 |
|
Plants could override climate change effects on wildfires
April 22, 2009Paleoecological data reveal strong influence of vegetation changes on wildfire frequency
The increase in warmer and drier climates predicted to occur under climate change scenarios has led many scientists to also predict a global increase in the number of wildfires. But a new study in the May issue of Ecological Monographs shows that in some cases, changes in the types of plants growing in an area could override the effects of climate change on wildfire frequency.
Philip Higuera of Montana State University and his colleagues show that although changing temperatures and moisture levels set the stage for changes in wildfire frequency, they can often be trumped by changes in the distribution and abundance of plants. Vegetation plays a major role in determining the flammability of an ecosystem, he says, potentially dampening or amplifying the impacts that climate change has on fire frequencies.
"Climate is only one control of fire regimes, and if you only considered climate when predicting fire under climate-change scenarios, you would have a good chance of being wrong," he says. "You wouldn't be wrong if vegetation didn't change, but the greater the probability that vegetation will change, the more important it becomes when predicting future fire regimes."
Higuera and his colleagues examined historical fire frequency in northern Alaska by analyzing sediments at the bottom of lakes. Using meter-long samples, called sediment cores, Higuera and his colleagues measured changes in the abundance of preserved plant parts, such as pollen, to determine the types of vegetation that dominated the landscape during different time periods in the past. Like rings in a tree, different layers of sediment represent different times in the past.
The researchers used radiocarbon dating to determine the sediment's age, which dates as far back as 15,000 years. They then measured charcoal deposits in the sediment to determine fire frequency during time periods dominated by different vegetation. Finally, they compared their findings to known historical climate changes.
In many cases, the authors discovered, changes in climate were less important than changes in vegetation in determining wildfire frequency. Despite a transition from a cool, dry climate to a warm, dry climate about 10,500 years ago, for example, the researchers found a sharp decline in the frequency of fires. Their sediment cores from that time period revealed a vegetation change from flammable shrubs to fire-resistant deciduous trees, a trend which Higuera thinks was enough to offset the direct effects of climate on fire frequencies.
"In this case, a warmer climate was likely more favorable for fire occurrence, but the development of deciduous trees on the landscape offset this direct climatic effect. Consequently, we see very little fire," Higuera says.
Similarly, during the development of the modern spruce-dominated forest about 5000 years ago, temperatures cooled and moisture levels increased, which -- considered alone -- would create unfavorable conditions for frequent fires. Despite this change, the authors observed an increase in fire frequency, a pattern they attribute to the high flammability of the dense coniferous forests.
Higuera thinks this research has implications for predictions of modern-day changes in fire regimes based on climate change. These findings, Higuera says, emphasize that predicting future wildfire frequency shouldn't hinge on the direct impacts of climate change alone.
"Climate affects vegetation, vegetation affects fire, and both fire and vegetation respond to climate change," he says. "Most importantly, our work emphasizes the need to consider the multiple drivers of fire regimes when anticipating their response to climate change."
Ecological Society of America
"Climate is only one control of fire regimes, and if you only considered climate when predicting fire under climate-change scenarios, you would have a good chance of being wrong," he says. "You wouldn't be wrong if vegetation didn't change, but the greater the probability that vegetation will change, the more important it becomes when predicting future fire regimes."
Higuera and his colleagues examined historical fire frequency in northern Alaska by analyzing sediments at the bottom of lakes. Using meter-long samples, called sediment cores, Higuera and his colleagues measured changes in the abundance of preserved plant parts, such as pollen, to determine the types of vegetation that dominated the landscape during different time periods in the past. Like rings in a tree, different layers of sediment represent different times in the past.
The researchers used radiocarbon dating to determine the sediment's age, which dates as far back as 15,000 years. They then measured charcoal deposits in the sediment to determine fire frequency during time periods dominated by different vegetation. Finally, they compared their findings to known historical climate changes.
In many cases, the authors discovered, changes in climate were less important than changes in vegetation in determining wildfire frequency. Despite a transition from a cool, dry climate to a warm, dry climate about 10,500 years ago, for example, the researchers found a sharp decline in the frequency of fires. Their sediment cores from that time period revealed a vegetation change from flammable shrubs to fire-resistant deciduous trees, a trend which Higuera thinks was enough to offset the direct effects of climate on fire frequencies.
"In this case, a warmer climate was likely more favorable for fire occurrence, but the development of deciduous trees on the landscape offset this direct climatic effect. Consequently, we see very little fire," Higuera says.
Similarly, during the development of the modern spruce-dominated forest about 5000 years ago, temperatures cooled and moisture levels increased, which -- considered alone -- would create unfavorable conditions for frequent fires. Despite this change, the authors observed an increase in fire frequency, a pattern they attribute to the high flammability of the dense coniferous forests.
Higuera thinks this research has implications for predictions of modern-day changes in fire regimes based on climate change. These findings, Higuera says, emphasize that predicting future wildfire frequency shouldn't hinge on the direct impacts of climate change alone.
