Study Yields Surprising Insights into Global Effects of Wood Fuel Burning

Courtesy of Adrian Ghilardi

The harvesting of wood to meet the heating and cooking demands for billions of people worldwide has less of an impact on global forest loss and carbon dioxide (CO2) emissions than previously believed, according to a new Yale-led study.

Writing in the journal Nature Climate Change, a team of researchers, including Prof. Robert Bailis of the Yale School of Forestry & Environmental Studies (F&ES), concludes that only about 27 to 34 percent of wood fuel harvested worldwide would be considered “unsustainable.” According to the assessment, “sustainability” is based on whether or not annual harvesting exceeds incremental re-growth.

The other authors are Rudi Drigo, an independent forestry specialist with international experience; and Adrian Ghilardi and Omar Masera of the National Autonomous University of Mexico.

According to the authors, the findings point to the need for more nuanced, local-specific policies that address forest loss, climate change, and public health. They also suggest that existing carbon offset methodologies used to reduce carbon emissions likely overstate the CO2 emission reductions that can be achieved through the promotion of more efficient cookstove technologies.

The study identifies a set of “hotspots” where the majority of wood extraction exceeds sustainable yields. These hotspot regions — located mainly in South Asia and East Africa — support about 275 million people who are reliant on wood fuel.

“If forests and woodlands would have been cut down anyway, then the projects designed to reduce wood fuel demand are not actually going to reduce deforestation.”— Robert Bailis

However, in other regions, the authors say, much of the wood used for this traditional heating and cooking is actually the byproduct of deforestation driven by other factors, such as demand for agricultural land, which would have occurred anyway.

“If forests and woodlands would have been cut down anyway, then the projects designed to reduce wood fuel demand are not actually going to reduce deforestation,” said Bailis, an associate professor at F&ES and lead author of the study. “Sure, you’re reducing wood use, but the underlying pressures driving deforestation are still out there.”

The results stand in contrast to a long-held assumption that the harvesting of wood fuels — which accounts for more than half of the wood harvested worldwide — is a major driver of deforestation and climate change.
  
Using a model originally developed by Drigo and Masera, and already applied in more than 20 countries, the researchers produce a spatially explicit snapshot of wood fuel supply and demand in 90 countries across the world’s tropical regions, where burning wood is a critical source of energy for cooking and heating.

“One of the problems with traditional bio-energy is that the situation is very locally specific, so you can’t come up with a general response for all places,” said Masera. “One of the real strengths of this paper is that it demonstrates a methodology that allows you to identify priority regions for intervention”

The study identified a set of “hotspot” regions in South Asia and Eastern Africa where the majority of wood extraction exceeds sustainable yields.

In addition to the global analysis, the researchers are using the same model to evaluate the sustainability of wood fuel resources in three case studies: Honduras, Kenya, and the Indian state of Karnataka.

“Even within a given country the situation varies a great deal,” said Drigo. “Some areas are over-exploited while others are under-exploited or totally untouched. A better understanding of the relationship between supply and demand requires this type of spatial approach to clarify what the impacts of different policies will be.”

Emissions from wood fuels account for about 1.9 to 2.3 percent of global emissions, the study says. The deployment of 100 million improved cookstoves could reduce this by 11 to 17 percent, said Bailis, who also studies the factors that influence the adoption of cleaner cookstoves in developing nations.

These reductions would be worth more than $1 billion per year in avoided greenhouse gas emissions if black carbon were integrated into carbon markets, he said.

“We need to be able to understand where these different components of non-renewability are coming from in order to get a better sense of the positive impacts of putting stoves into peoples' homes or promoting transitions to cooking with gas or electricity,” he said.

The research was funded by the Global Alliance for Clean Cookstoves, an initiative supported by the UN Foundation.

Source: Yale University

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Stanford scientists team with indigenous people to produce detailed carbon calculations of Amazon rainforest

The late Dr. Kye Epps teaches Wapichana field researchers how to measure tree diameter, information that can then be used to calculate a tree's biomass and carbon storage.

When it comes to measuring the carbon storage potential of the Amazon forest, indigenous people might outperform sophisticated satellites.

The results from a long-term collaboration between Stanford scientists and indigenous people in Guyana suggests that traditional remote sensing techniques might be undervaluing the region's carbon storage potential by as much as 40 percent. The work could influence how indigenous people in Guyana and elsewhere manage their forests and lead to greater opportunities for these communities to engage in carbon offset programs.

The project, led by Jose Fragoso, a senior scientist in the Department of Biology at Stanford, grew out of his earlier efforts to engage indigenous peoples to gain a better understanding of ecosystems relatively undisturbed by modern civilization.

What is carbon?

The first challenge was teaching people with little to no exposure to the outside world just what carbon is. Co-author Kimberly "Kye" Epps, a postdoctoral scholar in Stanford School of Earth Sciences (who passed away during the project,) developed lesson plans for explaining that all life is based on carbon.

Epps pointed out that the black charcoal from a burnt twig is primarily carbon, and how the carbon-laden smoke enters the atmosphere and ultimately affects the global climate. The plants and trees suck carbon from the atmosphere, she explained, and store it in their trunks and leaves.

"Kye's innovative lessons helped get them to where they not only understand what carbon is, but also understand its global implications and how much they actually hold themselves on their land," said Fragoso, the senior author on the paper. "When they realized its importance, they became very invested in the work."

Next came lessons on establishing survey plots, cataloging plant species and learning how to measure plant trunk circumferences, which is a standard measurement used to calculate biomass and thus how much carbon is contained in the plot.

"The people know the trails really well, and some of them will walk two days to get to their plot and make measurements," Fragoso said. "They can make really good measurements in really isolated areas, where government workers would never get to. Generally, professional scientists will not travel these distances on foot to verify carbon estimates."

Biomass specifics

Whereas satellite observations would most likely have identified each of these plots as "forest" and assigned them a standardized value for carbon storage, Fragoso said that the field workers identified 11 habitat types with trees, each of which requires a different set of calculations for determining its carbon storage potential. Because the researchers could be more specific about the biomass of each vegetation type making up a plot, they were able to calculate that forests in Guyana contain 20 to 40 percent more carbon than previously estimated.

