Tree growth never slows

Idea debunked that young trees have the edge on their older siblings in carbon accumulation. by Jeff Tollefson

 

Native forest in Ancares Mountains, NW of Iberian Peninsula. Rubén Portas Copyright.

Many foresters have long assumed that trees gradually lose their vigour as they mature, but a new analysis suggests that the larger a tree gets, the more kilos of carbon it puts on each year.

“The trees that are adding the most mass are the biggest ones, and that holds pretty much everywhere on Earth that we looked,” says Nathan Stephenson, an ecologist at the US Geological Survey in Three Rivers, California, and the first author of the study, which appears today inNature1. “Trees have the equivalent of an adolescent growth spurt, but it just keeps going.”

The scientific literature is chock-full of studies that focus on forests’ initial growth and their gradual move towards a plateau in the amount of carbon they store as they reach maturity2. Researchers have also documented a reduction in growth at the level of individual leaves in older trees3.

In their study, Stephenson and his colleagues analysed reams of data on 673,046 trees from 403 species in monitored forest plots, in both tropical and temperate areas around the world. They found that the largest trees gained the most mass each year in 97% of the species, capitalizing on their additional leaves and adding ever more girth high in the sky.

Although they relied mostly on existing data, the team calculated growth rates at the level of the individual trees, whereas earlier studies had typically looked at the overall carbon stored in a plot.

Estimating absolute growth for any tree remains problematic, in part because researchers typically take measurements at a person’s height and have to extrapolate the growth rate higher up. But the researchers’ calculations consistently showed that larger trees added the most mass. In one old-growth forest plot in the western United States, for instance, trees larger than 100 centimetres in diameter comprised just 6% of trees, but accounted for 33% of the growth.

The findings build on a detailed case study published in 2010, which showed similar growth trends for two of the world’s tallest trees — the coast redwood (Sequoia sempervirens) and the eucalyptus (Eucalyptus regnans)4, both of which can grow well past 100 metres in height. In that study, researchers climbed, and took detailed measurements of, branches and limbs throughout the canopy to calculate overall tree growth. Stephen Sillett, a botanist at Humboldt State University in Arcata, California, who led the 2010 study, says that the latest analysis confirms that his group’s basic findings apply to almost all trees.

The results are consistent with the known reduction in growth at the leaf level as trees age. Although individual leaves may be less efficient, older trees have more of them. And in older forests, fewer large trees dominate growth trends until they are eventually brought down by a combination of fungi, fires, wind and gravity; the rate of carbon accumulation depends on how fast old forests turn over.

“It’s the geometric reality of tree growth: bigger trees have more leaves, and they have more surface across which wood is deposited,” Sillett says. “The idea that older forests are decadent — it’s really just a myth.”

The findings help to resolve some of these contradictions, says Maurizio Mencuccini, a forest ecologist at the University of Edinburgh, UK. The younger trees may grow faster on a relative scale, he says, meaning that they take less time to, say, double in size. ”But on an absolute scale, the old trees keep growing far more.”

The study has broad implications for forest management, whether in maximizing the yield of timber harvests or providing old-growth habitat and increasing carbon stocks. More broadly, the research could help scientists to develop better models of how forests function and their role in regulating the climate.

Nature: doi:10.1038/nature.2014.14536
Source: http://www.nature.com/news/tree-growth-never-slows-1.14536? 

References

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UMD Leads 1st Local-to-Global Mapping of Forest

COLLEGE PARK, Md. – A University of Maryland-led, multi-organizational team has created the first high-resolution global map of forest extent, loss and gain. This free resource greatly improves the ability to understand human and naturally-induced forest changes and the local to global implications of these changes on environmental, economic and other natural and societal systems, members of the team say.

In a new study, the team of 15 university, Google and government researchers reports a global loss of 2.3 million square kilometers (888,000 square miles) of forest between 2000 and 2012 and a gain of 800,000 square kilometers (309,000 square miles) of new forest.

