The dramatic growth in plant cover will not offset the damage made from deforestation

Tom Bawden in the Independent (UK): The dramatic growth in plant cover in the past decade gives a huge boost to the battle against global warming. But any celebrations should be muted by this sobering fact: the extra carbon being stored by this additional vegetation, while enormou
s, only represents seven per cent of the 60 billion tonnes of carbon that has been emitted into the atmosphere over the same period, which will remain there for centuries.

There is no sense, then, in which the increased carbon uptake of our plantlife detracts from the urgent need to step up the fight against climate change by cutting fossil fuel use and protecting woodland. eThe need to preserve our diminishing rainforests is particularly acute.

This report may have identified a surprisingly big increase in plant cover, but there is nothing unexpected about the confirmation it provided about tropical deforestation.

The devastation of the rainforests is particularly worrying because these not only act as a major carbon sink – they also provide one of the most “biodiverse” habitats in the world, supporting vast networks of inter-dependent species.

Total plant cover has increased in the past decade, but in many cases the quality of this cover is far lower than the loss of the tropical forests it is helping to offset. Only about half of the rainforest loss has been offset by growth in coniferous and mixed-leaf forests, with much of the rest of the increase coming from shrubland and savannas...

Canada wild rye, shot by Dehaan, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license

Sea level rise won’t only affect infrastructure

Scoop via Forest & Bird (New Zealand): The independent conservation organisation Forest & Bird is asking the Parliamentary Commissioner for the Environment (PCE) to widen the focus of her next report on climate change-driven sea level rise.

A preliminary report on sea level rise was released by the PCE today. The PCE will release another report next year on the impacts of sea level rise on the most vulnerable areas of coastline around the country, and the risks to infrastructure in those areas.

Forest & Bird Group Manager Campaigns and Advocacy Kevin Hackwell says the next report should also take into account the impacts of sea level rise on our natural coastal ecosystems, and recommend the best ways to deal with sea level rise.

He says some critical natural features could be changed forever by sea level rise. “For example the huge Kaipara Harbour north of Auckland covers 947 square kilometres at high tide, with nearly half of that area exposed as mudflats and sandflats at low tide,” Kevin Hackwell says.

...“Quite a few of our shore birds breed just above the current high tide level on our open coasts or at the head of estuaries. For instance the four remaining nesting sites of New Zealand’s Seabird of the Year, the fairy tern, could be wiped out by storm surges,” Kevin Hackwell says.

“We would also like to see the PCE make recommendations on how sea level rise should be dealt with. Building extensive sea walls is likely to be very expensive, in many places unrealistic, and in the long run may create more problems than they would solve....

Sphinx Rock in Marie's Leg Cove, New Zealand, shot by Pseudopanax, Wikimedia Commons, under the Creative Commons 3.0 license 

Earth’s plants could be too carbon-saturated to slow global warming by century’s end

Rick Docksai in Science Recorder: Earth’s plant life puts a damper on global warming for now, but researchers do not expect this to last. In a study published this week in the Proceedings of the National Academy of Sciences, they explain that while plants’ photosynthesis process ingests huge concentrations of carbon dioxide from the air, the plants can only retain so much and will tap out by century’s end as human civilization’s carbon dioxide pollution continues to rise.

The study assumes that global temperatures rise another four degrees Celsius by 2100, a scenario that the UN Intergovernmental Panel on Climate Change and other climate research institutions have indicated will probably happen if the world community doesn’t make unprecedented reductions in carbon-emitting emissions in the next few years.

At that four-degree high point, plant reuptake of carbon dioxide will be most likely to flat-line. This will in turn set off a further upward spiral in greenhouse warming as atmospheric carbon dioxide levels’ rise not only continues, but accelerates.

Andrew Friend, Cambridge University environmental scientist and the study’s lead researcher, told reporters that plants’ capacity to take up carbon dioxide at all falls when temperatures get too high. So when there is a heat wave, the affected ecosystems thus release more carbon-dioxide than usual.

