carbon sequestration – Conservation Sense and Nonsense

UC Berkeley tries to dodge environmental impact review of its FEMA projects

On March 1, 2016, UC Berkeley published an Addendum to the Environmental Impact Report (EIR) for its Long Range Development Plan. They claim the Addendum is a substitute for an EIR for its portion of the FEMA Grant projects in Strawberry and Claremont Canyons. The Addendum is available HERE.

Public comments on the Addendum are accepted prior to 5:00 pm on Tuesday March 22, 2016. Send public comments to planning@berkeley.edu. The announcement of the Addendum says, “The University will consider whether to approve the proposed project, as described and analyzed in the addendum, as well as all comments received, in the spring of 2016.”

The project is unchanged

Our reading of this document is that it makes no changes in the project as described by the Environmental Impact Statement for the FEMA Grants (available HERE). Therefore, whatever comments you submitted on the EIS for the FEMA Grants are equally relevant to UC’s Addendum.

Frowning Ridge after 1,900 trees were removed from 11 acres in 2004

Additional justification for the project

We read only the “guts” of the Addendum, Sections I to V. We did not read sections regarding “Mitigating Monitoring Program” or “Biological Opinion Post Treatment Monitoring Plan.” Therefore, our comments here should not be considered comprehensive. However, we noted new justifications for the project that seem legally bogus in some cases and scientifically unsound in others.

UC Berkeley destroyed about 600 trees on Frowning Ridge in August 2014, before the Environmental Impact Statement was complete. FEMA has therefore refused to fund that portion of the grant.

Justification for carbon loss

The Addendum cites Cal-FIRE policy regarding quantifying carbon loss. Cal-FIRE states that although “There is not an approved forest carbon protocol for fuel reduction projects,” it suggests: “On an acre treated for fuels the carbon balance emitted from the treatment subtracted from the carbon retained multiplied by its reduced probability of loss [by fire] over the time of treatment is effective.” (Addendum page 18)

In other words, Cal-FIRE suggests that if the probability of fire is lowered by the project, carbon loss associated with such a theoretical fire can be subtracted from the carbon loss resulting from the destruction of trees by the project.

There are several problems with this justification for the carbon loss associated with the destruction of trees by the project:

The claim that the probability of fire will be lowered by the proposed project is entirely theoretical. Many highly qualified analysts of this project believe that the project will increase the probability of fire, not decrease it. For example, the US Forest Service said, “Removal of the eucalyptus overstory would reduce the amount of shading on surface fuels, increase the wind speeds to the forest floor, reduce the relative humidity at the forest floor, increase the fuel temperature, and reduce fuel moisture. These factors may increase the probability of ignition over current conditions.”
The law that defines and regulates environmental impact reviews is the California Environmental Quality Act (CEQA), not Cal-FIRE policy. CEQA requires that environmental impact is defined by a comparison of existing conditions with post-project conditions. In other words, environmental impact is not measured by comparing some theoretical landscape in which a theoretical fire occurred with the post-treatment landscape. Therefore, the methods used by the Addendum to quantify carbon loss do not conform to the law (CEQA) that regulates environmental impact reviews.
The Cal-FIRE policy defines its fuels reduction program as follows: “vegetation treatment…will focus on selectively removing understory trees and brush to reduce fire hazards, improve tree growth, and increase forest health and resilience.” Therefore, the Cal-FIRE policy is not relevant to the project of UC Berkeley, which intends to destroy ALL non-native canopy trees and does not intend to remove understory brush and trees. Consequently, carbon loss will be significantly greater than the projects proposed by Cal-FIRE because carbon storage is greater in the large, mature trees that will be destroyed than carbon stored in the understory.

The science of carbon storage

We have heard many absurd statements about carbon storage in the many years we have defended our urban forest, such as “grass stores more carbon than trees.” But the explanations provided by UC’s Addendum that their project will not cause carbon loss enter the realm of science fiction:

UC claims, “The report concluded that the HCFRR project area currently stores an estimated 61,565 CO2e tons, the majority of which will remain stored in the project area in the form of post-treatment chips.” (Addendum, page 19)

When questioned by the consultant (URS Corporation) that was hired to complete the Environmental Impact Statement for the FEMA projects about the flammability of 2 feet of wood chip mulch in the project area, UCB responded that the chips would decay within 3 to 5 years (available HERE). Now UCB wishes us to believe that the wood chips will not decay, but will continue to store carbon forever. UCB contradicts itself or it is ignorant of the role of decomposition in the release of carbon stored during the life of the tree. As the wood decomposes, the carbon stored in the wood is released into the atmosphere:

“Two common tree disposal/utilization scenarios were modeled: 1) mulching and 2) landfill. Although no mulch decomposition studies could be found, studies on decomposition of tree roots and twigs reveal that 50% of the carbon is lost within the first 3 years. The remaining carbon is estimated to be lost within 20 years of mulching. Belowground biomass was modeled to decompose at the same rate as mulch regardless of how the aboveground biomass was disposed” (1)

UC claims, “Remaining native trees will continue to grow and sequester carbon at a rate of ~ 530 ton equivalents per decade therefore…this will increase to 10,560 in year l00.” (Addendum, page 19) In other words, UC assumes, without factual support and in defiance of reality that native trees will not burn for 100 years. UC also ignores the much larger amounts of carbon that the eucalypts would sequester if left in place because larger trees store more carbon than smaller, younger trees.
UC claims that a project area currently storing 61,565 CO₂ₑ tons will release 50,000 tons of CO₂ₑ if it burns. That is a gross over-estimate of the degree of carbon loss from trees in a fire. According to the National Park Service, 2/3^rd of the fuel load in a eucalyptus forest is in the trunks and only 1/3^rd in fine fuels (branches, twigs, leaves, etc). (2) The trunks of the trees do not burn in a fire, which is why they are left lying on the ground after they are destroyed. Therefore only 1/3^rd of the wood burns in the fire and only 1/3^rd of the carbon stored in the tree – approximately 20,000 tons – would be lost in the fire.

We are profoundly disappointed that a world-class scientific institution, such as UC, would make such scientifically unsound claims in defense of its destructive project in the East Bay Hills.

If you read UC’s Addendum and you see other issues that we don’t mention here, we hope you will post a comment to inform others of what you have found. This is a collaborative effort that we invite everyone to participate in. The Hills Conservation Network believes the strongest criticism of UC’s Addendum to the EIR for their Long Range Development Plan is that it is not a legally acceptable substitute for a complete EIR. You can read their arguments on their website. There is also a petition to UCB on their website.

Status of lawsuit of Hills Conservation Network

Meanwhile, the lawsuit of the Hills Conservation Network (HCN) against the UC Berkeley and City of Oakland portions of the FEMA grants projects in the East Bay Hills is moving forward. HCN Informed its supporters of the current status of its lawsuit on March 2, 2016:

“Hills Conservation Network took a momentous step yesterday with the filing of our opening brief for the lawsuit against FEMA, the City of Oakland, UC, EBRPD and Cal OES. Despite extensive efforts to find another solution we decided this was the only reasonable course of action open to us.

While this is a complex matter and we are told that one never knows how a NEPA suit will turn out, we believe we have a very strong case and hope that we will prevail and these forests will be saved. If you are interested you can read the brief at http://www.hillsconservationnetwork.org

Needless to say, this has been expensive. We have spent well over $10,000 on legal fees in the past 3 months and expect that it will take at least that much more to see this through the process, which is expected to result in a ruling in the summer.

Yesterday we were notified by UC that they intend to obtain CEQA clearance for their projects (which we hope will not be funded by FEMA) by issuing an addendum to their 2020 Long Range Development Plan. We are consulting with our lawyers on how best to respond to this and expect to propose a strategy to the public by Monday.

Again, your contributions are what makes all this possible. Were it not for your support these forests would have been long gone, but with your support we are able to prevent this environmental disaster from unfolding.

Please do what you can to support this important cause.” [You can make a donation to the lawsuit at http://www.hillsconservationnetwork.org]

Nowak, David, et.al., “Effects of urban tree management and species selection on atmospheric carbon dioxide,” Journal of Arboriculture 28(3) May 2002
http://www.nps.gov/pore/learn/management/upload/firemanagement_fireeducation_newsletter_eucalyptus.pdf

Mopping up the last load of Sierra Club propaganda

This is the last in a series of rebuttals to the Sierra Club’s “pre-buttal” to a letter from a Sierra Club member to members of the San Francisco Bay Chapter of the Sierra Club about the Club’s support for deforestation and pesticide use on our public lands.

The truth about how much herbicide will be used

Sierra Club misrepresents volume of herbicide use: “If used, herbicide would be applied in minute quantities under strict environmental controls.” (1)

East Bay Regional Park District (EBPRD) informs us in the Draft Environmental Impact Statement (DEIS) for the FEMA project in the East Bay Hills that it intends to use 2,250 gallons of herbicide on its project acres to destroy non-native vegetation and prevent the trees they destroy from resprouting. You can see the detailed table of their intended herbicide use for yourself by looking at the DEIS. (2) On what planet would 2,250 gallons be called “minute quantities?”

EBRPD intentions were to “thin” non-native trees, not destroy them all. The Sierra Club has sued EBRPD to force them to destroy ALL non-native trees on their project acres. If the Sierra Club lawsuit is successful, EBRPD will be forced to destroy MORE trees than it wanted to destroy. That means it will be forced to use EVEN MORE herbicide than it intended to use, i.e., MORE than 2,250 gallons.

EBRPD is only ONE of the three public land owners that are participating in the FEMA project. The other two public land owners (UC Berkeley and City of Oakland) intend to destroy ALL non-native trees on their project acres. That means they will have to use EVEN MORE herbicide than EBRPD intended to use per acre of project area.

