Recently in Forestry Category

Paper has a long history of "grass" based feedstock -- think papyrus and even cotton!  Maybe it's time to rethink trees as the best natural resource for papermaking.  The chemicals used to convert wood into pulp requires enormous quantities of very caustic, very toxic chemicals. Green chemistry could be a way of exploring other fibers that require less chemicals and less toxic chemicals for the papermaking process.    

Canopy has launched an online survey to gather information that will help assess market interest in North America for papers made with agricultural residues.

Agricultural Residues such as Wheat Straw

"This study is the first of its kind in North America. Up until now, information about the market viability of non-wood paper has been anecdotal," says Neva Murtha, Second Harvest Campaigner with Canopy. "When done, we'll be able to translate demands for eco-paper into initiatives that help make straw papers a North American reality."

Straw Based Papers

Last year's successful trial of the Wheat Sheet issue of Canadian Geographic showed that non-wood papers pass the technical and quality requirements of the North American market. Also apparent during last year's trial was a significant level of interest by large paper consumers in agricultural residue paper alternatives such as the Wheat Sheet. With environmental concern on the rise, so is support for innovative business solutions that alleviate the stress on intact and endangered forests and the climate. Diversifying North America's paper fibre basket to include agricultural residues rather than carbon and species rich forests is one such solution that could also help ensure a secure supply of fibre for domestic producers.

Environmental Paper

This study is designed to help Canopy identify new and emerging opportunities for environmental paper. The survey will provide further information about what level of support exists for non-wood paper development in North America - a key element in new pulping capacity being developed in the US and Canada.

All survey input shall remain confidential and only used in aggregate numbers, unless otherwise approved by participating companies. Data collection will be targeted primarily at large paper consumers, such as publishers, printers, office retailers, and will capture data such as demand tonnage, priority grades, and how participants would like to engage in further stages of non-wood paper development.

To complete the survey about agricultural residue paper


For more information:
Canopy's work to build a market for agricultural residue papers, please visit their website.
For more information on the Wheat Sheet
CONTACT:
Neva Murtha, Second Harvest Campaigner
604-817-4974 | neva@canopyplanet.org 

Google's philanthropic arm, Google.org, recently unveiled new software that can actually track and monitor global deforestation. If the software becomes more widely implemented, it could serve as a useful tool in helping to cut carbon emissions and combat climate change.

Google.org worked with Greg Asner of the Carnegie Institution for Science and Carlos Souza of Imazon to develop the deforestation program. To evaluate deforestation in a certain area of the world, the software relies on past, present and future models of satellite image data. 

Handle computation in the cloud
What if we could offer scientists and tropical nations access to a high-performance satellite imagery-processing engine running online, in the "Google cloud"?

And what if we could gather together all of the earth's raw satellite imagery data -- petabytes of historical, present and future data -- and make it easily available on this platform?

Google decided to find out, by working with Greg and Carlos to re-implement their software online, on top of a prototype platform we've built that gives them easy access to terabytes of satellite imagery and thousands of computers in our data centers.

By processing a decades  of historical images, it is able to extract scientific information on how the size and shape of tree cover has changed over the years. Google hopes that by arming scientists and forest managers with this valuable data, they can better protect the world's forests.

Start with satellite imagery
Satellite imagery data can provide the foundation for measurement and monitoring of the world's forests. For example, in Google Earth today, you can fly to Rondonia, Brazil and easily observe the advancement of deforestation over time, from 1975 to 2001:

Restoring devastated rainforest is a noble goal...but is it possible? 

Yes, says ZERI founder, Gunter Pauli.  Their organization turned waste into a productive, living, sustainable community.  It's a demonstration of natural systems-based environmental and economic development.

The Las Gaviotas reforestation project is not only about planting trees for climate stabilization; it is, primarily, about catalyzing a development program that will pave the way for creating a sustainable future for our children where society is able to provide for the basic needs of all in terms of water, food, health care, shelter, energy, jobs and education with local resources. Las Gaviotas is poised to do nothing less than reshape the face of sustainable development and, consequently, the world.