Europe’s summer 2003 heat wave was an example of this, Friend added—as the continent’s heat index soared, carbon dioxide levels rose, as well. They did so to such an extent, in fact, that they negated all of the carbon reuptake that the continent’s plant life had done over the previous four years....

Interior main greenhouse at the Jardin des Plantes in Paris, shot by Marie-Lan Nguyen, Wikimedia Commons, under the Creative Commons Attribution 2.5 Generic license

Adaptability to local climate helps invasive species thrive

University of British Columbia News: The ability of invasive plants to rapidly adapt to local climates – and potentially to climate change – may be a key factor in how quickly they spread. According to new research published in Science by University of British Columbia evolutionary ecologist Rob Colautti, rapid evolution has helped purple loosestrife to invade, and thrive in, northern Ontario.

“Factors such as escape from natural enemies including herbivores, predators, pathogens or parasites were thought to explain how species become invasive,” says Colautti, an NSERC Banting Postdoctoral Fellow with the UBC Department of Botany, who started the research in 2007 as a PhD student at the University of Toronto. “The ability of invasive species to rapidly adapt to local climate has not generally been considered to be an important factor affecting spread.

“We found that the evolution of local adaptation to climate in purple loosestrife increased reproduction as much as or more than escaping natural enemies. Understanding that species can evolve rapidly to local climates is important for predicting how invasive species spread and how native and non-native species alike will respond to climate change.”

To determine whether populations have evolved local adaptation, Colautti and University of Toronto professor Spencer Barrett collected seeds from three different climatic regions and grew them at three sites spanning the distribution of the species in eastern North America. They found that ‘home’ plants collected from latitudes most similar to each common garden location always had higher fitness than the ‘away’ plants.

They then measured Darwinian natural selection on flowering time and found differences in flowering times that have evolved over the past 50 years as the species moved northwards, following its initial introduction to the east coast of the USA....

Purple loosestrife, shot by liz west, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Sea ice decline spurs the greening of the Arctic

A press release from the Geophysical Institute at the University of Alaska: Sea ice decline and warming trends are changing the vegetation in nearby arctic coastal areas, according to two University of Alaska Fairbanks scientists. Uma Bhatt, an associate professor with UAF’s Geophysical Institute, and Skip Walker, a professor at UAF’s Institute of Arctic Biology, contributed to a recent review of research on the response of plants, marine life and animals to declining sea ice in the Arctic.

“Our thought was to see if sea ice decline contributed to greening of the tundra along the coastal areas,” Bhatt said. “It’s a relatively new idea.” The review appeared in a recent issue of Science magazine. It is a close, comprehensive look at how the losses of northern sea ice affect surrounding areas. Bhatt and Walker were two of ten authors.

The review team analyzed 10 years worth of data and research on the subject. The findings show that sea ice loss is changing marine and terrestrial food chains. Sea-ice disappearance means a loss of sea-ice algae, the underpinning of the marine food web. Larger plankton is thriving, replacing smaller, but more nutrient dense plankton. What that means exactly is not yet understood.

Above water, loss of sea ice has destroyed old pathways of animal migration across sea ice while opening new pathways for marine animals in others. Some animals and plants will become more isolated. In the case of the farthest north and coldest parts of the Arctic, entire biomes may be lost without the cooling effects of disappearing summer sea ice.

Walker, a plant biologist, says warming soils provide an opportunity for new vegetation to grow where less vegetation occurred previously. This contributes to a general greening of the Arctic that is visible from space. Bhatt, an atmospheric scientist, examined a 1982-2010 time series of remote sensing data to examine trends in sea ice, land-surface temperatures and changes in the vegetation abundance....

Barrier islands and lagoons at Cape Espengerg, in Kotzebue Sound. A US Fish and Wildlife photo

Seeing photosynthesis from space: NASA scientists use satellites to measure plant health

NASA: NASA scientists have established a new way to use satellites to measure what's occurring inside plants at a cellular level.

Plants grow and thrive through photosynthesis, a process that converts sunlight into energy. During photosynthesis, plants emit what is called fluorescence – light invisible to the naked eye but detectable by satellites orbiting hundreds of miles above Earth. NASA scientists have now established a method to turn this satellite data into global maps of the subtle phenomenon in more detail than ever before.