Sierra Club fabricates an argument we have not made: “Comparing this use of herbicide to the regular broadcast spraying of farmland elsewhere is a misrepresentation of fact.” (1)

This is a red herring, intended to confuse you with an argument that no one has made in opposition to this project. We have not likened pesticides used for these projects with agricultural use of pesticides. We aren’t being given a choice between agricultural pesticides and pesticides in our parks. The Sierra Club is asking us to accept additional pesticides in our parks on top of the agricultural pesticides we are already exposed to and over which we have no control. Since many pesticides accumulate in our bodies over our lifetimes, additional pesticide exposure results in greater toxicity and potential for damage to our health.

Horticultural fiction

Sierra Club fantasizes about the post-project landscape: “Concerns about not planting trees to replace those being removed miss the mark. Replanting is not necessary. (1)

Knowledgeable organizations do not share the Sierra Club’s fantasy that native trees will magically emerge from 2 feet of eucalyptus wood chip mulch to colonize the bare ground. Here is a partial list of the environmental consultants, governmental agencies, and environmental organizations that have refuted this fiction:

URS Corporation is the environmental consultant initially hired to complete the environment impact review of the FEMA projects. Their report said: “However, we question the assumption that the types of vegetation recolonizing the area would be native. Based on conditions observed during site visits in April 2009, current understory species such as English ivy, acacia, vinca sp., French broom, and Himalayan blackberry would likely be the first to recover and recolonize newly disturbed areas once the eucalyptus removal is complete.”
The US Forest Service evaluated the FEMA projects. This is their prediction of the post-project landscape: “a combination of native and non-native herbaceous and chaparral communities.”
The California Native Plant Society predicted the post-project landscape in its written public comment on the Draft Environmental Impact Statement (DEIS) with this rhetorical question: “What mechanism is being instituted by FEMA in this DEIS to guarantee a commitment of money and personnel for management of greatly increased acreages of newly created annual weedy grassland?”
The Audubon Society predicted the post-project landscape in its written public comment on the DEIS: “There is no support for the conclusion that native vegetation will return on its own. This plan may not result in an increase in native trees and plants…Heavy mulching will delay or prevent the growth of native species.”

Trees were destroyed here by UC Berkeley over 10 years ago. The landscape is now non-native annual grasses. This is the typical outcome of tree removals on sunny hills without a water source.

Sierra Club and Claremont Canyon Conservancy (CCC) repeatedly refer to Site 29 on Claremont Blvd as a model for the FEMA projects. They fail to acknowledge that Site 29 is not representative of most FEMA project areas because CCC planted native trees (primarily redwoods) on Site 29 and the microclimate of Site 29 is not typical of other project areas. Site 29 is a riparian corridor—there is a creek running through it—so there is more available water than in most project areas. It is also protected from wind and sun by hills on north and south sides of the site. CCC has not made a commitment to plant native trees on 2,000 acres of the FEMA project areas and even if it did, it could not expect the same results in radically different microclimates such as sunny, windy ridge lines with no available water source.

Fundamentals of carbon storage

Sierra Club does not understand the fundamentals of carbon storage: “Carbon sequestering and erosion control will not be reduced by removing eucalyptus trees… Indeed, reducing the fire danger by removing the eucalyptus will do much to prevent the release of tons of carbon that occurs during a wildfire. [x]” (1)

Sierra Club continues with the fiction that non-native trees will burn while native trees will not. There is no evidence behind that story, and much evidence to the contrary. The numerous wildfires throughout California each summer demonstrate that native trees and shrubs are extremely flammable—easily ignited and burning vigorously once ignited. Native trees, shrubs, and grasses also release their stored carbon when they burn. The NSF article cited by the Sierra Club in support of its bogus statement does not suggest that prospectively destroying forests is a means of preventing carbon loss.

Destroying eucalyptus trees will release hundreds of thousands of tons of carbon stored in those trees. That’s a simple, inarguable fact. There are no plans to replace the eucalyptus with “native trees.” A small portion of the carbon released by eucalyptus destruction may be recaptured by the grasses and shrubs that will grow in place of the eucalyptus, but the net loss of stored carbon to the atmosphere from the eucalyptus is huge and permanent. Further, the eucalyptus would have continued to store even more carbon if left in place. That future carbon sequestration is also lost.

The DEIS for the FEMA-funded projects tries to minimize the loss of stored carbon from destruction of eucalyptus by quantifying only carbon loss from the destruction of tree trunks, ignoring leaves, branches, roots, understory, forest floor litter, and soil. But even they acknowledge, “…the planned growth of oak and bay woodlands and successional grassland containing shrub islands would not sequester as much carbon as the larger eucalyptus and pines and the denser coastal scrub that would be removed.” (DEIS 5.6-11)

Killing habitat needed by wildlife

Sierra Club does not know who lives in our urban landscapes: “Native landscapes provide habitat for much more diverse ecosystems.” (1)

There are many studies that find that our non-native landscape provides valuable habitat and no studies that say otherwise:

“Most California natives in cultivation are of no more butterfly interest than nonnatives, and most of the best butterfly flowers in our area are exotic.” (3)
“[T]he science does not support the supposition that native plantings are required for biodiversity…it is clear that an automatic preference for native trees when planning in urban areas is not a science-based policy.” (4)
“Three types of trees were used most frequently by roosting monarchs [in California]: eucalyptus (75% of the habitats primarily Eucalyptus globulus), pine (20% of the habitats primarily Pinus radiata), and cypress (16% of the habitats primarily Cupressus macrocarpa)” (5)
“In the first half of the 20^th century, the Anna’s Hummingbird bred only in northern Baja California and southern California. The planting of exotic flowering trees provided nectar and nesting sites, and allowed the hummingbird to greatly expand its breeding range…Anna’s Hummingbird populations increased by almost 2% per year between 1966 and 2010, according to the North American Breeding Bird Survey…Thanks to widespread backyard feeders and introduced trees such as eucalyptus, it now occurs in healthy numbers all the way to Vancouver, Canada.” (6)
Red-tailed hawk nesting in eucalyptus. Courtesy urbanwildness.org

“Fourteen of 27 nests in 1994 and 38 of 58 nests in 1995 were in exotic trees, predominantly eucalyptus. Nesting and fledging success were higher in exotic trees than in native trees in both years, owing in part to greater stability and protective cover. Most nest trees in upland areas were exotics, and even in riparian habitats, where tall native cottonwoods and sycamores were available, Red-shouldered Hawks selected eucalyptus more often than expected based on availability.” (7)
A study that compared species diversity and abundance of plants, invertebrates, amphibians, birds, and rodents in eucalyptus forest with oak-bay woodland in Berkeley, California reported this finding: “Species richness was nearly identical for understory plants, leaf-litter invertebrates, amphibians and birds; only rodents had significantly fewer species in eucalypt sites. Species diversity patterns…were qualitatively identical to those for species richness, except for leaf-litter invertebrates, which were significantly more diverse in eucalypt sites during the spring.” (8)

We could provide many more citations from studies that consistently find that our existing non-native landscape is essential to wildlife and that destroying it will be harmful to wildlife, particularly considering the enormous amount of herbicide that will be used. We ask this common-sense, rhetorical question, “How could destroying most of our landscape provide a more diverse ecosystem?” It defies logic.

Environmentalism gone awry

If the Sierra Club would replace a few of its lawyers with a few scientists, perhaps we would not be having this debate. Environmentalism has gone astray because it is not knowledgable about some basic scientific issues, such as carbon storage, the toxicity of herbicides, and the habitat needed by our wildlife. Climate change is the environmental issue of our time. If an environmental organization does not understand the fundamentals of carbon storage it is not capable of doing its job. The Sierra Club must improve its knowledge of the Bay Area environment or it will fade into irrelevance in the struggle to protect that environment.

(1) http://sierraclub.org/san-francisco-bay/hillsfacts

(2) See Table 2.1 in Appendix F: http://www.fema.gov/media-library-data/1416861356241-0d76d1d9da1fa83521e82acf903ec866/Final%20EIS%20Appendices%20A-F_508.pdf

(3) Arthur Shapiro, Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions, University of California Press, 2007

(4) Linda Chalker-Scott, “Nonnative, Noninvasive Woody Species Can Enhance Urban Landscape Biodiversity,” Arboriculture & Urban Forestry, 2015, 41(4): 173-186

(5) Dennis Frey and Andrew Schaffner, “Spatial and Temporal Pattern of Monarch Overwintering Abundance in Western North America,” in The Monarch Butterfly Biology and Conservation, Cornell University Press, 2004.

(6) Cornell Ornithology Laboratory https://www.allaboutbirds.org/guide/annas_hummingbird/id

(7) Stephen Rottenborn, “Nest-Site selection and reproductive success of urban red-shouldered hawks in Central California,” J. Raptor Research, 34(1):18-25

(8) Dov Sax, “Equal diversity in disparate species assemblages: a comparison of native and exotic woodlands in California,” Global Ecology and Biogeography, 11, 49-52, 2002.

FEMA projects in the East Bay deny carbon loss

Hummingbird in eucalyptus flower. Courtesy Melanie Hoffman — Hummingbird in eucalyptus flower. Courtesy Melanie Hofmann

Our readers know that one of many reasons why we object to the destruction of healthy trees is that they are sequestering and storing carbon which is released as carbon dioxide into the atmosphere when the trees are killed and as wood decays. Carbon dioxide is the predominant greenhouse gas that is causing climate change. We believe that addressing climate change should be considered our highest environmental priority.

Although we like native plants and would like to conserve them, they will not survive in their historical ranges in a changing climate. Therefore, native plant advocates should join us in making climate change a higher priority than destroying our existing landscape in places where native plants may no longer be adapted if that destruction contributes to climate change.

Federal and State policies and laws have been adopted to address climate change and the main point of an environmental impact study is to assure the public that the project complies with all laws. Therefore, the Draft Environmental Impact Study (DEIS) for the FEMA projects in the East Bay that will destroy tens of thousands of healthy trees stands on its proverbial head trying to deny that carbon loss resulting from these projects will not violate these laws. These projects are described in detail HERE.