Aerial view of the 8,000 hectares, replanted with Caribbean Pine.

Imagine miles and miles of desolate savannah in Eastern Colombia, without a tree or bird or child in sight, a veritable no-man's land. For Paolo Lugari this was the perfect place to implement a vision: if a sustainable community could be created in such adverse environmental, social and political conditions, it could be done anywhere on the planet. Las Gaviotas has done just that, and much more.

In 1992, in conjunction with the Kyoto Protocol and the Japanese government, the Environmental Research Center at Las Gaviotas began substantiating the concept of carbon sinks to sequester carbon dioxide and stabilize the climate. Based on the cash generated by its renewable energy project, complemented with funding secured through the Japanese government, Las Gaviotas, founded and directed by Paolo Lugari, planted 8,000 HA of Caribbean pine trees in a savannah that had been unproductive for centuries. It was considered impossible to plant trees in such acidic, inhospitable soil (pH 4) but thanks to the innovative use of mycorrhizal fungi which acts as the saliva for the tree, the forestation was successful. More than just successful, this initiative to initiate economic activities and to validate carbon sinks unleashed a chain reaction of positive effects that surprised even the initiators of the program...

Today, more than a decade later, the forestation of 8,000 HA has resulted in 10 percent more precipitation (some 110,000 m³ per day), converting Las Gaviotas into a net supplier of drinking water, a crystalline water of superior quality. With the cost of drinking water exceeding the cost of petroleum, Las Gaviotas demonstrated that reforestation allows us to address one of the most critical issues the world is facing: access to natural potable water!

For a case study, visit the article "The Renaissance of the Rainforest" by Gunter Pauli.

New Science Estimates Carbon Storage Potential of U.S. Lands
Nation's Forests and Soils Store Equivalent of 50 Years of U.S. CO2 Emissions

The first phase of a groundbreaking national assessment estimates that U.S. forests and soils could remove additional quantities of carbon dioxide (CO2) from the atmosphere as a means to mitigate climate change.

The lower 48 states in the U.S. hypothetically have the potential to store an additional 3-7 billion metric tons of carbon in forests, if agricultural lands were to be used for planting forests.

This potential is equivalent to 2 to 4 years of America's current CO2 emissions from burning fossil fuels.

"Carbon pollution is putting our world--and our way of life--in peril," said Secretary of the Interior Ken Salazar in a keynote speech at the global conference on climate change in Copenhagen, Denmark.  "By restoring ecosystems and protecting certain areas from development, the U.S. can store more carbon in ways that enhance our stewardship of land and natural resources while reducing our contribution to global warming."

U.S. Geological Survey scientists also found that the conterminous U.S. presently stores 73 billion metric tons of carbon in soils and 17 billion metric tons in forests.

This is equivalent to more than 50 years of America's current CO2 emissions from burning fossil fuels. This shows the need to protect existing carbon stores to prevent additional warming and future harm to ecosystems.

Habitat Carbon Absorption = 30% of Fuel Emissions

America's forests and soils are currently insufficient in soaking up the nation's accelerating pace of emissions. They currently absorb about 30 percent (0.5 billion metric tons of carbon) of the nation's fossil fuel emissions per year (1.6 billion metric tons of carbon). Enhancing the carbon storage capacity of America's and the world's ecosystems is an important tool to reduce carbon emissions and help ecosystems adapt to changing climate conditions.

Biologic carbon sequestration

"The tools the USGS is developing--and the technologies behind those tools--will be of great use to communities around the world that are making management decisions on carbon storage," said USGS Director Marcia McNutt. "The USGS is conducting a national assessment of biologic carbon sequestration, as well as an assessment of ecosystem carbon and greenhouse gas fluxes, which will help determine how we can reduce atmospheric CO2 levels while preserving other ecological functions."

To determine how much more carbon could be stored in forests and soils, USGS scientists analyzed maps that represent historical vegetation cover before human alterations, as well as maps of vegetation that might occur if there were no natural disturbances, such as fires, pests and drought. These maps were compared to maps of current vegetation and carbon storage.