Healthy plants use the energy from sunlight to perform photosynthesis, and re-emit some of that light as a faint but measureable glow. In short, abundant fluorescence indicates active photosynthesis and a well functioning plant, while low or no fluorescence can mean that the plant is stressed or shutting down. Maps of the phenomenon give scientists a direct look at plant health.

The new maps – produced by Joanna Joiner of NASA's Goddard Space Flight Center in Greenbelt, Md., and colleagues – boast a 16-fold increase in spatial resolution and a three-fold increase in temporal resolution over the first proof-of-concept maps released in 2011 from a different satellite instrument. Improved global measurements could have implications for farmers interested in early indications of crop stress and ecologists looking to better understand global vegetation and carbon cycle processes.

"For the first time, we are able to globally map changes in fluorescence over the course of a single month," Joiner said. "This lets us use fluorescence to observe, for example, variation in the length of the growing season."

Vegetation dynamics, including the northward migration of plant growth during the northern hemisphere springtime, is already observed indirectly by satellite data used measure the "greenness" of light reflected from Earth's surface. Fluorescence measurements complement the greenness measurements by providing direct and immediate information about plant productivity. For example, the researchers saw plants start to shut down in the fall before their leaves turned colors. They also clearly detected early plant growth during the warm spring of 2012...

Machinery inside the chloroplasts of plant cells converts sunlight to energy, emitting fluorescence in the process. Scientists can detect the fluorescence fingerprint in satellite data.
Image Credit: NASA Goddard's Conceptual Image Lab/T. Chase

Climate change is happening too quickly for species to adapt

Robin McKie in the Guardian (UK): Among the many strange mantras repeated by climate change deniers is the claim that even in an overheated, climate-altered planet, animals and plants will still survive by adapting to global warming. Corals, trees, birds, mammals and butterflies are already changing to the routine reality of global warming, it is argued.

Certainly, countless species have adapted to past climate fluctuations. However, their rate of change turns out to be painfully slow, according to a study by Professor John Wiens of the University of Arizona. Using data from 540 living species, including amphibians, reptiles, birds and mammals, Wiens and colleagues compared their rates of evolution with the rates of climate change projected for the end of this century. The results, published online in the journal Ecology Letters, show that most land animals will not be able to evolve quickly enough to adapt to the dramatically warmer climate expected by 2100. Many species face extinction, as a result.

"We found that, on average, species usually adapt to different climatic conditions at a rate of only by about 1C per million years," Wiens explained. "But if global temperatures are going to rise by about four degrees over the next 100 years as predicted by the Intergovernmental Panel on Climate Change, that is where you get a huge difference in rates. What that suggests overall is that simply evolving to match these conditions may not be an option for many species."

The study indicates there is simply not enough time for species to change their morphologies – for example, by altering their bodies' shapes so they hold less heat – to compensate for rising heat levels. Too many generations of evolutionary change are required. Nor is moving habitat an option for many creatures. "Consider a species living on the top of a mountain," says Wiens. "If it gets too warm or dry up there, they can't go anywhere."...

A snow leopard, shot by Irbis1983, public domain 

Elevated carbon dioxide making arid regions greener

The American Geophysical Union: Scientists have long suspected that a flourishing of green foliage around the globe, observed since the early 1980s in satellite data, springs at least in part from the increasing concentration of carbon dioxide in Earth’s atmosphere. Now, a study of arid regions around the globe finds that a carbon dioxide “fertilization effect” has, indeed, caused a gradual greening from 1982 to 2010.

Focusing on the southwestern corner of North America, Australia’s outback, the Middle East, and some parts of Africa, Randall Donohue of the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Canberra, Australia and his colleagues developed and applied a mathematical model to predict the extent of the carbon-dioxide (CO2) fertilization effect. They then tested this prediction by studying satellite imagery and teasing out the influence of carbon dioxide on greening from other factors such as precipitation, air temperature, the amount of light, and land-use changes.