"Climate affects vegetation, vegetation affects fire, and both fire and vegetation respond to climate change," he says. "Most importantly, our work emphasizes the need to consider the multiple drivers of fire regimes when anticipating their response to climate change."
Ecological Society of America
Climate Change Current Events and Climate Change News RSSFlax and yellow flowers can produce bioethanol
Surplus biomass from the production of flax shives, and generated from Brassica carinata, a yellow-flowered plant related to those which engulf fields in spring, can be used to produce bioethanol.
Aquatic creatures mix ocean water
Understanding mixing in the ocean is of fundamental importance to modeling climate change or predicting the effects of an El Niño on our weather. Modern ocean models primarily incorporate the effects of winds and tides. However, they do not generally take into account the mixing generated by swimming animals.
How green is your house?
Preliminary results from 1500 respondents show that those who own their own home are more likely to separate their rubbish (83 per cent) than those in rented accommodation (59 per cent), whilst less than one in a hundred households have solar water heating (0.5 per cent) or solar energy panels (0.5 per cent). Initial findings also show that switching off the lights in unused rooms (82 per cent) and not leaving the television on standby (67 per cent) are significantly more popular than taking fewer flights (16 per cent), car sharing (15 per cent) and not buying items because they have too much packaging (8 per cent).
Scientists at UA, collaborating institutions decode maize genome
Scientists from the University of Arizona led by Arizona Genomics Institute director Rod A. Wing and from collaborating institutions have deciphered the complete genetic code of the maize plant for the first time.
ORNL, Los Alamos pioneer new approach to assist scientists, farmers
Sustainable farming, initially adopted to preserve soil quality for future generations, may also play a role in maintaining a healthy climate, according to researchers at the Department of Energy's Oak Ridge and Los Alamos national laboratories.
Research challenges for understanding landscape changes identified
Nine research challenges and four research initiatives that are poised to advance the study of how Earth's landscapes change were unveiled today in a new report by the National Research Council.
Berkeley Lab Lends Expertise to India to Promote Energy Efficiency
ndia may rank only a distant fourth in terms of carbon dioxide emissions, behind China, the United States and Russia, but its rapid economic growth rate coupled with aging and inefficient energy infrastructure suggest dire environmental consequences if "business as usual" continues.
Experts: Failure to focus on farming will undermine global climate agreement and increase hunger
Alarmed by a substantial oversight in the global climate talks leading up to the United Nations Climate Change Conference in Copenhagen next month, more than 60 of the world's most prominent agricultural scientists and leaders underscored how the almost total absence of agriculture in the agreement could lead to widespread famine and food shortages in the years ahead.
Study: Sea stars bulk up to beat the heat
A new study finds that a species of sea star stays cool using a strategy never before seen in the animal kingdom. The sea stars soak up cold sea water into their bodies during high tide as buffer against potentially damaging temperatures brought about by direct sunlight at low tide.
Emulating Western lifestyles: Consumption and carbon footprints in less industrialized countries
In recent decades, a new global middle class has exploded, with a total population exceeding one billion people. A new study in the Journal of Consumer Research explores the consumption attitudes of some of these members of the "new class."
More Climate Change Current Events and Climate Change News Articles
 |
Climate Change: Picturing the Science by Gavin Schmidt (Author), Joshua Wolfe (Author), Jeffrey D. Sachs (Foreword) An unprecedented union of scientific analysis and stunning photography illustrating the effects of climate change on the global ecosystem. Going beyond the headlines, this work by leading NASA climate scientist Gavin Schmidt and master photographer Joshua Wolfe illustrates as never before the ramifications of shifting climate. Photographic spreads show retreating glaciers, sinking villages in Alaska’s tundra, and drying lakes. The text follows adventurous scientists through the ice caps at the poles to the coral reefs of the tropical seas. Marshaling data spanning centuries and continents, the book sparkles with cutting-edge research and visual records, including contributions from experts on atmospheric science, oceanography, paleoclimatology, technology, politics, and... |
 |
The Rough Guide to Climate Change, 2nd Edition by Robert Henson (Author) The Rough Guide to Climate Change gives the complete picture of the single biggest issue facing the planet. Cutting a swathe through scientific research and political debate, this completely updated 2nd edition lays out the facts and assesses the options- global and personal- for dealing with the threat of a warming world. The guide looks at the evolution of our atmosphere over the last 4.5 billion years and what computer simulations of climate change reveal about our past, present, and future. This updated edition includes new information from the 2007 report from the Intergovernmental Panel on Climate Change and an updated politics section to reflect post-Kyoto developments. Discover how rising temperatures and sea levels, plus changes to extreme weather patterns, are already affecting... |
 |
