FEMA Rule Change Could Make Tree-felling Easier

Very often, land managers seeking funding for a project look to the Federal Emergency Management Agency (FEMA) for funds. FEMA provides money for fire hazard reduction, and if the project can be presented in those terms, the land managers can apply for a grant.

Until now, if a project seeking FEMA funding was large enough, FEMA asked the project sponsors for an Environmental Impact Report. This made a lot of sense: Fire hazard reduction projects have massive impacts on the landscape and habitat, much of it negative.

BUT THERE’S A NEW PLAN

Now,  FEMA plans a “programmatic environmental assessment (PEA) to evaluate the potential beneficial and adverse impacts from eligible wildfire mitigation activities funded under the Hazard Mitigation Grant Program (HMGP) and Pre-Disaster Mitigation (PDM) Program.” What this amounts to is that fire hazard reduction projects would be “pre-cleared” from an environmental standpoint. FEMA is planning to make this a nationwide measure.

It would apply to  three types of wildfire mitigation projects to protect buildings and structures on the Wildland-Urban Interface (i.e. where structures are within 2 miles of a wildland):

  • “Defensible space—The creation of perimeters around residential and non-residential buildings and structures through the removal or reduction of flammable vegetation;
  • “Structural Protection through Ignition-Resistant Construction—The application of non-combustible building envelope assemblies, the use of ignition-resistant materials, and the use of proper retrofit techniques in new and existing structures; and
  • “Hazardous Fuels Reduction—Vegetation management to decrease the amount of hazardous fuels; vegetation thinning; and reduction of flammable materials to protect life and property beyond defensible space perimeters but proximate to at-risk structures.”

The first two measures are not controversial, and can reduce hazard with a relatively minor environmental impact. However, the third one – Hazardous Fuels Reduction – is much more problematic for the environment.

WHY IS THIS A PROBLEM?

Tree removal – for whatever reason – is one of the costliest activities for a land manager. This makes any potential source of outside funding attractive.  FEMA is one such source. So if any tree-felling project can be presented as hazard reduction, it has a chance of obtaining such funds. Not having to do an environmental impact report would make the money more easily accessible.

However, removing  trees also has a significant environmental impact, which can be greater or lesser depending on the size of the project, the topography of the site, and the ecological system that would be affected. Some of the impacts:

  • Hydrology: Removing trees affects water flow and can lead to problems with erosion
  • Slope stabilization issues: The root systems of trees – especially older, mature trees that may have intergrafted roots – stabilize slopes. Removing trees can contribute to slope failures years – even decades – later.
  • Carbon sequestration: Trees capture and store carbon, fighting global warming. Felling trees stops them from collecting the carbon, and  returns it to the atmosphere.
  • Toxic herbicides: In many of these projects, managers plan to use large amounts of herbicides to prevent tree regrowth. This can end up in the soil and water, and also affect people, pets and wildlife using the lands.
  • Pollution: Trees and vegetation help fight pollution, particularly particulate pollution, by trapping particles on their leaves until they’re washed to the ground by rain.

And of course, removing trees affects the beauty and recreational value of these areas. It’s only by evaluating the environmental impact of individual projects that FEMA can determine if the negative environmental impact would be worth the hazard reduction – if any. Ironically, many of these projects would actually increase fire hazard, because removing the trees encourages growth of scrub and grass that ignite more easily and support fast-moving fires.

We’ve been concerned because we think that Native Plant “restoration” projects are often presented as hazard reduction projects. In 2008, FEMA received such an application for tree-felling in Sutro Forest. More recently, FEMA was asked to fund the removal of hundreds of thousands of trees in the East Bay.

HOW AND WHERE TO COMMENT

FEMA is accepting comments until August 18th, 2014 – this coming Monday. The comments have to be submitted at their website (not by email). Here’s how:

  1. Go to the Federal eRulemaking Portal: http://www.regulations.gov
  2.  In the Search space that comes up, input FEMA-2014-0021
  3.  Then click on Open Docket folder at the right.
 (Or try this link: HERE )

They’re not interested in comments that look like a mass mail campaign, so to have an impact, you would have to write a the comment individually.

Great horned owlets in eucalyptus. San Francisco. Janet Kessler

Don’t Cut Trees in the Nesting Season!

This year, the issue of tree-trimming or cutting during the nesting season was highlighted by the sad destruction of black-crowned night herons’ nests when the Oakland Post Office decided to get its trees trimmed. Five young herons were injured, others may have died. The tree trimmer potentially faced criminal charges, but was so remorseful – and so willing to pay for the care of the baby herons – that everyone was relieved when he didn’t.

