Posts tagged forest
CU study: Some primates sleep in caves for safety
Dec 4th
The ring-tailed lemurs may be opting to sleep in caves for several reasons, said University of Colorado Boulder anthropology Associate Professor Michelle Sauther, who led the study. While the cave-sleeping behavior is likely important because it provides safety from potential predators, it also can provide the primates with access to water and nutrients, help to regulate their body temperatures during cold or hot weather and provide refuge from encroaching human activities like deforestation, she said.
“The remarkable thing about our study was that over a six-year period, the same troops of ring-tailed lemurs used the same sleeping caves on a regular, daily basis,” she said. “What we are seeing is a consistent, habitual use of caves as sleeping sites by these primates, a wonderful behavioral adaptation we had not known about before.”
A paper on the subject appeared in the November issue of the journal Madagascar Conservation and Development. Funding for the project came from Primate Conservation Inc., the International Primate Society, the American Society of Primatologists, the National Geographic Society, CU-Boulder, the University of North Dakota, Colorado College and the National Science Foundation.
Although sleeping in caves by ring-tailed lemurs — which are found only in Madagascar — has likely been going on for millennia, it is only now being recognized as a regular behavior, said Sauther. The endangered Fusui langurs, slender, long-tailed Asian monkeys roughly 2 feet tall, also have been documented sleeping in caves but as a direct result of extreme deforestation, moving from cave to cave every few days. There also have been isolated reports of South African baboons sleeping in caves.
Ring-tailed lemurs are easily identified by their characteristic, black and white ringed tails, which can be twice as long as their bodies. They weigh roughly 5 pounds with a head-body length of up to 18 inches and are highly social, congregating in groups of up to 30 individuals. Sporting fox-like snouts and slender frames, they are unusual among lemurs, spending a considerable amount of time on the ground feeding on leaves and fruit and socializing, said Sauther.
In “gallery forests” near rivers, ring-tailed lemurs regularly sleep high in the canopies of tall trees. But in “spiny forests,” most of the trees with woody stems are covered in rows of spines, making them uncomfortable as well as dangerous sleeping sites because predators can easily climb them, Sauther said. The new study documents their cave sleeping behavior in the dry spiny forest habitat adjacent to limestone cliffs.
The lemur observations were made at the 104,000-acre Tsimanampesotse National Park and the Tsinjoriake Protected Area in southwestern Madagascar between 2006 and this year. The research team used field observations and motion-detector camera traps to chart the behavior and movements of 11 different troops of ring-tailed lemurs.
One of the early clues to the cave sleeping by the lemurs was their presence on limestone cliffs adjacent to spiny forest trees or on the ground when Sauther’s research team arrived at the study sites early in the morning. “They seemed to come out of nowhere, and it was not from the trees,” she said. “We were baffled. But when we began arriving at the study sites earlier and earlier in the mornings, we observed them climbing out of the limestone caves.”
The primary predator of the lemurs is a cat-like, carnivorous mammal called a fossa native only to Madagascar that is closely related to the mongoose and may weigh up to 20 pounds. Fossil evidence shows a cougar-sized relative of the fossa that only became extinct several thousand years ago likely preyed on lemurs as well, she said.
There is evidence that some early ancestors of humans in South Africa may have used caves to protect themselves from predators, said Sauther. The remains of hominids going back several million years have been found inside or near limestone caves there, and some fossil bones have evidence of damage consistent with the bite of saber-toothed cats.
“We think cave-sleeping is something ring-tailed lemurs have been doing for a long time,” she said. “The behavior may be characteristic of a deep primate heritage that goes back millions of years.”
Co-authors of the new study included Associate Professor Frank Cuozzo of the University of North Dakota, Ibrahim Antho Youssouf Jacky, Lova Ravelohasindrazana and Jean Ravoavy of the University of Toliara in Madagascar, Krista Fish of Colorado College in Colorado Springs, Colo., and Marni LaFleur of the University of Veterinary Medicine in Vienna. Fish and LaFleur are former CU-Boulder students of Sauther.
Sauther co-directs the Beza Mahafalay Lemur Biology Project in southwestern Madagascar with Cuozzo, a former CU-Boulder doctoral student. Centered at the roughly 1,500-acre Beza Mahafalay Special Reserve, the research focuses on how climate- and human-induced change affects lemur biology, behavior and survival.
Sauther and her team were aided by field observations made by students and faculty from the University of Toliara in Madagascar. In addition, undergraduate and graduate students from CU-Boulder regularly travel to Madagascar to conduct research under Sauther, including students from CU’s Undergraduate Research Opportunities Program, which provides hands-on research and fosters student-faculty relationships.
