nsf.gov - National Science Foundation - Fruits of the forest gone: Overhunting of large animals has catastrophic effects on trees.- Frutos del bosque ido: Durante caza de animales grandes tienen efectos catastróficos sobre los árboles

Hola amigos: A VUELO DE UN QUINDE EL BLOG., hemos recibido información de la Fundación Nacional de Ciencias de Los Estados Unidos, que no dice que la caza sin piedad de los grandes animales del bosque  han tenido efectos catastróficos, como por ejemplo tenemos: "El elefante ha sido durante mucho tiempo un símbolo espiritual, cultural y nacional importante en Tailandia. A principios del siglo 20, sus números superaron 100.000........
Hoy en día, esos números han caído a 2.000. Los elefantes, así como otros animales grandes, carismáticos, como los tigres, monos y gatos de algalia, están bajo el ataque de los cazadores y los cazadores furtivos..........

 

Mientras que la pérdida de estos animales es preocupante para la conservación de especies, ahora los investigadores de la Universidad de Florida han demostrado que la caza excesiva puede tener efectos generalizados en el bosque mismo.

Caza excesiva conduce a la extinción de una especie arbórea dominante, Miliusa horsfieldii, o el haya Miliusa, con efectos en cascada sobre la probable otra biota del bosque.

Los científicos informan de sus resultados en la edición actual de la revista Proceedings de la Royal Society B....................

As the animals go, so go tropical forests

The cherry-sized fruits of a tree species in Thailand are eaten by large animals, including bears. Credit and Larger Versión

November 12, 2014

The elephant has long been an important spiritual, cultural and national symbol in Thailand. At the beginning of the 20th century, its numbers exceeded 100,000.

Today, those numbers have plunged to 2,000. Elephants, as well as other large, charismatic animals such as tigers, monkeys and civet cats, are under attack from hunters and poachers.

 

Overhunting of animals affects entire forest

 

While the loss of these animals is concerning for species conservation, now researchers at the University of Florida have shown that overhunting can have widespread effects on the forest itself.

Overhunting leads to the extinction of a dominant tree species, Miliusa horsfieldii, or the Miliusa beech, with likely cascading effects on other forest biota.

The scientists report their results in the current issue of the journal Proceedings of the Royal Society B.

Co-authors of the paper are Trevor Caughlin and Jeremy Lichstein of the University of Florida and Doug Levey, formerly of the University of Florida and now a program director in the National Science Foundation's Division of Environmental Biology.

Other co-authors are researchers at King Mongkut's University of Technology Thonburi in Thailand, Wageningen University in the Netherlands and the Royal Thai Forest Department.

 

Loss of one tree species has far-reaching implications

 

The ecologists show how vital large animals are to maintaining the biodiversity of tropical forests in Thailand.

The team looked at how these mammals contribute to moving seeds through the forest.

"It's not surprising that seed dispersers help trees get to new places," says Levey. "The effects of hunting can extend far beyond the hunted, threatening the overall health of the trees that make up the forest."

Adds Caughlin, "On the surface, it doesn't seem that seed dispersal would be important for tree populations. But seed dispersal has an effect over the whole life of a tree."

 

Animals critical to seed transport through the forest

 

The scientists looked at the growth and survival of trees that sprouted from parent trees and grew up in crowded environs, compared to trees from seeds that were widely transported across the forest by animals.

The information was supplemented with a dataset from the Thai Royal Forest Department that contains more than 15 years of data on trees.

The researchers then created a long-term simulation and ran it on the University of Florida's supercomputer, the HiPerGator.

"Having that computing power was very important," says Caughlin, "because we had to simulate the fate of millions of seeds."

The scientists discovered that trees that grow from seeds transported by now-overhunted animals are hardier and healthier.

"Our study is the first to quantify the decades-long effects of animal seed dispersal across the entire tree life cycle, from seeds to seedlings to adult trees," says Lichstein.

 

Probability of tree extinction increased tenfold

 

The results show that loss of animal seed-dispersers increases the probability of tree extinction by more than tenfold over a 100-year period.

"The entire ecosystem is at risk," says Caughlin.