The team’s model predicted that foliage would increase by some 5 to 10 percent given the 14 percent increase in atmospheric CO2 concentration during the study period. The satellite data agreed, showing an 11 percent increase in foliage after adjusting the data for precipitation, yielding “strong support for our hypothesis,” the team reports.

“Lots of papers have shown an average increase in vegetation across the globe, and there is a lot of speculation about what’s causing that,” said Donohue of CSIRO’s Land and Water research division, who is lead author of the new study. “Up until this point, they’ve linked the greening to fairly obvious climatic variables, such as a rise in temperature where it is normally cold or a rise in rainfall where it is normally dry. Lots of those papers speculated about the CO2 effect, but it has been very difficult to prove.”

...In addition to greening dry regions, the CO2 fertilization effect could switch the types of vegetation that dominate in those regions. “Trees are re-invading grass lands, and this could quite possibly be related to the CO2 effect,” Donohue said. “Long lived woody plants are deep rooted and are likely to benefit more than grasses from an increase in CO2.”

“The effect of higher carbon dioxide levels on plant function is an important process that needs greater consideration,” said Donohue. “Even if nothing else in the climate changes as global CO2 levels rise, we will still see significant environmental changes because of the CO2 fertilization effect.”

Photo by Brian Thomas, hereby released into the public domain

Decline in biodiversity of farmed plants, animals gathering pace

Alister Doyle in Reuters: A decline in the diversity of farmed plants and livestock breeds is gathering pace, threatening future food supplies for the world's growing population, the head of a new United Nations panel on biodiversity said on Monday.

Preserving neglected animal breeds and plants was necessary as they could have genes resistant to future diseases or to shifts in the climate to warmer temperatures, more droughts or downpours, Zakri Abdul Hamid said.

"The loss of biodiversity is happening faster and everywhere, even among farm animals," Zakri told a conference of 450 experts in Trondheim, central Norway, in his first speech as founding chair of the U.N. biodiversity panel.

Many traditional breeds of cows, sheep or goats have fallen out of favor, often because they yield less meat or milk than new breeds. Globalization also means that people's food preferences narrow down to fewer plants.

Zakri said there were 30,000 edible plants but that just 30 crops accounted for 95 percent of the energy in human food that is dominated by rice, wheat, maize, millet and sorghum.

He said it was "more important than ever to have a large genetic pool to enable organisms to withstand and adapt to new conditions." That would help to ensure food for a global population set to reach 9 billion by 2050 from 7 billion now....

Artwork of a bull on an antique steam-powered tractor at the Wooden Shoe Tulip Farm. Image from Gary Halvorson, Oregon State Archives, Wikimedia Commons

One-third of animal species will be hit by climate change, scientists warn

The Guardian (UK): One-third of common land animals could see dramatic losses this century because of climate change, scientists predict. More than half of plants could be hit the same way as habitats become unsuitable for numerous species. The collapse of ecosystems would have major economic impacts on agriculture, air quality, clean water access, and tourism.

Global temperatures are set to rise 4C above preindustrial levels by 2100 if nothing is done to stem greenhouse gas emissions. This could have a hugely destructive effect on thousands of common as well as rare and endangered species around the world, according to the researchers.

An estimated 57% of plants and 34% of animals were likely to lose half or more of their habitat range. But the damage would be greatly reduced if emissions were scaled down in time, the study shows. Losses are reduced by 60% if global warming is cut to 2% above preindustrial levels, with emissions peaking in 2016 and then being reduced by 5% a year. If emissions peak in 2030, losses are reduced by 40%.

Lead scientist Dr Rachel Warren, from the University of East Anglia's school of environmental science, said: "While there has been much research on the effect of climate change on rare and endangered species, little has been known about how an increase in global temperature will affect more common species....

A tree frog in Portland, Oregon, shot by CopyrightFreePhotos.HQ101.com, who has generously released the image into the public domain

Decline in snow cover spells trouble for many plants, animals

University of Wisconsin-Madison News: For plants and animals forced to tough out harsh winter weather, the coverlet of snow that blankets the north country is a refuge, a stable beneath-the-snow habitat that gives essential respite from biting winds and subzero temperatures.