The next phase of this work will assess the additional amount of carbon stored in Alaska's ecosystems, including its soils and forests. The USGS plans to collaborate with U.S. Department of Agriculture and other agencies to examine potential carbon storage in soils.

The USGS is conducting research on a number of other fronts related to carbon sequestration. These efforts include evaluating the potential for storing carbon dioxide in geologic formations below the Earth's surface, potential release of greenhouse gases from Arctic soils and permafrost, and mapping the distribution of rocks suitable for potential mineral sequestration efforts.

For more information about this assessment, visit http://pubs.usgs.gov/ofr/2009/1283.

Christmas trees are big business in the United States.  Here are a couple slideshows that can help you make sustainable choices regarding your holiday use of real and artificial Christmas trees.
 


If you do indulge in harvested Christmas trees, here are some tips to prevent Christmas Tree Fires:

• Air filtration of regional pollutants

• Sequestration of carbon dioxide

• Restoration of soils

• Replenishment of underground fresh water storage and aqufers

• Reduction of mountainous flooding, and storage of snow pack for water supplies

• Habitat for wildlife and biodiversity preservation

• Outdoor recreation places and spaces

• Temperature moderation with moisture, shade and the cooling effects of solar absorption

Forestry Carbon Sequestration

Atmospheric carbon dioxide is a gas and forests play a role in its natural regulation.  CO2  - carbon dioxide -- is a gas that occurs naturally in the atmosphere, but it is also being produced with modern transportation and industry.  The result is an imbalance.

Sustainable forestry can hold sequestered carbon in its wood, leaves, root systems, and the soil fertility that results from natural decomposition of organic matters.  Sequestration is the scientific term used for a "storage tank".  Trees act as storage tanks for carbon dioxide by naturally absorbing carbon through photosynthesis.  As trees reach maturity, their growth rates slow depressing any new storage capacity.  Sustainably harvesting mature trees that have extremely slow sequestration rates is a way to keep carbon captured in woods that can be used in housing, furnishings and other long term applications.

Carbon Offset Credits

Sustainably manged forests can document their long term forestry management plan and keep an accurate inventory as the baseline for a sustainably managed, working forest.  These sustainable forests provide multiple benefits in the natural resources system.  In addition to producing carbon sequestering wood products, the working forest also filters ground water, controls erosion, restores soil quality, improves air quality by absorbing pollutants and carbon dioxide ... and provides recreational opportunities.

Carbon Credits

Carbon credits are an attempt by regional and national conservation economies to mitigate the growth of greenhouse gases.  Forests are a key player in the new carbon credits market.

Carbon trading is an emissions trading approach that lets companies buy sustainable credits to offset their not-so-environmentally friendly operations such as transportation or industrial production that uses fossil fuels and produces greenhouse gases.  By purchasing carbon credits to meet their legal compliance levels, these companies buy a little extra time to implement their own emissions reduction strategies.

Greenhouse gas emissions are capped by agencies such as the EPA as well as state based environmental and air quality agencies.  Markets are used to allocate the load of emissions among the group of regulated sources -- usually large manufacturing corporations. 

By having to purchase high priced carbon credits, compaies are encouraged to implement better, less expensive options that reduce their own emissions.  The more they succeed internally in reducing particulates and carbon dioxide, the fewer carbon credits they need to purchase to meet their compliance allocations.

Mitigation projects generate credits, so highly effective companies can sell their extra credits to generate revenue.  This income can be used to finance carbon reduction programs between partners and around the world. 

These carbon offset players can purchase credits from an investment fund or carbon development company that aggregates credits from approved, sustainable programs such as the Michigan Timber Conservation Carbon Off-Set Program.

Two current approaches to carbon reduction ar recognied as effective ways to reduce carbon emissions and climate change.  

Carbon offset credits consist of clean forms of energy production such as wind, solar, hydro and bio-fuels.

