced RPD to leave that tree alone for now. It has a substantial lean but, if it were to fall, it would not cross the path especially if RPD would cut off the top limbs right above the crotch where the limbs grow out of the main trunk. That’s been our recommendation but it has not yet been done to reduce the risks if it were to fall.

As usual RPD does what it wants — under-doing things by not cutting the limbs to reduce the risks if the tree were to fall which has been their stated concern but also over-doing things by placing the orange fence around the tree unreasonably suggesting the bees are a safety hazard when they are not. Nonetheless, the orange fence has served to be educational to bring park goers’ attention to honey bees in a natural habitat.

Finally, the very large mother bee tree, fenced down near Silvertree, with the opening in the base is undisturbed but the colony died out after many years of perpetuating itself.

I have not seen any bee activity there since late last year. 

the remaining bee tree

The old bee tree. Photo (c) Janet Kessler

Give the wax moths another year or more and, hopefully, the cavity will be cleaned out sufficiently to be deemed suitable by a future swarm looking to set up residence.

Karen Peteros,
Glen Park neighborhood resident & beekeeper
San Francisco Bee-Cause

Relentless War on Eucalyptus – The Example of Glen Canyon

This article is reproduced from MillionTrees.me – the website of Death of a Million Trees with permission and minor formatting changes.

A new front has opened in the relentless war on eucalyptus in California. The drought has given native plant advocates an opportunity to develop a new narrative to justify their demands for eradication of eucalyptus. The opening gambit in this new strategy is an item in Jake Sigg’s “Nature News” of May 16, 2014:

“The prolonged drought of the last 2-3 years seems to be taking its toll. The Tasmanian blue gums in Glen Canyon along O’Shaughnessy Boulevard strongly show drought stress. The stress is more evident from the high cliffs above O’Shaughnessy than it is at ground level. Thinning crowns and discolored foliage was striking. And that was before the recent heat wave. Barring substantial rains–unlikely, but not impossible–the trees are in serious trouble. The City could have an emergency situation and no money to address it.”

RECAP OF THE WAR ON EUCALYPTUS

When public land managers began the war on eucalyptus in the 1980s it did not occur to them that the public would object. So deep was their prejudice against eucalyptus, that they assumed the public shared their opinion. The first two massive projects in the 1980s on National Park Service and State Park properties were greeted with angry public protests. Land managers quickly learned that it was not going to be as easy to eradicate eucalyptus as they had thought. They developed a series of story-lines to justify their projects, which were designed to convince the public that the eradication of eucalyptus is both necessary and beneficial. This is a summary of some of their cover stories with links to articles that debunk them:

Based on our experience, we were immediately suspicious of the new claim that San Francisco’s eucalyptus forest is dying of drought. We know that our predominant species of eucalyptus—Tasmanian blue gum—grows successfully throughout California, all the way to the Mexican border in climates that are much hotter and drier than the Bay Area. We also know that the central and north coast of California is foggy during the dry summer months, which doubles the amount of annual precipitation in the eucalyptus forest. All reliable sources of horticultural information describe blue gum eucalyptus as drought tolerant. Frankly, we couldn’t see how our eucalyptus could be dying of drought.

WHAT IS WRONG WITH OUR EUCALYPTUS FOREST IN GLEN CANYON?

The picture became clearer when Jake Sigg posted the following on his “Nature News” on June 12, 2014:

“The June 10 newsletter [see below*] included an editorial on an evolving catastrophe, mostly involving our numerous plantations of Tasmanian blue gums. The editorial focused primarily on the plantations on O’Shaughnessy Blvd in Glen Canyon and on Mt Sutro, and included a photo of a grove of Mt Sutro dying trees. Here is a photo of the Glen Canyon plantation, taken from above the high cliffs on O’Shaughnessy. The damage is most visible from high, looking down. The discoloration of leaves was very dramatic, but the foliage color and condition is not fully conveyed in the photograph. Some trees defoliated entirely in the prolonged winter dry spell. Look very closely at the juvenile blue leaves of the coppice shoots; anything that appears faintly bluish are new coppice shoots which grew in response to the late rains we had in February and March. Once you see coppice shoots on old trees you know the trees are in trouble. These trees are in double jeopardy, as they invested energy in new shoots, but were betrayed by another dry spell which, under normal circumstances, will last until autumn. Note that you can now see the grassland through the trees; that slope was not previously visible. Even a casual inspection of these groves reveals dead, dying, and stressed trees, and under normal circumstances we will have four or five months of dry. The fire situation is serious right now and is likely to become worse.”

 

View of west side of Glen Canyon Park from Marietta Drive, June 2014

View of west side of Glen Canyon Park from Marietta Drive, June 2014

With more specific information in hand about what Jake Sigg is looking at, we went to see for ourselves. We could see what he was describing from a vantage point on Marietta Drive, west of Glen Canyon Park. We could see lighter colored leaves, but they were more localized than Jake Sigg’s description implied. We didn’t feel qualified to speculate about why the leaves were lighter colored so we recruited an arborist to help us figure out what is happening there. We were fortunate to enlist the help of a certified arborist who has been responsible for urban forests on public lands in the Bay Area for several decades. This is what we learned.

EPICORMIC SPROUTS

Looking through binoculars from our vantage point on Marietta Drive, the arborist said immediately, “Those are epicormic sprouts.” The leaves of epicormic sprouts are distinctively lighter colored than the darker green of mature eucalyptus leaves. They are also a more rounded shape than the long, pointed mature leaves of eucalyptus. This is how Wikipedia describes epicormic sprouts: “Epicormic buds lie dormant beneath the bark, their growth suppressed by hormones from active shoots higher up the plant. Under certain conditions, they develop into active shoots, such as when damage occurs to higher parts of the plant. Or light levels are increased following removal of nearby plants.”

Epicormic sprouts on trees in Glen Canyon Park, June 2014

Epicormic sprouts on trees in Glen Canyon Park, June 2014

The remaining question was why some of the eucalypts, were producing these epicormic sprouts, when most were not. We went down to O’Shaughnessy Blvd to get a closer look, hoping to answer that question. This is what we learned:

  • The understory of non-native shrubs between O’Shaughnessy Boulevard and the trees with epicormic sprouts has been cleared in the past year. We could see the dead brush piled up next to the trees. We had to wonder how people who claim to be concerned about fire hazard could think such huge piles of dead brush were nothing to be concerned about.

 

Remains of dead non-native brush destroyed along O'Shaughnessy Boulevard, June 2014

Remains of dead non-native brush destroyed along O’Shaughnessy Boulevard, June 2014

  • We could see the stumps of some of the dead brush and we wondered if the stumps had been sprayed with herbicides after they were cut. Pesticide use reports for Glen Canyon indicate that O’Shaughnessy was sprayed several times in the past year, twice with products containing imazapyr. Imazapyr is known to be harmful to trees if sprayed in proximity to their roots. The trees with epicormic sprouts were downhill from the understory shrubs that were destroyed, in the probable direction of water and herbicide flow.
  • We found several trees that had been girdled in the past and are now dead.
Girdled tree in Glen Canyon Park, now dead, June 2014

Girdled tree in Glen Canyon Park, now dead, June 2014

THE TREES IN GLEN CANYON PARK

Then we walked into Glen Canyon Park from its southern end. It’s not a pretty sight. Many huge, old eucalypts have been destroyed. When they were destroyed, their stumps were immediately sprayed with herbicide to prevent them from resprouting. The stumps are simultaneously painted with dye so that workers can tell which trees have been sprayed. The dye is no longer visible, but regular visitors took photos of the painted stumps before the dye faded. The spraying of the stumps do not appear on the pesticide use reports of the Recreation and Park Department. We assume that’s because the spraying was done by the sub-contractors who destroyed the trees.

Poisoned and dyed eucalyptus stump, Glen Canyon Park, 2013.  Courtesy San Francisco Forest Alliance

Poisoned and dyed eucalyptus stump, Glen Canyon Park, 2013. Courtesy San Francisco Forest Alliance

The arborist who walked in the forest with us said, “The painting of stumps with RoundUp or Garlon in proximity to trees that are being preserved can kill the neighboring preserved tree. Stumps near living, residual (preserved) trees should not be painted with RoundUp or Garlon if the stumps are within 40’ of mature, blue gums that are slated for preservation.” If the remaining trees are damaged by herbicides, their mature leaves fall and epicormic sprouts will then emerge as the tree recovers.

Some of the stumps of the trees that were destroyed in Glen Canyon Park in 2013.  Taken June 2014

Some of the stumps of the trees that were destroyed in Glen Canyon Park in 2013. Taken June 2014

While the trees were being destroyed in 2013, the Natural Areas Program was eradicating non-native vegetation in the Canyon. They sprayed ivy, blackberry, and valerian with Milestone, which is another herbicide that is known to damage trees if sprayed near their roots. In addition to these official applications of herbicide in this park, there is a long history of unauthorized, illegal herbicide applications by “volunteers,” more appropriately called vandals. We saw a lot of epicormic growth in the Canyon, sprouting from stumps that must be cut back and resprayed with herbicides. It usually takes several retreatments to successfully kill the roots of eucalypts that are destroyed. We also saw epicormic growth from eucalypts that had been severely pruned and were also exposed to a great deal more light because they had lost the shelter of their neighboring trees.

Epicormic growht, Glen Canyon Park, June 2014

Epicormic growth, Glen Canyon Park, June 2014

WRAPPING UP

The trees in Glen Canyon are reacting to the traumas to which they have been subjected: the loss of their neighbors that were either girdled or cut down thereby exposing them to more light and wind, the loss of the shelter of their understory, the application of herbicides known to be harmful to trees. The good news is that there are still plenty of trees in Glen Canyon that have not yet been destroyed and they are in great shape. Here is the view of the tree canopy in Glen Canyon taken from the east side of the park near Turquoise Way. The first picture was taken in December 2012 (before the current round of tree destruction in Glen Canyon Park) and the second picture was taken in May 2014.

Eucalyptus canopy on east side of Glen Canyon Park, taken from Turquoise Way December 2012, before tree destruction began.  Courtesy San Francisco Forest Alliance

Eucalyptus canopy on east side of Glen Canyon Park, taken from Turquoise Way December 2012, before tree destruction began. Courtesy San Francisco Forest Alliance

Same perspective of Glen Canyon tree canopy, taken May 2014.  Courtesy San Francisco Forest Alliance.

Same perspective of Glen Canyon tree canopy, taken May 2014. Courtesy San Francisco Forest Alliance.

These trees are doing just fine because the Natural Areas Program has not yet gone that deeply into the park. But NAP intends to destroy many more trees in Glen Canyon (and elsewhere) when the Environmental Impact Report (EIR) for their management plan (SNRAMP) is finally approved. Then we will see more consequences of the destructive practices of the Natural Areas Program and we will probably hear more bogus explanations for that damage. We expect the EIR to finally be considered for approval at the end of 2014. We will do whatever we can to convince San Francisco’s policy makers that they should approve the “Maintenance Alternative” which would enable NAP to continue to care for the native plant gardens they have created in the past 15 years, but prevent them from expanding further. We hope that our readers will help to accomplish this important task.