But in a warming world, winter and spring snow cover in the Northern Hemisphere is in decline, putting at risk many plants and animals that depend on the space beneath the snow to survive the blustery chill of winter.

In a report published May 2 in the journal Frontiers in Ecology and the Environment, a team of scientists from the University of Wisconsin-Madison describes the gradual decay of the Northern Hemisphere's "subnivium," the term scientists use to describe the seasonal microenvironment beneath the snow, a habitat where life from microbes to bears take full advantage of warmer temperatures, near constant humidity and the absence of wind.

"Underneath that homogenous blanket of snow is an incredibly stable refuge where the vast majority of organisms persist through the winter," explains Jonathan Pauli, a UW-Madison professor of forest and wildlife ecology and a co-author of the new report. "The snow holds in heat radiating from the ground, plants photosynthesize, and it's a haven for insects, reptiles, amphibians and many other organisms."

Since 1970, snow cover in the Northern Hemisphere — the part of the world that contains the largest land masses affected by snow — has diminished by as much as 3.2 million square kilometers during the critical spring months of March and April. Maximum snow cover has shifted from February to January and spring melt has accelerated by almost two weeks, according to Pauli and his colleagues, Benjamin Zuckerberg and Warren Porter, also of UW-Madison, and John P. Whiteman of the University of Wyoming in Laramie.

"The winter ecology of Wisconsin and the Upper Midwest is changing," says Zuckerberg, a UW-Madison professor of forest and wildlife ecology. "There is concern these winter ecosystems could change dramatically over the next several years."...

A brown wood frog can survive happily under the snow. Shot by Thomas Brown, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license 

Plants moderate climate warming

The International Institute for Applied Systems Analysis: As temperatures warm, plants release gases that help form clouds and cool the atmosphere, according to research from IIASA and the University of Helsinki.

The new study, published in Nature Geoscience, identified a negative feedback loop in which higher temperatures lead to an increase in concentrations of natural aerosols that have a cooling effect on the atmosphere. “Plants, by reacting to changes in temperature, also moderate these changes,” says IIASA and University of Helsinki researcher Pauli Paasonen, who led the study.

Scientists had known that some aerosols – particles that float in the atmosphere – cool the climate as they reflect sunlight and form cloud droplets, which reflect sunlight efficiently. Aerosol particles come from many sources, including human emissions. But the effect of so-called biogenic aerosol – particulate matter that originates from plants – had been less well understood. Plants release gases that, after atmospheric oxidation, tend to stick to aerosol particles, growing them into the larger-sized particles that reflect sunlight and also serve as the basis for cloud droplets. The new study showed that as temperatures warm and plants consequently release more of these gases, the concentrations of particles active in cloud formation increase.

“Everyone knows the scent of the forest,” says Ari Asmi, University of Helsinki researcher who also worked on the study. “That scent is made up of these gases.” While previous research had predicted the feedback effect, until now nobody had been able to prove its existence except for case studies limited to single sites and short time periods. The new study showed that the effect occurs over the long-term in continental size scales.

The effect of enhanced plant gas emissions on climate is small on a global scale – only countering approximately 1 percent of climate warming, the study suggested. “This does not save us from climate warming,” says Paasonen. However, he says, “Aerosol effects on climate are one of the main uncertainties in climate models. Understanding this mechanism could help us reduce those uncertainties and make the models better.”

The study also showed that the effect was much larger on a regional scale, counteracting possibly up to 30% of warming in more rural, forested areas where anthropogenic emissions of aerosols were much lower in comparison to the natural aerosols. That means that especially in places like Finland, Siberia, and Canada this feedback loop may reduce warming substantially....

Misty Forest. Looking across to Gale Hill Point from the Roman road. Shot by Steve Partridge, Wikimedia Commons via Geograph UK, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Nature adapts to survive climate change

Jonathan Silver in Reuters: While the climate change discussion in Washington is moving at a glacial pace, nature is responding to climate change at record speed. The animal, plant and insect kingdoms aren’t interested in public policy. They don’t read political blogs. They adapt because they have to. They must change to survive. We would be wise to heed the signs.