The point of this article is to inform the public of some of the flaws in the DEIS with respect to its analysis of carbon loss resulting from these projects. (This will not be a complete list of omissions and errors in the DEIS regarding carbon loss. A complete list would be too technical and lengthy.)

Only 15% of carbon storage in the existing forest has been quantified by the DEIS

The DEIS quantifies only two sources of carbon dioxide emissions resulting from this project: the fossil fuels used by motorized equipment during the project and the trunks of the trees greater than 5” in diameter that will be destroyed. Calculating loss of stored carbon based solely on the trunks of the trees that will be destroyed excludes the following sources of stored carbon in the forest: the understory, the forest floor layer (e.g., duff and litter), the bark, roots, and branches of the trees, and the soil. RA Birdsey of the US Forest Service reports (1) that only 15% of total carbon stored in forest ecosystems in the United States is contained in the trunk:

Allocation of carbon in forest ecosystems and trees

US Forests, 1992

1%	Foliage
5%	Roots
15%	Bole (trunk)
9%	Other wood above ground
	29%	Tree
	61%	Soil
	8%	Forest floor
	1%	Understory
	99%	Total

Although the soil will remain when the trees are destroyed, there is scientific evidence that there will be some loss of soil carbon as a result of this project: “…a major forest disturbance, such as a clearcut harvest, can increase coarse litter and oxidation of soil organic matter. The balance of these two processes can result in a net loss of 20% of the initial carbon over a 10-15 year period following harvest.” (1) The destruction of all non-natives trees on 400 acres of UC Berkeley and the City of Oakland properties and 90% of the trees on 1,600 acres of East Bay Regional Park District, surely qualifies as a “major forest disturbance” which will result in loss of carbon stored in the soil of the forest.

The DEIS pretends there is no carbon loss from prescribed burns

East Bay Regional Park District plans to chip the trees that are destroyed and distribute them on 20% of the project areas to a depth of 4-6 inches. They plan to burn the wood that cannot be distributed on the ground without exceeding these limits. This excess wood will be burned in piles. In addition to pile burns, EBRPD also plans to conduct broadcast burns for the purpose of destroying non-native vegetation and vegetation debris considered potential fuel for a fire.

The DEIS does not quantify the carbon that will be released by these burns, citing an EPA policy of 1996: “It should be noted that the emission of CO₂ from burning has not been calculated since the removal of the vegetation would allow new vegetation to grow, eventually consuming at least a portion [of] the CO₂ released during burning, as noted in EPA emission factor guidance (EPA 1996)”

This EPA policy regarding CO₂ emissions from prescribed burns has been revised to include carbon emissions from prescribed burns. In response to climate change, the EPA established an “Emission Inventory Improvement Program” (EIIP) in 1997. Since then, the EIIP has continuously expanded and improved the National Emissions Inventory (NEI). The NEI for 2008 is available on the EPA website. It includes reporting of CO₂ emissions resulting from prescribed burns. Data for each type of emission is available on the internet. It can be sorted by state. The 2008 NEI reports that the State of California emitted 2,156,547 tons of carbon dioxide from prescribed burns in 2008.

Obviously, the DEIS is mistaken in its outdated claim that the EPA excludes emissions from prescribed burns from calculations of greenhouse gas emissions. Furthermore, whether or not the carbon released by prescribed burns must technically be reported, that carbon is, in fact, released to the atmosphere. Such a legalistic quibble ignores the fact that carbon released by prescribed burns has the same harmful environmental consequences as any other carbon release.

Loss of the ability of the existing forest to sequester carbon in the future is not quantified

In addition to the grossly underestimated loss of carbon stored in the existing forest ecosystem, the DEIS does not quantify the loss of the ability of the existing forest to sequester carbon in the future. The DEIS acknowledges that the post-treatment landscape will be less capable of sequestering carbon than the existing landscape:

“The proposed and connected actions would also be self-mitigating to some degree in the absence of a wildfire, because native vegetation would partially replace the non-native vegetation removed. However, the planned growth of oak and bay woodlands and successional grassland containing shrub islands would not sequester as much carbon as the larger eucalyptus and pines and the denser coastal scrub that would be removed.” (DEIS 5.6-11)

The DEIS cannot claim that legal thresholds for carbon loss are not violated without quantifying this decrease in the ability to sequester carbon.

Blue gums live in Australia from 200 to 500 years. (2) They live toward the longer end of the range in milder climates such as the San Francisco Bay Area. Most Blue Gum eucalypts were planted in the East Bay between 1886 and 1913, according to David Nowak of the US Forest Service. (3) Therefore, they are not more than 130 years old. They can be expected to continue to sequester carbon for at least 100 years and perhaps 300 years.

The native trees that the proposed projects claim will occupy the ground now occupied by non-native trees are significantly smaller than the existing trees. Since carbon sequestration and storage are proportionate to biomass, the native trees will not compensate for the loss of the ability of the existing forest to sequester carbon. The DEIS reports in Table 4.7-1 that the oak-bay woodland in the project areas is storing only 8.97 metric tons of CO2 per acre, compared to 325.91 metric tons per acre in the eucalyptus forest and 184.61 metric tons per acre in the Monterey pines.

Furthermore, the predominant native tree is being killed by Sudden Oak Death (SOD) at an epidemic rate, so its future is both unlikely and unknown. SOD exists in the project areas, which is reported HERE.

Misinterpreting or misrepresenting science

The DEIS sets up a straw man to support its claim that the FEMA projects will not increase carbon dioxide emissions by offering a false choice between theoretical carbon loss from a wildfire vs. carbon loss from destruction of the non-native forest. This false choice violates both federal and state law regulating environmental impact studies because the measure of environmental impact as defined by those laws require that the study compare the existing, baseline condition to the potential impact resulting from the proposed project. In other words, the existing condition is the forest that exists now, not a theoretical forest that has been destroyed by fire.

Adding insult to injury, the DEIS tries to prove its theoretical straw man by misinterpreting or misrepresenting scientific studies:

“Studies indicate that if a wildfire occurs, the proposed type of vegetation management sequesters more carbon in the long term than leaving the sites untreated. Two wildfire modeling studies indicated that thinning would reduce damage caused by wildfires, allowing faster regrowth after a fire (Hurteau and North 2010; Wiedinmyer and Hurteau 2010). The Wiedinmyer and Hurteau (2010) study included the use of prescribed burning as a treatment method.” (DEIS 5.6-11)

In fact, these studies don’t say what the DEIS claims they say:

In “Prescribed fire as a means of reducing forest carbon emissions in the Western United States,” (4) the authors compare carbon loss from prescribed burns with carbon loss from wildfires in the same locations and reach the conclusion that prescribed burns result in less carbon loss than wildfires without prescribed burns. However, the prescribed burns they are considering were restricted to the understory and did not include any trees: “The fraction of fuel consumed in prescribed fires was applied only to the surface fuel fraction (including herbaceous, fine, and coarse fuels of the total fuel loading model…); no live or standing dead trees are assumed to burn in prescribed fires.” Therefore, this study is not applicable to the proposed project which intends to burn the remains of hundreds of thousands living trees which will obviously release far more carbon into the atmosphere than the prescribed burns in this study as well as reduce carbon sequestration into the foreseeable future.

In “Carbon recovery rates following different wildfire risk mitigation treatments,” (5) the authors compare several different methods of fuel reduction with respect to how long it takes for the forest to recoup the carbon loss from those methods. It finds that the forest is unable to recoup the loss of carbon when the destruction of the overstory canopy is the method used because of the large amount of carbon stored in large trees: “Overstory tree thinning treatments resulted in a large carbon deficit and removed many of the largest trees that accumulate the most carbon annually, thereby increasing carbon stock recovery time.” In fact, this is precisely the method that will be used by the proposed project. Therefore, this study makes the point that this project will permanently reduce the ability to sequester carbon by destroying large trees that will not be replaced. In other words, this study contradicts rather than supports the assumptions of the DEIS regarding carbon storage.

In “High-severity wildfire effects on carbon stocks and emissions in fuels treated and untreated forests,” (6) the authors compare carbon loss from wildfires in a thinned forest (both loss from treatment and loss from subsequent wildfires) with carbon loss from wildfires in the same locations without thinning. They conclude that such thinning results in more total carbon loss than wildfires without such thinning in the short run. However, because more trees remain after wildfire in a treated forest, the ability of the forest to sequester carbon in the long term can recoup much of the loss of the treatment. The forests they are considering have average densities of 1536 stems per hectare and thinning is limited to stems of less than 18 inches in diameter. This study is therefore not relevant to the proposed project because the forests in the proposed project are significantly less dense and are being completely destroyed by UCB and Oakland and more drastically thinned by EBRPD compared to the study. In other words, a much greater percentage of total carbon storage will be lost by the proposed projects in the short run because a higher percentage of total trees will be destroyed, including all large trees which store more carbon than smaller trees. In addition much more capability to sequester carbon will be lost in the long run because few trees will remain.

All of these studies have in common that they have measured all sources of carbon in the forest: carbon in the soil and roots, in the branches and leaves, in the understory, in the duff and leaf litter. In contrast, the DEIS quantifies only the amount of carbon stored in the trunks of the trees. All other sources of carbon are ignored.

It’s time to send your public comment on these projects

Remember that public comments are due by June 17^,2013. You may submit written comments in several ways:

Via the project website: http://ebheis.cdmims.com
By email: EBH-EIS-FEMA-RIX@fema.dhs.gov
By mail: P.O. Box 72379, Oakland, CA 94612-8579
By fax: 510-627-7147

These public lands belong to you and the money that will be used to implement these projects is your tax dollars. So, please tell the people who work for you what you think of these projects.