“I never thought I would have a chance as a CU undergraduate to conduct research in an exotic place like Madagascar,” said former UROP student Anthony Massaro, who was part of a team that trapped ring-tailed lemurs, measured their physical characteristics including dentition, and released them back into the wild. “Dr. Sauther and Dr. Cuozzo mentored and guided me through the process of creating and conducting a unique research project.”
Unfortunately, habitat destruction, including deforestation, is increasing in many parts of Madagascar. In southwestern Madagascar, trees are being harvested for cattle forage, construction materials and firewood, and the mining of limestone there — used for the production of cement, fertilizer and other products — is increasing. Ring-tailed lemurs are now listed as an endangered species by the International Union for the Conservation of Nature’s Species Survival Commission.
Sauther has been conducting research on Madagascar for 25 years, beginning as a University of Washington graduate student. Today she has several CU-Boulder doctoral students working with her, including James Millette, who is studying how the tooth wear of lemurs relates to their foraging behaviors.
“Madagascar is a challenging place to conduct research,” Millette said. “Part of our job is to work with local communities, because without the support of these people there would be no lemur conservation. We consider Beza, where we have been working with the community for several decades, to be a real success story.”
A video of ring-tailed lemurs climbing into a cave is available at https://www.youtube.com/watch?v=vjWF3_SmYS0&feature=youtu.be.
-CU-
CU study: Spruce beetle infestation in N. Colo. tied to drought
Oct 10th
The new study is important because it shows that drought is a better predictor of spruce beetle outbreaks in northern Colorado than temperature alone, said lead study author Sarah Hart, a CU-Boulder doctoral student in geography. Drought conditions appear to decrease host tree defenses against spruce beetles, which attack the inner layers of bark, feeding and breeding in the phloem, a soft inner bark tissue, which impedes tree growth and eventually kills vast swaths of forest.
Spruce beetles, like their close relatives, mountain pine beetles, are attacking large areas of coniferous forests across the West. While the mountain pine beetle outbreak in the Southern Rocky Mountains is the best known and appears to be the worst in the historical record, the lesser known spruce beetle infestation has the potential to be equally or even more devastating in Colorado, said Hart, lead author on the new study.
“It was interesting that drought was a better predictor for spruce beetle outbreaks than temperature,” said Hart of the geography department. “The study suggests that spruce beetle outbreaks occur when warm and dry conditions cause stress in the host trees.”
A paper on the subject was published online in the journal Ecology. Co-authors include CU-Boulder geography Professor Thomas Veblen; former CU-Boulder graduate student Karen Eisenhart, now at Edinboro University of Pennsylvania; and former CU-Boulder students Daniel Jarvis and Dominik Kulakowski, now at Clark University in Worcester, Mass. The National Science Foundation and the National Geographic Society funded the study.
The new study also puts to rest false claims that fire suppression in the West is the trigger for spruce beetle outbreaks, said Veblen.
Spruce beetles range from Alaska to Arizona and live in forests of Engelmann spruce and subalpine fir trees in Colorado. The CU-Boulder study area included sites in the White River, Routt, Arapaho, Roosevelt and Grand Mesa national forests as well as in Rocky Mountain National Park.
The CU-Boulder team assembled a long-term record of spruce beetle outbreaks from the northern Front Range to the Grand Mesa in western Colorado using a combination of historical documents and tree ring data from 1650 to 2011. Broad-scale outbreaks were charted by the team from 1843-1860, 1882-1889, 1931-1957 and 2004 to 2010.
The researchers used a variety of statistical methods to tease out causes for variations in the dataset at 18 sites in Colorado. “The extent to which we could distinguish between the warming signals and the drought signals was surprising,” said Veblen. “These are two things that easily can get mixed together in most tree ring analyses.”
There are several lines of evidence that drought is the main driver of the spruce beetle outbreak. The new study showed when northwest Colorado was in a warm, wet climate period from 1976 to 1998, for example, both spruce beetle reproduction and tree defenses like “pitching” beetles out of tree interiors with resin were likely high. But during that period of warming, outbreak was minimal.
The strongest climate correlation to spruce beetle outbreaks was above average annual values for the Atlantic Multi-decadal Oscillation, or AMO, a long-term phenomenon that changes sea-surface temperatures in the North Atlantic. Believed to shift from cool to warm phases roughly every 60 years, positive AMO conditions are linked to warmer and drier conditions over much of North America, including the West.