*Jake Sigg’s Nature News of June 10, 2014, introduced the theories of Craig Dawson about the health of the Sutro Forest. Mr. Dawson’s speculations are different from Mr. Sigg’s and we will not address them in those post.

Understanding Eucalyptus in the Bay Area – Dr Joe R. McBride

Dr. Joe McBride of UC Berkeley spoke at the Commonwealth Club in April 2014 as part of the series “The Science of Conservation and Biodiversity in the 21st Century.”  His main message:

  • Eucalyptus groves in California provide habitat for as many native species as do most ‘native’ habitats.
  • They grow well at high densities and an average spacing of 8 feet between trees is quite typical.
  • They have relatively high fuel loads, but the cool and damp dense eucalyptus forests reduce the risk of fire.
  • Eucalyptus is subject to few diseases or pests, and parasitic wasps provide pest control.
  • It provides a host of ecosystem services including carbon sequestration, pollution reduction, slope stabilization, windbreaks, wildlife habitat, and recreational value.

Dr. Joe R. McBride was Professor of Landscape Architecture and Environmental Planning, Department of Environmental Science, Policy, and Management, UC Berkeley. (He has since retired.)

Read on for notes from Dr. McBride’s talk. (There are also links to his Powerpoint presentation.)

mt-davidson-forest 1

 THE HISTORY, ECOLOGY AND FUTURE OF EUCALYPTUS PLANTATIONS IN THE BAY AREA

Notes From a Talk By Dr. Joe R. McBride

Dr McBride’s wide-ranging talk covered a lot of ground. He talked about the ecology of the eucalyptus forest in the Bay Area: its structure, the variety of plants and animals that live within it, its health and the ecological functions it performs; the dynamics within these forest stands; and their invasive potential.

WHY EUCALYPTUS CAME TO CALIFORNIA

Eucalyptus was first planted in California during the Gold Rush, possibly for oil to use in gold-mining and in medicine.

eucalyptus king of the forest smIn the 1870s, eucalyptus planting was encouraged for many objectives: to beautify cities, to improve farmland, as windbreaks, and to dry out swamps to combat malaria.

It was grown in woodlots for firewood, but as people switched to natural gas and other fossil fuels this became rare. Later, it was planted for timber – which didn’t work out because the trees were harvested too young; and still later for bio-fuel, which did not become commercially attractive.

By the 1950s, it had become an integral part of the California landscape. Six species were planted, primarily blue gum in Northern California, and red gum and river gum in Southern California. (Worldwide, there are perhaps 640 species.)

Eucalyptus beautifies our cities, and helps stabilize soil on steep hills. The surface area of the leaves, broader than those of conifers, help trap particulate pollution. Unlike deciduous trees, the evergreen foliage of eucalyptus removes pollutants all year long.

HOW DENSE MAKES SENSE?

The density of eucalyptus plantations in Bay Area ranges from 150-160 trees per acre to about 1700 trees per acre. mt davidson understory(The highest density resulted from a freeze in 1970s: trees were cut down because of the perceived fire hazard, but the trees presumed dead later resprouted.) On Angel Island, the normal density was 8ft spacing (about 680 trees per acre) but it ranged to 30 feet between trees. In the East Bay, 8 ft. x 8 ft. is quite typical eucalyptus plantation density. Left to grow naturally, stands become denser through in-growth, mainly by sprouting and also by sibling establishment.

Is management by thinning necessary for the health of the forest, someone asked,  and what density is ideal?

Dr McBride had seen no examples of stands that could be improved by thinning. Eucalyptus grows well with a high density at an average of 8 ft x 8ft spacing between trees. In Australia and New Zealand no one thins; they just harvest the trees and let them regrow from sprouts.

In the US, eucalyptus was not marketable, so there’s no history of managing eucalyptus plantations.  Also, until recently there were no diseases or insects.  The long-horned borer and the psyllid have now appeared in some places, and thinning is not seen as a solution to these insect problems; they are better controlled by certain predatory wasps.

Logging eucalyptus would mean a lot of ground disturbance and erosion.  If the logs are removed, the skid trails can destabilize the soil.

MUCH GROWS UNDER EUCALYPTUS – NATIVE AND NOT

Contrary to popular belief,  eucalyptus forests have as many species (or more!) growing in their understory as do oak woodlands. A 1990 survey in Tilden Park found 38 species in the understory of eucalyptus forests (24 native plants; 14 introduced plants), while the oak woodland had 18 species in understory (14 native plants; 5 introduced plants). Only the riparian woodlands in Murray Park are somewhat richer in species than riparian eucalyptus forest (58 species vs 34).

In East Bay eucalyptus forests, California Bay, Coast live oak, poison oak, bedstraw, California blackberry, and chickweed were ubiquitous. The amount of light reaching the ground influences which species can be found in the understory.

What about allelopathy? Under experimental conditions, eucalyptus litter inhibited germination and growth of cucumber seeds, so eucalyptus litter may be somewhat allelopathic to some plants. But a study from UC Santa Barbara indicates that if eucalyptus litter is removed, within 2 years there’s no inhibitory effect on other plants germinating. And clearly, it isn’t allelopathic to all the species mentioned earlier.

ivy does not reach canopy of densely growing trees

Someone asked whether it would be advisable to “manage eucalyptus stands that have an invasive understory.”

Dr McBride responded: “I have no prejudice against invasive plants. I am an invasive Californian myself.” (There was amused applause.) He continued that each eucalyptus grove is different, so it’s important to look at it on a stand-by-stand basis and measure the fire hazard of eucalyptus plantations against the value of each stand for wildlife habitation, recreation, and wind break functions.

In response to a question about whether ivy kills eucalyptus trees, Dr McBride said he has not seen evidence the ivy shades the foliage of eucalyptus trees. He’s seen no evidence of ivy killing eucalyptus, although on Mt. Davidson, he did see ivy growing over trees that had been killed by girdling with an axe or chainsaw.

INSIDE A EUCALYPTUS FOREST

Shading and leaf litter changes the microclimate of a eucalyptus grove. As you move in from the edge to the interior of the forest, conditions change. The species change from the edge to the interior of the forest as the amount of light decreases, so  there are different species at the edge of the forest and inside it.

A 1980s study in the Presidio compared conditions outside a eucalyptus forest and inside it. It showed:

  • Temperature moderation: Daytime temperature fell an average of 10%, and night-time temperature rose an average of 5%
  • Windbreak: Wind velocity dropped 40%
  • Relative humidity was 5% higher (from the edge to the interior).
  • Shade: Light intensity was 90% lower.
  • Moisture: Precipitation (rain) decreased 12%; but fog-drip (i.e., moisture precipitated from the fog) increased 300%

EUCALYPTUS STORES CARBON

Eucalyptus increases the carbon content in the soil compared to grasslands (Zinke et al, 1988). Its fast growth and large size means it sequesters a lot of carbon in its trunk and root systems.

EUCALYPUS SUPPORTS WILDLIFE

Young Great Horned Owls being raised in Eucalyptus tree Again, contrary to belief, eucalyptus provides a good environment for a wide variety of wildlife. A number of studies demonstrate this.

  • A 1970 study showed many birds make “moderate use” of eucs as habitat and a few birds make “great use” of eucs. (Almost all these species are native.) Birds that make most use: mourning doves; Great Horned Owls,  whose range has been extended by CA eucalyptus; Stellar’s jays; yellow-bellied sapsuckers; Allen’s hummingbirds; olive-sided flycatchers; brown creepers; dark-eyed juncos; Audubon warblers.
  • Some reptiles make great use of eucalyptus groves: Southern Alligator lizard and the slender salamander. Among mammals, deer mice make “heavy” use of eucalyptus.
  • Brown creeper forages on eucalyptusRobert Stebbins’ monumental 1978 study on the attractiveness of eucalyptus for habitat in the East Bay found that all species making use of eucalyptus for habitat found eucalyptus about the same as grasslands in attractiveness,  but oak/bay woodlands were even more attractive.
  • Monarch butterflies most commonly use eucalyptus trees  in state parks. But some of the insects in eucalyptus hurt the trees. One is the eucalyptus long horned borer – but can be controlled by a parasitic wasp. The red gum lerp psyllid is more of a problem in Southern California, which has more red gum. However, it’s part of the food chain: woodpeckers and other bird species feed on their larvae.
  • A study showed that eucalyptus in a riverside environment doesn’t impact species diversity of stream insects or pollution tolerance compared with native riparian environments.

NATURAL SUCCESSION IN EUCALYPTUS?

Over the next 200-300 years, the eucalyptus forests in the East Bay could gradually – and naturally – shift to oak-bay woodlands. In the East Bay (though not at Mt. Davidson or Mt. Sutro), the eucalyptus plantations have California Coast live oaks and California bay trees in the understory, and they are doing well. The live oaks are “tolerant” of shade and the bays are “very tolerant” of shade.  If they aren’t disturbed, the oaks and bays regenerate well in the understory, and being even longer-lived than the eucalyptus trees, they will eventually naturally succeed the eucalyptus. The bay tree is higher in regeneration than the Coast live oak in Tilden Park (McBride, 1990).

WHAT ABOUT FIRE HAZARD?

EEucs support considerable fuel load on the ground because of rapid decay of foliage and shredding of its bark. They have a higher fuel load than California bays or Coast live oaks. They release an aromatic compound that can ignite with sparks, and they burn  hot.

However, while the tree density of eucalyptus plantations can mean a greater accumulation of fuel in the understory, the higher density means a cooler, wetter understory that might not dry out as fast. Three risk factors in fire risks of any tree: amount of fuel it produces; tissue moisture content; fuel ladder based on presence of other plants in its understory.

IS EUCALYPTUS INVASIVE?

Under certain circumstances, eucalyptus can spread – for instance, on Angel Island, some stands spread through road cuts and prescribed burns (which destroyed competing vegetation).  However, in most cases they don’t: aerial photographs show that boundaries are stable. The eucalyptus forests on Mount Davidson and in Tilden Park show stable boundaries.

mt D comparison 1927 -2010

In the Bay Area, Dr McBride found eucalyptus forest area declined between 1939 and 1997. The natural spread hasn’t increased the area of eucalyptus groves.

DO TREES DEPLETE AQUIFERS?

Someone mentioned attending a talk where the speakers said that tree removal would help to replenish aquifers. Was that true? Dr McBride thought it very unlikely; most aquifers are much deeper than tree roots.

WHAT ABOUT PESTICIDES?

Someone speaking for people with disabilities owing to chemicals said herbicide use in these areas violated their right to access, and wondered how “environmental” organizations – like the Sierra Club – could support this. Dr McBride sympathized, said he was also concerned about toxic herbicide use. He mentioned that the East Bay tree-felling project is on hold owing to a number of unanswered questions that would need further research.

Here are his Powerpoint presentation in ppt , pptx and PDF formats.