***********************************

(1) “Carbon Changes in US Forests,” RA Birdsey and LS Heath, US Forest Service Gen. Tech. Report RM-GTR-271, 1995

(2) Eucalypt ecology: Individuals to ecosystems, by Jann Elizabeth Williams, John Woinarski ,Cambridge University Press, 1997

(3) David Nowak, “Historical vegetation change in Oakland and its implications for urban forest management,” Journal of Arboriculture, 19(5), September 1993,

(4) Christine Wiedinmyer and Matthew Hurteau, “Prescribed fire as a means of reducing forest carbon emissions in the Western United States,” Environmental Science Technology, 2010, 44, 1926-1932

(5) Matthew Hurteau and Malcolm North, “Carbon recovery rates following different wildfire risk mitigation treatments,” Forest Ecology and Management, 260 (2010) 930-937

(6) Malcolm North and Matthew Hurteau, “High-severity wildfire effects on carbon stocks and emissions in fuels treated and untreated forest,” Forest Ecology and Management, 261 (2011) 1115-1120

Carbon storage in our urban forest

We believe that addressing climate change should be our highest environmental priority because it is the cause of many environmental problems. For example, a recent study found that changes in climate accounted for over half of the significant changes in vegetation all over the world in the past 30 years: “The climate governs the seasonal activity of vegetation…In humid mid-latitudes temperature is the largest influencing factor in plant growth. In predominantly dry areas, however, it is the availability of water and in the high altitudes incident solar radiation.” (1) Animals are affected by both changes in vegetation and climate, as exemplified by the shrinking home of the polar bear as Arctic ice melts.

The consensus amongst scientists is that increases in greenhouse gas emissions are the primary cause of climate change and carbon dioxide is the predominant greenhouse gas. Although the burning of fossil fuels is often considered the biggest source of greenhouse gas emissions, in fact transportation is responsible for only 10% of emissions. In contrast, deforestation is contributing 20% of greenhouse gas emissions because trees store carbon as they grow and release it into the atmosphere as carbon dioxide when the tree is destroyed. For that reason—and many others– we are opposed to the destruction of our urban forest.

Mount Sutro Forest is threatened with destruction because it is noy native. Courtesy Save Sutro Forest. — Mount Sutro Forest is threatened with destruction because it is not native. Courtesy Save Sutro Forest.

Because our urban forest is predominantly non-native, native plant advocates are committed to defending the projects that are destroying the urban forest, which puts them in the awkward position of claiming that its destruction will not contribute to climate change. Here are a few of the arguments used by native plant advocates and the scientific evidence that those arguments are fallacious:

Since the native landscape in the Bay Area is grassland and scrub, native plant advocates often claim that these landscapes store more carbon than trees. In fact, trees store far more carbon than the native landscape because carbon storage is largely proportional to biomass. In other words, the bigger the plant, the more carbon it is capable of storing. (Carbon storage in plants and soils is explained in detail here.)
In the Draft Environmental Impact Report for San Francisco’s Natural Areas Program, native plant advocates claimed that destroying the forest and restoring grassland would lower ground temperatures based on a scientific study about the arctic north at latitudes above 50°. In fact, the point of that study was that snow reflects more light than trees. The Bay Area is far below 50° latitude and it doesn’t snow here, so that study is irrelevant to the Bay Area. (That study and its misuse by native plant advocates are reported here.)
Since most of the urban forest in the Bay Area was planted over 100 years ago, native plant advocates often claim that only young trees store carbon. Since carbon storage is largely proportional to biomass, mature trees store more carbon than small young trees. That is illustrated by this graph from the US Forest Service survey of San Francisco’s urban forest.

Larger trees store more carbon at a faster rate

The claim that young trees store more carbon is often made in connection with the equally bogus claim that “restoration” projects in the Bay Area will replace non-native trees with native trees. None of the plans for these projects propose to plant native trees where non-native trees are destroyed because that wasn’t the native landscape. In any case, native trees don’t tolerate the windy, dry conditions in which non-native trees are growing. For example, a study of historic vegetation in Oakland, California reported that only 2% of pre-settlement Oakland was forested with trees. (2)

A new study about carbon storage in forests

Now that science has established the reality of climate change, most scientific inquiry has turned to how to stop it and/or mitigate it. For example, a recent study reports that planting forests where they did not exist in the past, quickly stores far more carbon in the soil than the treeless landscape. Scientists “…looked at lands previously used for surface mining and other industrial uses, former agricultural lands, and native grasslands where forests have encroached….[they] found that, in general, growing trees on formerly non-forested land increases soil carbon.” (3)

Here are their specific findings on each type of previously non-forested land:

“On a post-mining landscape, the amount of soil carbon generally doubled within 20 years and continued to double after that every decade or so.”
“The changes after cultivation of farm fields was abandoned and trees became established are much subtler, but still significant…at the end of a century’s time, the amount of soil carbon averages 15 percent higher than when the land was under cultivation…”
“In places where trees and shrubs have encroached into native grassland, soil carbon increased 31 percent after several decades…”

Mainstream environmental organizations such as the Sierra Club claim to be concerned about climate change, yet they are the driving force behind the destruction of the urban forest in the San Francisco Bay Area. When will they wake up to the fact that advocating for the destruction of the urban forest is irresponsible for an environmental organization in the age of climate change?

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(1) “A Look at the World Explains 90 Percent of Changes in Vegetation,” Science Daily, April 22, 2013.

(2) Nowak, David, “Historical vegetation change in Oakland and its implications for urban forest management,” Journal of Arboriculture, 19(5): September 1993

(3) “Soils in Newly Forested Areas Store Substantial Carbon That Could Help Offset Climate Change,” Science Daily, April 4, 2013.

Why does UCSF want to destroy the Sutro forest?

The short answer to that question is “I don’t know.” However, since many of the over 1,200 signers of the petition to University of California San Francisco (UCSF) to save the forest have asked this question, it seems that they deserve some answer. So, in this post, we will tell you the reasons that UCSF has given for its plans to destroy the forest.

UCSF makes two erroneous claims about the Sutro forest which it uses to justify its destruction. They claim that the forest is unhealthy and that destroying most of the forest will benefit the few trees that remain. They also claim that the forest is very flammable and that destroying most of the forest will make it less flammable. This is our response to these claims.

The Sutro Forest is not unhealthy

The Save Sutro website recently posted the professional opinion of two arborists who evaluated the Sutro forest and pronounced it healthy. We recommend that article as a starting point for anyone who wishes to be reassured on this important point.

The Draft Environmental Impact Report for UCSF’s planned project claims that the forest is old and dying. If we don’t beat it to the punch and kill it first, it will soon die without our help. An analogy comes to mind: “We had to destroy the village to save it,” which was the explanation given for the destruction of a village during the Vietnam War. It didn’t make sense then and it doesn’t make sense now.

The fact is, the Sutro forest is young and in the prime of its life. Eighty-two percent of the forest is blue gum eucalyptus. Blue gums live in Australia from 200 to 500 years. (1) They live toward the longer end of that range in milder climates such as the San Francisco Bay Area. The blue gum eucalypts were planted on Mount Sutro in the 1880s. It is still a young forest.

Another indication that the forest is young is that the individual trees are small by blue gum standards. The study plots used by the Draft Environmental Impact Report (DEIR) to calculate how much carbon is stored in the trees found that 77% of the trunks of the trees are 5 inches in diameter at breast height or less (if the study plots are representative of the entire forest, which is questionable). It also says that this species of eucalyptus grows very fast and that its trunk is 9 inches in diameter after only three years of growth. In other words, the DEIR claims that the trees are old and no longer growing, yet it says that most of the trees are very small and it intends to destroy the small trees, not the big ones. This is just one of many contradictions that we find in the DEIR.

There is little risk of wildfire in the Sutro Forest

One of the most powerful rhetorical tools used by native plant advocates to justify the destruction of our urban forest and motivate the public to pay for these expensive projects is the fear of fire. UCSF uses this strategy as well. Frankly, we doubt that UCSF believes it themselves because they applied for a Federal Emergency Management Agency (FEMA) grant to pay for this project in 2008. FEMA informed UCSF that there is little risk of wildfire on Mount Sutro. UCSF withdrew its grant application rather than answer FEMA’s questions.

FEMA asked UCSF to supply scientific evidence that the project would reduce fire risk despite the fact that the project would reduce fog condensation from the tall trees which moistens the forest floor, making ignition unlikely. FEMA also asked for scientific evidence that a wind driven wildfire would not be more likely after the destruction of the wind break provided by the forest. UCSF chose to withdraw its grant application, presumably because they could not answer those questions.

In 2010, UCSF applied for another fire hazard mitigation grant from the California Fire Safe Council. The Council has funded 150 such grants in California, but they denied UCSF’s application. That suggests that the California Fire Safe Council shares FEMA’s opinion.

You might ask, where is UCSF getting the money to pay for this project? We don’t know, but we consider that a legitimate and important question given that UCSF is a publicly funded enterprise.

UCSF may not be able to answer FEMA’s questions, but we can, using specific scientific studies. In 1987, 20,000 hectares burned in a wildfire in the Shasta-Trinity National Forest. The effects of that fire on the forest were studied by Weatherspoon and Skinner of the USDA Forest Service. They reported the results of their study in Forest Science. (2) They found the least amount of fire damage in those sections of the forest that had not been thinned or clear-cut. In other words, the more trees there were, the less damage was done by the fire. They explained that finding:

“The occurrence of lower Fire Damage Classes in uncut stands [of trees] probably is attributable largely to the absence of activity fuels [e.g., grasses] and to the relatively closed canopy, which reduces insolation [exposure to the sun], wind movement near the surface, and associated drying of fuels. Conversely, opening the stand by partial cutting adds fuels and creates a microclimate conducive to increased fire intensities.”

In other words the denser the forest,

The less wind on the forest floor, thereby slowing the spread of fire
The more shade on the forest floor.
- The less flammable vegetation on the forest floor
- The more moist the forest floor

All of these factors combine to reduce fire hazard in dense forest. Likewise, in a study of fire behavior in eucalyptus forest in Australia, based on a series of experimental controlled burns, wind speed and fire spread were significantly reduced on the forest floor.(3) Thinning the forest will not reduce fire hazard. In fact, it will increase fire hazard.