Source: Hansen, Potapov, Moore, Hancher et al., 2013Their study, published online on November 14 in the journal Science, documents the new database, including a number of key findings on global forest change.  For example, the tropics were the only climate domain to exhibit a trend, with forest loss increasing by 2,101 square kilometers (811 square miles) per year.  Brazil’s well-documented reduction in deforestation during the last decade was more than offset by increasing forest loss in Indonesia, Malaysia, Paraguay, Bolivia, Zambia, Angola and elsewhere.

“This is the first map of forest change that is globally consistent and locally relevant,” says University of Maryland Professor of Geographical Sciences Matthew Hansen, team leader and corresponding author on the Science paper.

“Losses or gains in forest cover shape many important aspects of an ecosystem, including climate regulation, carbon storage, biodiversity and water supplies, but until now there has not been a way to get detailed, accurate, satellite-based and readily available data on forest cover change from local to global scales,” Hansen says.

To build this first of its kind forest mapping resource, Hansen, UMD Research Associate Professor Peter Potapov and five other UMD geographical science researchers drew on the decades-long UMD experience in the use of satellite data to measure changes in forest and other types of land cover. Landsat 7 data from 1999 through 2012 were obtained from a freely available archive at the United States Geological Survey’s center for Earth Resources Observation and Science (EROS).  More than 650,000 Landsat images were processed to derive the final characterization of forest extent and change.

Source: Hansen, Potapov, Moore, Hancher et al., 2013
The analysis was made possible through collaboration with colleagues from Google Earth Engine, who implemented the models developed at UMD for characterizing the Landsat data sets.  Google Earth Engine is a massively parallel technology for high-performance processing of geospatial data and houses a copy of the entire Landsat image catalog.  What would have taken a single computer 15 years to perform was completed in a matter of days using Google Earth Engine computing.

Hansen and his coauthors say their mapping tool greatly improves upon existing knowledge of global forest cover by providing fine resolution (30 meter) maps that accurately and consistently quantify annual loss or gain of forest over more than a decade. This mapping database, which will be updated annually, quantifies all forest stand-replacement disturbances, whether due to logging, fire, disease or storms. And they say it is based on repeatable definitions and measurements while previous efforts at national and global assessments of forest cover have been largely dependent on countries’ self-reported estimates based on widely varying definitions and measures of forest loss and gain.

Dynamics from local to regional to global scale are quantified.  For example, subtropical forests were found to have the highest rates of change, largely due to intensive forestry land uses.  The disturbance rate of North American subtropical forests, located in the Southeast United States, was found to be four times that of South American rainforests during the study period; more than 31 percent of U.S. southeastern forest cover was either lost or regrown.  At national scales, Paraguay, Malaysia and Cambodia were found to have the highest rates of forest loss.  Paraguay was found to have the highest ratio of forest loss to gain, indicating an intensive deforestation dynamic.

The study confirms that well-documented efforts by Brazil – which has long been responsible for a majority of the world’s tropical deforestation – to reduce its rainforest clearing have had a significant effect. Brazil showed the largest decline in annual forest loss of any country, cutting annual forest loss in half, from a high of approximately 40,000 square kilometers (15,444 square miles) in 2003-2004 to 20,000 square kilometers (7,722 square miles) in 2010-2011. Indonesia had the largest increase in forest loss, more than doubling its annual loss during the study period to nearly 20,000 square kilometers (7,722 square miles) in 2011-2012.

Hansen and colleagues say the global data sets of forest change they have created contain information that can provide a “transparent, sound and consistent basis to quantify critical environmental issues,” including the causes of the mapped changes in the amount of forest; the status of world’s remaining intact natural forests; biodiversity threats from changes in forest cover; the carbon stored or emitted as a result of gains or losses in tree cover in both managed and unmanaged forests; and the effects of efforts to halt or reduce forest loss.

For example, Hansen says, that while their study shows the efforts of Brazil’s government to slow loss of rainforest have been effective, it also shows that a 2011 Indonesian government moratorium on new logging licenses was actually followed by significant increases in deforestation in 2011 and 2012.