Carbon reduction credits consist of the collection and storage of carbon from the atmosphere through reforestation, forestation ocean and soil collection and storage processes.

Carbon Financial Instruments (CFI)

Forest owners who provide a sustainable, working forest can sequester carbon dioxide and offset current carbon levels through sustainably certified forest management and certified wood products.  The Forest Stewardship Council (FSC) program is one example of sustainable forestry and product certification programs.

Carbon Offset Programs typically include forestry management strategies such as:

• land management portfolio
• complete forest inventory
• written management plan
• record keeping of all forest studies
• market driven carbon royalty payments
• aerial, land, and soil maps
• revenue from land tax credits
• using FSC certified harvesters
• ongoing forest analysis

 

Some of the benefits of participating in a sustainable forestry and offset program include:

• guaranteed market value of wood products
• sustainable forest recognition
• improved roi on timber products
• unlimited access to online forestry portal
• timber theft prevention program
• member referral program

The goal of sustainably harvested forests and timberland is a responsible, ethical business approach that promotes positive forestry growth and sequestration of carbon in wood products.  This is a promising approach to reducing greenhouse gas effects caused by environmental emissions and heat from urban, industrial, transportation and other sources of modern energy side effects.

If your private forest has harvestable, merchantable timber, you can still use your timberland for wood production as long as it is managed in a sustainable, planned, measured and long term way. 

Many regional sustainable forestry organizations, such as the Michigan Timber Conservation Carbon Off-Set Program, will help train and support landowners and forestry companies with management plans and a forest inventory to prepare the forest for carbon credit program participation.

In a 2008 report, the Governor's Minnesota Climate Change Advisory Group (MCCAG) recognized the importance of forests in greenhouse gas reduction by suggesting that nearly 30% of the state's 2025 greenhouse gas emission reduction goals could be achieved through forest management initiatives.

Forestry Carbon Credits help provide new funds for conservation. 

Protection of our natural resources in becoming increasingly dependent on careful monitoring, data collection and interpretation of these observations of how our world works.  The AmeriFlux network provides scientific development of methods as well as gathering and analysis of ecosystem data. These scientists quantify and advance understanding of processes regulating carbon assimilation, respiration, and storage, and linkages between carbon, water, energy and nitrogen through measurements and modeling.

The AmeriFlux network includes more than 120 independently funded sites operating across North, Central, and South America. AmeriFlux sites include tundra, grassland, agricultural crops, tropical forests and temperate coniferous and deciduous forests.

Nations of the world face challenges in developing sound policies and directions for addressing global change. The scientific community has the responsibility to provide the scientific basis for those policies.

This includes developing the understanding of the influence of land, ocean and atmospheric processes in climate change.

The goal of AmeriFlux is to develop a coordinated research network of long-term flux sites in the Americas for quantifying and understanding the role of the terrestrial biosphere in global climate change. Specifically, Ameriflux aims to provide reliable estimates of carbon storage, carbon dioxide and water vapor exchange, and improve our description and understanding of variation, and its causes at relevant temporal and spatial scales. We expect to provide the quantitative information to adequately predict large-scale long-term responses to changing environmental conditions.

This will be accomplished using micrometeorological and biological measurements at the intensive flux sites coupled with extensive measurements (e.g. surveys and remote sensing) and modeling.

The AmeriFlux network was established in 1996. The network provides continuous observations of ecosystem level exchanges of CO₂, water, energy and momentum spanning diurnal, synoptic, seasonal, and interannual time scales and is currently composed of sites from North America, Central America, and South America.

AmeriFlux is part of a "network of regional networks" (FLUXNET) which coordinates regional and global analysis of observations from micrometeorological tower sites. Learn more about FLUXNET and other regional carbon flux networks.

The network role is to address the scientific uncertainties associated with global change. AmeriFlux' focus is to address these scientific questions:

1. What are the magnitudes of carbon storage and the exchanges of energy, CO₂ and water vapor in terrestrial systems? What is the spatial and temporal variability?