Jon E. Keeley of the USGS is a world-renowned expert on the fire ecology of California. We have read his recently published book (Fire in Mediterranean Ecosystems: Ecology, Evolution and Management, Cambridge University Press, 2011) and many of his articles. Anyone with a sincere interest in wildfire hazards in California would be wise to read these publications. Reference to Keeley’s work is conspicuously absent from the Draft EIR.

Keeley’s most recently published study of specific wildfires in the Wildland-Urban-Interface (WUI) of California is most relevant to consideration of wildfire hazard in the Sutro Reserve. (4) The authors studied the property damage resulting from specific wildfires in California “…and identified the main contributors to property loss.” Keeley and his colleagues found that steep slopes in canyons that create wind corridors were the best predictors of fire damage and that grassy fuels were more likely to spread the fire than woody fuels. Applying these observations to Mount Sutro, its topography is the biggest factor in the potential for wildfire and substituting the forest with grassland and scrub will result in more dangerous fuel loads.

Scripps Ranch fire, San Diego, 2003. All the homes burned, but the eucalypts that surrounded them did not catch fire. New York Times — Scripps Ranch fire, San Diego, 2003. All the homes burned, but the eucalypts that surrounded them did not catch fire.

UCSF and native plant advocates make allegations about the flammability of eucalypts by misrepresenting actual wildfires in the Bay Area. These allegations are addressed elsewhere on Million Trees, which we invite you to visit if you have more questions:

All pain, no gain

So, if the forest is healthy and destroying it does not reduce fire hazards, how can UCSF justify all the damage this project will do to the environment:

Releasing thousands of tons of carbon dioxide into the atmosphere that are stored in the trees and significantly reducing the ability of the forest to sequester carbon in the future, thereby contributing to climate change.
Increasing air pollution by reducing the ability of the forest to absorb air pollutants.
Using pesticides to destroy the vegetation in the understory and preventing the trees that are destroyed from resprouting.
Destroying the food and cover of the birds and animals that live in the forest.
Eliminating the noise and wind barrier that protects UCSF’s neighbors
Increasing the risk of wildfire by eliminating the windbreak, reducing the moisture in the forest, and littering the forest with the dead logs and wood chips of the trees that are destroyed.

We can’t imagine why UCSF wants to destroy its forest. We understand why native plant advocates support this project because they are making the same demands all over the Bay Area. They want land managers to destroy non-native trees because they believe that destroying them will result in the return of native plants. The UCSF project makes no commitment to plant native plants after the forest is destroyed, with the exception of a few small areas and then only if “money is available.” Native plants will not magically emerge from the wood-chip tomb on the forest floor. Is it possible that UCSF shares the fantasy of native plant advocates that this destructive project will result in a landscape of grassland and chaparral which is the native landscape on Mount Sutro? Surely a scientific institution of such distinction knows better. Or it should.

Here are the things you can do to help us save this beautiful forest:

Sign the petition to save the forest. Available here.
Attend and speak at a UCSF hearing about the project: Monday, February 25, 2013, 7 pm, Millberry Union Conference Center, 500 Parnassus Ave, Golden Gate Room
Submit a written public comment by 5 PM, March 19, 2013 to UCSF Environmental Coordinator Diane Wong at EIR@planning.ucsf.edu or mail to UCSF Campus Planning, Box 0286, San Francisco, CA 94143-0286. Include your full name and address.
Write to the Board of Regents to ask why a public medical institution is engaging in such a controversial, expensive, and environmentally destructive act. Address: Office of the Secretary and Chief of Staff to the Regents, 1111 Franklin St., 12^th Floor, Oakland, CA 94607  Fax: (510) 987-9224
Subscribe to the website SaveSutro.com for ongoing information and analysis.

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(1) Eucalypt ecology: Individuals to ecosystems, by Jann Elizabeth Williams, John Woinarski ,Cambridge University Press, 1997

(2) Weatherspoon, C.P. and Skinner, C.N., “An Assessment of Factors Associated with Damage to Tree Crowns from the 1987 Wildfires in Northern California,” Forest Science, Vol. 41, No 3, pages 430-453

(3) Gould, J.S., et. al., Project Vesta: Fire in Dry Eucalyptus Forests, Commonwealth Scientific and Industrial Research Organisation and Department of Environment and Conservation, Western Australia, November 2007

(4) Alexandra Syphard, Jon E. Keeley, et. al., “Housing Arrangement and Location Determine the Likelihood of Housing Loss Due to Wildire.” PLOS ONE, March 18, 2012

Response to Nature in the City

Nature in the City (NIC) is one of many organizations that support native plant “restorations” in San Francisco as well as the principle entity which engages in them, the Natural Areas Program (NAP) of the Recreation and Park Department. NIC is consistently critical of anyone who questions the value of these restorations, but in their most recent newsletter they confront our objections directly. Although we don’t presume to represent the many constituencies which are critical of the Natural Areas Program, we are responding in this post to NIC based on our knowledge of the issues. (The NIC newsletter is in quotes and is italicized. Our response is not italicized.)

“Natural Areas in 2012

Last fall saw the the [sic] Planning Commission public meeting for the Draft Environmental Impact Report (DEIR) for the Significant Natural Resource Areas Management Plan. Some time later this year, the City will issue a Final Environmental Impact Report, which may be appealed by opponents of the Natural Areas Program.

Unfortunately, a handful of people are still propagating misinformation about the rationale, values, and intention of ecological restoration, management and stewardship, and of the City’s celebrated Natural Areas Program.”

Webmaster: Critics of the Natural Areas Program cannot be described accurately as a “handful of people.” We now have four websites(1) representing our views and there have been tens of thousands of visits to our websites. Comments on our websites are overwhelmingly supportive of our views. Our most recently created website, San Francisco Forest Alliance, lists 12 founding members. That organization alone exceeds a “handful of people.”

Our objections to the Natural Areas Program have also been reported by three major newspapers in the past month or so (San Francisco Examiner, Wall Street Journal, Sacramento Bee).

Many critics of NAP have been engaged in the effort to reduce its destructive and restrictive impacts on our parks for over 10 years. Scores of public meetings and hearings have been held to consider our complaints. We consistently outnumbered public speakers in support of NAP until 2006, when the NAP management plan was finally approved by the Recreation and Park Commission. Although we were outnumbered for the first time, there were over 80 speakers who asked the Recreation and Park Commission to revise NAP’s management plan to reduce its negative impact on our parks.

The public comments on the NAP DEIR are the most recent indicator of the relative size of the groups on opposite sides of this issue. These comments were submitted in September and October 2011. We obtained them with a public records request. The Planning Department reported receiving about 400 comments. In analyzing these comments, we chose to disregard about half of them because they were submitted as form letters, even though they were from dog owners who were protesting the loss of their off-leash privileges in the natural areas. We also leave aside the comments from golfers whose only interest is in retaining the golf course at Sharp Park. In other words, we set aside the majority of the comments critical of the NAP management plan in order to focus on those comments that demonstrate a comprehensive understanding of the impact of NAP on the city’s parks. Of the comments remaining, those critical of NAP and its deeply flawed DEIR outnumbered comments in support of the NAP DEIR about three to one. We urge NAP supporters to read these public comments to learn about the wide range of criticisms of NAP, including pesticide use, destruction of trees, recreational access restrictions, loss of wildlife habitat and more.

We will challenge NIC’s accusation that we are “propagating misinformation” within the context of their specific allegations:

“Contrary to the many myths that continue to percolate, the Natural Areas Plan and Program seek to do the following (among other worthwhile endeavors):

1. Protect and conserve our City’s natural heritage for its native wildlife and indigenous plant habitats and for the overall health of our local ecosystem;”

Webmaster: Since the majority of acreage claimed as natural areas by NAP 15 years ago had no native plants in them, there is little truth to the claim that NAP is protecting our “natural heritage.” The so-called “natural area” at Balboa and the Great Highway is typical of the “natural areas.” There is photographic evidence that it was built upon for about 150 years. It was the site of Playland by the Beach before it was designated a “natural area.” Sand had to be trucked onto the property and disked down 18” into the construction rubble, then shaped into dunes by bulldozers before native plants could be planted on it.

Natural Area at Balboa & Great Highway under construction

We don’t make any distinction between “native wildlife” and any other wildlife currently living in our city. We value them all. Most are making use of existing vegetation, whether it is native or non-native. They do not benefit from the loss of the blackberries that are their primary food source or the loss of the thickets or trees that are their homes. We do not believe that wildlife in San Francisco benefits from the destructive projects of the Natural Areas Program. See photos of insects, birds, and other wildlife using non-native plants in the natural areas here.

Damseflies, Glen Canyon — Damselflies mating on ivy, Glen Canyon Park

We do not think an ecosystem that has been sprayed with herbicides qualifies as a “healthy ecosystem.” NAP sprayed herbicides at least 86 times in 2011. Their use of herbicides has increased over 330% in the last 4 years. NAP uses herbicides that are classified as more toxic than those most used by other city departments. Last spring, 1,000 visitors to Glen Canyon Park signed a petition, asking the Natural Areas Program to stop using pesticides in their park. This petition was given to Scott Wiener, the Supervisor representing the district in which Glen Canyon Park is located.

These are statements of fact that can be easily verified by the public record.

2. “Educate our culturally diverse city about the benefits of local nature and about helping with natural areas stewardship in your neighborhood;”

Webmaster: Although we value education, we do not consider the staff of NAP and/or its supporters qualified to provide it. We hear them make statements that are demonstrably not true, such as “grassland stores more carbon than trees.” We see them spray herbicides in the dead of winter that are supposed to be sprayed in the spring when the plants are actively growing. We watch them plant things where they won’t grow, such as sun-loving plants in deep shade and plants in watersheds where they will soon be drowned by seasonal rains.