“Brazil used Landsat data to document its deforestation trends, then used this information in its policy formulation and implementation. They also shared these data, allowing others to assess and confirm their success,” Hansen says.  “Such data have not been generically available for other parts of the world. Now, with our global mapping of forest changes every nation has access to this kind of information, for their own country and the rest of the world.”

Global map of forest change: http://earthenginepartners.appspot.com/science-2013-global-forest

Support for Landsat data analysis and characterization was provided by the Gordon and Betty Moore Foundation, the United States Geological Survey and Google, Inc. GLAS data analysis was supported by the David and Lucile Packard Foundation. Development of all methods was supported by NASA through its Land Cover and Land Use Change, Terrestrial Ecology, Applied Sciences and Measures programs (grants NNH05ZDA001N, NNH07ZDA001N, NNX12AB43G, NNX12AC78G, NNX08AP33A and NNG06GD95G) and by the United States Agency for International Development through its CARPE program.

High-resolution global maps 21st-century forest cover change, Science, Nov. 15, 2013, Vol 342 #6160, authors M. C. Hansen, P. V. Potapov, S. A. Turubanova, A. Tyukavina, L. Chini, C. O. Justice and J. R. G. Townshend of the University of Maryland; R. Moore, M. Hancher and D. Thau of Google, Inc.;  S. V. Stehman of the State University of New York; S. J. Goetz of Woods Hole Research Center; T. R. Loveland of the United States Geological Survey; and A. Kommareddy, and A. Egorov of South Dakota State University.

Contacts:

Lee Tune, 301-405-4679
Laura Ours, 301-405-5722

Photos: Source: Hansen, Potapov, Moore, Hancher et al., 2013

Source: http://umdrightnow.umd.edu/news/umd-leads-1st-local-global-mapping-forest

The Ecological Importance of California’s Rim Fire

Large, intense fires have always been a natural part of fire regimes in Sierra Nevada forests BY CHAD HANSON

Since the Rim fire began in the central Sierra Nevada on August 17, there has been a steady stream of fearful, hyperbolic, and misinformed reporting in much of the media. The fire, which is currently 188,000 acres in size and covers portions of the Stanislaus National Forest and the northwestern corner of Yosemite National Park, has been consistently described as “catastrophic”, “destructive”, and “devastating.” One story featured a quote from a local man who said he expected “nothing to be left”. However, if we can, for a moment, set aside the fear, the panic, and the decades of misunderstanding about wildland fires in our forests, it turns out that the facts differ dramatically from the popular misconceptions. The Rim fire is a good thing for the health of the forest ecosystem. It is not devastation, or loss. It is ecological restoration.

The Rim Fire in the Stanislaus National ForestPhoto courtesy USDAPatches of high-intensity fire, wherein most or all trees are killed, creates “snag forest habitat” which is the rarest and one of the most ecologically important forest habitat types in the entire Sierra Nevada.

What relatively few people in the general public understand at present is that large, intense fires have always been a natural part of fire regimes in Sierra Nevada forests. Patches of high-intensity fire, wherein most or all trees are killed, creates “snag forest habitat,” which is the rarest, and one of the most ecologically important, forest habitat types in the entire Sierra Nevada. Contrary to common myths, even when forest fires burn hottest, only a tiny proportion of the aboveground biomass is actually consumed (typically less than 3 percent). Habitat is not lost. Far from it. Instead, mature forest is transformed into “snag forest”, which is abundant in standing fire-killed trees, or “snags,” patches of native fire-following shrubs, downed logs, colorful flowers, and dense pockets of natural conifer regeneration.

This forest rejuvenation begins in the first spring after the fire. Native wood-boring beetles rapidly colonize burn areas, detecting the fires from dozens of miles away through infrared receptors that these species have evolved over millennia, in a long relationship with fire. The beetles bore under the bark of standing snags and lay their eggs, and the larvae feed and develop there. Woodpecker species, such as the rare and imperiled black-backed woodpecker (currently proposed for listing under the Endangered Species Act), depend upon snag forest habitat and wood-boring beetles for survival.