Animals, plants and even insects are now adapting quickly to shifts in temperatures, often by migrating to cooler climates, modifying their diets and altering breeding cycles.

This is happening at blinding speed in large, complex ecosystems. Throughout most of the 20th century, for example, tree range shift occurred at about 0.4 miles a year. Since 1990, however, climate changes have caused species range to move by an average of 12 miles a year. A 2009 U.S. Forest Service study, tracking 40 major tree species in 30 Eastern states, concluded that tree ranges had moved, on average, more than 60 miles north in less than a century.

More than 60 percent of the birds the National Wildlife Federation tracked in a recent study have expanded their range northward by an average of 35 miles in the last 40 years. Fourteen small mammal species in the Sierra Nevada Mountains were found to have extended the elevation at which they can survive by an average of 1,640 feet.

...The climate may now be changing so quickly that some species do not have time to adapt. With the Antarctic warming, for example, penguins now need to lay their eggs far earlier, according to research at Stony Brook University in New York. Yet of the three species studied – the Adelie, Chinstrap and Gentoo – only the Gentoo has been able to adapt quickly. As a result, that population has exploded, while the other two are dwindling....

A gentoo penguin in Antarctica, shot by christopher, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

European invader outcompetes Canadian plants outside usual temperature range

Seed Daily: Dog-strangling vine (Vincetoxicum rossicum) is an exotic plant originating from the Ukraine and southeastern Russia that is becoming increasingly invasive in southern Ontario, Canada.

It has been found growing successfully in both disturbed and undisturbed areas, in open fields, forest edges and understories, parks, road edges and railway embankments.

The invasive plant effectively competes for light by forming large and dense stands that climb over other plants. A study published in the open access, peer-reviewed journal NeoBiota explores the effects of V. rossicum invasion in Canada.

Apart from displacing local plant species, among the ecological effects of a possible V. rossicum invasion are endangered populations of local soil organisms and pollinator species.

Another concern is the dog strangling vine's good adaptability to and possible invasion of the alvar environment in the region, which for the Ontario is a rare kind of habitat supporting a number of important habitat-specific species....

Vincetoxicum rossicum, shot by Epibase, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license

NASA eyes declining vegetation in the eastern United States from 2000 to 2010

NASA: NASA scientists report that warmer temperatures and changes in precipitation locally and regionally have altered the growth of large forest areas in the eastern United States over the past 10 years. Using NASA’s Terra satellite, scientists examined the relationship between natural plant growth trends, as monitored by NASA satellite images, and variations in climate over the eastern United States from 2000 to 2010.

Monthly satellite images from the MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) showed declining density of the green forest cover during summer in four sub-regions, the Upper Great Lakes, southern Appalachian, mid-Atlantic, and southeastern Coastal Plain. More than 20 percent of the non-agricultural area in the four sub-regions that showed decline during the growing season, were covered by forests. Nearly 40 percent of the forested area within the mid-Atlantic sub-region alone showed a significant decline in forest canopy cover.

“We looked next at the relationships between warmer temperatures, rainfall patterns, and reduced forest greenness across these regions,” said Christopher Potter, a research scientist at NASA’s Ames Research Center, Moffett Field, Calif. “This comprehensive data set gave us the evidence to conclude that a series of relatively dry years since 2000 has been unfavorable for vigorous growth of forest cover over much of the eastern U. S. this past decade.” Potter is the first author of the paper titled “Declining Vegetation Growth Rates in the Eastern United States from 2000 to 2010,” published by Natural Resources, Dec. 2012, (3), 184-190.

...More recent studies indicate that climate change could be having many adverse and interrelated impacts on the region. The warming climate this century has caused new stresses on trees, such as insect pest outbreaks and the introduction of new pathogens. Scientists consider both climate change and disease to be dominant driving forces in the health of forests in this region....