This difference can affect a number of different areas. For one, it means that climate models that include blanket estimations of carbon storage in lands governed by indigenous people might be missing significant data – indigenous people govern about half of all remaining undeveloped land on the planet.

Indigenous lands probably play a much larger role in the global climate than previously assumed, Fragoso said, and indigenous people need to be better represented at global climate talks. These land-owners have more carbon storage at their disposal to sell as carbon credits to governments and corporations looking to offset their greenhouse gas-producing activities.

"Having a good measurement of carbon storage really helps them to enter into discussions with the national government and surrounding communities," Fragoso said. "This helps them to both prevent global climate change while also benefiting, and that is something that the people we worked with were very interested in."

This is the first model for turning indigenous people into field researchers capable of producing scientifically rigorous calculations for carbon, said Fragoso, who is now planning to share the concept with other indigenous nations around the world.

The paper was published recently in the journal Forest Ecology and Management. The work was co-authored by Nathalie Butt of the University of Queensland, Australia, who completed Epps' work; Stanford postdoctoral fellow Takuya Iwamura; and Han Overman, a postdoc at State University of New York. While not official co-authors, Stanford professors Peter Vitousek and Pamela Matson were instrumental in providing guidance for Epps' work.

Source: Stanford

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Study shows Brazil’s Soy Moratorium still needed to preserve Amazon

Soybeans grow near a forested area in the Brazilian state of Mato Grosso. Under the Soy Moratorium, major trading companies do not purchase soybeans produced in the Brazilian Amazon on recently deforested areas. Credit: Lisa Rausch

Today, fewer chicken nuggets can trace their roots to cleared Amazon rain forest.

In 2006, following a report from Greenpeace and under pressure from consumers, large companies like McDonald's and Wal-Mart decided to stop using soy grown on cleared forestland in the Brazilian Amazon. This put pressure on commodity traders, such as Cargill, who in turn agreed to no longer purchase soy from farmers who cleared rain forest to expand soy fields.

The private sector agreement, a type of supply chain governance, is called the Soy Moratorium and it was intended to address the deforestation caused by soy production in the Amazon. In a new study to evaluate the agreement, published today (Jan. 22, 2015) in Science, the University of Wisconsin-Madison's Holly Gibbs and colleagues across the U.S. and Brazil show that the moratorium helped to drastically reduce the amount of deforestation linked to soy production in the region and was much better at curbing it than governmental policy alone.

"What we found is that before the moratorium, 30 percent of soy expansion occurred through deforestation, and after the moratorium, almost none did; only about 1 percent of the new soy expansion came at the expense of forest," says Gibbs, a professor of environmental studies and geography in the UW-Madison Nelson Institute's Center for Sustainability and the Global Environment (SAGE).

Between 2001 and 2006, prior to the moratorium, soybean fields in the Brazilian Amazon expanded by 1 million hectares, or nearly 4,000 square miles, contributing to record deforestation rates. By 2014, after eight years of the moratorium, almost no additional forest was cleared to grow new soy, even though soy production area had expanded another 1.3 million hectares. Farmers were planting on already cleared land.

The findings are intended to help policy makers and industry leaders make informed decisions going forward.

"We really wanted to understand if the Soy Moratorium mattered," says Gibbs. "There was a lot of discussion about ending the moratorium in 2014 and we wanted to know what the agreement meant on the ground and how it compared with governmental policy, which is the proposed replacement."

Brazil, Gibbs says, has some of the world's most stringent environmental legislation. Public policies, including increased enforcement of state and federal laws, have gone a long way to slow the destruction of rain forest. Yet, the study shows that "government policy alone is simply not enough," Gibbs says. At least, not yet.

Photo: Brazilian farmers examine their soybean crop Brazilian farmers examine their soybean crop. Credit: Lisa Rausch

Using 15 years (2000-2014) of satellite-based imagery covering the Brazilian Amazon forest and the Cerrado, another large tropical biome in Brazil comprising woodlands and scrublands, the researchers assessed how much land had been cleared to grow soy. They examined land use on thousands of individual farms and identified substantial large-scale deforestations not penalized by Brazilian authorities.

The team also mapped already-cleared areas suitable for soy production to assess the potential for future expansion under the Soy Moratorium and determined how much illegal deforestation was still occurring for purposes other than soy and in direct violation of Brazil Forest Code laws.

What the team found was surprising.

"Only 115 people out of several thousand soy farmers have violated the Soy Moratorium since 2006, but over 600 of them have violated the Forest Code," Gibbs says. "So, this same group of farmers is five times more likely to violate the governmental policy than they are to violate the private sector agreement."

For instance, the Forest Code dictates that 80 percent of Amazon rain forest on a person's property must be held in reserve; they can only clear 20 percent. Yet, just 2 percent of soy farmers have maintained their legal reserve and even farmers abiding by the moratorium were still illegally clearing forest on their properties, just not for growing soy.

A provision in the Forest Code also requires that property owners register their land, after which their name and a clear map of their property becomes publicly available. While the researchers say this is a huge step forward, the study found that property registration alone does not safeguard forests. For example, nearly a quarter of the illegal deforestation that occurred over the last year in the state of Mato Grosso, the Amazon's "soy capital," happened on these registered properties.

An island of forest in a sea of soy agriculture in Mato Grosso. Credit: Rhett Butler

Additionally, the researchers found that while soy-linked deforestation diminished in the Amazon biome, 20 percent of new soy areas created in the Cerrado over the study period directly led to deforestation. Expanding the moratorium to the Cerrado would reduce this conversion.

"It reinforces the idea that private sector interventions will be needed in the long term to maintain the deforestation-free production of soy," says Gibbs, who notes that soy is Brazil's most profitable crop and that most goes to feed animals produced for food. "Without the moratorium, chicken nuggets would once again contribute to rain forest destruction."

Implementing environmental laws across the Brazilian Amazon, an area more than six times the size of Texas, is a huge challenge, and Gibbs points out that enforcement has significantly ramped up in recent years. Despite this, the study found that government enforcement efforts capture only between 15 and 50 percent of illegal, large-scale deforestation. Even then, many factors make execution of fines and other penalties difficult.