2. How is this variability influenced by vegetation type, phenology, changes in land use, management, and disturbance history, and what is the relative effect of these factors?


3. What is the causal link between climate and the exchanges of energy, CO₂ and water vapor for major vegetation types, and how does seasonal and inter-annual climate variability and anomalies influence fluxes?


4. What is the spatial and temporal variation of boundary layer CO₂ concentrations, and how does this vary with topography, climatic zone and vegetation?

Recommendations for enhanced instrumentation at research sites

• Aspirated temperature. The AmeriFlux network needs to ensure temperature measurements are unbiased and stable with time
• Net Radiation. All sites should consistently use aspirators and account for any wind-speed corrections in their radiation measurements.
• Photosynthetic Photon Flux Density (PPFD) and incident radiation.
• Sonic Anemometry. There is no model of sonic anemometer-thermometers (SATs) that is ideal for all situations. Model type should be chosen by the site PI to best suit the site conditions and overall research questions.Scalar density measurements for CO2 and H2O. Precise scalar concentrations are needed to quantify the high frequency turbulent fluctuations of scalar density in making flux measurementsProfile systems. Because any 30-min scalar flux is the sum of both turbulent exchange and the vertical integrated rate of change of the scalar, it is important to have a CO2 profile system particularly at sites that have a developed canopy > 1 m in height.
• Soil respiration. Automated continuous measurements of soil respiration, and accompanying spatial representation with portable chambers, plus soil temperature and moisture profiles should be added to Tier 1 sites, and possibly some Tier 2 sites. We have found that automated chamber measurements of soil respiration (hourly)Water budget components. One key AmeriFlux objective is to explain the processes that control the fluxes of water vapor, and to determine how water vapor flux temporally and spatially affect the exchange of carbon (AmeriFlux Science Plan).
• Reporting calibration records (metadata) and data quality flags (for each 30-min period) in a centralized data repository (i.e., CDIAC) should also be explored to enhance overall network data quality
  

Contrary to 40 years of conventional wisdom, a new analysis published in the journal Nature suggests that old growth forests are usually "carbon sinks" - they continue to absorb carbon dioxide from the atmosphere and mitigate climate change for centuries.

Old growth forest store more carbon than they release.

Worldwide, forests between 15 and 800 years old remove a net 1 billion metric tons of carbon dioxide from the atmosphere each year.

This study, which analyzed more than 500 forests worldwide, challenges the conventional wisdom that old growth forests give off as much carbon as they take in and are thus carbon neutral. The authors of this report argue that, based on this research, the Kyoto Protocol and other "Cap and Trade" systems for greenhouse gases should allow credits for protecting old growth forests.

However, these old growth forests around the world are not protected by international treaties and have been considered of no significance in the national "carbon budgets" as outlined in the Kyoto Protocol.  That perspective was largely based on findings of a single study from the late 1960s which had become accepted theory, and scientists now say it needs to be changed.

"Carbon accounting rules for forests should give credit for leaving old growth forest intact," researchers from Oregon State University and several other institutions concluded in their report. "Much of this carbon, even soil carbon, will move back to the atmosphere if these forests are disturbed."

Northern Hemisphere Old Growth Forests

The analysis of 519 different plot studies found that about 15% of the forest land in the Northern Hemisphere is unmanaged primary forests with large amounts of old growth, and that rather than being irrelevant to the Earth's carbon budget, they may account for as much as 10 percent of the global net uptake of carbon dioxide.

Forests of 15 to 800 Years of Age

In forests anywhere between 15 and 800 years of age, the study said, the net carbon balance of the forest and soils is usually positive -- meaning they absorb more carbon dioxide than they release.

"If you are concerned about offsetting greenhouse gas emissions and look at old forests from nothing more than a carbon perspective, the best thing to do is leave them alone," said Beverly Law, professor of forest science at OSU and director of the AmeriFlux network, a group of 90 research sites in North and Central America that helps to monitor the current global "budget" of carbon dioxide.