Trends in forest canopy green cover over the eastern United States from 2000 to 2010 derived from NASA MODIS satellite sensor data. Green shades indicate a positive trend of increasing growing season green cover, whereas brown shades indicate a negative trend of decreasing growing season green cover. Four forest sub-regions of interest are outlined in red, north to south as: Great Lakes, Southern Appalachian, Mid-Atlantic, and southeastern Coastal Plain. Image credit: NASA

Marsh plants actively engineer their landscape

EurekAlert via Duke University: Marsh plants, far from being passive wallflowers, are "secret gardeners" that actively engineer their landscape to increase their species' odds of survival, says a team of scientists from Duke University and the University of Padova in Italy.

Scientists have long believed that the distribution of plants within a marsh is a passive adaption in which species grow at different elevations because that's where conditions like soil aeration and salinity best meet their needs. But this team found intertidal marsh plants in Italy's famed Venetian lagoon were able to subtly tune, or adjust, their elevations by producing different amounts of organic soil, and trapping and accumulating different amounts of inorganic sediments as part of a complex interplay with the environment.

"Our study identifies the visible signature of a two-way feedback occurring between the vegetation and the landscape," said Marco Marani, professor of ecohydrology at Duke's Nicholas School of the Environment and Pratt School of Engineering. "Each species builds up the elevation of its substrate to within a favorable range for its survival, much the way corals in the animal kingdom do." The finding may help scientists better predict marsh ecosystems' resilience to climatic changes such as sea level rise. "Obviously, this is not a conscious choice on the part of the plants," Marani said. "It's a natural mechanism -- how marshes work. We just didn't understand it in such detail until now."

...The team used numerical modeling to visualize the dynamic interactions of marsh ecosystems over time, and tested the models against detailed topographical surveys of elevations and distributions of plant species in the Venetian lagoon.

"We've been studying this same marsh for 15 years and, as in similar studies around the world, we were using GPS technology with an accuracy of plus or minus one centimeter in elevation," Marani explained. For the new study, they used a more precise surveying instrument, an electronic theodolite, which measure elevations accurately to within less than one millimeter. "It allowed us to observe differences so subtle that they went unnoticed before," he said....

A digital map of one portion of the Venetian marsh shows the distribution of several species of marsh plants. Courtesy of Marco Marani, Duke University

Invading species can extinguish native plants despite recent reports

Seed Daily via SPX: Ecologists at the University of Toronto and the Swiss Federal Institute of Technology Zurich (ETH Zurich) have found that, given time, invading exotic plants will likely eliminate native plants growing in the wild despite recent reports to the contrary.

A study published in Proceedings of the National Academy of Sciences (PNAS) reports that recent statements that invasive plants are not problematic are often based on incomplete information, with insufficient time having passed to observe the full effect of invasions on native biodiversity.

"The impacts of exotic plant invasions often take much longer to become evident than previously thought," says Benjamin Gilbert of U of T's Department of Ecology and Evolutionary Biology (EEB) and lead author of the study. "This delay can create an 'extinction debt' in native plant species, meaning that these species are slowly going extinct but the actual extinction event occurs hundreds of years after the initial invasion."

Much of the debate surrounding the threat posed to biodiversity by the invasions of non-native species is fueled by recent findings that competition from introduced plants has driven remarkably few plant species to extinction. Instead, native plant species in invaded ecosystems are often relegated to patchy, marginal habitats unsuitable to their nonnative competitors....

Crows on a cross at Pere Lachaise cemetery in Paris, with an invasive ailanthus in the background, shot by jphilipg, Wikimedia Commons via Flickr,  under the Creative Commons Attribution 2.0 Generic license

Emerging consensus shows climate change already having major effects on ecosystems and species

US Geological Survey: Plant and animal species are shifting their geographic ranges and the timing of their life events – such as flowering, laying eggs or migrating – at faster rates than researchers documented just a few years ago, according to a technical report on biodiversity and ecosystems used as scientific input for the 2013 Third National Climate Assessment.