"We hope the study will provide a boost for those trying to curb overhunting," he says, "and provide incentives to stop the wildlife trade."

--	Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
--	Gigi Marino, University of Florida (352) 294-3393 gigimarino@ufl.edu

Related WebsitesNSF Discovery: Seed dispersal study shows value of conservation corridors: http://www.nsf.gov/news/news_summ.jsp?cntn_id=130515
NSF Discovery: Seeing the Forest for the Trees: Seed Dispersal, Environmental Conditions Matter in African Forests:
 http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=127949&org=NSF
NSF Discovery: Landscape Corridors Provide Pathway for Seed Dispersal: http://www.nsf.gov/news/news_summ.jsp?cntn_id=104277
NSF Discovery: Border crossing: 10 things to know about invasive fire ants on the march: http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=132165&org=NSF
NSF Award: Spatial Ecology and Evolution: Quantitative Training in Biology, Statistics, and Mathematics:
 http://www.nsf.gov/awardsearch/showAward?AWD_ID=0801544&HistoricalAwards=false

An Asian black bear photographed by a camera-trap; the overhunted bears disperse tree seeds.
Credit and Larger Version

A full-grown adult Thai forest study tree; the trees are threatened by overhunting of animals.
Credit and Larger Version

Researcher surveying the tropical forest at the Huai Kha Khaeng Wildlife Sanctuary in Thailand.
Credit and Larger Version

Thousands of seedlings were tagged to learn how trees and seed-disperser animals interact.
Credit and Larger Version

One of countless tree seedlings growing in the understory of the Thai tropical forest.
Credit and Larger Versión
The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@yahoo.com
ayabaca@hotmail.com
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nsf.gov - NATIONAL SCIENCE FOUNDATION - Earth Week: Bark beetles change Rocky Mountain stream flows, affect water quality

 