PPT: McBride Presentation – Eucalyptus

PPTX: McBride Presentation – Eucalyptus

PDF: McBride Presentation – Eucalyptus

 

 

Damp Forest on Mt Davidson – Tony Holiday

This is another of our Park Visitor series: First-person accounts of visits to our San Francisco parks. This photo-essay is by Tony Holiday, a San Francisco hiker and blogger.  It’s adapted from his blog, Stairways are Heaven and published with permission. (Visit his blog for more pictures, and for the second post that details the route out of the forest down the Bengal steps.)

It’s high summer now, and elsewhere in California, fires have started. In our forests, it’s damp, even wet. We were struck by the contrast between the wetness of the forested area, and the dry open space adjacent to it on Mount Davidson. This is the cloud forest effect: The trees harvest the moisture from the fog and keep the forest cool and damp.

DAMP FOREST by Tony Holiday

The #36 Teresita stops at Mount Davidson Park’s main south entrance (Dalewood & Myra) where a steep trail climbs to the openspace part of the park. I love this trail: forested to start out, with a vast view to the east a little way up.

Here’s the south trail head.

4334894_orig - 1 South trailhead

And a small offshoot trail…

8176020_orig 2 offshoot trail

I climbed out of the forest to the open space.

7570617_orig 4 curving around

7082684_orig 3 climbing to the open space

THE OPEN SPACE AND VIEWS

This is the open space part of the mountain, with views to the east  and south over the city.

5027966_orig 5 view east

7960836_orig 8 looking south

2513967_orig 9 openspace bench

3514794_orig 10 view north

7411013_orig 11 view north

It’s a good place to pause for tea and admire the view…

5093980_orig 12 pausing for tea

Climbing 22 steps from the open space brings you to the plateau on top of the mountain with the 103-foot cross.

2858920_orig 16 summit cross

BACK INTO THE COOL LUSH FOREST

Down 22 old wood steps from the north side of the cross…

4275316_orig 17 old wood step start down from the side of the monument

… there’s a short trail…

5819148_orig 19 ferns and a damp trail

2691069_orig 20 down to a main trail

…then 12 more stone steps to the next main trail down.

1660245_orig 22 foot of one of the short stone stairways

Up here the trails were damp or muddy, including some actual puddles.

7940036_orig 23 muddy upper trail

Another short stone stairway:

572463_orig 24 anothr stone stairway

Following the trailing down, enjoying the cool, lush forest…

6294871_orig 25 trees and rocks

3227413_orig 26 down through the forest

… and the greenery below the trail…

4428599_orig 27 below the trail

4787964_orig 28 forest view

The trail went winding down…
3864834_orig 29 winding around

… and it was just me, the forest, and birdsong.

8763025_orig 30 just me, the forest, and birdsong

The forest was peaceful…

806571_orig 31 peaceful and cool

… as I followed the narrow and winding path to its end.

1526681_orig 33 narrow and winding

Love the ferns here!

6534432_orig 34 love the ferns

Natural Areas Program and Tree-Felling

Some time ago, we received a response from Phil Ginsburg, General Manager of the San Francisco Recreation and Parks Department (SFRPD) , to our concerns regarding the “Natural Areas Program”  (NAP). We thank him for the March 2014 letter – copied to the Board of Supervisors –  regarding the Significant Natural Resources Area Plan (SNRAMP), but as we stated in our response regarding pesticide use, we still have a number of points of disagreement. This one’s about trees – and “endangered species.”

7. The steps below the cross - most of these trees are doomed

THAT’S NOT WHAT THE TREE EVALUATION SAID

The letter states that more than 80% of the trees planned for replacement with native shrubs have been classified by an arborist as being in poor or fair condition.

We made a sunshine request for the arborist’s report. It summarizes previous evaluations of trees “adjacent to areas of high use such as streets, playgrounds, adjacent to properties and parking lots.” This is not where trees have been designated for removal by SNRAMP. Therefore, Hort Science’s evaluation is irrelevant to tree removals designated by SNRAMP.

Mr. Ginsburg states that, “By prioritizing the removal of these trees we can promote the health and sustainability of…the forest.” Since these aren’t the trees that SNRAMP proposes to remove, his statement contradicts SNRAMP’s stated plans to remove trees based on their location, not their condition. Also, as indicated in the analysis of Mt. Davidson Park by Dr. McBride of UC Berkeley, the eucalyptus forest will not be sustained by the clear-cutting proposed in the SNRAMP: “The proposed cutting of trees will increase the wind throw and wind breakage of the remaining trees.”

The arborist’s report is based on a non-scientific and non-representative number of trees in the four natural areas. Only 800 trees were sampled and their condition evaluation was more severe due to being adjacent to areas of high use. Take Mt Davidson for example. An extremely small sample of 78 trees were in the Mt. Davidson Park tree risk assessment completed by HORT Science in July 2012. All of them were adjacent to the perimeter parking area or the bus stop. None of these trees were actually in the 10-acre area of the park designated up to 82% tree removal for SNRAMP.

In Stern Grove, Hort Science evaluated trees in 2003. It says “While approximately 1,000 trees were inspected, we tagged 284 trees as having significant defects (28% of trees). Of those 284 trees that Hort Science evaluated as having “significant defects” 225 were Blue Gums.

In other words, Hort Science did not find that 80% of Blue Gums in Stern Grove were in “fair or poor” condition. As Hort Science says, Blue Gums in San Francisco were all planted around the same time. Therefore Blue Gums in Stern Grove are about the same age as the trees evaluated by Hort Science in the “four natural areas” (attached).

WHAT ENDANGERED SPECIES?

Mr. Ginsburg states “These areas support an array of native habitats and species, some found nowhere else in the world, such as the San Francisco Garter Snake and the Mission Blue Butterfly.” These two species are not found the in the natural areas designated within the City limits of San Francisco. Instead, there’s an ongoing program to reintroduce the Mission Blue Butterfly to the Twin Peaks area by moving dozens of butterflies each year from San Bruno Mountain, which has a thriving population.  In the five years since it started, the results are uncertain.

Anise swallowtail butterfly breeds on fennel

Anise swallowtail butterfly breeds on fennel

In fact, there are no endangered species in the parks designated for tree removal. The native species that are present are found throughout the Bay Area. There’s also no evidence that native species of birds and animals favor Native Plant gardens. The native Anise Swallowtail butterfly relies on fennel, a plant frequently targeted for toxic herbicide applications. Native birds such as the Great Horned Owl, the red-tailed hawk, and various woodpeckers nest in eucalyptus trees.  In fact, the variety of habitats – including dense forests like that on Mt Davidson – have helped expand the number of species found in San Francisco.

What is endangered in San Francisco’s parks are its trees and the public’s access to them.

stop sign tree stump 1

Opposing ROSE’s Policy 4.2 – Update

Two weeks ago, we explained why we oppose the ROSE (Recreation and Open Space Element of the General Plan for the city of San Francisco), and asked San Franciscans to write to the Land Use Committee of the Board of Supervisors. The main issue is that the draft ROSE includes Policy 4.2, which potentially could extend the same principles as the Natural Areas Program (i.e. cutting down trees, restricting access, using toxic herbicides, all to favor Native Plant museums) to all the city’s Open Spaces.

Here’s an update.

  • The Land Use Committee decided not to decide. Thanks to your emails and phone calls, the three Supervisors on the Land Use Committee grew concerned about the issue. Though they did not vote NO on the ROSE, they did not vote yes either. Instead, they passed it on to the full Board of Supervisors without a recommendation. The Board was expected to vote on June 24th, 2014.
  • The Full Board postponed the vote to July 8th, 2014. Because of the uproar against the ROSE, the Board decided to postpone the vote for two weeks, until July 8. Supervisor Scott Wiener (District 8) said that some of his colleagues had not been “briefed” on the ROSE. We are not sure if that means briefed by one of the city departments that is hoping to push the ROSE through with the egregious Policy 4.2 still included; or if they wish to take the time to understand the concerns of those so vehemently opposed.

The good news is this gives us more time to get even more people to ask them to Vote NO on the ROSE. The West of Twin Peaks Central Council voted this week to send a letter urging the Supervisors to Vote NO on the ROSE. Others are trying to visit the supervisors to brief them from our point of view. We encourage you to write (e-mail) and/or call your Supervisor to urge him/her to enter a no vote on July 8th.

The Natural Areas Program is a really bad model to extend all over the city. Even within its current bounds, it generates enormous controversy, quite disproportionate to its size. There is no reason to use the same principles elsewhere.

OUR VIDEO

Watch our video on Youtube, (where you can also sign up for the SF Forest Alliance Youtube channel):

OUR MESSAGE TO SAN FRANCISCO’s BOARD OF SUPERVISORS AND SFRPD

What we stand for can be summarized in four key areasTreesAccessToxinsTaxes.

This is an opportunity for the Supervisors to stop something that would be bad for our city, for residents and families, and wildlife. It would build conflict into the General Plan, possibly for decades.

The San Francisco Forest Alliance asks the Supervisors to vote NO on the ROSE, to send it back to Planning until Policy 4.2 is removed. We’re a grass-roots organization of people who love nature and the environment, pay taxes responsibly, and want access to our parks and wild places – with our families.

Citizens care about their city Parks, and want to keep healthy trees and to open access to natural areas. Citizens expect city management to act responsibly and in the public trust.

No Grant for “Biodiversity” Plan!

Mt D 6-17-2013Last month, we wrote about the city’s new proposed “Biodiversity” Plan that is even worse than the Natural Areas Program (NAP). In that post, we talked about their effort to get a $250,000 grant from the California Strategic Growth Council, and urged you to write to oppose it.

We’re pleased to say that your voices were heard in Sacramento. The California Strategic Growth Council (SGC) did not select the application from the Office of Biodiversity from the Dept. of Environment. Their staff did not recommend the application to the full Council.

Had the application been granted, it would have funded developing a city-wide master plan to manage all of San Francisco’s open spaces, including private backyards, like NAP areas – cutting down trees, using toxic herbicides, and restricting access. Your many letters and calls expressing community opposition to this idea were clear, well-articulated and convincing.

All of us are stakeholders in San Francisco’s open spaces. Many of us have a long history of objecting to NAP, but our voices have been ignored by representatives of our “public servants.” This time our voices were heard.

The state received 184 grant proposals to compete for the $23.9 million in award funds through the Urban Greening Grant Program. Thirty-seven projects received $22.9 million in funding, and 3 Urban Greening plans out of 14 submitted shared $1 million in funding. San Francisco Rec and Park did receive funding for the Noe Valley Town Square Development, and for Mansell Corridor Improvement.  Literacy for Environmental Justice received funding for Candlestick Point State Recreation Area. These are worthwhile projects. At this point all the funding through the SGC for the Urban Greening Grant Program for Sustainable Communities has been awarded and will not be available beyond this year.

BEWARE OF THE ROSE

Next up  is the review of the ROSE (Recreation and Open Space Element of the General Plan), by the Land Use and Economic Development Committee of the Board of Supervisors. The ROSE contains the dangerous “Policy 4.2″ which gives the City the right to bring NAP practices even into private open spaces. This proposed policy will allow implementation of NAP and destroy our mature eucalyptus forests in places such as Mt. Sutro and Mt. Davidson. It allows the same Biodiversity Coordinator in the Department of the Environment to get involved in land use decisions prohibited by the City Charter. Click HERE for details on what it is, and what you can do.