Meanwhile, the study shows that a small number of soy traders, like Cargill, ADM and Bunge, have "a lot of power and control to influence land management decisions on the ground," says Gibbs.

The study also found there is enough already-cleared, suitable land in the Amazon to allow soy production area to expand by 600 percent. Presently, the area of land used to grow soy in the Amazon is comparable to the size of Vermont. Brazil rivals only the U.S. in terms of soy production and trade.

The team continues to use satellite data and field surveys to better understand deforestation dynamics and land use decisions in the Brazilian Amazon and Cerrado, the most active land use frontiers in the world. Gibbs and colleagues are also conducting econometric analysis to evaluate the interplay between deforestation and the Soy Moratorium, one of the first voluntary zero-deforestation agreements in the world.

Ensuring this reduced deforestation continues is a priority for those involved, and Gibbs says new approaches to the policy — that combine elements from public and private strategies — are being considered.

"We work closely with policymakers, the agricultural industry and nongovernmental organizations, and aim to use our rigorous scientific analysis to help inform decisions going forward," Gibbs says.

The study was funded by the Gordon and Betty Moore Foundation, the Norwegian Agency for Development Cooperation's Department for Civil Society, NASA and several Brazilian agencies. Co-authors include researchers from NASA; the University of Maryland, College Park; the National Wildlife Federation; Universidade Federal de Minas Gerais, Belo Horizonte; IMAZON Institute of People and the Environment; and Instituto Centro de Vida.

Material Source: UW
Source: Center for Sustainability and the Global Environment(SAGE).

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Primates indispensable for regeneration of tropical forests

Moustached tamarins (Saguinus mystax) contribute crucially to the seed dispersal of the neotropical tree Parkia panurensis. Credit: Julia Diegmann

Primatologist and plant geneticists have studied the dispersal of tree seeds by New World primates.

Primates can influence seed dispersal and spatial genetic kinship structure of plants that serve as their food source. This is the result of a cooperation project of behavioral ecologist Eckhard W. Heymann from the German Primate Center (DPZ) with plant geneticists Birgit Ziegenhagen and Ronald Bialozyt from the Philipps-University Marburg. This study was funded by the German Research Foundation.

At the DPZ-field station Estación Biológica Quebrada Blanco in the Peruvian Amazonian lowlands, scientists studied how feeding, sleeping, and ranging habits of two species of New World monkeys affect the dispersal of the neotropical legume tree Parkia panurensis. For this, the researchers observed a group of Brown-mantled tamarins (Saguinus nigrifrons) and Moustached tamarins (Saguinus mystax), who jointly moved through home ranges in search of edible plants which included Parkia trees.

Fruits from these trees are pods that contain 16 to 23 seeds, each of which is surrounded by edible gum. The monkeys feed on the gum content of the pods and at the same time swallow the Parkia seeds which are later defecated intact in a different area.

During behavioral observations, researchers recorded the food intake of tamarins as well as the location of the Parkia trees that they visited. In addition, they collected faecal samples of the tamarins that contained seeds. "With the help of genetic analyses of the DNA found in the seed coat, which is of maternal origin, we could make an exact assignment of the corresponding "mother tree" for the seeds," says Eckhard W. Heymann from the DPZ. "This allowed us to determine how far Parkia seeds were dispersed by the monkeys."

In order to analyze the effect of seed dispersal by monkeys on a spatial genetic level, the scientists examined three different developmental stages of the trees. In addition to the seeds that contain the plant embryo, they collected leaves from young and mature Parkia trees in the home range of tamarins. "With the help of analysis from microsatellites, short repeated DNA sequences, we were able to identify genetic similarities of individual trees," says Heymann.

The analysis of the spatial genetic structure of the Parkia population revealed a significant genetic relationship of the plant embryos and young trees within a radius of 300 meters, which coincides with the distance within which most seeds are dispersed by the tamarins. For mature trees, the relationship was reduced to a radius of only up to 100 meters.

"In tropical rain forests, the seeds of 80 to 90 percent of trees and lianas are dispersed by animals. In addition to primates, birds and bats are the major animal groups that are responsible for seed dispersal," says behavioral ecologist Heymann. "For the plants, transport of their seeds is extremely important. As sedentary organisms, this is the only way that their offspring -- the embryos contained in the seeds -- can reach appropriate sites for germination and growth. Furthermore, this reduces the density-dependent mortality which occurs when the seeds fall under the mother plants," says Eckhard W. Heymann. Fruit-eating primates such as tamarins are therefore invaluable to the natural regeneration and diversity of ecosystems in which they live.

Source: German Primate Center

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Female frogs modify offspring development depending on reproduction date

Breeding male of Rana arvalis from the study area. Credit: Germán Orizaola

Global warming is altering the reproduction of plants and animals, notably accelerating the date when reproduction and other life processes occur. A study by the University of Uppsala (Sweden), including the participation of Spanish researcher Germán Orizaola, has discovered that some amphibians are capable of making their offspring grow at a faster rate if they have been born later due to the climate.

Over recent decades many organisms, both plants and animals, have experienced a notable advance in the date when many of their life processes (like reproduction, migration or flowering) occur, attributed to the impact of climate change. An article published in the journal Ecology examines the effects that these changes in the reproduction date have on the life cycles of the amphibians.

"We specifically examined whether changes in the reproduction date of a common amphibian species in the north of Europe, Rana arvalis, can condition the growth and development of their offspring," the Spanish researcher Germán Orizaola, from the University of Uppsala (Sweden) and co-author of the study, said.

Results revealed that female frogs have the ability to influence both the growth rate and the development of their offspring, and they adjust it depending on the date of reproduction.

According to Orizaola, "the mechanism by which the female frogs can condition the growth of their larvae could be due to the genes associated with the maintenance of their biological clock being transferred to the embryos and becoming active even before fertilisation. This would provide the larvae with the exact information regarding the progression of the growing season."

The later the birth, the faster the growth

One of the characteristics associated with climate change is an increase in the interannual variability of climatic conditions, so organisms are also exposed to greater uncertainty when it comes to determining the right time to reproduce. This explains why the existence of mechanisms adjusting growth and development rates depending on the variation in the start of breeding is highly advantageous for many species.