What happens when millions of dead trees, killed by beetles, no longer need water? Gray trees killed by bark beetles pepper the landscape in Rocky Mountain National Park. Credit and Larger Version April 21, 2014 The following is part fourteen in a series on the National Science Foundation's Science, Engineering and Education for Sustainability (SEES) investment. Parts one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve and thirteen in this series are available on the NSF website. On Earth Week--and in fact, every week now--trees in mountains across the western United States are dying, thanks to an infestation of bark beetles that reproduce in the trees' inner bark. Some species of the beetles, such as the mountain pine beetle, attack and kill live trees. Others live in dead, weakened or dying hosts. In Colorado alone, the mountain pine beetle has caused the deaths of more than 3.4 million acres of pine trees. What effect do all these dead trees have on stream flow and water quality? Plenty, according to new research findings reported this week.   Dead trees don't drink water "The unprecedented tree deaths caused by these beetles provided a new approach to estimating the interaction of trees with the water cycle in mountain headwaters like those of the Colorado and Platte Rivers," says hydrologist Reed Maxwell of the Colorado School of Mines. Maxwell and colleagues have published results of their study of beetle effects on stream flows in this week's issue of the journal Nature Climate Change. As the trees die, they stop taking up water from the soil, known as transpiration. Transpiration is the process of water movement through a plant and its evaporation from leaves, stems and flowers. The "unused" water then becomes part of the local groundwater and leads to increased water flows in nearby streams. The research is funded by the National Science Foundation's (NSF) Water, Sustainability and Climate (WSC) Program. WSC is part of NSF's Science, Engineering and Education for Sustainability initiative. "Large-scale tree death due to pine beetles has many negative effects," says Tom Torgersen of NSF's Directorate for Geosciences and lead WSC program director. "This loss of trees increases groundwater flow and water availability, seemingly a positive," Torgersen says. "The total effect, however, of the extensive tree death and increased water flow has to be evaluated for how much of an increase, when does such an increase occur, and what's the water quality of the resulting flow?" The answers aren't always good ones.   Green means go, red means stop, even for trees Under normal circumstances, green trees use shallow groundwater in late summer for transpiration. Red- and gray-phase trees--those affected by beetle infestations--stop transpiring, leading to higher water tables and greater water availability for groundwater flow to streams. The new results show that the fraction of late-summer groundwater flows from affected watersheds is about 30 percent higher after beetles have infested an area, compared with watersheds with less severe beetle attacks. "Water budget analysis confirms that transpiration loss resulting from beetle kill can account for the increase in groundwater contributions to streams," write Maxwell and scientists Lindsay Bearup and John McCray of the Colorado School of Mines, and David Clow of the U.S. Geological Survey, in their paper.   Dead trees create changes in water quality "Using 'fingerprints' of different water sources, defined by the sources' water chemistry, we found that a higher fraction of late-summer streamflow in affected watersheds comes from groundwater rather than surface flows," says Bearup. "Increases in stream flow and groundwater levels are very hard to detect because of fluctuations from changes in climate and in topography. Our approach using water chemistry allows us to 'dissect' the water in streams and better understand its source." With millions of dead trees, adds Maxwell, "we asked: What's the potential effect if the trees stop using water? Our findings not only identify this change, but quantify how much water trees use." An important implication of the research, Bearup says, is that the change can alter water quality. The new results, she says, help explain earlier work by Colorado School of Mines scientists. "That research found an unexpected spike in carcinogenic disinfection by-products in late summer in water treatment plants." Where were those water treatment plants located? In bark beetle-infested watersheds. -- Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov Investigators Reed Maxwell Eric Dickenson Jonathan Sharp Alexis Navarre-Sitchler Related Institutions/Organizations Colorado School of Mines Related Awards#1204787 WSC-CATEGORY 2 COLLABORATIVE: WATER QUALITY AND SUPPLY IMPACTS FROM CLIMATE-INDUCED INSECT TREE MORTALITY AND RESOURCE MANAGEMENT IN THE ROCKY MOUNTAIN WEST Total Grants $2,307,644 Related WebsitesNSF Awards Grants for Study of Water Sustainability and Climate:  http://www.nsf.gov/news/news_summ.jsp?cntn_id=117819 How Is Earth's Water System Linked With Land Use, Climate Change and Ecosystems?:  http://www.nsf.gov/news/news_summ.jsp?cntn_id=125434 NSF Discoveries in Sustainability:  http://www.nsf.gov/pubs/2012/disco12001/disco12001.pdf Ghosts of Forests Past: Bark Beetles Kill Lodgepole Pines, Affecting Entire Watersheds:  http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=128398 Trees go from green and healthy, to red and dying, and finally to gray and dead, from bark beetles. Credit and Larger Version Precipitation samples were collected to determine their unique chemical fingerprints. Credit and Larger Version Snow processes change as beetles kill lodgepole pines and trees no longer shade snowbanks. Credit and Larger Version Water samples were taken from the Big Thompson River in Rocky Mountain National Park. Credit and Larger Version Lodgepole pines are beginning to regrow in areas where trees had once been beetle-killed. Credit and Larger Version

 

 the National Science Foundation(NSF)

Guillermo Gonzalo Sánchez Achutegui

ayabaca@gmail.com

ayabaca@hotmail.com

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nsf.gov - News - Whitebark Pine Trees: Is Their Future at Risk?

Widespread tree death from beetle infestations, tree disease outbreaks affecting seed production.-

 
Ecologist Josh Rapp climbs a whitebark pine to sample cone-bearing branches.
Credit: Dash Donnelly
Download the high-resolution JPG version of the image. (693 KB)
 
Whitebark pine trees killed by mountain pine beetle (foreground and on mountain).
Credit: Josh Rapp
Download the high-resolution JPG version of the image. (394 KB)
 
Current range of the whitebark pine tree: Will it soon be much smaller?
Credit: Wikimedia Commons
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Clark's Nutcrackers are the main carriers of whitebark pine seeds to new areas.
Credit: Clarisse Hart
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Whitebark pine seed cones are found in clusters of two-to-four cones at ends of branches.
Credit: Josh Rapp
Download the high-resolution JPG version of the image. (434 KB)
 
 
Grizzlies: likelier to come into conflict with humans when whitebark pine cone crops fail.
Credit: Josh Rapp
Download the high-resolution JPG version of the image. (412 KB)

There's trouble ahead for the whitebark pine, a mountain tree that's integral to wildlife and water resources in the western United States and Canada.