One black-backed woodpecker eats about 13,500 beetle larvae every year — and that generally requires at least 100 to 200 standing dead trees per acre. Black-backed woodpeckers, which are naturally camouflaged against the charred bark of a fire-killed tree, are a keystone species, and they excavate a new nest cavity every year, even when they stay in the same territory. This creates homes for numerous secondary cavity-nesting species, like the mountain bluebird (and, occasionally, squirrels and even martens), that cannot excavate their own nest cavities. The native flowering shrubs that germinate after fire attract many species of flying insects, which provide food for flycatchers and bats; and the shrubs, new conifer growth, and downed logs provide excellent habitat for small mammals. This, in turn, attracts raptors, like the California spotted owl and northern goshawk, which nest and roost mainly in the low/moderate-intensity fire areas, or in adjacent unburned forest, but actively forage in the snag forest habitat patches created by high-intensity fire — a sort of “bedroom and kitchen” effect. Deer thrive on the new growth, black bears forage happily on the rich source of berries, grubs, and small mammals in snag forest habitat, and even rare carnivores like the Pacific fisher actively hunt for small mammals in this post-fire habitat.

Black-backed woodpeckerPhoto by Rachel FazioThe imperiled black-backed woodpecker, a forest management indicator species, has been reduced to a mere several hundred pairs in the Sierra Nevada due to fire suppression, post-fire logging, and commercial thinning of forests.

In fact, every scientific study that has been conducted in large, intense fires in the Sierra Nevada has found that the big patches of snag forest habitat support levels of native biodiversity and total wildlife abundance that are equal to or (in most cases) higher than old-growth forest. This has been found in the Donner fire of 1960, the Manter and Storrie fires of 2000, the McNally fire of 2002, and the Moonlight fire of 2007, to name a few. Wildlife abundance in snag forest increases up to about 25 or 30 years after fire, and then declines as snag forest is replaced by a new stand of forest (increasing again, several decades later, after the new stand becomes old forest). The woodpeckers, like the black-backed woodpecker, thrive for 7 to 10 years after fire generally, and then must move on to find a new fire, as their beetle larvae prey begins to dwindle. Flycatchers and other birds increase after 10 years post-fire, and continue to increase for another two decades. Thus, snag forest habitat is ephemeral, and native biodiversity in the Sierra Nevada depends upon a constantly replenished supply of new fires.

It would surprise most people to learn that snag forest habitat is far rarer in the Sierra Nevada than old-growth forest. There are about 1.2 million acres of old-growth forest in the Sierra, but less than 400,000 acres of snag forest habitat, even after including the Rim fire to date. This is due to fire suppression, which has, over decades, substantially reduced the average annual amount of high-intensity fire relative to historic levels, according to multiple studies. Because of this, and the combined impact of extensive post-fire commercial logging on national forest lands and private lands, we have far less snag forest habitat now than we had in the early twentieth century, and before. This has put numerous wildlife species at risk. These are species that have evolved to depend upon the many habitat features in snag forest — habitat that cannot be created by any other means. Further, high-intensity fire is not increasing currently, according to most studies (and contrary to widespread assumptions), and our forests are getting wetter, not drier (according to every study that has empirically investigated this question), so we cannot afford to be cavalier and assume that there will be more fire in the future, despite fire suppression efforts.  We will need to purposefully allow more fires to burn, especially in the more remote forests.

The black-backed woodpecker, for example, has been reduced to a mere several hundred pairs in the Sierra Nevada due to fire suppression, post-fire logging, and commercial thinning of forests, creating a significant risk of future extinction unless forest management policies change, and unless forest plans on our national forests include protections (which they currently do not). This species is a “management indicator species”, or bellwether, for the entire group of species associated with snag forest habitat. As the black-backed woodpecker goes, so too do many other species, including some that we probably don’t yet know are in trouble. The Rim fire has created valuable snag forest habitat in the area in which it was needed most in the Sierra Nevada: the western slope of the central portion of the range. Even the Forest Service’s own scientists have acknowledged that the levels of high-intensity fire in this area are unnaturally low, and need to be increased. In fact, the last moderately significant fires in this area occurred about a decade ago, and there was a substantial risk that a 200-mile gap in black-backed woodpeckers populations was about to develop, which is not a good sign from a conservation biology standpoint. The Rim fire has helped this situation, but we still have far too little snag forest habitat in the Sierra Nevada, and no protections from the ecological devastation of post-fire logging.

photonamePhoto by Doug BevingtonThe big patches of snag forest habitat support levels of native biodiversity and total wildlife abundance that are equal to or (in most cases) higher than old-growth forest.