The current data now makes it clear that carbon accumulation can continue in forests that are centuries old.

The creation of new forests, whether naturally or by humans, is often associated with disturbance to soil and the previous vegetation, resulting in decomposition that exceeds for some period the net primary productivity of re-growth.

Old growth forests, the study said, continue to sequester carbon for many centuries. And when individual trees die due to lightning, insects, fungal attack or other causes, there is generally a second canopy layer waiting in the shade to take over and maintain productivity.

Offset Greenhouse gas Emissions with Intact Forests

One implication of the study, Law said, is that nations with significant amounts of old forests may find it somewhat easier to offset greenhouse gas emissions if those forests are left intact. It will also be necessary  for land surface models that attempt to define carbon balance to better characterize function of old forests.

Many of the conclusions from the study were based on data acquired from the AmeriFlux and CarboEurope programs, researchers said.

A newly discovered disease caused by a previously undescribed fungus hitchhiking on a tiny native bark beetle, is infecting and killing hundreds of black walnut trees in California and seven other Western states.

The havoc wreaked by the combined pests, coined "Thousand Cankers Disease," represents a serious threat to black walnut trees, says chemical ecologist and forest entomologist Steve Seybold of the Davis-based Pacific Southwest Research Station, USDA Forest Service, and an affiliate of the Department of Entomology, University of California, Davis.
 
"The black walnut trees could go the way of the American chestnut or American elm," warns entomologist Lynn Kimsey, chair of the UC Davis Department of Entomology and director of the Bohart Museum of Entomology, which houses one of the largest insect collections in North America.
 
"By itself the very tiny walnut twig beetle, does relatively little damage," Seybold said.  But combined with the aggressive fungus, it can kill a walnut tree in one to three years.  Despite the "twig" in its common name, the walnut twig beetle also bores holes in large branches and even in the trunk of walnut trees.
 
The beetle, Pityophthorus juglandis, native to Arizona, California, New Mexico, and Mexico is widely distributed in California, from San Diego to Shasta counties. Known since 1959 as just another specimen in the drawers of California insect museums, it has emerged on the radar screens of entomologists and plant scientists because it has been found in abundance on dying walnut trees statewide.  The disease has also been found in Colorado, Arizona, New Mexico, Idaho, Utah, Washington, and Oregon.
 
"It's a hard time for hardwoods," said Seybold, who organized and chaired a symposium at the Entomological Society of America's 65th annual meeting, held last fall in Reno.  "This is behaving like an invasive pathogen that has run amuck."
 
Scientists are concerned that the disease may also impact English walnut and California walnut production. "There are hints that the fungus may have infected English walnuts in Utah," Seybold said, "and there are several symptomatic English walnut trees at the USDA National Germplasm collection located in nearby Winters but beyond that we do not know the extent of the threat to the industry."
 
The fungus, with its barrel-shaped spores, appears to be an undescribed and perhaps exotic species within the genus Geosmithia, said postdoctoral researcher Andrew Graves of the UC Davis Department of Plant Pathology. Graves, part of a Davis-based team working on the project since June 2008, has noted that there are seven named species of Geosmithia.
 
Colorado State University plant pathologist Ned Tisserat, who placed the fungus in the genus, Geosmithia and named the disease, "Thousand Cankers," told the ESA symposium:   "It is really, really a scary disease; it's as bad as butternut (walnut) canker." Butternut (Juglans cinerea) is also known as white walnut.   
 
Graves, who also holds a doctorate in entomology from the University of Minnesota, described the beetle as reddish-brown bark beetle, about 1.5 to 1.9 millimeters long. "It's much smaller in size than a grain of rice," he said. The entrance holes into the black walnut tree look like pin pricks.
 
"But if you peel back the bark, you'll see the well-developed beetle galleries and blotches of fungal-stained wood and bark that look like a thousand cankers,"said Graves, who is researching the host colonization behavior of the beetle. He described some of the coalescing cankers as "enormous."  The cankers widen and girdle twigs and branches, resulting in die back of the tree crown.
 