Over the last decade, some populations of whitebark pines have declined by more than 90 percent. But these declines may be just the beginning.

New research results, supported by the National Science Foundation (NSF) and published today in the Journal of Ecology, suggest that as pine stands are increasingly fragmented by widespread tree death, surviving trees may be hindered in their ability to produce their usually abundant seeds.

"With fewer seeds, you get less regeneration," says ecologist Joshua Rapp, affiliated with NSF's Harvard Forest Long-Term Ecological Research (LTER) site and lead author of the paper.

Whitebark pine populations vary between producing a high number of seed cones some years, and a low number of seed cones other years.

This variation depends on four factors: male pollen cones, female seed cones, wind and proximity.

Each year, pollen from male cones is carried on the air to fertilize female seed cones perched atop nearby trees.

"In low-cone years, less pollen is released, reaching extremely few female cones," says Elizabeth Crone, senior ecologist at the NSF Harvard Forest LTER site and co-author of the paper.

"But as more and more whitebark pines die, every year becomes a low-cone year."

In isolated pockets of trees, the gene pool is also diminished, meaning the seeds produced may be less viable over time.

"For decades, researchers have struggled to understand why many different organisms--trees, fish, corals, insects--from various habitats reproduce synchronously and at certain intervals," says Saran Twombly, program director in NSF's Division of Environmental Biology, which funded the research.

"By combining field data on seed and pollen production for whitebark pines with models that simulate mature cone production, this study helps to answer that question for these pines."

To reach their conclusions, the scientists had to look back in time.

They inspected branches from seven whitebark pine sites in western Montana, counting the scars left by pollen cones and seed cones.

"All the years with a high number of seed cones had one thing in common: a high number of pollen cones," says Rapp. "The success of the seeds seems to depend on the amount of pollen produced."

Whitebark pine seeds are an essential food source for many animals in mountain habitats.

The Clark's Nutcracker, a mountain bird, can store up to 100,000 seeds in underground caches each year. Squirrels also store thousands of seeds underground.

A diminished number of seed cones has an effect on grizzly bears, the scientists say; the bears regularly raid squirrel seed caches to prepare for winter hibernation.

"In the past, low years for whitebark pine cones have led to six times more conflicts between grizzlies and humans, as hungry bears look for food in campgrounds," says Crone.

"Now, concerns about viability of whitebark pine populations are one of the main reasons grizzly bears in Yellowstone National Park are still listed as threatened under the Endangered Species Act."

Birds, squirrels and bears are not the only species that depend on whitebark pine.

Vast stands of whitebark pine help to maintain the mountain snowpacks that provide water to more than 30 million people in 16 U.S. states each year.

Whitebark pines are often the only trees at the highest elevations. Their branches retain snow as it blows across gusty mountaintops. Their shade moderates snow-melt in the spring, keeping flows down the mountain in check.

A small percentage of whitebark pine trees have outlived the ongoing destruction by pests and disease. These trees are the next area of focus for Crone's team.

"We want to find out whether the surviving trees are still producing cones," Crone says. "They represent the future of whitebark pines."

-NSF-

Media Contacts Cheryl Dybas, NSF (703) 292-7734

 cdybas@nsf.gov
Clarisse Hart, NSF Harvard Forest LTER Site (978) 756-6157

 hart3@fas.harvard.edu

Related WebsitesNSF Long-Term Ecological Research (LTER) Network: 

http://www.lternet.edu
NSF Harvard Forest LTER Site:

 http://harvardforest.fas.harvard.edu/research/LTER
NSF Publication: Discoveries in Long-Term Ecological Research:

 http://www.nsf.gov/pubs/2013/nsf13083/nsf13083.pdf?WT.mc_id=USNSF_25&WT.mc_ev=click
NSF Publication: Discoveries in Sustainability:

 http://www.nsf.gov/pubs/2012/disco12001/disco12001.pdf

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget was $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.

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 The National Science Foundation (NSF).

Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
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