Please try to attend the meeting on Monday, June 16th, 1:30 pm, Room 263 of City Hall (double check the agenda after it’s posted on the sfgov website.) It is the ONLY time public comment will be taken.

Please ask the Supervisors to vote NO on the ROSE until Policy 4.2 is removed.

Ideally, please attend the meeting and speak. If not, please write to the Supervisors involved and let them know. Here are the meeting details: 

Land Use Committee
Monday, June 16, 2014, 1:30 pm
Room 263, City Hall – San Francisco

If you cannot attend, please write/ call the Supervisors on the Committee to say you want Policy 4.2 removed:

  • Supervisor Scott Wiener: scott.wiener@sfgov.org 415-554-6968
  • Supervisor Jane Kim: jane.kim@sfgov.org 415-554-7970
  • Supervisor Malia Cohen: malia.cohen@sfgov.org 415-554-7670

We have been heard in Sacramento, and we will continue to speak up in San Francisco. We have established ourselves as stakeholders with a strong voice to help shape the future management of our city’s open spaces.

Thank you!

 

Watch Out for ROSE (Action Alert)

Next Monday- June 16, 2014 – San Francisco Board of Supervisors’ Land Use Committee will consider whether to approve the Draft Recreation and Open Space Element (ROSE). The ROSE is a document that will govern how SF manages its open space for decades to come. In many ways, this is an excellent document. Unfortunately,  it includes a  very problematic section.

“Policy 4.2″ is designed to ensure that nearly all open spaces in San Francisco, even those in private hands – like your backyard – would be managed like the Rec and Park Department’s controversial Natural Areas Program (NAP).

 

Please ask the Supervisors to remove Policy 4.2 from the ROSE.  Ideally, please attend the meeting and speak. If not, please write to the Supervisors involved and let them know. Here are the meeting details:

Land Use Committee
Monday, June 16, 2014, 1:30 pm
Room 263, City Hall – San Francisco

If you cannot attend, please write/ call the Supervisors on the Committee  to say you want Policy 4.2 removed:

  • Supervisor Scott Wiener:  scott.wiener@sfgov.org 415-554-6968
  • Supervisor Jane Kim:  jane.kim@sfgov.org 415-554-7970
  • Supervisor Malia Cohen:  malia.cohen@sfgov.org 415-554-7670

 

 THE PROBLEM OF ROSE’S POLICY 4.2

Policy 4.2 in the Draft ROSE begins by praising SFRPD’s Natural Areas Program (NAP). NAP is the program that wants to cut down over 18,000 healthy non-native trees, tear out existing healthy non-native habitat, and re-create a habitat that existed in SF before western colonization, a habitat they perceive to be “better” than the existing non-native one – despite all the evidence that “restorations” only create Native Plant Gardens, not the eco-systems that existed before.

NAP uses a lot of toxic herbicides – repeatedly – to destroy non-native plants.  It restricts access to its areas to people and families, including children and pets – they’re all about “Stay on the Designated Trail” so kids, dogs, and naturalists have no permission to explore. NAP is not a science-based program; it is a gardening preference. And a destructive one, at that.

Policy 4.2 goes on to say: “The City should ensure that a comprehensive inventory of all natural areas owned by city agencies other than the Recreation and Park Department [RPD], and by private landholders is developed, in order to preserve the City’s biodiversity and natural areas more holistically… Once the significant natural resources outside the jurisdiction of RPD are identified, the City should develop a management plan for these natural areas.”

Policy 4.2 defines “natural areas” so broadly that it includes not only areas that currently contain existing remnants of SF’s pre-colonization habitat, but also areas that could support native plants if they were planted there, or, in other words, nearly all open space in SF. Including people’s back yards. It would become City policy that nearly ALL open space in San Francisco, including that in private hands (including back yards), should be managed the same way as NAP manages its lands. That means

  • More tree removals,
  • Tearing up existing healthy non-native habitats and replacing them with native plant gardens,
  • More herbicides, and
  • More restrictions on access.

snramp sign STAY ON THE TRAIL

TALKING POINTS

Please tell the Supervisors to please remove Policy 4.2 from the Draft ROSE:

1) San Franciscans do not want nearly ALL of our open space managed the same way as RPD’s controversial Natural Areas Program. NAP is a bad model for management of other open space.

2) Policy 4.2 would allow the SF Dept of the Environment’s Biodiversity Program (which focuses almost exclusively on native species) to become deeply involved in land use and land management decisions on open space. San Francisco’s City Charter prohibits the Dept of the Environment from being involved in land use decisions.  The Planning Commission should be the only city agency that makes decisions about land use and, in particular, what can be done on and in open space. Not NAP, nor the Dept of the Environment or its Biodiversity Program.

3) Policy 4.2 is a major land grab for NAP and the Dept of the Environment’s Biodiversity Program. Neither NAP nor the Biodiversity program is controlled by elected officials, which means there’s little oversight.  Their values do not reflect community values. They are anti-environmental (cutting down trees, using herbicides), and they are anti-people.  Do not let them plan to turn more areas into native plant gardens, or get involved in controlling how our city’s open space can be used in the future.

3) The program to inventory all open space in SF and develop management plans for it, as set forth in Policy 4.2, is much too specific a program to be included in the ROSE, which is supposed to be a general policy document. Therefore it should go.

The rest of Objective 4, which talks about preserving local biodiversity, but also defines “local biodiversity” as including both native and non-native species, is okay.  Please ask the Supervisors to insist that Policy 4.2 is removed before they pass the ROSE.

Please come to the meeting on June 16, or contact the Supervisors  – especially those on the Land Use Committee – and tell them not to pass the Draft ROSE until Policy 4.2 is removed.

Supporting “Clean, Green and Safe” from Scott Wiener

tree preservation zone madison WI

Tree preservation zone, Madison WI – Perhaps San Francisco can do this too?

We’re asking the Board of Supervisors at San Francisco’s City Hall to support Supervisor Scott Wiener’s “Clean, Green and Safe” budget package. Here’s what he’s proposing (this is taken from a note from his office):

  • $2 million to increase tree maintenance in our parks (Recreation and Parks Department). Rec and Park has only enough staff to maintain an average of 750 trees per year – out of a total of 131,000 trees in our parks. With an aging tree population, we are approaching a crisis of hazardous tree conditions in our parks. This funding will allow Rec and Park to increase tree maintenance to address hazardous tree conditions before these trees cause damage or injury and to better ensure the long-term health of all park trees.
  • $2.6 million to expand Park Patrol (Recreation and Parks Department). Currently, there are no more than two Park Rangers per shift to patrol all 220 of San Francisco’s parks. The increase in patrol officers would provide one dedicated Park Ranger on 24/7 patrol for each of the six Park Service Areas throughout the city. With more coverage of our parks, Park Rangers will be better equipped to enforce park rules and address the nearly $1 million in graffiti, property damage, and illegal dumping that occurs in our parks every year.
  • $2.7 million to landscape maintenance and cleaning in our public spaces (Department of Public Works). Years of staffing cuts have left DPW with insufficient personnel to keep our streets, sidewalks, and public spaces clean and our green landscaping thriving. Getting the debris and waste cleaned off our sidewalks and out of our public spaces is a primary responsibility of city government. These funds will increase landscape maintenance staff and cleaning crews to make our neighborhoods cleaner and healthier.

———————-

Here’s our letter to the Board of Supervisors:

The San Francisco Forest Alliance urges you to support Supervisor Wiener’s “Green, Clean and Safe” budget package.

We hope this proposal will help to address the need to maintain our park and Natural Areas trees, and thus preserve them rather than allowing them to deteriorate and then using contractors to cut them down when Capital funds become available.

Maintaining the trees in our forests and our parks – and planting new ones – will help the city maintain and expand its tree canopy, which in turn reduces pollution, provides fresh air, battles global warming through carbon sequestration, and provides a habitat for hundreds of species of birds and animals. Research has shown that trees improve human health, and that when urban forests are destroyed, death rates rise.

We also hope that this would fund park patrols particularly at night, thus reducing vandalism in our parks, and making them safer for everyone. It should also enable the city to clean up, maintain, and police our urban parks and plazas that fall into disrepair and misuse.

Sincerely,

Carolyn Johnston, President, San Francisco Forest Alliance

Wisconsin, Trees and Our Health

This is another of our first-person accounts. A reader visited Madison, Wisconsin and returned this report.

We were riding to the airport when traffic slowed on a tree-lined street owing to roadwork. I was reminded of a  friend’s comment about Minnesota: “We have two seasons – winter, and road repair.” Madison isn’t as extreme, but the warm days of spring are when this kind of  project gets done.

street lined with trees with yellow ribbons - madison WI

Necessary work, of course, but as I looked out the window I was saddened to see the trees on either side had yellow tape around their trunks. In San Francisco, colored tape  or paint spots usually mean the tree’s going to be cut down.

another tree with yellow ribbon in madison WINearly every tree along the road had a yellow ribbon. Madison’s a very green city with a lot of tree canopy, so perhaps they figured they could spare the trees that impinged on the road work or grew through power lines.

yellow ribbon tree in madison WI

But then, as we stopped completely, I could read what was actually written on the yellow ribbons. It said “TREE PRESERVATION ZONE.”

tree preservation zone madison WI

THE MENTAL HEALTH BENEFITS OF MORE TREES

Perhaps they had paid attention to the research from University of Wisconsin (whose campus is only a few miles from where we’d paused). It showed less stress and depression in people who live in areas with more tree canopy. Here’s an excerpt from the UW-Madison press release on the research, which was published in April 2014.

“Across neighborhoods of Wisconsin, from the North Woods to the cities, the results are striking,” says Dr. Kristen Malecki, assistant professor of population health sciences at the UW School of Medicine and Public Health. “Higher levels of green space were associated with lower symptoms of anxiety, depression and stress.”

The study, published recently in the International Journal of Environmental Research and Public Health, combines mental-health data from the Survey of the Health of Wisconsin (SHOW) and Landsat 5 satellite data from July 2009 that analyzed how much vegetation was present in each of the SHOW census blocks.

About 2,500 Wisconsin residents from 229 neighborhoods answered an assessment that asked them to rate their symptoms of depression, anxiety and stress. The research team, which was also led by Dr. Kirsten Beyer of the Medical College of Wisconsin in Milwaukee, adjusted the results to make sure they weren’t confounded by race, age, income level, education, marital status, employment and other factors.

They found that across all strata of society, people who lived in a neighborhood with less than 10 percent tree canopy were much more likely to report symptoms of depression, stress and anxiety. So, for example, a poor person living on a logging road in the Chequamegon-Nicolet National Forest was more likely to be happy than a wealthier person living on a treeless block in Milwaukee.