Climate Change: A Multidisciplinary Approach by William James Burroughs (Author) Providing a concise, up-to-date presentation of current knowledge of climate change and its implications for society as a whole, this new edition has been thoroughly updated and extended to include the latest information. The text describes the components of the global climate, considers how the many elements of climate combine to define its behaviour, and reviews how climate change is measured. The author discusses how the causes of climate change can be related to the evidence of change, and modelled to predict future changes. This book is ideally suited for introductory courses in meteorology, oceanography, environmental science, earth science, geography, agriculture and social science. It contains review questions at the end of each chapter to enable readers to monitor their... |
 |
The Science and Politics of Global Climate Change: A Guide to the Debate by Andrew E. Dessler (Author), Edward A. Parson (Author) Climate variability has become the primary environmental concern of the 21st Century. Yet, despite the scientific community's warnings of the imminent dangers of global warming, politicians world-wide have failed to agree on what to do about this potentially devastating environmental problem. This introductory primer informs scientists, policy makers and the general public by clarifying the conflicting claims of the debate. |
 |
What We Know About Climate Change (Boston Review Books) by Kerry Emanuel (Author), Judith A. Layzer (Afterword), William R. Moomaw (Afterword) The vast majority of scientists agree that human activity has significantly increased greenhouse gases in the atmosphere—most dramatically since the 1970s. In February 2007 the Intergovernmental Panel on Climate Change found that global warming is "unequivocal" and that human-produced carbon dioxide and other greenhouse gases are chiefly to blame, to a certainty of more than 90 percent. Yet global warming skeptics and ill-informed elected officials continue to dismiss this broad scientific consensus. In What We Know About Climate Change, MIT atmospheric scientist Kerry Emanuel outlines the basic science of global warming and how the current consensus has emerged. Although it is impossible to predict exactly when the most dramatic effects of global warming will be felt, he argues, we can... |
 |
Climate Change: The Science of Global Warming and Our Energy Future by Edmond A. Mathez (Author) Climate Change is geared toward a variety of students and general readers who seek the real science behind global warming. Exquisitely illustrated, the text introduces the basic science underlying both the natural progress of climate change and the effect of human activity on the deteriorating health of our planet. Noted expert and author Edmond A. Mathez synthesizes the work of leading scholars in climatology and related fields, and he concludes with an extensive chapter on energy production, anchoring this volume in economic and technological realities and suggesting ways to reduce greenhouse-gas emissions. Climate Change opens with the climate system fundamentals: the workings of the atmosphere and ocean, their chemical interactions via the carbon cycle, and the scientific... |
 |
The Ethics of Climate Change: Right and Wrong in a Warming World (Think Now) by James Garvey (Author) The debate about the existence of climate change seems finally at an end. We now have to decide what to do about it. Here, James Garvey argues that the ultimate rationale for action on climate change cannot be simply economic, political, scientific or social, though no doubt our decisions should be informed by such things. Instead, climate change is largely a moral problem. What we should do about it depends on what matters to us and what we think is right.This book is an introduction to the ethics of climate change. It considers a little climate science and a lot of moral philosophy, ultimately finding a way into the many possible positions associated with climate change. It is also a call for action, for doing something about the moral demands placed on both governments and individuals... |
 |
Climate Confusion: How Global Warming Hysteria Leads to Bad Science, Pandering Politicians and Misguided Policies that Hurt the Poor by Roy Spencer (Author) The current frenzy over global warming has galvanized the public and cost taxpayers billons of dollars in federal expenditures for climate research. It has spawned Hollywood blockbusters and inspired major political movements. It has given a higher calling to celebrities and built a lucrative industry for scores of eager scientists. In short, ending climate change has become a national crusade. And yet, despite this dominant and sprawling campaign, the facts behind global warming remain as confounding as ever. In Climate Confusion, distinguished climatologist Dr. Roy Spencer observes that our obsession with global warming has only clouded the issue. Forsaking blindingly technical statistics and doomsday scenarios, Dr. Spencer explains in simple terms how the climate system... |
 |
The Atlas of Climate Change: Mapping the World's Greatest Challenge (Atlas Of... (University of California Press)) by Kirstin Dow (Author), Thomas Downing (Author) Today's headlines and recent events reflect the gravity of climate change. Heat waves, droughts, and floods are bringing death to vulnerable populations, destroying livelihoods, and driving people from their homes. Rigorous in its science and insightful in its message, this atlas examines the causes of climate change and considers its possible impact on subsistence, water resources, ecosystems, biodiversity, health, coastal megacities, and cultural treasures. It reviews historical contributions to greenhouse gas levels, progress in meeting international commitments, and local efforts to meet the challenge of climate change. With more than 50 full-color maps and graphics, this is an essential resource for policy makers, environmentalists, students, and everyone concerned with this... |
 |
Climate Change (DK Eyewitness Books) by John Woodward (Author) The most trusted nonfiction series on the market, Eyewitness Books provide an in-depth, comprehensive look at their subjects with a unique integration of words and pictures. An in-depth look at the phenomenon of global warming--what's causing it, what it might lead to, and what we can do to fight back. |
| © 2009 BrightSurf.com |