Recent scientific studies have caused scientists to substantially revise previous assumptions about historic fire regimes and forest structure. We now know that Sierra Nevada forests, including ponderosa pine and mixed-conifer forests, were not homogenously “open and parklike” with only low-intensity fire. Instead, many lines of evidence, and many published studies, show that these areas were often very dense, and were dominated by mixed-intensity fire, with high-intensity fire proportions ranging generally from 15 percent to more than 50 percent, depending upon the fire and area. Numerous historic sources, and reconstructions, document that large high-intensity fire patches did in fact occur prior to fire suppression and logging. Often these patches were hundreds of acres in size, and occasionally they were thousands — even tens of thousands — of acres. So, there is no ecological reason to fear or lament fires like the Rim fire, especially in an era of ongoing fire deficit.

Most fires, of course, are much smaller, and less intense than the Rim fire, including the other fires occurring this year. Over the past quarter-century fires in the Sierra Nevada have been dominated on average by low/moderate-intensity effects, including in the areas that have not burned in several decades. But, after decades of fear-inducing, taxpayer-subsidized, anti-fire propaganda from the US Forest Service, it is relatively easier for many to accept smaller, less intense fires, and more challenging to appreciate big fires like the Rim fire. However, if we are to manage forests for ecological integrity, and maintain the full range of native wildlife species on the landscape, it is a challenge that we must embrace.

Encouragingly, the previous assumption about a tension between the restoration of more fire in our forests and home protection has proven to be false. Every study that has investigated this issue has found that the only way to effectively protect homes is to reduce combustible brush in “defensible space” within 100 to 200 feet of individual homes. Current forest management policy on national forest lands, unfortunately, remains heavily focused not only on suppressing fires in remote wildlands far from homes, but also on intensive mechanical “thinning” projects — which typically involve the commercial removal of upwards of 80 percent of the trees, including mature trees and often old-growth trees —that are mostly a long distance from homes. This not only diverts scarce resources away from home protection, but also gives homeowners a false sense of security because a federal agency has implied, incorrectly, that they are now protected from fire — a context that puts homes further at risk.

The new scientific data is telling us that we need not fear fire in our forests. Fire is doing important and beneficial ecological work, and we need more of it, including the occasional large, intense fires. Nor do we need to balance home protection with the restoration of fire’s role in our forests. The two are not in conflict. We do, however, need to muster the courage to transcend our fears and outdated assumptions about fire. Our forest ecosystems will be better for it.

Chad Hanson
Chad Hanson, the director of the John Muir Project (JMP) of Earth Island Institute, has a Ph.D. in ecology from the University of California at Davis, and focuses his research on forest and fire ecology in the Sierra Nevada. He can be reached at cthanson1@gmail.com, or visit JMP’s website at www.johnmuirproject.org for more information, and for citations to specific studies pertaining to the points made in this article.

Source: http://www.earthisland.org/journal/index.php/elist/eListRead/the_ecological_importance_of_californias_rim_fire/

Key facts about Forests

Forest cover1

  • The total forest area of the world is about 4 billion hectares, which represents nearly 30 percent of the Earth’s landmass. Approximately 56 percent of these forests are located in tropical and subtropical areas.
  • Forest cover is unevenly distributed. Only seven countries possess about 60 percent of it, 25 countries around 82 percent and 170 countries share the remaining 18 percent.
  • Planted forests account for approximately 3.8 percent of total forest area, or 140 million hectares.

Forest loss2

  • Net global forest loss is estimated to be about 7.3 million hectares per year for the period 2000-2005.
  • This represents a decrease from the period 1990–2000, for which the average deforestation rate was 8.9 million hectares per year.
  • The highest amounts of deforestation occurred in South America, with 4.3 million hectares per year, followed by Africa with 4 million hectares per year.