Veblen said the AMO shifted from its cool to warm phase in the 1990s, meaning the climate phenomenon could be contributing to drought conditions in the West into the middle of this century. A 2006 tree-ring study involving Veblen, his former student, Thomas Kitzberger and researchers from several other institutions concluded that the warm phase of AMO also was correlated to increased wildfires in the West.
In addition to AMO, the researchers looked at two other ocean-atmosphere oscillations — the El Nino Southern Oscillation and the Pacific Decadal Oscillation — as well as past temperatures, precipitation and aridity to better understand the spruce beetle outbreaks. The team found that another effective predictor of drought conditions was summer “vapor pressure deficit,” a measurement of atmospheric dryness, said Veblen.
In the new study, the researchers were particularly interested in “radial growth” rates of tree rings from sub-canopy trees of various species in the study areas that thrived following outbreaks. One hallmark of spruce beetle outbreaks is that slow radial growth rates in such areas are followed by extremely rapid radial growth rates, an indication smaller trees flourish in the absence of the larger spruce trees because of decreased competition for water and increased opportunities for photosynthesis, said Hart.
The area of high-elevation forests affected by spruce beetles is growing in the West, Hart said. “In 2012, U.S. Forest Service surveys indicated that more area was under attack by spruce beetles than mountain pine beetles in the Southern Rocky Mountains, which includes southern Wyoming, Colorado and northern New Mexico,” she said. “The drought conditions that promote spruce beetle outbreak are expected to continue.”
One big concern about spruce beetle outbreaks is their effects on headwater streams that are important for water resources, said Veblen. “In the short term, trees killed by spruce beetles will lead to less water use by trees and more water discharge into streams. But in the long term, the absence of the trees killed by beetles may lead to less persistence of snow and earlier runoff.”
Veblen said it might seem counterintuitive to some that spruce-fir subalpine forests in Colorado are larger by area than lodgepole/ponderosa pine forests. “It is probably because spruce and subalpine forests are found in more remote areas not as visible to most people,” he said. “But potentially, the current spruce beetle outbreak could affect a larger area than the mountain pine beetle outbreak.”
The study had its beginnings in 1986, when Veblen and his students began compiling spruce and subalpine fir tree rings from various study sites in the Colorado mountains. Tree rings from individual trees — which carry information about weather, climate and even events like volcanic eruptions — can be matched up and read with rings from other trees, much like the pages of a book, from year to year and even from season to season.
-CU-
Free firewood? What a deal!
Jul 25th
Firewood Program:
Wood generated by the City of Boulder’s forest management operations is made available to the public, at the OSMP South Boulder Creek West Trailhead. The wood is available on a first-come, first-served basis and is usually on-site between the months of May and November.
Beginning July 15, 2013, due to recently enacted restrictions, wood pick-up will require users to sign a contract, pay an annual $15 administration fee, and get a gate key to access the wood.
Contracts and keys are available at the OSMP Administrative Offices at 66 S. Cherryvale Road between the hours of 8:30 am and 4:30 pm, M-F. The contract and key will allow users to access the firewood during the following hours:
- Tuesday, Wednesday, Thursday 10 am to 5 pm
- The 1st and 3rd Saturday of each month from 10 am to 2 pm
For additional information please call OSMP at 303-441-3440.
The following Terms and Conditions apply to all woodlot users:
- Only those who have a current, signed contract with OSMP may get firewood.
- The signed contract must be in your possession when picking up wood. You must present it to OSMP staff, if requested to do so;
- You may access and remove firewood only during the hours of operation noted below;
- You may take no more than one-half cord (4’x4’x4’) of wood per day;
- You must return the woodlot key within 30 days upon termination of this contract, or sooner, if OSMP staff so directs;
- You must comply with all OSMP rules and regulations, including not entering areas that are temporarily or permanently restricted or closed;
- You must respect the rights and privileges of others, including those picking up firewood under similar contracts;
- Dogs accompanying anyone picking up wood must be leashed and under your control;
- Please remove all trash or litter; and
- You are responsible for any damage to your vehicle or to City property resulting from your participation in firewood cutting or removal.
No one may:
- Use a woodlot key without a current, signed contract;
- Duplicate or permit another person to use their assigned key to the woodlot;
- Conduct sales or solicitation for sales on OSMP property;
- Block traffic or parking or create an unsafe or hazardous situation;
- Use a chainsaw without a spark arrestor; or
- Use heavy equipment such as tractors or bulldozers to aid in picking up wood.
REMINDER:
- All motor vehicles not registered in Boulder County must display either a daily or an annual parking permit to park at the South Boulder Creek West trailhead parking lot. A parking permit is NOT required inside the woodlot area while picking up firewood.
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