In particular, as part of this study they observed that by delaying the date of reproduction (which simulated a time of environmental instability), the result was an equivalent reduction in the growth period for the larvae. "That means the later this species of frog breeds, the faster the larvae develop," explains the scientist.

An interesting aspect of the study is that the acceleration in growth is produced under constant lab conditions. "The larvae were not exposed to any outside sign that would indicate the progression of the growing season," adds Orizaola.

"This result is very novel and demonstrates that the acceleration in the development of the larvae is conditioned by the breeding females, which reveals the existence of a 'transgenerational effect' in which the breeding adults are capable of altering key aspects of the life cycle for the following generations, to better prepare them to survive the environmental conditions that they are going to experience," concludes the expert.

Source: Plataforma SINC.

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Odor that smells like blood: Single component powerful trigger for large carnivores

African wild dogs compete for a log impregnated with blood or a single component. Both were equally attractive. Credit: Linköping University

People find the smell of blood unpleasant, but for predatory animals it means food. When behavioural researchers at Linköping University in Sweden wanted to find out which substances of blood trigger behavioural reactions, they got some unexpected results.

Matthias Laska is professor of zoology, specialising in the sense of smell. For some time his focus has been on scents that directly affect the behaviour of animals.

"For predators, food scents are particularly attractive, and much of this has to do with blood. We wanted to find out which chemical components create the scent of blood," he says.

The study, conducted at Kolmården Wildlife Park, found that for the animals, one particular component of blood odour was just as engaging as the blood odour itself.

"It's a completely new discovery that raises interesting questions on evolution," says Prof Laska.

The study has been published in the scientific journal PLOS ONE.

When Prof Laska did a search for the contents of volatile substances in mammalian blood, he found nothing. Human blood has been analysed for disease markers, but we have very little information on the substances that give blood its characteristic scent.

A master's student was sent to Friedrich-Alexander-Universität in Erlangen Germany, to analyse mammalian blood with the help of gas chromatography and mass spectrometry, methods used for separating and identifying chemical compounds in a sample. The machine detected some 30 substances, of which some are decomposition products from fats. But the machine lost the job to the human scent experts who had also been engaged. They identified scents that the gas chromatograph missed completely.

One substance stood out: an aldehyde called trans-4,5-epoxy-(E)-2-decenal, which emits the typical metallic scent that humans associate with blood.

Once the researchers had identified a scent candidate that the predators should be attracted to, they wanted to test whether the predators were actually attracted to it in reality. So they designed a study to be conducted at Kolmården Wildlife Park, involving four predator species. How would the four predators -- Asian wild dogs, African wild dogs, South American bush dogs and Siberian tigers -- react when they caught a whiff of the scent?

Half-metre long wooden logs were impregnated with four different liquids: lab-produced aldehyde, horse blood, fruit essence, and a near-odourless solvent. The animals were exposed to one scent per day in their regular enclosure, while a group of students carefully observed their behaviour.

The results were unequivocal. The logs containing aldehyde were just as attractive stimuli as those containing blood, while the two other logs aroused little interest. The commonest behaviours were sniffing, licking, biting, pawing and toying. The tiger was the most persistent, while the South American bush dogs lost interest more quickly than the other species.

The study is the first to show that a single component can be just as attractive as the complex odour.

"How this has developed through evolution is an interesting question. Perhaps there is a common denominator for all mammalian blood," says Prof Laska.

He has plans for several follow-ups of the study, including how prey animals such as mice react to blood odour.

For the wildlife park, the study provided results that can be used in its daily operations. Animals in captivity require stimulation, so as not to deteriorate or become fat. The odourised logs can be a popular addition to the animal's environment.

Source: Linköping University

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Global consumption an increasingly significant driver of tropical deforestation

The EU and China are the largest importers of carbon dioxide emissions linked to deforestation for the production of beef, soy, palm oil and timber between 2000-2009. The researchers have focused on seven countries (Argentina, Bolivia, Brazil, Paraguay, Indonesia, Malaysia and Papua New Guinea), all of which are major exporters of goods that contribute to deforestation. Credit: Center for Global Development

International trade with agricultural and wood products is an increasingly important driver of tropical deforestation. More than a third of recent deforestation can be tied to production of beef, soy, palm oil and timber. "The trend is clear, the drivers of deforestation have been globalized and commercialized," says assistant professor Martin Persson, Chalmers University of Technology.

In a report commissioned by US think-tank Center for Global Development (CGD) Martin Persson and colleagues in Linköping, Sweden, and Vienna, Austria, have investigated to which extent international trade in agricultural and silvicultural products drives deforestation in seven case countries: Argentina, Bolivia, Brazil, Paraguay, Indonesia, Malaysia and Papua New Guinea.

"From having been caused mainly by smallholders and production for local markets, an increasing share of deforestation today is driven by large-scale agricultural production for international markets. More than a third of global deforestation can be tied to rising production of beef, soy, palm oil and wood products," says Martin Persson.

"If we exclude Brazilian beef production, which is mainly destined for domestic markets, more than half of deforestation in our case countries is driven by international demand."

The research group has also analyzed the magnitude of the associated carbon dioxide emissions embodied in these trade flows. In total 1.7 billion tons of carbon dioxide emissions can be linked to the production of the analyzed commodities, with one third being embodied in commodity exports. The biggest recipients of these embodied carbon emissions are China and the EU. By elucidating the links between consumption and environmental impacts, the aim is to identify more effective measures to address tropical forest loss by targeting key commodities and countries.

"Another key trend is that more and more corporations have pledged to rid their supply chains from deforestation. Pushed by environmental organizations and seeing the risks of being associated with environmental destruction, companies like Unilever and McDonalds are pressuring their suppliers to stop expanding production on forest land," says Martin Persson.

It is no longer enough to just focus on the countries where deforestation happens and the potential policy measures available there, he adds.

"Today both public and private consumers, be it individuals or corporations, have the possibility to contribute to the protection of tropical forests by holding suppliers accountable for the environmental impacts of their production," Martin Persson concludes.