San Francisco has among the smallest tree canopies of any major city, and the number of trees is shrinking each year. The “Natural Areas Program” plans to cut down 18,500 trees. Every project, whether it’s a playground renovation by SF Recreation and Parks, or road improvements by SFMTA, or water system work by the SF PUC, becomes an excuse to cut down more trees. If they replace the trees at all, it’s with saplings that will take decades to become mature and provide those health benefits.

Wisconsin has to contend with the Emerald Ash Borer, a beetle that is killing off ash trees as voraciously as California’s Sudden Oak Death is killing our oaks. San Francisco, with its windy climate, doesn’t have many oaks or Sudden Oak Death, nor does it have ash trees and the Ash Borer. The main pest killing off San Francisco’s trees is the chainsaw.

Even Worse Than Natural Areas Program?

If you’ve been concerned, as we are, about the Natural Areas Program and the proposed Management Plan (the SNRAMP) that would cut down 18,500 healthy trees, use large amounts of toxic herbicides, and restrict access to families and pets – there’s worse.

The new Biodiversity Plan proposes extending this same management strategy to all open lands in the city – including, possibly, your back yard.

(This post is modified – with permission – from one that appeared on SutroForest.com)

19. vista with garlon pesticide notice mt davidson feb 2012

Mt Davidson vista with Garlon herbicide notice

BACKGROUND

Last year, San Francisco’s Department of the Environment (SFDOE) hired Peter Brastow as ‘Senior Biodiversity Coordinator.’ He’s creating a “Biodiversity and Ecology Master Plan” for the city, seeking a quarter-million dollar grant from the Strategic Growth Council to do this. (The Strategic Growth Council is a California state organization.)

This Plan is hugely problematic on two counts.

  • First, the ‘biodiversity’ being considered is specifically modeled on the controversial and destructive Natural Areas Program (NAP) of the San Francisco Recreation and Parks Department (SFRPD). NAP seeks to destroy thousands of trees, restrict access in ‘Natural Areas,’ and last year used more of the “most hazardous” herbicides than the rest of SFRPD put together (excluding Harding Golf Course, which is managed by the PGA Tour and not by SFRPD).
  • Second, it plans to extend this Plan to all the open areas of the city, no matter what the ownership. It would even include people’s backyards. It is not stated what agency or department would manage all open space, although it seems apparent that Brastow’s office intends one agency/department to do so. NAP is named as the model for management.

Biodiversity is a poorly defined term, and as Professor Art Shapiro pointed out “Biodiversity means whatever you want it to mean.” The promoters of this Biodiversity Plan are not friendly to trees, particularly non-native trees. In a recent meeting of the SFDOE, Peter Brastow commented on the Urban Forestry Plan – which seeks to stabilize and then expand San Francisco’s sparse 17.3% tree canopy – with “You can’t plant trees willy nilly” and noted that the “tree-canopy objective could conflict with the ‘biodiversity’ objective”, suggesting that biodiversity would be better increased by planting more native scrubs and grasses than necessarily by just planting more native and non-native trees. In a meeting some years ago, Peter Brastow called eucalyptus “the largest weed.”

Clearly, how they define ‘biodiversity’ is “native grasses, plants and shrubs.”

WHY WE OPPOSE THE “BIODIVERSITY” PLAN

We oppose this Plan, which could have far-reaching adverse consequences for our city and its environment. Trees sequester carbon to battle climate change, fight pollution, provide windbreaks, absorb sound, and stabilize slopes in ways that low-growing plants and shrubs cannot do. Trees are more environmentally valuable, and expanding the tree-canopy is an important objective – as is preserving what we have in our parks and forests and on our streets. We need native and non-native trees, but we should not model a Biodiversity and Ecology Master Plan on destroying non-native trees to plant native grasses and scrub bushes.

The Biodiversity Plan is a poor idea. It’s based on NAP, whose own Management Plan is still undergoing a million-dollar Environmental Impact Report process that may take until the end of 2014. It covers private property, including, specifically, people’s back yards; it’s not impossible that homeowners would find they needed permission in deciding what to plant or how they manage their own spaces if the Plan produces guidelines that get written into regulations. It doesn’t clarify how this whole effort will be funded.

WHO TO WRITE

We hope that the Strategic Growth Council will not waste our money funding this anti-environmental effort. The decision whether to consider the proposal will be taken on May 14th, 2014. The person to write to is Polly Escovedo (polly.escovedo@resources.ca.gov) She is interested in hearing from the public before that date.

mt davidson forest - hiker on trail

Natives and Newcomers Can Get Along – Dr. Scott Carroll

Dr. Scott Carroll of UC Davis, and the founder of the Institute for Contemporary Evolution in Davis, spoke at the Commonwealth Club as part of the series “The Science of Conservation and Biodiversity in the 21st Century.” His main message:

Mixed communities, consisting of non-native and native species of plants, animals and other organisms, are here to stay. We need to find ways to live with these new neighbors. Once they are introduced, they will evolve, and so will the species that were already there. Trying to eradicate “invasive” and non-native species is expensive, likely to cause unforeseen problems, and have uncertain success – in part because evolution will make a moving target of an introduced species.

Read on for notes from Dr. Carroll’s talk. (There are also links to his Powerpoint presentation, and to the audio recording from the Commonwealth Club.)

 

CONCILIATION BIOLOGY:
THE ECO-EVOLUTIONARY MANAGEMENT OF PERMANENTLY INVADED BIOTIC SYSTEMS

(Notes from a talk by Dr Scott Carroll)

Plants and animals have always moved around the planet, but gradually enough that the world had distinct bio-regions with their own indigenous species. About 500 years ago, shipping greatly increased the pace – people deliberately or inadvertently introduced species into new places. It’s what people do.

historical bioregions - dr scott carroll talk at commonwealth club 2014Invasion biology” as a discipline originated with Charles Elton’s 1958 book. The response to Invasion Biology is a deeply emotional one, coming from a sense of how an ecosystem should look and how species should interact. The transfer of species around the globe has been called the greatest ecological spasm since the extinction of the dinosaurs. But is it?

brown earthIn fact, there’s been a much more important change. The amount of wilderness on the earth’s surface has fallen sharply, from around 50% in the 1700s, to around 20% by the year 2000. The rest is cultivated or range lands or built-up. We need to look at invasion biology – permanently mixed communities of native and introduced organisms – in the context of that land use change.

These land use changes drastically altered the environment for all species, with a major impact on all species and ecological relationships. Natural selection picks new winners: Changed environments have different fitness criteria, so plants or animals that were successful before may become losers. If populations decline, it reduces their chances of evolving to meet the new environment: fewer individuals mean a smaller gene pool, fewer potentially beneficial random mutations, and fewer offspring. Some species go extinct.

But others don’t. They adapt and evolve and use the resources the new environment or new introduced species provide. Some players in these novel interactions have the capacity to solve their own problems, restoring more balanced kinds of ecological interactions than one would expect from the terms “invasion” and “takeover” and “destruction.”

DEFINING “INVASIVE SPECIES”

How do we define an “Invasive Species”?

It’s a species not native to a bio-region that are:

  • Introduced
  • Reproducing independent of our assistance (naturalized, in the case of plants) and
  • Very specifically, they are doing something that we do not like.

This means that it has to be defined with reference to who “we” are. The definition of “invasive” must include who is doing the defining.

In some cases there’s broad agreement. Nearly everyone agrees on fighting invasive disease-causing insects, for instance. In the case of plants and trees and animals, people may diverge sharply in their opinions. Eucalyptus is an example; those who dislike it make consider it invasive; others would disagree vehemently.

The ‘eradication’ arm of Invasion Biology – i.e. those looking to destroy introduced species, perhaps 90% of invasion biologists – is fighting a very difficult battle. It’s extremely expensive, and risks doing much more harm than good.

THE RISKS OF “ERADICATION”

What are the problems of Eradication policies? Here are 8 issues:

1. It’s extremely expensive, both in time and effort.
Even in cases that seem possible – eliminating rats on an island, for instance, it may be an uphill battle. The first 75% are easy to kill. The next 20% are more difficult. By the time you’re down to the last 5%, your team is exhausted and you’ve “spent $3.2 mn of your $2.7 mn budget.” You haven’t seen a rat recently, so you leave. And then – the 2% of the rats that remain reproduce and repopulate the entire island in five years.

2. It doesn’t necessarily solve the problem.
Even if you succeed in killing off the invader, it won’t necessarily bring back the ecosystem that existed before. For instance, soil conditions may have changed so instead of native plants returning, other non-native plants – or nothing at all – grows.

3. It can disrupt ecological systems.
For instance, an introduced predator may have been keeping an introduced plant-feeding prey species in check. Once the predator is eliminated, the prey may destroy vegetation and the ecosystem as it exists.

4. It can disrupt replacement ecological relationships that existing plants and animals may have developed with the “invaders.” They may be providing food, seed dispersal, pollination, cover and other ecosystem services. For instance, if a native plant species is declining because of climate change, an introduced species can provide food for birds, animals and insects.

Loggerhead_sea_turtle_hatchlings_caretta_caretta public domain5. Sometimes, the new species provide a new ecosystem service to existing species, and destroying them would hurt the native species too. For instance, beachside non-native trees may protect turtle hatchlings from artificial lights that can disorient them, and so improve their survival rates. Or the non-native species may be controlling a different non-native species that might otherwise become a pest.

6. Trying to kill off non-natives can drive them to evolve resistance to the agent used to kill them. This is a common problem when herbicides are widely used to kill “invasive” plants.

7. Killing non-natives may reduce biodiversity of the area by reducing the pressure on native species to diversify and become new species.

8. The new species may directly increase biodiversity in the area, and eradicating them reduces this biodiversity.

THE CAUTIONARY TALE OF THE MYXOMATOSIS VIRUS

rabbit public domain clipartA story that illustrates many of these problems is that of the myxoma virus, used to control Australia’s huge rabbit population.

The Iberian (or European) rabbit was introduced into Australia by Europeans in the 19th century, and eventually bred so prolifically that it started to destroy the environment. In the 1950s, the Australian government introduced the myxoma virus, a New World rabbit disease lethal to European rabbits. Initially, that killed 99.5% of infected rabbits, and the population plummeted.

But the surviving rabbits continued to breed until the next time the disease went around. With each successive outbreak, the mortality declined. Frank Fenner, the scientist overseeing the project, found that the virus was attenuating – becoming less lethal – while the rabbits were developing resistance to it. Eventually, each outbreak killed only 20% of the rabbits in the area.

In 1952, a landowner in France introduced the virus on his farm to control rabbits. Soon it spread across that country, and then to Britain, where it killed 95% of the rabbit population.

Large Blue Butterfly - wikimedia commons cca3 - PJC&coThis led to the extinction of the British population of the Large Blue Butterfly. The butterfly is an unusual species whose caterpillars mimic larvae of the ant species Myrmica sabuleti, so they get carried into the ant’s nests where they eat the larvae. Rabbits cropping meadow-grasses had kept them short, providing ideal conditions for the ants. With the rabbits gone, the grass grew, ants declined, and the Large Blue Butterflies vanished.

iberian lynx wikimedia commons cca25-klia Meanwhile, the myxoma virus also reached the Iberian peninsula, where it devastated the native rabbit population. The rare Iberian lynx, which depends solely on rabbits as a food source, became critically endangered, and the Iberian eagle – which also preyed on rabbits – declined sharply. Aquila_adalberti wikimedia commons cca3Officials are looking to vaccinate the wild rabbit population against myxomatosis.