Disease symptoms include dark stains on the outer bark tissue that extend into the cambium; yellowing and thinning of the upper crown; wilting of leaves; flagging branches; die back and eventual death, all within three years.  Seybold said that the disease is so recently discovered that specialists have not had time to develop and test integrated pest management tools to address the issue.  The natural system of attraction of the beetles to the trees and to each other might form the basis of a future monitoring and tree protection toolkit.
 
"The impact of these beetles and their fungus," Kimsey said, "may be devastating to yet another of our native trees. When I think of the possibility of losing all of the magnificent black walnuts in Davis, it makes me very sad."
 
The disease complex first gained notice in the Española Valley of New Mexico in 2001 when walnut trees declined and died.  Scientists initially attributed the mortality to drought stress. However, when the drought subsided, the massive dieoffs did not.  
 
The beetle-disease complex is associated with widespread deaths of black walnuts planted as street or highway trees in Boulder, Co., Portland, Ore., Prosser, Wash., and several counties in California, including Los Angeles, Sutter, Ventura, and Yolo.  It was first noted by scientists in California in 2008.
 
UC Davis walnut specialist Charles Leslie, a member of the Davis-based thousand cankers disease research team, says two species of black walnut are native to California: Juglans californica (a southern California shrublike black walnut) and Juglans hindsii (the northern California black walnut).
 
Northern California black walnut is widely planted in Yolo County as an ornamental tree, lining roads and ranches, Leslie said.  "These black walnuts are different from the commercial walnuts grown in the Central Valley, which are Persian, commonly called "English" walnut trees grown on black walnut root stock."
 
California black walnut "is prized more as a shade tree than for its nuts," Leslie said. "To crack the nut, you need to run over it with the family Hummer or hit it with a sledgehammer," he quipped.
 
However, eastern black walnut is a favorite in the ice cream industry, and the wood is especially prized for furniture and guitars.
 
To confirm the extent of the disease in the state, the Davis researchers are participating in a federally funded project to collect diseased branches throughout California, particularly in the native ranges of Juglans californica (Los Angeles and Ventura counties) and Juglans hindsii (Mt. Diablo and elsewhere in Contra Costa and Yolo counties. They are also rearing the beetles and studying host colonization behavior.  "The beetle appears to pump out at least two generations a year in California," Graves said.
 
Colorado State University plant sciences professor Whitney Cranshaw, who is on the front lines of the research in Boulder and Denver, said people continually ask him "How can a little twig beetle be killing healthy trees?"
 
"With Geosmithia," he said. "The fungus is carried into the tree when the beetle tunnels into and wounds the tree. The fungus produces large cankers."
 
The aggressive fungus girdles the tree and "it's death by 1000 cankers," Cranshaw said.
The attacks generally occur from mid-April through mid-September. At the end of summer, the beetles and the fungus that they carry move into the lower part of the trunk to hibernate.
 
In their continuing research, scientists hope to establish a baseline of the beetle and fungal populations to understand the full extent of the problem.  Native black walnut trees in the western U.S. are important components of the vegetation along streams and riparian zones, Seybold said, so their "loss may have significant ecological implications."
 
The scientists also advocate research on vector transmission, overwintering biology, an estimation of the risk and threat to the walnut-growing industry in California and to commercially valuable native black walnut trees in the eastern U.S., development of attractive baits, and an insecticide treatment.
 
Insecticides may prove useful, but only if used prior to the beetle arriving at the tree, Graves said. "Insecticide sprays are of limited effectiveness due to the extended period when the beetles are active, and because the beetles are feeding beneath the bark, insecticides will not be useful in killing beetles that have already entered the tree.  Even if the insecticide kills the adult beetles and larvae, the Geosmithia may continue to colonize the bark and phloem."
 
The scientists also discussed their research this past spring at meetings in Savannah, Georgia (National Forest Health Monitoring Workshop) Spokane, Wash. (Western Forest Insect Work Conference); and San Diego (Pacific Branch ESA Meeting).