Source: Chalmers University of Technology

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Camera trap images help wildlife managers ID problem tigers in India

Researchers with WCS and other partners in India are camera traps to ID individual tigers in conflict and relocate them out of harm's way for the benefit of both tigers and people. Credit: WCS

Researchers with the Wildlife Conservation Society and other partners in India are using high-tech solutions to zero in on individual tigers in conflict and relocate them out of harm's way for the benefit of both tigers and people.

In recent tiger-conflict cases involving both a human fatality and the predation of livestock, both occurring near two of India's national parks, WCS scientists helped to identify problem tigers using stripe pattern-matching software and additional information to make the connections. Both tigers have been captured and relocated to a nearby zoo.

Reducing human-wildlife conflict while promoting human welfare and conservation in important wildlife habitats is one of many topics under discussion of the World Parks Congress, a once-in-a-decade event focusing on the management and expansion of the world's protected area networks and the wildlife they contain. The congress, which took place in Sydney, Australia concluded today.

A new paper titled "Photographic Database Informs Management of Conflict Tigers" appears in the latest version of the journal Oryx. The authors are: Ullas Karanth, N. Samba Kumar, and Divya Vasudev of WCS's India Program.

"The vast majority of tigers generally avoid humans and focus only on natural prey species," said Dr. Ullas Karanth, WCS's Director for Science-Asia and lead author on the paper. 

"Using scientific methods to locate individuals involved in conflict with humans and livestock helps us to mitigate threats to people and prevent the capture of the wrong tigers, especially wherever tigers may venture beyond protected area borders."

While tigers struggle to survive in other landscapes across their range through Asia, the big cats in the Malenad Tiger Landscape of southwest India have thrived, becoming one of the largest tiger populations in the world with an estimated 400 animals.

Part of this conservation success has been due to a WCS research program focused on the identification of individual tigers. The system uses unique stripe patterns to identify and track individual animals, and software programs have greatly improved the speed and accuracy of the process. Since the initiation of the research protocol, more than 750 tigers have been identified from six protected areas in the Malanad Tiger Landscape in the Western Ghats across India. The system also enables researchers to keep track of other data such as home range locations, age and ex of individual animals, activity patterns. Over the longer term it even enables estimation of survival and recruitment rates and changes in numbers, all of which can be used to inform management decisions on wild tigers.

The tiger database has become a key factor in finding and capturing problem tigers. One of the recently captured animals was involved in the loss of human life near Bandipur National Park in late December of 2013. Scientists managed to get pictures of the animal from camera traps set up near the area of conflict and discovered a match with an animal photographed over a 5-year period and probably past its prime. Old tigers unable to catch natural prey animals can sometimes resort to hunting livestock, bringing them in conflict with people.

Another tiger, involved in the killing of cattle in a village next to Nagarahole National Park, was by contrast a 2-3 year old youngster some 35 kilometers from locations in which it was previously photographed. Scientists concluded this young tiger was likely searching for a territory, beyond protected areas.

Once ranging across Asia from Turkey to Indonesia, the tiger has been decimated by a combination of habitat destruction, overhunting of prey animal, poaching for the illegal trade and retaliatory killing by humans. The total wild population has been reduced in numbers from perhaps 100,000 at the turn of the 20th Century to a current estimate of fewer than 3,500 animals remaining in only 6 percent of the species' historic range.

Source: Wildlife Conservation Society

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'Probiotics' for plants boost detox abilities; untreated plants overdose and die

The Doty lab conducts work to see how plants treated with naturally occurring endophytes might handle soils contaminated with a variety of pollutants. Graduate student Robert Tournay, for example, is interested in how the plants handle arsenic. Credit: M Levin/U of Washington

Scientists using a microbe that occurs naturally in eastern cottonwood trees have boosted the ability of two other plants -- willow and lawn grass -- to withstand the withering effects of the nasty industrial pollutant phenanthrene and take up 25 to 40 percent more of the pollutant than untreated plants.

The approach could avoid the regulatory hurdles imposed on transgenic plants -- plants with genes inserted from or exchanged with other plant or animal species -- that have shown promise in phytoremediation, the process of using plants to remove toxins from contaminated sites, according to Sharon Doty, associate professor of environmental and forestry sciences and corresponding author on a paper about the new work in Environmental Science & Technology.

"Our approach is much like when humans take probiotic pills or eat yogurt with probiotics to supplement the 'good' microbes in their guts," she said.

The microbe from the cottonwood was encouraged to colonize the roots of willows simply by dipping rooted and trimmed cuttings in solutions with the microbe. Grasses were treated with microbes in solution as seeds sprouted in soil. Once integrated into the plants, the microbe supplemented their own microbial defenses.

Microbes that take up residence in the inner tissue of plants and don't cause negative symptoms are called endophytes. In nature, endophytes have a welcomed, symbiotic relationship with plants. In polluted soil, for instance, if the right endophytes are present they consume toxins coming up through plant roots. The endophytes get fed and the plant gets help neutralizing pollutants that could kill it.

That's been one challenge of phytoremediation: plants removing pollutants can, all too quickly, succumb to the toxins.

"When the endophyte in these experiments was given to willow and grasses, it reduced the phytotoxic effects of phenanthrene compared to the control plants that did not receive the endophyte and died," said lead author Zareen Khan, a UW research scientist in environmental and forest sciences.

Phenanthrene is carcinogenic, on the Environmental Protection Agency's priority pollutants list and belongs to a class of polycyclic aromatic hydrocarbons that get deposited into the environment via fossil fuel combustion, waste incineration or as byproducts of industrial processes. Soils that become contaminated can be capped with layers of uncontaminated soil or dug up and removed for cleaning at soil remediation facilities or storage at waste disposal facilities.

In their search, UW researchers tested six different endophytes from cottonwood and willow varieties and found one -- lab name PD1 -- from the eastern cottonwood to be superior at breaking down phenanthrene.

They introduced this endophyte into willow cuttings and lawn grass. Willows were chosen because some varieties have already proven adept at removing toxins and the shrubs have extensive root systems, take up a lot of water and grow rapidly. Lawn grass was included because it also grows fast and could be useful in parks and open-space areas.