And we also have had bad experiences with the volunteers who are called “stewards” by NAP, but sometimes act more like vandals. We see them spraying herbicides that they aren’t authorized to use. We see them hacking away at trees that haven’t been designated for removal. NAP is not providing the necessary guidance and supervision to the volunteers many of whom seem to consider themselves the de facto owners of the parks.

3. “Manage the City’s wildlands for public access, safety and the health of the “urban forest.””

Webmaster: We do not oppose the removal of hazardous trees. However, we also know that most of the trees that have been designated for removal by the NAP management plan are NOT hazardous. They have been selected for removal solely because they are not native and are perceived to be obstacles to the reintroduction of native plants. Claims to the contrary are inconsistent with the management plan as well as our experience in the past 15 years. (Watch video about the destruction of 1,600 trees over 15 feet tall planned for Mt. Davidson.)

“We hear occasional complaints about public access and tree removal. Three simple facts are thus:

1. Every single natural area in the City has at least one trail through it, where one can walk a dog on a leash;”

Webmaster: The loss of recreational access in the natural areas is real, not imagined. The following are verbatim quotes from the NAP management plan:

“Approximately 80 percent of the SFRPD off-leash acreage is located within Natural Areas.” (page 5-8). The NAP DEIR proposes to close or reduce the size of several off-leash areas. The DEIR provides no evidence that these areas have been negatively impacted by dogs. It also states that all off-leash areas in the natural areas are subject to closure in the future if it is considered necessary to protect native plants. Since NAP has offered no evidence that the proposed immediate closures are necessary, one reasonably assumes it will offer no evidence if it chooses to close the remainder of the 80% of all off-leash areas in San Francisco located in natural areas. We know from the DEIR public comments that NAP supporters demand their closure.
“Public use in all Natural Areas, unless otherwise specified, should encourage on-trail use… Additionally, interpretive and park signs should be installed or modified as appropriate to include “Please Stay on Trails” with information about why on-trail use is required.” (page 5-14) In other words, the only form of recreation allowed in the natural areas is walking on a trail. Throwing a ball or frisbee, having a picnic on the grass, flying a kite, climbing the rocks are all prohibited activities in the natural areas. And in some parks, bicycles have been prohibited on the trails by NAP.
“Finally, this plan recommends re-routing or closing 10.3 miles of trail (approximately 26 percent of total existing trails).” (page 5-14) So, the only thing visitors are allowed to do in a natural area is walk on the trails and 26% of all the trails in the natural areas will be closed to the public.

2. “The act of removing (a small subset of) non-native trees, e.g., eucalyptus, that are in natural areas has the following benefits:
   a. Restores native habitat for indigenous plants and wildlife;
   b. Restores health, light and space to the “urban forest,” since the trees are all crowded together and being choked by ivy;
   c. Contributes to the prevention of catastrophic fire in our communities.”

Webmaster: Destroying non-native plants and trees does not restore indigenous plants and wildlife. Native plants do not magically emerge when non-native plants and trees are destroyed. Planting indigenous plants might restore them to a location if they are intensively gardened to sustain them. However, in the past 15 years we have seen little evidence that NAP is able to create and sustain successful native plant gardens. Native plants have been repeatedly planted and they have repeatedly failed.

NAP has not “restored” the health of the urban forest. They remove trees in big groups as they expand their native plant gardens. They are not thinning trees. They are creating large openings for the grassland and dune scrub that they plant in the place of the urban forest. Every tree designated for removal by the NAP management plan is clearly selected for its proximity to native plants. It is disingenuous to suggest that NAP’s tree removal plans are intended to benefit the urban forest.

Of all the fictions fabricated by native plant advocates to justify the destruction of our urban forest, the claim that its destruction will “prevent catastrophic fire” is the most ridiculous. The native ecology of California is highly flammable. Most fires in California are in native chaparral. According to San Francisco’s hazard mitigation plan, there has never been a wildfire in San Francisco (2) and one is unlikely in the future because the climate is mild and moist. When it is hot in the interior, it is foggy in San Francisco. The hot winds that drive most fires in California never reach San Francisco because it is separated from the hot interior by the bay. San Francisco is surrounded by water, which moderates its climate and virtually eliminates the chances of wildfire. The tall non-native trees precipitate moisture from the summer fog, which moistens the forest floor and reduces the chances of ignition. In the unlikely event of a wind-driven fire, the trees provide the windbreak which would stop the advance of the fire.

3. “The overall visual landscape of the natural areas will not change since only a small subset of trees are planned to be removed over a 20-year period.”

Webmaster: In addition to the 18,500 trees over 15 feet tall which NAP proposes to destroy, the NAP management plan also states its intention to destroy non-native trees less than 15 feet tall. In other words, the future of the forest will also be killed. The intention is to eliminate the urban forest in San Francisco’s parks over the long term. Yes, this will take some time, but the long-term intention to eliminate the forest is clear.

“Please feel free to email steward@natureinthecity.org if you would like more clarification about the intention, values and rationale of natural resources management.”

Webmaster: We urge our readers to take NIC up on this offer to provide ”more clarification” of its spirited defense of the Natural Areas Program.

Do you think NIC is deluded about there being only a “handful of people” that are critical of the Natural Areas Program?
Did you notice that NIC does not acknowledge the use of herbicides by NAP? Do you think that a fair representation of criticism of NAP can omit this issue?
If you visit a park that is a natural area, do you think NAP has demonstrated in the past 15 years what NIC claims it is accomplishing?
Do you think NIC has accurately described recreational access restrictions in the natural areas?
Do you think that San Francisco’s urban forest will be improved by the destruction of 18,500 mature trees and countless young trees?

(1) Save Sutro Forest, Urban Wildness, San Francisco Forest Alliance, Death of a Million Trees

(2) “The California Department of Forestry and Fire Protection (CAL FIRE) has no record of any wildfire in San Francisco.” San Francisco Hazard Mitigation Plan, 2008, page 5-18.

Fabricating “facts” to support native plant restorations.

We have been debating with native plant advocates for a long time, so we’re never surprised when they repeat vague generalities to support their ideology. But when these fabricated “facts” are repeated in legal documents such as the Draft Environmental Impact Report (EIR) for the Natural Areas Program (NAP) we must admit that we’re shocked! Apparently, the highly paid professionals who write such documents don’t expect the public to actually read the references they cite to support the statements they fabricate. We will take our readers on a tour of some of the phony “science” used to defend the destruction of San Francisco’s urban forest in order to restore native grassland and scrub to San Francisco’s urban parks.

Why is carbon storage such an issue in this debate about the Natural Areas Program?

The urban forest of San Francisco stores 196,000 tons of carbon and adds to that accumulated store of carbon at an annual rate of 5,200 tons per year according to the US Forest Service survey. About 25% of the annual rate of sequestration and the accumulated storage of carbon are accomplished by the blue gum eucalyptus, the chief target for destruction by NAP’s plans. When a tree is destroyed, it releases the carbon that has accumulated throughout its lifetime into the atmosphere as Carbon Dioxide as it decays. Carbon Dioxide is the predominant greenhouse gas that is causing climate change.

Carbon storage by tree species, San Francisco. US Forest Service

Since greenhouse gases are regulated in California by a law that commits the state to reduce greenhouse gas emissions, the Environmental Impact Report (EIR) for the Natural Areas Program (NAP) goes to great lengths to make the case that destroying thousands of trees will not violate California law. Here are just a few of the “facts” fabricated by the EIR to convince the public that NAP’s plans to convert San Francisco’s urban forest into grassland and scrub will not harm the environment.

Grassland in the San Francisco Bay Area does NOT lower ground temperature

The EIR claims:

“According to a study presented at the American Geophysical Union’s meeting, grasslands above 50 degrees latitude reflect more sun than forest canopies, thereby keeping temperatures lower by an average of 0.8 degree Celsuis.” ( EIR, page 457, cited source(1))

This statement in the EIR does not apply to the San Francisco Bay Area and the reference used to support it misrepresents the cited study:

The entire continental United States, including the San Francisco Bay Area, is below 50 degrees latitude. In other words, this statement—even if it were true—does not apply to the San Francisco Bay Area.
The statement is taken out of the context of the article. The entire sentence in which this statement appears actually says, “Grassland or snowfields, however, reflected more sun, keeping temperatures lower. Planting trees above 50 degrees latitude, such as in Siberia, could cover tundras normally blanketed in heat-reflecting snow.” It does not snow in the San Francisco Bay Area. Therefore, this statement does not apply to the San Francisco Bay Area.
The article being quoted by the EIR is NOT the scientific study, but rather a journalistic article in The Guardian, a newspaper in England, in which the author of the study has been misquoted and his study misrepresented.
The day after this article appeared in The Guardian (and also in the New York Times), The Guardian published an op-ed (which also appeared in the New York Times) by the author of the scientific study, Ken Caldeira in which he objected to the misrepresentation of his study:

“I was aghast to see our study reported under the headline “Planting trees to save planet is pointless, say ecologists.” (December 15). Indeed, our study found that preserving and restoring tropical forests is doubly important, as they cool the earth both by removing the greenhouse gas carbon dioxide from the atmosphere and by helping produce cooling clouds. We did find that preserving and restoring forests outside the tropics does little or nothing to help slow climate change, but nevertheless these forests are a critical component of Earth’s biosphere and great urgency should be placed on preserving them.”(2) (emphasis added)

As if this misrepresentation of the facts weren’t bad enough, we find in Appendix A of the EIR that this isn’t the first time that someone has informed the authors of the EIR that this statement is not accurate. One of the public comments submitted in 2009 in response to the Initial Study quotes Ken Caldeira’s op-ed in the New York Times. Yet, two years later, the author of the EIR persists in repeating this misrepresentation of Professor Caldeira’s (Stanford University) research. One wonders if the public comments were even read, judging by the repetition of the pseudoscience in the Initial Study that the public commented on in the first round. It seems that the “public process” is merely going through the motions.