Another unforeseen consequence occurred on Macquarie Island. This desolate Australian island was a breeding place for seals and sea-birds. Human introductions of rats (inadvertently), rabbits (for food), and cats (to combat the rats) impacted the sea-bird populations. The eradicators first introduced fleas to the island as a vector for the myxoma virus, and then the actual virus in 1978. Then they eradicated the cats. However, the cats had been hunting the rabbits, and now the rabbits multiplied out of control reversing years of conservation efforts. The myxoma virus had likely attenuated, and failed to control the rabbit numbers. The rabbits grazing destroyed the hillsides where the penguins nested, causing landslides that harmed their breeding success.

CONCILIATION WITH SOAPBERRY BUGS

The story of the soapberry bug is more encouraging.

Soapberries are a plant family with a number of separate species, two of which are invasive vines in Australia. They invade along water-courses, and grow over trees in those areas. One vine species reached Northern Australia around 1680; the other, much taller species arrived in Eastern Australia around in the 1920s and has become particularly damaging to the forests there.

soapberry bug smSoapberry plants have fruit of varying sizes with nutritious (to insects) seeds at the center. Soapberry bugs are specialized soapberry eaters, with long beaks to pierce the fruit and reach the seed. The beak-lengths of these bugs are evolved to fit the particular species of soapberry they prey on.

When the introduced soapberry plants arrived in Australia, the native soapberry bugs had beaks too small to use the new food source. But with time, they started to evolve.

In Eastern Australia, it took 30 years for the soapberry bug’s beak to evolve from 7 mm to 7.5 mm. That doesn’t sound like much, but an increase of 0.5 mm doubles the number of seeds the bug can reach.

In Northern Australia, where the bugs have had over 300 years to evolve, their beaks have grown from about 5.5 mm in length to around 8 mm – exactly the length they need to attack the introduced soapberry plant. They match as well as if the soapberry plant was native.

It’s the same species of bug.

One interesting experiment would be to see if breeding the two strains would help the Eastern bugs grow a longer beak and control the soapberry vines better. Dr. Carroll recommended stopping the plant eradication program in Northern Australia to protect the long-beaked soapberry bugs there while evaluating whether interbreeding the two bug strains could accelerate the evolution to slow the spread of the large vine in Eastern Australia.

MORE INFORMATION

Dr. Carroll stopped his presentation there because time ran out. But if you would like to see his PowerPoint slides, they are here (in ppt and pptx formats). The Commonwealth Club’s Audio recording of his talk is also linked here. (There’s a lively question and answer session at the end, which isn’t included in these notes.)

Powerpoint presentation in ppt format: S Carroll Commonwealth Club Jan 2014

Powerpoint presentation in pptx format:S Carroll Commonwealth Club Jan 2014 (2)

Audio recording from Dr Carroll’s Commonwealth Club talk: http://www.commonwealthclub.org/events/archive/podcast/scott-carroll-conciliation-biology-13014

Open Letter to SF Weekly

Recently, journalist Rachel Swan saw our post Fighting the NAP Nativist Agenda and our video caught her attention. (Here’s  our video on Youtube, where you can also sign up for the SF Forest Alliance Youtube channel)

She  had some questions for us for an article she intended to write for SF Weekly. We sent her an email in response. Of course,  she didn’t repeat it in her short and hard-hitting article, but we thought our readers might be interested in seeing what we said. We’ve put it in this open letter to SF Weekly.

 

Dear SF Weekly,

Thank you for reporting on the rift within the environmental community, and to Rachel Swan for planning the article. This is something too few San Franciscans are aware of.

(We hope we’re not actually slinging mud when we oppose the destruction of trees, use of toxic herbicides, and access restrictions in our parks. We think it’s possible to oppose the Nativist Agenda in the strongest terms while being respectful of the people who support it.)

Your reporter sent us a few questions, which we answered at some length. Obviously she couldn’t include all of that in the article. But we’d like to share it with our readers, and perhaps you would like to share it with yours.

WHAT’S WITH GLEN CANYON?

Her first question was what plant we thought was being preserved in Glen Canyon Park, justifying herbicides and tree-cutting?

We don’t actually think the tree-cutting and herbicide application in Glen Canyon is targeted at preserving any specific native plant. Instead, it’s a more generalized preference for “native” plants, so that herbicides are used to remove non-native plants naturalized to the Canyon, and non-native trees are cut down, to be replaced (if at all) with “native” shrubs and other smaller plants. Though the original Environmental Impact Report for the Glen Canyon project said it would not be in the Natural Areas of the canyon, in fact the work area did include a substantial “Natural Areas” portion.

WHAT RESULTS DO YOU SEEK?

Who, she wanted to know, did we target our video at, and what result did we wish to see?

Our video is intended to get the word out to people who care. San Francisco Recreation and Parks Department policy is hostile to the 117,000 non-native trees in the park system’s Natural Areas. (They are on the wrong side of the climate change issue). We hope this video will show our concerns about tree removals, trail closures and herbicide usage, and show that native plant gardens provide very limited recreation opportunities and are not sustainable.

Most people don’t understand what’s happening in their parks until they see trees being removed or pesticide notices or trails being blocked, and then it’s usually too late. They also can’t understand why a program like NAP is funded at around $1.5 mn annually (which would go up by a factor of 4 or more if the Significant Natural Resource Areas Management Plan is adopted), while recreation centers are closed because the Director was fired, or the retiring gardener in their local park was not replaced, or park patrols are infrequent because of staffing issues.

Here’s what we would like to see happen:

  • We would like trees to be preserved as far as possible unless they are truly hazardous (and it’s not used as an excuse). They should be the responsibility of a department that wants to protect them instead of one which wants them gone. San Francisco’s tree canopy at 13.7% is low compared to most major cities – and we lose more trees each year than we plant. Trees fight pollution and save lives. In this era of global warming, trees are a crucial resource, sequestering carbon. (Eucalyptus, a fast-growing and long-lived tree with dense wood, is particularly effective at doing this.) We want tree-felling for native plant “restoration” to be stopped and prevented.
  • We want to stop use of toxic herbicides in Natural Areas (all Tier I and Tier II herbicides).
  • We want no additional access restrictions on people or pets in Natural Areas.
  • We want financial resources to be allocated in line with people’s actual priorities – which would include functioning (and open!) restrooms, funding for recreational programs people enjoy, patrols that improve safety, trash removal.

DO NATIVE-PLANT PEOPLE REALLY HAVE A UNIFIED AGENDA?

Have we encountered different sub-groups within the native plants community, she asked, or did we really think there was one unified agenda?

Let’s be clear: We don’t object to native plants, or to the people who value them. When we speak of the “nativist agenda” we mean the ideological preference for native plants that drives such entities as the Natural Areas Program (NAP) to try to destroy existing trees, habitats, and recreation opportunities – and use powerful herbicides in natural areas. They are a small minority of our park users, and large areas of our parks shouldn’t be landscaped to their preferences, ripping out of plants that the rest of us enjoy and that are important to birds and other wildlife. (NAP has 1100 acres, about 1/4 of the total SFRPD land.) “Nature” does not favor one plant over another.

We have people from the “native plant community” among our supporters: they like native plants, but not the destruction of existing trees, wildlife habitats, and access opportunities.

WHO DOES SAN FRANCISCO FOREST ALLIANCE REPRESENT?

Finally, she wanted to know who the San Francisco Forest Alliance was. Were we homeowners? Off-leash dog-walkers? Opposers of pesticides? (In the article – which we link below- she quoted Jake Sigg’s definition of us: “Forest lovers, feral cat activists, and off-leash dog walkers.”)

So who are we, really? We’re very broad group with one thing in common: People who enjoy nature and our parks and advocate for trees, the environment and for wildlife.  SF Forest Alliance is not a membership organization, so we don’t have a roster or dues. We’re a grass-roots organization with many supporters, some of whom are active in helping us to spread the word. Our Change.org petition to Mayor Lee is currently at over 1500 signatures – and this is only the latest of several of our petitions that got thousands of signatures (including many on paper only). If you want a better sense of who we are, read some of the comments on that petition – or on the earlier MoveOn.org one HERE.

We have hikers, birders, and people who want public money spent on making parks more beautiful and accessible for recreation. We have homeowners, renters, and people who share apartments. Some of us have pets and walk them on- or off-leash; others don’t.  Some are parents or grandparents, others not.

We all want unrestricted access to our parks, for us and for our families (including children and pets) for active – not just passive recreation. We’re all opposed to toxic herbicide use in “natural” areas. We all oppose removing of healthy trees. We believe most people have these values.

The SFWeekly article said in conclusion: “So it’s not enough to be a tree-hugger anymore; you have to hug the right tree.”

For our part, we think all trees that aren’t actually hazardous are “the right tree” wherever they originated. Perhaps she referred to the Native Plants Community, who dislike non-native trees (and nearly all the trees in San Francisco are non-native, because it had hardly any trees before.)

Sincerely,

The San Francisco Forest Alliance

If you’d like to read Rachel Swan’s article in the SF Weekly, it’s here: Going Native: A Plant Lovers’ War Turns Political

 

McLaren Park: Stairways, Wildflowers, and Great Blue Heron

This is another of our Park Visitor series: First-person accounts of visits to our San Francisco parks. This is by Tony Holiday, a San Francisco hiker and blogger. It’s adapted from his blog, Stairways are Heaven and published with permission.

Go HERE for the original post on McLaren Park (and more pictures).

 

1 Starts from Visitacion Ave.

Passing on recent pix of a McLaren Park stairway that some SF stairway walkers may not be familiar with: The longest in the park with 195 steps, and starts up at the dead-end of Campbell Ave  in the Visitacion Valley neighborhood. It’s set back a bit from the street, thus slightly “hidden.”

195 steps

195 steps

Down into Vis Valley neighborhood

Down into Vis Valley neighborhood and out to Campbell Ave

It climbs past Visitacion Valley Middle School and up to Visitacion Ave. When you reach the top, continue up steep Visitacion to divided Mansell.

hidden stairs at dead end of Campbell

South of Mansell is the Visitacion Valley neighborhood. North of Mansell, to the east of the park, is the Portola ‘hood.

From the foot of the stairs, this time downhilled on Campbell a couple of streets to Delta. Left on Delta to the next street up, Tucker, and onto the skinny, steep, rough concrete walk (seven steps to start).

Delta pathway Tucker to Tioga

INTO THE PARK

At the top of this pathway, the next cross-street up is Tioga, then Wilde. Turn left on Wilde to Ervine for a steep curving trail into the park, the old observation tower above.

Vis Valley below

You can’t see the stairs until you’re partway up (about 56 steps) at the top of which are a couple of Philosopher’s Way musing stations and view benches.