Most people just don’t know that it’s a bad idea to trim trees (or worse, remove them) during the nesting season. Even aggressively trimming undergrowth could damage or destroy birds’ nests.  In San Francisco, the season extends approximately from February to September, depending on many factors including the weather.

Each year, Wildcare, a wonderful organization that rehabilitates hurt or orphaned wildlife,  gets a deluge of baby birds during the summer. Most of  them are displaced by tree-trimming or removal.

2012-04-11 bewick's wren nesting

Birds nests are difficult to spot, even for experts. Herons’ nests are large and noisy, and the Oakland Post Office staff surely knew the birds were there. But most birds hide their nests. Unless they are huge ones like nests of hawks or owls, the parent birds need to conceal their young from predators. Humans, who typically aren’t really looking out for them, would usually miss seeing them altogether. It may take even experienced birders hours of observation to be sure. Nests of hummingbirds, for instance, are around the size of a quarter. They’re common in San Francisco but very difficult to spot.

BROCHURES AND INFORMATION

Here’s Wildcare’s page  “Stop! Don’t Prune Those Trees!”  It explains the problem in a user-friendly way, and also gives references of two bird-friendly arborists who can do emergency work if needed.

 “Spring (and summer!) are busy baby season— procrastinate now!

When is wildlife nesting? There is some variation, but most wild animals have their babies in the spring, between March and June. However, many species will also have a second brood in July or August if food supplies are sufficient. If you can plan to trim your trees in the winter months, you can completely avoid the possibility of damaging a nest. It’s also a healthier time for the trees, when the sap has gone down and trees will be in their dormant phase. Call WildCare at 415-456-7283 if you’re unsure when it is a safe time to trim or remove a tree. “

The Golden Gate Audubon Society has published an excellent brochure:  Healthy Trees, Healthy Birds that is available as a PDF on their website. Here are pictures of the brochure (the download will be clearer and can be printed).

GGAS Healthy Trees Healthy Birds brochure 1

GGAS Healthy Trees Healthy Birds brochure 2

IT’S ILLEGAL TO DISTURB BIRDS’ NESTS

Disturbing – or worse, destroying – a birds nest is illegal. It’s a strict liability offense punishable by up to six months in jail and/or a $1,000 fine per offense.  There are laws at the Federal, State and City level. Here’s what they say:

  • Federal Migratory Bird Treaty Act. This applies to over 1,000 bird species, including many that are found in San Francisco. It makes it ” …illegal for anyone to take, possess, import, export, transport, sell, purchase, barter, or offer for sale, purchase, or barter, any migratory bird, or the parts, nests, or eggs of such a bird…” (“Taking” means to harass, harm, or pursue a bird.)
  •  California State Code 3503, 3503.5: ” It is unlawful to take, possess, or needlessly destroy the nest or eggs of any bird, except as otherwise provided by this code or any regulation made pursuant thereto.”  California State Code 3503.5 relates to birds of prey: ” It is unlawful to take, possess, or destroy any birds in the orders Falconiformes or Strigiformes (birds-of-prey) or to take, possess, or destroy the nest or eggs of any such bird except as otherwise provided by this code or any regulation adopted pursuant thereto.”
  • San Francisco County Municipal Code 5.08: It’s unlawful “to hunt, chase, shoot, trap, discharge or throw missiles at, harass, disturb, taunt, endanger, capture, injure, or destroy any animal in any park...” (with exceptions for small rodents like gophers).

The general rule is to stay 50 feet away from song-bird nests, and 500 feet from raptor nests.

TREES IN “POOR CONDITION” ARE GREAT FOR BIRDS

Sometimes, trees are removed because they’re in poor condition – dead or dying. Those are often the very trees that birds love, especially those that nest in cavities. Like this flicker (a kind of woodpecker) nesting in a half-dead eucalyptus tree. If you weren’t watching very patiently, you would have no idea that a family of young birds (three in this case) were being raised here.

The eucalyptus-tree nest hole of the red-shafted flicker - San Francisco. Janet KesslerPLAYING SAFE

The only safe way is to NEVER cut trees or thin dense bushes during the nesting season – and even when working in the off-season, typically September to February, to be very observant and watchful before starting work.

Young Great Horned Owls being raised in Eucalyptus tree

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

Here’s a link to audio notes taken by a member of the audience: LINK TO AUDIO

 

 

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

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