Grassland does NOT store more carbon than forests

The EIR also claims:

“Research studies have concluded that grassland and scrub habitat could act as a significant carbon sink.” (page 457, cited studies(3))

Once again, the cited study does not support the statement in the EIR:

Again, the statement has been taken out of context. The entire sentence reads, “We conclude that grasslands can act as a significant carbon sink with the implementation of improved management.” This sentence appears in the abstract for the publication.(4)
One wonders if the authors of the EIR read the entire article or just the abstract. The point of the study is that land management techniques such as fertilization, irrigation, introduction of earthworms, plowing and fallow techniques, etc., can improve the sequestration of carbon in the soil of croplands and pastures. This study is obviously irrelevant to the Natural Areas Program, which is not engaged in agriculture or pasturage and will not use any of these techniques.
However, the study is relevant in one regard. It reports that when forest is converted to grassland, no amount of “management techniques” compensates for the loss of the carbon in the trees that are destroyed:

“Though more than half of the rain forest conversion studies (60%) resulted in increased soil Carbon content, net ecosystem Carbon balance…decreased substantially due to the loss of large amounts of biomass carbon.”

The second study cited in support of the claim about carbon storage in grassland reports that increased levels of Carbon Dioxide in the air increases carbon accumulation in the soil. This study tells us nothing about the relative merits of grassland and forests with respect to carbon storage. Another study reports a similar relationship between global warming and carbon storage in trees: “…warmer temperatures stimulate the gain of carbon stored in trees as woody tissue, partially offsetting the soil carbon loss to the atmosphere.” (5)

A pointless debate that misses the point

The misuse of these studies illustrates one of the fundamental issues with this pointless debate about the relative merits of grassland and forests. Even if grassland were superior to forests with respect to carbon storage—and it’s NOT—it would never compensate for the loss of carbon associated with destroying a forest that is storing hundreds of thousands of tons of carbon. The merits of planting trees where none presently exist is a fundamentally different argument than the merits of destroying trees. The trees are here now. No amount of grassland will compensate for the loss of the carbon presently stored by the forest that native plant advocates demand be destroyed.

If there is a sound argument for destroying trees, this isn’t it. Grassland does not store more carbon than trees and will never compensate for the loss of the tons of carbon released into the atmosphere when trees are destroyed. (Please visit our post “Facts about carbon storage do not support assumptions of native plant advocates”) Native plant advocates would be wise to abandon this particular line of unreasoning.

Although we are not scientists, we read the work of scientists. The studies conducted by scientists are not theoretical speculations about the benefits of one plant compared to another. Rather they report the results of controlled experiments, such as actually measuring the amount of carbon in the plant and/or soil and reporting the results of those experiments. Native plant advocates would be wise to spend less time trading baseless generalizations amongst themselves and spend more time reading the scientific reports of actual evidence.

Please comment on the Draft Environmental Impact Report for the Natural Areas Program

Please keep in mind that the public will have an opportunity to comment on the proposal to remove thousands of trees in the city’s parks. There will be a public hearing on October 6, 2011, and the deadline for submitting a written comment is October 17, 2011*. Here are the details about the public’s opportunities to comment on the EIR for the Natural Areas Program:

“A public hearing on this Draft EIR and other matters has been scheduled by the City Planning Commission for October 6, 2011, in Room 400, City Hall, 1 Dr. Carlton B. Goodlett Place, beginning at 1:30 p.m. or later. (Call 558‐6422 the week of the hearing for a recorded message giving a more specific time.)”

“Public comments will be accepted from August 31, 2011 to 5:00 p.m. on October 17, 2011*. Written comments should be addressed to Bill Wycko, Environmental Review Officer, San Francisco Planning Department, 1650 Mission Street, Suite 400, San Francisco, CA 94103. Comments received at the public hearing and in writing will be responded to in a Summary of Comments and Responses document.”

*[ETA: The deadline for written comments has been extended to October 31, 2011 at the request of the Planning Commission.]

“If you have any questions about the environmental review of the proposed project, please call Jessica Range at 415‐575‐9018.”

(1) Jha, Alok. The Guardian. “Planting Trees to Save Planet is Pointless, Say Ecologists.” Friday, December 15, 2006.

(2) Caldeira, Ken, “Planting trees is far from pointless.” The Guardian, December 16, 2006.

(3) Conant, L., Paustian K, and Elliot E. 2001. “Grassland Management and Conversion into Grassland Effects on Soil Carbon.” Natural Resource Ecology Laboratory. Colorado State University. Fort Collins, USA. Sponsor: US Environmental Protection Agency, Ruminant Livestock Efficiency Program. 2001, and

Hu, S., Chapin, Firestone, Field, Chiariello. 2001. “Nitrogen limitation of microbial decomposition in a grassland under elevated C02,” Nature 409: 188-191.

(4) Conant, Paustian, Elliott, “Grassland Management and Conversion into Grassland Effects on Soil Carbon,” Ecological Applications, 11 (2) 2001, 341-355.

(5) Melillo, J., Butler, S., Johnson, J., Mohan, J., Steudler, P., Lux, H., Burrows, E., Bowles, F., Smith, R., Scott, L., Vario, C., Hill, T., Burton, A., Zhouj, Y, and Tang, J. Soil warming carbon-nitrogen interactions and carbon-nitrogen budgets. PNAS, May 23, 2011

Destroying the Trees of San Francisco

The San Francisco Natural Areas Program (NAP) plans to destroy thousands of trees in San Francisco’s parks. The Draft Environmental Impact Report (EIR) for NAP’s destructive plan reaches the bizarre conclusion that removing thousands of trees will have no significant impact on the environment. This conclusion is based on several fictional premises. In this post we will examine one of those premises: that all the trees that are removed will be replaced within the natural areas by an equal number of trees that are native to San Francisco.

The EIR supports this fictional premise by falsely reducing the number of trees that will be removed by:

Not counting trees less than 15 feet tall, despite the fact that the US Forest Service survey of San Francisco’s urban forest reports that the trunks of most (51.4%) trees in San Francisco are less than 6 inches in diameter at breast height, the functional equivalent of trees less than 15 feet tall.
Not counting the hundreds of trees that were destroyed prior to the approval of the NAP management plan at Pine Lake, Lake Merced, Bayview Hill, Glen Canyon parks, etc.
Not counting tree removals proposed by the “Maximum Restoration Alternative” which the EIR says is the “Environmentally Superior Alternative.” [ETA: The Planning Department later admitted that this is a mistake in the EIR. The “Maintenance Alternative” is the “Enviromentally Superior Alterantive.”]

However, even artificially reducing the number of tree removals does not make “one-to-one” replacement a realistic goal.

The natural history of trees in San Francisco

The primary reason why we know that it will not be possible to grow thousands more native trees in the natural areas in San Francisco is that there were few native trees in San Francisco before non-native trees were planted by European settlers in the late 19^th century. San Francisco’s “Urban Forest Plan” which was officially adopted by the Urban Forestry Council in 2006 and approved by the Board of Supervisors describes the origins of San Francisco’s urban forest as follows:

“No forest existed prior to the European settlement of the city and the photographs and written records from that time illustrate a lack of trees…Towards the Pacific Ocean, one saw vast dunes of sand, moving under the constant wind. While there were oaks and willows along creeks, San Francisco’s urban forest had little or nothing in the way of native tree resources. The City’s urban forest arose from a brief but intense period of afforestation, which created forests on sand without tree cover.”

San Francisco in 1806 as depicted by artist with von Langsdorff expedition. Bancroft Library

The horticultural reality of trees native to San Francisco

More importantly, the reality is that even if we want to plant more native trees in San Francisco, they will not grow in most places in San Francisco. We know that for several reasons:

There are few native trees in San Francisco now. According to the US Forest Service survey of San Francisco’s urban forest only two species of tree native to San Francisco were found in sufficient numbers to be counted in the 194 plots they surveyed: Coast live oak was reported as .1% (one-tenth of one percent) and California bay laurel 2.1% of the total tree population of 669,000 trees.
The city of San Francisco maintains an official list of recommended species of trees for use by the Friends of the Urban Forest and the Department of Public Works. The most recent list categorizes 27 species of trees as “Species that perform well in many locations in San Francisco.” There is not a single native tree in that category. Thirty-six tree species are categorized as “Species that perform well in certain locations with special considerations as noted.” Only one of these 36 species is native to San Francisco, the Coast live oak and its “special considerations” are described as “uneven performer, prefers heat, wind protection, good drainage.” The third category is “Species that need further evaluation.” Only one (Holly leaf cherry) of the 22 species in that category is native to San Francisco.
Finally, where native trees have been planted by NAP to placate neighbors who objected to the removal of the trees in their neighborhood parks, the trees did not survive.

Will NAP plant trees that won’t survive?

Given what we know about the horticultural requirements of the trees that are native to San Francisco, what are we to think of the claim that all non-native trees removed by the Natural Areas Program will be replaced by native trees? Is there any truth to this claim? Will native trees be planted that won’t survive? Or will they just not plant the trees that they claim will be planted?

We turn to the management plan for the Natural Areas Program for the answer to this question. In fact, the management plan proves that NAP has no intention of planting replacement trees for the thousands of trees they intend to destroy. The “Urban Forestry Statements” in Appendix F of the management plan contain the long-term plans for the natural areas in which trees will be destroyed. All but one of these specific plans is some variation of “conversion of some areas of forest to scrub and grasslands.” The exception is Corona Heights for which the plans are “converted gradually to oak woodland.” The Corona Heights natural area is 2.4 acres, making it physically impossible to plant thousands of oaks in that location.

Mt Davidson 1885 — NAP plans to destroy 1,600 trees over 15 feet tall on Mt. Davidson and more if the EIR is approved.