Musing Station on the Philosophers Way

There’s a seriously steep trail off the stairway, also up to the view benches.

Steep trail up from the stairway

Especially love the south, open space part of McLaren with big sis San Bruno Mountain across, everything green and wildflowery now at both parks.

san bruno mountain in the distance

San Bruno mountain in the distance

What is this flower seen south of Mansell?

[Webmaster: Gaillardia?]

wildflowers

Unfortunately one of the nearby musing station plaques had been graffitied-upon; hope there are ways to remove the paint from the artwork.

Check out these daisies all over the place, just north of the tennis courts, with Bernal Hill in distance.

Daisies on the lawn, Bernal Hill in the distance

A favorite trail descends to Lake McNab that starts a short distance below the tennis courts, north of Mansell.

Trail to Lake McNab

It’s steep, switchbacked, hard-packed dirt.

Trail sign climbing back up

Critters seen: a squirrel (too far away), a lizard (too fast), and this guy.

great blue heron gopher-hunting

McLaren is around 318 acres and the third largest park within SF city limits. However, since the Presidio’s a national park, some people don’t include it when talking about acreage, even though it’s larger than Golden Gate Park. So one is likely to hear city park McLaren still spoken of as being the second largest SF park.

Great Blue Heron - long-legged beauty

Fighting The NAP Nativist Agenda

Once in a while, we want to affirm the values that San Francisco Forest Alliance stands for. We’re a grass-roots organization of people who love nature and the environment, pay taxes responsibly, and want access to our parks and wild places – with our families.

Citizens care about their city Parks, and want to keep healthy trees and to open access to natural areas. Citizens expect city management to act responsibly and in the public trust, for FAIR allocation of 2008 Clean & Safe Neighborhood Parks Bond funds.

SF Recreation and Parks Department (SFRPD) and particularly the Natural Areas Program (NAP), obsessed with Native Plants, is cutting down trees, restricting access, using more toxic herbicides than any other section of SFRPD (excluding Harding Park Golf Course), and using financial resources that could better be used for things our city’s residents really want.

OUR VIDEO

Watch our video on Youtube, (where you can also sign up for the SF Forest Alliance Youtube channel):

OUR MESSAGE TO SAN FRANCISCO AND SFRPD

What we stand for can be summarized in four key areas: Trees, Access, Toxins, Taxes.

 

The Logic of Ecological Change – Prof Art Shapiro

Recently, UC Davis Professor Art Shapiro gave a talk at the Commonwealth Club.  It was a tour-de-force. He described it as a very quick resume of a course he’s been teaching for 40 years at UC Davis.

The takeaway: The conventional wisdom about ecology is often wrong.

[You can listen to the one-hour audio recording of his talk HERE.]

SPECIES THROWN TOGETHER

eco-jigsaw2Nativists idealize an ecosystem as a community of plants, animals, fungi, and other organisms that have evolved together over many thousands of years in a particular place so that they fit like a complicated jigsaw – the balance of Nature. (We’ve heard them use phrases such as “lock and key” to describe the effect of this co-evolution.) When non-native and invasive species enter, nativists believe, they destroy this intricate mechanism, resulting in an impoverished and simplified ecosystem with fewer species and no natural balance – and even the dire possibility of ecosystem collapse. They talk in terms of plants and animals that “shouldn’t be there” – usually, immigrant species brought in by humans.

But it’s not often true. What the scientific data show is that “communities” of that interdependent kind are unusual. Instead, most ecosystems are groups of plants and animals that happen to be in a place where they can thrive. When they interact, it’s usually because of “ecological fitting” – they can use the other plants and animals in that area to help them survive. Depending on how ancient they are, communities may include tightly co-evolved mutually interdependent multispecies systems. But these make up only a fraction of the community as a whole.

Anise swallowtail butterfly breeds on fennel

Anise swallowtail butterfly breeds on fennel

Here’s the evidence against the concept of tight-knit interdependent “communities”:

1. There’s no functional difference between a heritage ecosystem and one with exotic species. If there was, scientists should be able to tell an undisturbed “community” from an invaded one without knowing its history. In fact, they can’t. There are no consistent  functional differences once an “invading” species has been established. Some ‘invaders’ can drastically transform the systems they enter – an example is cheatgrass in the Western deserts, which greatly amplified fire risk there. But most do nothing of the sort.

2. Species recolonize open land at different rates.Species move, communities don’t.” If a landscape is wiped clean – say by glaciers or a volcanic eruption – nature begins to move back in almost immediately. The pollen record allows scientists to understand which species of trees arrived at which time. It shows that tree-species move individually, not as communities.

3. Species that now don’t exist in the same place did so in the past, which would not be true if plants and animals normally lived in fixed communities. One example: the wood turtle and the southern toad are not found in the same areas now – but the fossil record shows that in the past, the ranges did overlap. This couldn’t have happened if they needed to be part of different communities. Vast areas were occupied in the past by “no-analogue” communities – ones that simply don’t exist anywhere at all today.

He ended by pointing out that we – humans – are an invasive species. So are most things, at least at one time.

Read on for detailed notes from Professor Shapiro’s talk at the Commonwealth Club.

Again, you can listen to an audio-recording of the whole talk HERE (on the Commonwealth Club website).

————————————————————————

NOTES FROM ART SHAPIRO’S TALK:

ECOLOGICAL COMMUNITIES AND THE MARCH OF TIME

(The talk was dedicated to Prof Shapiro’s late neighbor, Steven Warnock.)

commonwealth club motto

Commonwealth Club motto

The talk was in three parts: The first laid out the historic context for two opposing schools of thought about ecology. The second examined the data, and concluded that the evidence supports Gleason. The third part looked at the future, which includes climate change.

ECOLOGICAL “COMMUNITIES” OR “ASSEMBLAGES” ?

Here’s the conventional wisdom about ecology, associated with Frederic Clements: Plants, animals, insects, fungi and microscopic creatures form interdependent groups, or “communities.” The process by which this happens is “co-evolution” (sometimes described as evolving a “lock and key”), leading to an ecology where all the species fit together like a jigsaw puzzle. (“Co-evolution” is associated with Peter Raven and Paul Ehrlich, who described it in butterflies and plants that evolved together.) If an area is disturbed, it will go through a predictable process of “natural succession” that will lead to a stable “climax” situation, with all its species again interacting as a community.

This stable ecosystem is sometimes called “the balance of nature.” Tamper with  it, this theory says,  and you could destabilize the whole community, even leading to ecological collapse.

assemblageThe opposing view, associated with Henry Gleason, is that plants and animals do not necessarily form ecological communities. Instead, groupings or “assemblages” of plants and animals occur mainly by accident. They happen to arrive in that space at that time, and find conditions that allow them to survive and thrive. The species in such an assemblage will interact, not because they co-evolved, but because they find an opportunity to do so.

These theories about how species fit within an ecosystem were quantified when several ecologists – including the famous Robert McArthur – introduced mathematical models that looked at populations of plants and animals and their interactions. They used these models to look at Species Packing – i.e., how many different species of plants and animals could live in a particular ecosystem.  Assembly rules says that the distribution of plant and animals species in a given area isn’t random: both competition and cooperation between plants and animals affect what you find. Competing species can’t all live in the same area, but their niches can overlap. Where they do overlap, the two species may evolve more differences (“character displacement“) so they compete less. These mathematical models assumed a condition of equilibrium, i.e. stability. Opponents have argued that ecological niches are seldom stable because the physical environment is not stable for very long.

R.H. Whittaker introduced the idea that the levels of dependency could vary within communities. For any two species, you could assign a number: +1 meant that the species needed each other to survive; -1 meant that they could not live in the same space.  He speculated  that these relationships tended to be distributed in a bell curve – meaning that most species in a group didn’t depend on the presence or absence of another species. But some subsets of the community were tightly integrated.

How adaptable are living things? They can evolve, but only in certain ways.  Niche conservatism is the idea that most species cannot change very much or very fast in response to changes in their ecological niches.

The idea of co-evolution was fine-tuned with John Thompson’s concept of Geographic Mosaics. Co-evolution between two species can happen differently in different  geographic areas. So, for example, a plant in one place might depend totally on one insect for pollination, but elsewhere, the same species of plant might find alternative pollinators available. Such Fine-Tuning is the opposite of Niche Conservatism – and both occur in Nature.

TESTING THESE IDEAS

Cladistics (i.e., the system of showing how related species evolved from common ancestors) provided a way to test the Ehrlich-Raven co-evolution hypothesis. If one kind of animal or plant developed into a separate species (“speciation”) then did the plants and animals depending on it also co-evolve into a separate species? There was no evidence that this happened. Co-evolution was a lot sloppier and more unpredictable than that!

Every time you see two organisms working together, it doesn’t necessarily mean they are co-evolved. Dan Janzen, a great tropical ecologis, pointed out that organisms could be taking advantage of niches and resources that appear through  Ecological fitting, with no history of coevolution at all. We see this happen when introduced pests attack native plants, and native insects attack introduced plants, forming brand-new associations. It happens all the time.

pacific reed grass under eucalyptus

Pacific reed grass thrives in eucalyptus fog drip

Is there really a difference between “intact” ecosystems and ones that are disturbed or invaded? Mark Sagoff pointed out that if there really is a functional difference between “invaded” and “co-evolved” ecosystems, then scientists should be able to tell them apart without knowing their history.

“The theory that evolutionary processes structure ecosystems and endow them with a mathematical organization (e.g., rule-governed patterns that ecologists can study) has the following implication….scientists should be able to tell by observation whether a given ecosystem is heavily invaded or remains in mint condition…

“In fact, once non-native species have become established, which may take only a short time, ecologists are unable by observing a system to tell whether or not a given site has been heavily invaded. Invaded and heirloom systems do not differ in pattern or process, structure or function, in any general ways.”

There’s more evidence against the idea of stable interdependent communities as the norm in nature. For example: pollen core data shows that trees recolonizing lands after glaciation don’t move in “communities.” The tree species migrate at different rates. Only those species that have mutualistic relationships move together (for example, mycorrhizae and trees).

WoodTurtle public domain Ltshears sm“Communities” are like still shots from a movie. They show a set of relationships at a particular point in time. That doesn’t mean the relationships are stable or unchanging. Many species show different sets of relationships in the past. For instance: at present, the wood turtle and the southern toad have completely different ranges – but in the past, those ranges overlapped in places. In the UK, workers building Hadrian’s Wall nearly 2000 years ago left middens that have remains of beetles of species now found only in Lapland.  When an event that wipes out an ecosystem and recolonization starts, it takes trees 50-100 years to leave a pollen signature. Bufo_terrestris public domain Norman Benton smBeetles that can fly get there in  months to a few years.

If communities were stable groupings of interdependent co-evolved species, then we would expect to see the same communities repeated in similar conditions. But in fact, we often see different groupings in similar conditions.

THE FUTURE

Decisions about what ecosystems should look like are subject to human preferences. For most people, what they grew up with is “normal.” But the world has changed. The climate is changing.  The pool of available species has increased enormously. In terms of trying to “restore” an earlier ecosystem – there’s no going back.