In lab experiments, the willow cuttings with added endophyte protection continued to grow, kept their leaves and had denser root systems. Untreated plants wilted, lost leaves and their roots turned brown. When soils were analyzed, the treated willows took up 65 percent of the phenanthrene compared with untreated plants that removed 40 percent, an improvement of 25 percent.

Grass seed planted in contaminated soils and watered with solutions containing the PD1 endophyte germinated five days quicker, grew taller and had 100 more tillers, or new offshoots, after 13 days. Treated grass removed 50 percent of the phenanthrene from the soil, compared with untreated grass that removed 10 percent, an improvement of 40 percent.

In phytoremediation, plants that take up pollutants but don't degrade them have to be removed and treated as hazardous waste or otherwise disposed of safely. The willows treated in the UW experiment appear to have degraded some 90 percent of the phenanthrene to harmless components. The researchers said they'd like to determine if that promising finding holds up in mass-balance studies and want to examine the possible effects on bugs or animals that might bite the plants processing the toxins and other environmental considerations. Interestingly, other studies have shown that bugs can smell similar semi-volatile pollutants and avoid eating the plants containing them, Doty said.

The work was funded by a Small Business Innovation Research grant from the National Institute of Environmental Health Sciences and by funds provided through the Byron and Alice Lockwood Endowed Professorship that Doty holds. The other four co-authors on the paper were undergraduate volunteers: David Roman and Trent Kintz have since graduated while May delas Alas and Raymond Yap are still working on their bachelor's degrees.
Just down the road from UW is Seattle's Gas Works Park, a site Doty thinks is a prime candidate for the approach her lab reported. Contaminants in the soil, including phenanthrene, are from a now-dismantled gasification plant. Soils have been covered with uncontaminated soil.

"The idea of leaving a known carcinogen in a public place is not right," she said. "What about problems of erosion? We should do what we can to remove it. We spend so much money treating cancer, I'd like us to take steps to prevent it instead."

Source: University of Washington

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Lemurs: Gardeners of Madagascar rainforest at risk

Onja Razafindratsima, a graduate student at Rice University, observes a lemur in a Madagascar rainforest. Razafindratsima led a three-year study to explore the relationship between lemurs and trees. Lemurs eat the fruit and spread its seeds far from the parent tree to help ensure its survival. Credit: Photo courtesy of Onja Razafindratsima/Rice University

A majority of Madagascar's 101 species of lemurs are threatened with extinction, and that could have serious consequences for the rainforests they call home. A new study by Rice University researchers shows the positive impacts lemurs can have on rainforest tree populations, which raises concerns about the potential impact their disappearance could have on the region's rich biodiversity.

A large proportion of trees in Madagascar's rainforest have fruits eaten by lemurs. Lemurs in turn disperse the seeds of their fruit trees throughout the forest with their scat. Such dispersal can play a crucial role for a tree species' ability to regenerate, but effects are poorly understood, especially when there are multiple dispersers.

For the tree, the evolutionary advantage of having animal-dispersed seeds may be that the seeds land well away from their parent trees where survival is low or that seeds are directed into spots where they are the most likely to sprout and survive.

Amy Dunham, an assistant professor of biosciences, and graduate student Onja Razafindratsima set out to detail the symbiotic relationship between fruit-eating lemurs and the trees that feed them through a three-year study in a rainforest in southeastern Madagascar.

Their data from observations, experiments and mathematical models demonstrate that seeds of a common canopy tree have a 300 percent higher chance of sprouting and becoming a sapling when dispersed by lemurs versus simply falling to the ground. One of the three lemur species is particularly good at dropping seeds in spots that are most advantageous for sprouting and survival. Other lemurs are not so selective, but still benefit the tree by moving seeds away from the parent tree. By acting as forest gardeners, these animals give the tree's population a boost.

The study appeared online in the Ecological Society of America journal Ecology.

As part of the study, the researchers followed the seed-dispersal patterns of three of Madagascar's lemur species: the red-fronted brown lemur, the red-bellied lemur and the southern black-and-white ruffed lemur. That meant tracking and observing groups of lemurs as the animals leaped from tree to tree through the forest, dined in the 65-foot-high canopies and dropped their undigested seeds at ground level.

Razafindratsima led the study as part of a thesis project she expects to complete early next year. She built a team of local researchers near Ranomafana National Park, the home of Centre ValBio, a research station founded by Dunham's former Ph.D. adviser, primatologist Patricia Wright.

"We have a team of up to 10 local villagers who are trained to do research," said Razafindratsima, a native of Madagascar. "Their exceptional knowledge of the forest is very important to us when we're trying to track lemurs and identify seeds and seedlings in a forest with over 300 species of trees."

The research team tracked 24 groups of lemurs over a year without the benefit of radio collars, said Razafindratsima, who keeps in touch with her team via phone and Skype when she's at Rice. She said the study sites were as close as a short hike from Centre ValBio and as far as a two-day trek through steep terrain that entailed camping overnight.

In addition to tracking lemurs and their dispersed seeds, the research team spent three years carrying out experiments on seed sprouting and survival. They found that dispersal by lemurs dramatically increased the odds that seeds would take root and survive. In particular, the red-fronted brown lemurs tended to drop seeds away from their parent trees and in places where there were gaps in the canopy. This gave individual seeds the best shot at taking root.

Dunham said trees benefit from the wide dispersal of their seeds, and for some species in Madagascar, lemurs are the primary or only animal that can distribute those seeds. As the largest fruit-eaters in the system, these lemurs swallow seeds that may be too large for other fruit-eating animals, such as birds or bats.

"Seeds away from the parent tree survive better because there's less competition among seedlings," Razafindratsima said. "If they're close by the parent, they may also share the same natural enemies, like soil pathogens and seed predators, so there's higher mortality."

Trees that lose their dispersers will simply drop their seeds to the ground beneath their canopies, where chances of survival are slim, Dunham said. "Lemurs fill an important role as the gardeners for these trees. By ensuring that some seeds land in spots suitable for germination and survival, they increase the ability of these trees to replace themselves"

Dunham hopes the study will contribute to growing efforts to protect lemurs, and therefore the rainforest, which has been impacted in recent years by economic and political instability.