Putting the magnitude of the proposed tree removals into perspective

It isn’t easy to confront public policies. We all have better things to do. So, before we leave this issue, let’s consider the magnitude of the loss of thousands of trees in San Francisco. We turn to the survey of San Francisco’s urban forest by the US Forest Service to put the proposed tree removals into perspective:

There are only 669,000 trees in San Francisco, with a tree cover of only 11.9% of the land. Of the 14 cities in the US reported by this survey, only Newark, New Jersey has a smaller tree canopy, covering 11.5% of the land.
Most of these trees are small: 51.4% have trunk diameters of less than 6” at breast height.
The highest densities of trees are found in San Francisco’s open spaces, such as parks.
The trees and shrubs of San Francisco remove 260 tons of air pollutants (CO, NO₂ , O₃, PM₁₀, SO₂) per year
The trees of San Francisco now store 196,000 tons of carbon. Stored carbon is released into the atmosphere when trees are destroyed and as they decay as chips or logs on the ground.
In San Francisco, the blue gum eucalyptus stores and sequesters the most carbon (approximately 24.4% of the total accumulated carbon stored and 26.4% of annual rate of carbon sequestered). Most of the trees that have been destroyed in the past and will be destroyed in the future by NAP are blue gum eucalyptus.

If you care about the trees of San Francisco, please keep in mind that the public will have an opportunity to comment on the proposal to remove thousands of trees in the city’s parks. There will be a public hearing on October 6, 2011, and the deadline for submitting a written comment is October 17, 2011*. Details about how to comment are available here.

*[ETA: The deadline for written comments has been extended to October 31, 2011, at the request of the Planning Commission.]

Facts about carbon storage in grasses do not support assumptions of native plant advocates

We have received many comments from native plant advocates regarding carbon storage. These comments defend projects in the Bay Area to destroy non-native forests and “restore” native plants by claiming that native plants will actually sequester more carbon than the forest that they propose to destroy. As always, we are grateful for comments that give us the opportunity to research the issues and report what we have learned about this complex and important subject.

Carbon cycling in a terrestrial plant-soil system

The storage of carbon in plants and soil occurs as plants and soil exchange carbon dioxide (CO₂) with the atmosphere as a part of natural processes, as shown in the following diagram (1):

Green Arrow: CO₂ uptake by plants through photosynthesis

Orange Arrows: Incorporation of Carbon into biomass and Carbon inputs into soil from death of plant parts

Yellow Arrows: Carbon returns to the atmosphere through plant respiration and decomposition of litter and soil Carbon. Carbon in plant tissues ultimately returns to atmosphere during combustion or eventual decomposition.

Rates of carbon uptake and emissions are influenced by many factors, but most factors are related to temperature and precipitation:

Higher temperatures are associated with faster plant growth, which accelerates photosynthesis and carbon uptake.
Higher temperatures also accelerate decomposition of plant materials, thereby accelerating the return of stored carbon into the atmosphere.
The effect of moisture in the soil on decomposition can be graphed as a “hump.” In extremely dry soils, decomposition is slow because the organisms that decompose vegetation are under desiccation stress. Conditions for decomposition improve as moisture in the soil increases until the soil is very wet when lack of oxygen in the soil impedes decomposition.

Although temperature and precipitation are important factors in carbon storage, they don’t change appreciably when one type of vegetation is replaced with another. Therefore, these factors aren’t helpful in addressing the fundamental question we are considering in this post, which is “Does native vegetation store more carbon than the forests that presently occupy the land in question?”

Where is carbon stored?

Much of the carbon stored in the forest is in the soil. It is therefore important to our analysis to determine if carbon stored in the soil in native vegetation is greater than that stored in non-native forests. The answer to that question is definitely NO! The carbon stored in the soil of native vegetation in Oakland, California is a fraction (5.7 kilograms of carbon per square meter of soil) of the carbon stored in residential soil (14.4 kilograms in per square meter of soil). (9) Residential soil is defined by this study as “residential grass, park use and grass, and clean fill.” This study (9) reports that the amount of carbon stored in the soil in Oakland is greater after urbanization than prior to urbanization because Oakland’s “wildland cover” is associated with “low SOC [soil organic carbon] densities characteristic of native soils in the region.”

Native plant advocates have also argued that the carbon stored in the soil of perennial native grasslands is greater than non-native trees because their roots are deeper. In fact, studies consistently inform us that most carbon is found in the top 10 centimeters of soil and almost none is found beyond a meter (100 centimeters) deep. (1, 4) In any case, we do not assume that the roots of perennial grasses are longer than the roots of a large tree.

Another argument that native plant advocates use to support their claim that native perennial grasslands store more carbon in the soil than non-native trees is that native grasses are long-lived and continue to add carbon to the soil throughout their lives. In fact, carbon stored in the soil reaches a steady state, i.e., it is not capable of storing additional carbon once it has reached its maximum capacity. (1)

It is pointless to theorize about why grassland soils should store more carbon than forest soils. The fact is they don’t. In all regions of the United States forest soils store more carbon than either grassland or shrubland soils. (9, Table 5)

We should also describe Oakland’s native vegetation before moving on: “Vegetation before urbanization in Oakland was dominated by grass, shrub, and marshlands that occupied approximately 98% of the area. Trees in riparian woodlands covered approximately 1.1% of Oakland’s preurbanized lands…” (5) In other words, native vegetation in Oakland is composed of shrub and grassland. When non-native forests are destroyed, they will not be replaced by native trees, especially in view of the fact that replanting is not planned for any of the “restoration” projects in the East Bay.

The total amount of carbon stored within the plant or tree is proportional to its biomass, both above ground (trunk, foliage, leaf litter, etc.) and below ground (roots). Since the grass and shrubs that are native to the Bay Area are a small fraction of the size of any tree, the carbon stored within native plants will not be as great as that stored in the trees that are being destroyed.

Whether we consider the carbon stored in soil or within the plant, the non-native forest contains more carbon than the shrub and grassland that is native to the Bay Area.

Converting forests to grassland

If we were starting with bare ground, it might be relevant to compare carbon sequestration in various types of vegetation, but we’re not. We’re talking about specific projects which will require the destruction of millions of non-native trees. Therefore, we must consider the loss of carbon associated with destroying those trees. It doesn’t matter what is planted after the destruction of those trees, nothing will compensate for that loss because of how the trees will be disposed of.

The fate of the wood in trees that are destroyed determines how much carbon is released into the atmosphere. For example, if the wood is used to build houses the loss of carbon is less than if the wood is allowed to decompose on the forest floor. And that is exactly what all the projects we are discussing propose to do: chip the wood from the trees and distribute it on the forest floor, also known as “mulching.” As the wood decomposes, the carbon stored in the wood is released into the atmosphere: “Two common tree disposal/utilization scenarios were modeled: 1) mulching and 2) landfill. Although no mulch decomposition studies could be found, studies on decomposition of tree roots and twigs reveal that 50% of the carbon is lost within the first 3 years. The remaining carbon is estimated to be lost within 20 years of mulching. Belowground biomass was modeled to decompose at the same rate as mulch regardless of how the aboveground biomass was disposed” (8)

Furthermore, the process of removing trees releases stored carbon into the atmosphere, regardless of the fate of the destroyed trees: “Even in forests harvested for long-term storage wood, more than 50% of the harvested biomass is released to the atmosphere in a short period after harvest.” (1)

Will thinning trees result in greater carbon storage?

Native plant advocates claim that thinning the non-native forest will result in improved forest health and therefore greater carbon storage. In fact, the more open canopy of an urban forest with less tree density results in greater growth rates. (3) Although more rapid growth is associated with greater rates of carbon sequestration, rates of storage have little effect on the net carbon storage over the life of the tree. (6) Net carbon storage over the life of the tree is determined by how long the species lives and how big the tree is at maturity. These characteristics are inherent in the species of tree and are little influenced by forest management practices such as thinning. (6)

More importantly, even if there were some small increase in carbon storage of individual trees associated with thinning, this increase would be swamped by the fact that over 90% of the urban forest will be destroyed by the proposed projects we are evaluating in the East Bay. The projects of UC Berkeley and the City of Oakland propose to destroy all non-native trees in the project areas. The project of the East Bay Regional Park District proposes to destroy all non-native trees in some areas and thin in other areas from 25 to 35 feet between each tree, reducing tree density per acre by at least 90%. No amount of “forest health” will compensate for the loss of carbon of that magnitude.

Responding to native plant advocates

The vegetation that is native to the Bay Area does not store more carbon above or below the ground than the non-native forest.
Chipping the trees that are destroyed and distributing the chips on the ground will not prevent the release of carbon from the trees that are destroyed.
Thinning the trees in our public lands will not increase the capacity of the trees that remain to store carbon.

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Bibliography

Anderson, J., et. al., “The Potential for Terrestrial Carbon Sequestration in Minnesota, A Report to the Department of Natural Resources from the Minnesota Terrestrial Carbon Sequestration Initiative, February 2008.
Birdsey, Richard, “Carbon storage and accumulation in United States Forest Ecosystems,” USDA Forest Service, General Technical Report WO-59, 1992
Environmental Protection Agency, “Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2008,” April 15, 2010., EPA 430-R-10-006
Fissore, C., et.al., “Limited potential for terrestrial carbon sequestration to offset fossil-fuel emissions in the upper Midwestern US,” Frontiers in Ecology and the Environment, 2009, 10.1890/090059
Nowak, David, “Historical vegetation change in Oakland and its implication for urban forest management,” Journal of Arboriculture, 19(5): September 1993
Nowak, David, “Atmospheric Carbon Reduction by Urban Trees,” Journal of Environmental Management, (1993) 37, 207-217
Nowak, David. Crane, Daniel, “Carbon storage and sequestration by urban trees in the U.S.A.,” Environmental Pollution, 116 (2002) 381-389
Nowak, David, et.al., “Effects of urban tree management and species selection on atmospheric carbon dioxide,” Journal of Arboriculture 28(3) May 2002
Pouyat, R.V. (US Forest Service)., et.al., “Carbon Storage by Urban Soils in the United States,” Journal of Environmental Quality, 35:1566-1575 (2006)