Forests and livelihoods

  • More than 1 billion people rely heavily on forests for their livelihoods.3
  • More than 2 billion people, a third of the world’s population, use biomass fuels, mainly firewood, to cook and to heat their homes.
  • Hundreds of millions of people rely on traditional medicines harvested from forests.4
  • In some 60 developing countries, hunting and fishing on forested land supplies more than a fifth of protein requirements.5

Forests and the economy6

  • In 2003, the international trade in sawn wood, pulp, paper and boards amounted to almost US $150 billion, or just over 2 percent of world trade.
  • The developed world accounted for two-thirds of this production and consumption.
  • In many developing countries, forest-based enterprises provide at least one-third of all rural non-farm employment and generate income through the sale of wood products.
  • The value of the trade in non-timber forest products has been estimated at US $11 billion. These products include pharmaceutical plants, mushrooms, nuts, syrups and cork.

Forests and climate change7

  • It is estimated that 1.7 billion tonnes of carbon are released annually due to land use change. The major portion is from tropical deforestation.
  • This represents about 20 percent of current global carbon emissions, which is greater than the percentage emitted by the global transport sector with its intensive use of fossil fuels.

Sources:

[1] Food and Agriculture Organisation of the UN (FAO) 2007. State of the World’s Forests 2007, FAO, Rome.
[2] FAO 2009. State of the World’s Forests 2009, FAO, Rome.
[3] World Bank 2004. Sustaining Forests: A Development Strategy, Washington.
[4] UN Department of Economic and Social Affairs 2009. Indicators of Sustainable Development (1 June 2009).
[5] Mery, G., Alfaro, R., Kanninen, M. and Lobovikov, M. (eds.) 2005. Forests in the Global Balance: Changing Paradigms,
IUFRO World Series 17. International Union of Forest Research Organisations (IUFRO), Helsinki.
[6] World Bank 2004. Sustaining Forests: A Development Strategy, Washington D.C.
[7] IPCC 2007. Summary for Policymakers In: Climate Change 2007: The Physical Sciences Basis (1 June 2009).

http://www.cifor.org/mediamultimedia/newsroom/key-facts-about-forests.html

On Boreal forests, fires and natural processes

Charcoal records reveal that far northern wildfires have doubled in frequency recently

By Stephanie Paige Ogburn and ClimateWire

smokey forest

Image: Flickr/Drew Brayshaw

 

Alaska is burning more than it has in the past 10,000 years.

That’s the finding of research released yesterday in the journal Proceedings of the National Academy of Sciences.

The study analyzed charcoal found in sediment cores from 14 lakes in the Yukon Flats region of the state to determine the frequency of past fires.

Over the last 3,000 years, the average fire frequency in the area was about 10 fires per thousand years.

In the last 50 years, the fire frequency has nearly doubled, up to 20 every thousand years, or one fire every 50 years.

Climate scientists care about what might happen in boreal forests because they cover 10 percent of land surface and store a lot of carbon in their soil, said Ryan Kelly, an ecologist and doctoral candidate at the University of Illinois who was lead author of the study.

“It is a significant player in the global carbon cycle,” Kelly said. “When the forests burn, the carbon goes into the atmosphere. If they burn more frequently, they are releasing more carbon, and storing less.”

The researchers were particularly interested in comparing fire frequency from the recent past with that of a period called the Medieval Climate Anomaly, when conditions were warm and dry, similar to recent decades.

Forest may self-regulate
When they did this, they found a surprising—and possibly hopeful—result. They noted that fire frequency was also high about 1,000 years ago, during the anomaly.

But pollen records the researchers analyzed show that during that time of increased fire, the forest responded by changing the vegetation that regrew after the fires. The trees shifted from evergreen to deciduous. The deciduous trees, like aspen and birch, did not burn as easily, and this slowed down the fire frequency.

“So that’s really interesting to us as ecologists, because it is a mechanism by which ecosystems are kind of regulating themselves,” he said.