She noted grassroots efforts within Madagascar led to the first World Lemur Festival in late October to celebrate and protect the animals and their habitats in Madagascar.

"What got us interested is that frugivorous lemur populations are declining across the island, and we know very little about how these seed dispersers actually affect tree populations," she said. "Once we understand that better, maybe we'll have a better idea of how the community might change if the lemurs disappear.

"If some species suddenly lose their dispersers, but others dispersed by birds or the wind are doing fine, it may change population trajectories and alter which tree species are dominant in a community. To understand what happens when these species are lost, we need to understand their role in the ecosystem," she said.

Source: Rice University

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Live fast, die young: Soil microbes in a warmer world

Aerial view of the Northern Minnesota landscape including numerous conifer peatlands, deciduous uplands and lakes. Credit: USDA Forest Service Northern Research Station

Warmer temperatures shorten the lifespan of soil microbes and this may affect soil carbon storage, according to a new NSF-funded study published in Nature Climate Change this week.

A research team led by Shannon Hagerty and Paul Dijkstra from Northern Arizona University measured two key characteristics of soil microbes that determine their role in the soil carbon cycle: how efficiently they use carbon to grow and how long they live. "Higher temperatures make microbes grow faster, but they also die faster," said Hagerty, who conducted the research as part of her master's degree and was lead author on the study.

Soil microbes consume organic carbon compounds in soil, use some of it to make more microbes and release the rest to the atmosphere as carbon dioxide. The efficiency with which microbes use their food to make new microbes affects how much carbon remains in soil, and how much is released back to the atmosphere. The accepted idea before this study was that microbes would become less efficient at warmer temperatures.

The scientists incubated soil from a peatland and a forest in Minnesota at different temperatures and measured the efficiency with which microbes grew. They used a new method to measure microbial efficiency: they added small amounts of sugar and tracked how individual atoms in this sugar were turned into carbon dioxide.

"Microbes process sugars in similar ways as we do," says Paul Dijkstra. "We know very well how these processes work in laboratory studies, and can predict which carbon atoms in sugar molecules end up as carbon dioxide, and which are used to build new microbes. We applied this knowledge to the microbes living in soil."

The researchers found, contrary to expectation, that temperature had no effect on how microbes utilized their food, but instead boosted microbial death. "We don't yet know why microbes are dying faster at higher temperatures. Maybe they are eaten by nematodes or mites, or they die because of viruses," said Hagerty. "We need to know more about how temperature affects microbial death."

To explore what these new findings could mean for soil carbon storage in a warming world, the team compared output from a soil model that includes the effect of temperature on microbial lifespan to models unaffected by temperature change. "Models are used to predict how soil processes change, for example, in response to climate change," said Steve Allison, coauthor from the University of California, Irvine. "If we want to predict the future correctly, we'd better use models that accurately describe these microbial processes."

Including a temperature-dependent lifespan to the model increased the amount of carbon retained in soils at warmer temperatures compared to estimates from traditional models. The study concludes that incorporating this new insight into soil models will improve our understanding of how soils influence atmospheric carbon dioxide levels and global climate.

Does this mean that with climate change, more carbon will stay in the soil? "Too early to tell," said Bruce Hungate, Director of the Center for Ecosystem Science and Society at NAU. 

"The results suggest that the biochemistry of the microbes remains the same with warmer temperature, but that predation and death become more important. This laboratory study is just the first step, identifying a potential mechanism. Now we need to study how, in the real world, and in the long-term, the processes of biochemical efficiency and lifespan will change. And nobody has done that yet."

Source: Northern Arizona University

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Kudzu can release soil carbon, accelerate global warming

This layer of decomposing knotweed will eventually form soil organic matter in invaded ecosystems.
 Credit: Image courtesy of Clemson University

Clemson University scientists are shedding new light on how invasion by exotic plant species affects the ability of soil to store greenhouse gases. The research could have far-reaching implications for how we manage agricultural land and native ecosystems.

In a paper published in the scientific journal New Phytologist, plant ecologist Nishanth Tharayil and graduate student Mioko Tamura show that invasive plants can accelerate the greenhouse effect by releasing carbon stored in soil into the atmosphere.
Since soil stores more carbon than both the atmosphere and terrestrial vegetation combined, the repercussions for how we manage agricultural land and ecosystems to facilitate the storage of carbon could be dramatic.

In their study, Tamura and Tharayil examined the impact of encroachment of Japanese knotweed and kudzu, two of North America's most widespread invasive plants, on the soil carbon storage in native ecosystems.

They found that kudzu invasion released carbon that was stored in native soils, while the carbon amassed in soils invaded by knotweed is more prone to oxidation and is subsequently lost to the atmosphere.

The key seems to be how plant litter chemistry regulates the soil biological activity that facilitates the buildup, composition and stability of carbon-trapping organic matter in soil.

"Our findings highlight the capacity of invasive plants to effect climate change by destabilizing the carbon pool in soil and shows that invasive plants can have profound influence on our understanding to manage land in a way that mitigates carbon emissions," Tharayil said.

Tharayil estimates that kudzu invasion results in the release of 4.8 metric tons of carbon annually, equal to the amount of carbon stored in 11.8 million acres of U.S. forest.
This is the same amount of carbon emitted annually by consuming 540 million gallons of gasoline or burning 5.1 billion pounds of coal.

"Climate change is causing massive range expansion of many exotic and invasive plant species. As the climate warms, kudzu will continue to invade northern ecosystems, and its impact on carbon emissions will grow," Tharayil said.

The findings provide particular insight into agricultural land-management strategies and suggest that it is the chemistry of plant biomass added to soil rather than the total amount of biomass that has the greatest influence on the ability of soil to harbor stable carbon.

"Our study indicates that incorporating legumes such as beans, peas, soybeans, peanuts and lentils that have a higher proportion of nitrogen in its biomass can accelerate the storage of carbon in soils," Tharayil said.

Thrarayil's lab is following up this research to gain a deeper understanding of soil carbon storage and invasion.