The Natural Areas Program and Pesticide Use

Pesticide Application Notice - Mt Davidson (Nov 14 and 15th, 2013)

Pesticide Application Notice – Mt Davidson (Nov 14 and 15th, 2013)

We recently received a response from Phil Ginsburg, General Manager of the San Francisco Recreation and Parks Department (SFRPD) , to our concerns regarding the “Natural Areas Program”  (NAP). We thank him for the detailed response, but we still have a number of points of disagreement.

One of them is herbicide use. His letter states, “As a percentage of our overall total, herbicide usage in the Natural Areas comprises only 4%.”

As readers of this website know, that’s very different from our own analysis. We find that NAP uses nearly as much of the ‘Most Hazardous’ and ‘More Hazardous’ herbicide as the rest of SFRPD (ex Harding Golf Course).

And the discrepancy is the more surprising since the source documents are the same – the Monthly Pesticide Use Reports each section submits.

The graph below compares NAP and other SFRPD (ex Harding Golf Course). Not only is NAP clearly using much more than 4%, it also is the largest user of the Most Hazardous (Tier I) chemicals. (The San Francisco Department of the Environment – SFDoE – produces a  “Reduced Risk Pesticide” list each year. This lists pesticides that may be used on city-owned lands, and gives them Tier ratings.)

NAP vs SFRPD Other 2013 by Active Ingredient

WHY THE DISCREPANCY?

Since we don’t know how Mr Ginsburg’s percentage is derived, we can only speculate. Some possible reasons:

1)  Our numbers leave out Harding Golf Course, but they include it.

Here’s why we exclude it: Harding Park Golf Course is under contract to be maintained to tournament-ready standards. This means it uses a lot of pesticides; but it really is outside SFRPD control if San Francisco is to have a PGA-standard golf course. (The city’s other golf courses, where SFRPD actually can determine pesticide use, actually use very little.  Sharp Park, for instance, has used none since August 2010.)

2)  Our numbers are for the most recent year, 2013.

Though the phrasing of the sentence suggests that are considering current usage, they may actually have used historic numbers.  It’s possible that other sections of SFRPD reduced their herbicide usage, even while NAP’s herbicide usage went up. NAP herbicide use rose annually from 2009 through 2013.

B&W Herbicide Use - Natural Areas Program

3) We have only considered the chemicals that are most concerning – the “more hazardous” and “most hazardous” herbicides (those the San Francisco Department of the Environment classifies as Tier II and Tier I) and omitted the “least hazardous” ones (Tier III).   Possibly SFRPD has included Tier III herbicides. We think this would distort the comparison; it would be like comparing pineapples and hand-grenades.

4)  If it’s based on the SF DoE’s new database, it may have data-entry errors, especially for data since 2010 when the new database was instituted. We compiled the Monthly Pesticide Usage reports ourselves, and re-checked them.

HOW WE GOT OUR NUMBERS

For anyone who wants to replicate our calculations, here’s how we made them:

  • We obtained Monthly Pesticide Usage reports from SFRPD under the Sunshine Act. If any of them were unclear, we got clarifications.
  • We compiled this data into a spreadsheet. Then we calculated Tier I and Tier II herbicide usage separately for NAP and for all other SFRPD (excluding Harding Golf Course), using SF DoE’s ratings.
  • We show “Greenmatch” separately – it’s rated Tier II, but it’s an organic herbicide that is less harmful than most Tier II products. Until 2013, it was rated Tier III, least hazardous.
  • [ETA:  We calculated the "Active Ingredient" quantity by using conversion factors provided by the manufacturer of each chemical. (These are available online.)]

In the first two months of 2014, NAP was still the major user of Tier I herbicides, using 8 times as much as all the rest of SFRPD ex Harding.

 

 

 

What is Biodiversity?

There’s been a lot of talk of ‘biodiversity’ in San Francisco recently. The city’s ‘Recreation and Open Space Element’ (ROSE) mentions it without clearly defining it. The Natural Areas Program claims to preserve it. There’s a new position, the Director of Biodiversity Coordinator (currently Peter Brastow, formerly of Nature in the City) within San Francisco’s Department of the Environment.

One of our readers, puzzled by all the discussion, asked a simple question of UC Davis Professor Arthur Shapiro, who gave a talk at the Commonwealth Club a few days ago. Instead of the two-line answer they expected,  he sent this detailed response — which he kindly permitted us to publish.

Mt Davidson woodland path

WHAT IS BIODIVERSITY? BY ARTHUR M. SHAPIRO

A buzzword.
Biodiversity means whatever you want it to mean. I hate the word. Here’s why.

The following is from the introductory biology textbook we use at U.C. Davis, Life: The Science of Biology, (10th edition, Sadava et al., p.1229 — yes, I said p. 1229!):

“…the term BIODIVERSITY, a contraction of ‘biological diversity,’ has multiple definitions. We may speak of biodiversity as the degree of genetic variation within a species….Biodiversity can also be defined in terms of species richness in a particular community.  At a larger scale, biodiversity also embraces ecosystem diversity—particularly the complex interactions within and between ecosystems….One conspicuous manifestation of biodiversity loss is species extinction…”

Got that?

The glossary at the back of the book defines “biodiversity hot spot” (itself ambiguous, conflating numbers of species and degree of endemism), but NOT biodiversity itself. One can see why.

Where did this verbal monstrosity come from?

Anise swallowtail butterfly breeds on fennelThe raw number of species in a defined area or system – what many of us call “species richness”—is a useful number. There are more species of butterflies in Brazil than in California, and more in California than in Alaska. That is true even if we pro-rate species number by area, and it is not trivial to ask why.

But there is more to biodiversity than mere numbers of species. Ecologists are also interested in how individuals are divided among species, that is, the distribution of commonness and rarity among species. You can have a “community” consisting of exactly two species.  It could have, say, 50 individuals of each species, or it could have 99 of one and 1 of the other—or any ratio in between. Does this matter? Why? What can those numbers tell us?

QUANTIFYING DIVERSITY – A DIVERSITY INDEX

A century ago a Danish plant ecologist named Christen Raunkiaer observed that there was a statistical regularity to this; he called it the “law of frequency.” In subsequent years it was found to hold for bird censuses and moths collected at lights, as well as for old-field plants.  A whole series of mathematical models developed over the years attempted to account for this regularity by means of assumptions about how species interacted—competing for resources, for example. These exercises were at the core of community ecology for several decades, and were seen as immensely important.

During World War II an applied mathematician named Claude Shannon, working on war-related communications problems at Bell Labs, developed a formula that concisely expressed the information content of a message. Ecologists discovered the Shannon formula in the 1960s and realized it could easily be adapted to give a single number that combined the number of species in a community and their relative abundances.

Thus whole communities could be compared efficiently, a potentially informative and useful tactic in trying to understand how multispecies systems worked. The number generated by the Shannon formula came to be called diversity, and the formula became the first and most widely-used of several diversity indices. I learned it in high school and I still use it in teaching. Diversity had two components, then:

  • Species richness and
  • “Equitability,” (the difference between a 50:50 and a 99:1 community).

And we were off and running. Now everything could be quantified with a diversity index: “foliage height diversity” in a forest canopy, or “aspect diversity” in moth faunas (how many wing shape-pattern themes could be recognized?). The number of uses and abuses of the term multiplied like rabbits. By 1971 things had gotten so bad that a paper was published caustically titled “The nonconcept of species diversity.” It was widely applauded for its candor. Unfortunately, the author ended up inventing his own new measure of diversity—one he thought was better than the old ones.

MORE LEVELS OF ‘BIODIVERSITY’

But things could get worse. And they did. With the passage of the Endangered Species Act, which opened the door to protection of endangered subspecies (keep in mind that there is no concept of the subspecies; a subspecies is whatever some taxonomist says it is) and even “distinct population segments” (no one knows what that means), genetics got in on the diversity game. Now we would not be content with diversity at the species level; we needed to get inside species.

In the scramble to define what might be protectable, a search was launched for “evolutionarily significant units.” With modern molecular-genetic tools, we quickly learned that taxonomic subspecies may be genomically nearly identical, while organisms indistinguishable by the naked eye may be wildly different. Defining diversity at the genetic level is still, well, challenging.

One very useful dimension of biodiversity is known as alpha, beta and gamma diversity:

  • Alpha diversity is species richness at the local level.
  • Beta diversity is a measure of how much the biota of different localities within a region differ among themselves—that is, how quickly species composition “turns over” in space [i.e. when you have many different little ecosystems next to each other].
  • Gamma diversity is at a large spatial scale.

The Bay Area has phenomenally high beta diversity in almost everything.

THE BOTTOM LINE

So what is biodiversity? It’s species richness, plus the distribution of abundance and rarity, plus the geography of all that, plus the amount of genetic variation in selected species of interest, plus whatever you please.

Somehow or other concepts of “quality” have gotten mixed in, too. When you clear-cut a redwood forest (which has very low species richness), the early-successional communities that develop on the site, which may be dominated by “invasive weeds,” will have both much higher species numbers and a richer distribution of species abundances than the forest they replaced. But early-successional communities don’t get any respect despite being more diverse and despite the supposition that biodiversity is good. Because they’re made up of the ‘wrong’ species—whatever that means.

Because biodiversity, after all, is only a buzzword.

tony holiday glen canyon 7881491_orig

 

Good News on Rat Poison in California

dead barn owl found in Glen Canyon ParkAs our readers will know, we’ve been concerned about the use of second-generation rat poisons that cause death by slow internal bleeding. The poisoned mice and rats are likely to be captured and eaten by other animals – owls, coyotes, dogs, cats, hawks. When this happens, they can get poisoned too, and we’ve seen two owls die this way: a barn owl and a Great Horned Owl. These poisons are currently available in stores, and anyone can buy and use them – without knowing they could harm wildlife, pets, and even small children who pick up the bait by accident.

So here’s the GOOD NEWS! California is passing legislation restricting the sale of these products only to licensed applicators, which means that they won’t be available in stores for unthinking use by people who don’t realize their effects. (A link to the actual proposed legislation is HERE.)

The San Francisco Department of the Environment (SFDOE), which has been working on this for years, sent round a message about it, saying:

‘The California Dept. of Pesticide Regulation (DPR) has announced that it is designating the certain hazardous rat baits as “restricted materials.”

These are the products that the US EPA concluded (way back in 2008) pose an “unreasonable risk,” and tried to remove from the consumer market. The active ingredients affected by the DPR decision are brodifacoum, bromadiolone, difenacoum, and difethialone.

Restricting pesticide products means that they may only be applied by licensed applicators, or by those meeting the definition of “private applicator.” In essence, you will no longer see these products on the hardware store shelf. Considering all the data that has been amassed on poisonings of pets, wildlife and children, we consider this a very positive step.”

They asked for emails to be sent to the DPR thanking them to dpr13002@cdpr.ca.gov

If this is an issue you care about, please send them an email of thanks. We’d also like to thank all the organizations that have been involved in trying to get these restrictions, and all those that have campaigned against these rodenticides.

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