Jennifer Marlon, a scientist at the Yale School of Forestry and Environmental Studies who studies wildfires and climate change, said the study was unique because it used a lot of records from one location. “Their conclusions were very robust because of the scope and scale of the study,” Marlon said.

The findings were also unique because the researchers were able to so closely link historical records with what is happening in the present and what might happen in the future, she said. “Using the paleo records, long historical records like this, it is fairly rare to be able to connect it so closely to what is happening today.”

The fact that the number of forest fires in a past warm period was reduced by the regrowth of different trees might offer some hope for reduced fire frequency in the future, even though the frequency in recent decades has been high, Kelly said.

This idea could be validated by modeling studies. It also might play out in the next few decades, as scientists watch, Kelly said.

Whether the regulating mechanism of deciduous trees kicks in could depend on how much that region warms, said Philip Higuera, an ecologist from the University of Idaho and a co-author on the study.

“To me, the key thing that that hangs on is how much we turn that temperature knob up,” said Higuera.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

Source: http://www.scientificamerican.com/article.cfm?id=boreal-forests-burning-more-now-than-any-time-in-past-10000-years

Forest ‘management’ does far more harm than good

By George Wuerthner

There’s an old cliche that one can’t see the forest for the trees.It is used to describe people who are so focused on some detail that they fail to see the big picture.Nowhere is this failure to see the forest for the trees more evident than the presumed need to thin forests to reduce so-called dangers and/or damage from wildfire and beetle outbreaks.

Contrary to popular opinion, we probably do not have enough dead trees in our forest ecosystems.
And this deficit is a serious problem because dead trees are critical to the long term productivity of forests, and perhaps more important to forest ecosystems than live trees.

Dead trees are not a “wasted” resource. It is questionable whether we can we remove substantial quantities of live or dead wood from the forest without serious long-term biological impoverishment to forest ecosystems.

An abundance of dead trees — rather than a sign of forest sickness, as commonly portrayed — demonstrates that the forest ecosystem is functioning well.Wildfires and beetles are the major ecological processes that recruit dead wood that is the foundation for healthy forest ecosystems.

Recent research points out the multiple ways that dead trees and downed wood are critical to the forest as well as wildlife.Approximately 45 percent of all bird species and two-thirds of all wildlife (mammals, amphibians, etc.) depend on dead trees and downed wood at some point in their lives.
Dead trees are very important for functioning aquatic ecosystems as well. At least half of the aquatic habitat in small- to medium-size streams comes from dead wood. In general, the more wood you have in the stream, the more fish, insects and other aquatic life.

Once a tree falls to the ground and gradually molders back into the soil, it provides home to many small insects and invertebrates that are the lifeblood of the forest. For instance, hundreds of species of ground-nesting bees make their homes in downed trees.These bees are major pollinators of flowers and flowering shrubs in the forest.

And it’s not just wildlife that depends on dead trees. A recent review of 1,200 lichen species found that 10 percent were only found on dead trees and many others prefer dead trees as their prime habitat.
Lichens, among other things, are important converters of atmospheric nitrogen into fixed nitrogen, important for plant growth.

Contrary to the popular opinion that beetles “destroy the forest” and fires “sterilize” the soils or create biological deserts, several recent studies have concluded that both beetle-killed forests and the burned forests that remain after stand-replacement wildfires have among the highest biodiversity of any habitat type.

Logging, thinning, biomass removal and other forest management creates unhealthy forest ecosystems by removal of dead wood and thwarting the natural agents that recruit dead wood into the ecosystem.
Beyond impoverishing the forest ecosystem, logging also degrades forest ecosystems by spreading weeds, compacting soil, altering waterflow, disturbing wildlife, creating new ORV trails, and increasing sedimentation, among other impacts.

In short, current efforts to thwart and limit beetle outbreaks and wildfires create “unhealthy forests.”
In fact, nearly everything that foresters do — from thinning forests to suppressing fires — degrades and impoverishes the forest ecosystem. Forest “management” is so focused on trees and wood products that it represents a critical failure to see the forest for the trees.

Source: http://www.bendbulletin.com/archive/2013/04/16/forest_management_does_far_more_harm_than_good.html