Tharayil leads a laboratory and research team at Clemson that studies how the chemical and biological interactions that take place in the plant-soil interface shape plant communities. He is also the director of Clemson's Multi-User Analytical Laboratory, which provides researchers with access to highly specialized laboratory instruments.

Source: Clemson University

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Tree diseases can help forests

A healthy seedling of the tree Castilla elastica is on the left, while a dying seedling, attacked by a plant pathogen, is on the right. A study in the Journal of Ecology by University of Utah biologists shows that such tree diseases, while killing individual seedlings, can increase forest biodiversity. Credit: Erin Spear, University of Utah.

Plant diseases attack trees and crops and can hurt lumber and food production, but University of Utah biologists found that pathogens that kill tree seedlings actually can make forests more diverse.

While low rainfall has been blamed for a lack of drought-sensitive trees near the Pacific side of the Panama Canal, the new study answers a mystery about what keeps drought-tolerant trees from that area from living along the wetter Caribbean side of the canal. The answer: disease-causing plant pathogens, the researchers report in their study, published online Wednesday, Nov. 12 by the Journal of Ecology.

"Because seedlings of disease-sensitive tree species can't survive in the wetter forests and drought-sensitive tree species cannot survive in the drier forests, different tree species inhabit the wetter and drier forests even though they are only 30 miles apart" in Panama, says Phyllis Coley, a senior author of the study and a distinguished professor of biology.
In other words, tree pathogens contribute to the staggering diversity of trees in Panama's tropical forests, she adds.

The study's first author, biology doctoral student Erin Spear, says that is important because "conservation planning and predictions about how tree species distributions may shift with climate change require an understanding of the factors currently influencing where species can and cannot survive."

That is particularly important in tropical forests and other forests that are under elevated threat of deforestation.

Funding for the study came from Sigma Xi -- The Scientific Research Society, the Smithsonian Institution and the National Science Foundation.

Of Forests and Pathogens

Tropical forests are threatened, and dry tropical forests are even more threatened because sunnier, drier climates are better for growing crops and are favored by people. Some 90 percent of Panama's residents live on the nation's drier Pacific slope.

Forests are essential for feeding and sheltering animals, providing important medicines, storing carbon and water, and reducing erosion by holding soil in place. These functions are influenced by different species inhabiting a forest, so it is essential to understand why certain tree species can survive in certain areas but not others.

Panama's forests also are important economically because tree roots limit how much soil erodes into the Panama Canal, ensuring that huge container ships can pass. Researchers also believe the forests help maintain water levels in the canal because forest soil stores water, slowly releasing it into streams feeding the canal during the dry season.

Diversity is high in tropical forests. A 930-square-mile area bordering the Panama Canal has more than 800 tree species. By comparison, about half the state of Rhode Island -- or some 610 square miles -- is forested, and that area has only 51 tree species.

Part of the reason Panama's forests have more species is because the Pacific end of the canal receives less annual rainfall -- about 5.9 feet -- than the Caribbean end, where 9.8 feet of rain falls annually.

"While there is considerable evidence that less rain in the drier, Pacific forests means that drought-sensitive tree species can't survive there, it has been unclear what prevents the drought-tolerant species of the drier forests from living in the wetter forests," says University of Utah biology professor Tom Kursar, the study's other senior author. "Our study tackled that unanswered question."

So Spear braved mud, rain, insects and snakes to monitor seedlings of a variety of tree species in the wetter and drier forests of central Panama for pathogen-caused damage and death. Plant pathogens that make plants sick include bacteria, viruses and fungi.

Spear says the researchers' findings suggest that "all seedlings are at a greater risk of being injured and killed by pathogens in the wetter forests than in the drier forests." This could be because the damp environment of the wetter forests helps pathogens survive, and more rainfall helps pathogens move from one seedling to another.

But that's only half the story. Coley says that their study indicates "pathogens are implicated in the absence of the dry-forest tree species from the wetter forests, where they might otherwise be able to live. That is because dry-forest tree species are more likely to die from pathogen attack than wet-forest species."

Diagnosing Sick Seedlings

Spear collected the seeds for the study by hiking for miles, kayaking in the canal to collect fruit from overhanging branches, and even riding a crane-carried gondola more than 100 feet upward into the forest canopy.

She conducted the study at two forest sites in central Panama: one at the large Metropolitan Natural Park in Panama City on the drier Pacific side, and one on private property in the Santa Rita Ridge area on the wetter Caribbean side. She planted "gardens" of tree seeds -- including species typical of wetter and drier forests -- in 30 locations at each site. More than 1,000 seeds were planted; 725 of them sprouted.

Once the seeds were planted, the researchers covered them with wire mesh to protect the seeds and seedlings from being crushed by tree branches or eaten by animals.

Spear visited both sites weekly and took notes on the 725 seedlings. Weekly visits were essential because, diseased seedlings can be dead and decomposing within days.

"We monitored when the seeds germinated, the occurrence of and date when symptoms of pathogen attack were observed, if and when a seedling died, and we ascribed a cause of death," Spear says. Pathogen symptoms included patches of black, dead tissue in the leaves or stem. "In some cases, we could actually see the pathogen growing on the seedling," she says.

Of the 725 seedlings that germinated, 38 percent suffered pathogen-caused damage, including 11 percent of seedlings killed by pathogens.

Compared with seedlings in the drier forest, seedlings in the wetter forest were 74 percent more likely to suffer pathogen-caused damage and 65 percent more likely to be killed by pathogens.

"But what was really striking was that pathogen-caused damage was five times more likely to be lethal for seedlings of dry-forest species than for wet-forest species," suggesting dry- and wet-forest species differ in their ability to halt or slow infection, Spear says.

The researchers next plan to identify specific fungi, bacteria and other pathogens and whether they differ in wetter and drier forests.

During her study at the drier park site in Panama City, Spear discussed her research with tourists and other park visitors.

"I'd emerge from the tangles of vines sweaty, muddy and generally disheveled and people couldn't help but ask what I was doing," Spear recalls. "It was heartening to hear how the forest had touched these very different people."

A brief time-lapse video of a seedling dying from pathogen attack during a period of several days can be seen at: http://vimeo.com/58026978 Video by Erin Spear, University of Utah.


Source: University of Utah

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