The report, Impacts of Climate Change on Biodiversity, Ecosystems, and Ecosystem Services, synthesizes the scientific understanding of the way climate change is affecting ecosystems, ecosystem services and the diversity of species, as well as what strategies might be used by natural resource practitioners to decrease current and future risks. More than 60 federal, academic and other scientists, including the lead authors from the U.S. Geological Survey, the National Wildlife Federation and Arizona State University in Tempe, authored the assessment.

"These geographic range and timing changes are causing cascading effects that extend through ecosystems, bringing together species that haven't previously interacted and creating mismatches between animals and their food sources," said Nancy Grimm, a scientist at ASU and a lead author of the report.

...Another key finding is the mounting evidence that population declines and increased extinction risks for some plant and animal species can be directly attributed to climate change. The most vulnerable species are those already degraded by other human-caused stressors such as pollution or exploitation, unable to shift their geographic range or timing of key life events, or that have narrow environmental or ecological tolerance. For example, species that must live at high altitudes or live in cold water with a narrow temperature range, such as salmon, face an even greater risk due to climate change.

"The report clearly indicates that as climate change continues to impact ecological systems, a net loss of global species’ diversity, as well as major shifts in the provision of ecosystem services, are quite likely," said Michelle Staudinger, a lead author of the report and a USGS and University of Missouri scientist....

Snow geese at Sacramento National Wildlife Refuge, shot by Brocken Inaglory, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported licence

Too little nitrogen may restrain plants' carbon storage capability

University of Minnesota News: Plants’ ability to absorb increased levels of carbon dioxide in the air may have been overestimated, a new University of Minnesota study shows.

The study, published this week in the journal Nature Climate Change, shows that even though plants absorb large amounts of carbon dioxide and actually can benefit from higher levels of it, they may not get enough of the nutrients they need from typical soils to absorb as much CO2 as scientists had previously estimated. Carbon dioxide absorption is an important factor in mitigating fossil-fuel emissions.

The study, one of only three such long-term experiments in the world, is based on 13 years of research at the Cedar Creek Ecosystem Science Reserve north of the Twin Cities. U of M scientists Peter Reich and Sarah Hobbie monitored nearly 300 open-air plots planted with perennial grasses with varying levels of atmospheric carbon dioxide and soil nitrogen.

“Rather than building a time machine and comparing how ecosystems behave in 2070 – which is hard to do – we basically create the atmosphere of 2070 above our plots,” Reich says.

The results suggest that limited levels of fertility typical in most soils likely eliminate a large fraction of the capacity of plants to scrub CO2 out of the atmosphere, Reich says. “It would be better if there were experiments like ours in tropical rain forest, temperate forest, and tundra, to see how well responses there match with what we have found. But as such experiments do not exist, our results play an important role in addressing this issue for ecosystems everywhere.”....

Prairie grass, shot by Bronwen Lea (Seglea), public domain

Experts in plea for protection of obscure but at-risk animals

Alister Doyle in Reuters: Obscure flora and fauna that few people have ever heard of such as the Jamaican rock iguana need to be much better protected if the world is to achieve a goal of preventing species dying out by 2020, a study said on Tuesday.

The report, "Priceless or Worthless?", listed the 100 most threatened species and said critically endangered plants and animals such as Tarzan's chameleon in Madagascar merited conservation since they were irreplaceable for the Earth even if they had no economic value for people.

"Over half (of the 100 most endangered species) are receiving little or no attention," Professor Jonathan Baillie, Director of Conservation at the Zoological Society of London (ZSL), told Reuters by telephone from South Korea.

Few people fretted about the fate of the Singapore freshwater crab, Ethiopia's liben lark, the Seychelles sheath-tailed bat or the Luristan newt, found in only in the Zagros mountains in Iran, he warned.

And Tarzan's chameleon, colored bright green and yellow, was largely ignored in a shrinking patch of rainforest.

"We need a rethink" of conservation priorities, Baillie said of the 124-page report issued by the ZSL and the International Union for Conservation of Nature (IUCN), which is meeting in South Korea and groups governments, scientists and activists....

Lark eggs, shot by Beentree, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license