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

Disturbed ecosystems are more sensitive to climate change and its risks

Science World Report: When it comes to climate change, disturbed ecosystems may be at risk. Scientists have found that an ecosystem's resistance to changing climatic conditions is reduced when it's exposed to natural or human-caused disturbances.

The findings actually come from one of the world's longest running climate change experiments. Two of the studies were actually situated in Danish heathland ecosystems, which were studied over the period of several years. The scientists found that climate change impacts on the vegetation were minimal in undisturbed heathland. But that wasn't the case in heathland that was disturbed.

"After a heather beetle outbreak heather plants re-established in control plots, but not in plots subject to extended summer drought," said Inger Kappel Schmidt, one of the researchers, in a news release. "The combination of disturbance and drought caused a shift from heathland to grassland." Results from the experimental sites in other countries also showed similar results. It appeared that ecosystems that were more disturbed were less likely to recover.

"The long-term impact of climate change on plant communities is more dependent on short periods where plants are relatively vulnerable, like regeneration phases, than on the longer periods between disturbances where established vegetation is relatively robust," said Johannes Ransiin, one of the lead authors of the new article. "The higher sensitivity after disturbance should also be considered by land managers. Reducing disturbance intensity and frequency in ecosystems could help making them less vulnerable to climatic change."...

Gillis d'Hondecoeter (circa 1575/1580–1638) painted this image of "Paradise" after 1615

Adapting to climate change will bring new environmental problems

A press release from the University of East Anglia: Adapting to climate change could have profound environmental repercussions, according to a new study from the University of East Anglia. Research in Nature Climate Change reveals that adaptation measures have the potential to generate further pressures and threats for both local and global ecosystems.

Lead researcher Dr Carlo Fezzi, from UEA’s School of Environmental Sciences, said: “Climate change is a just a little bit more complicated than we previously thought.  We need to take into account not only the direct impact of climate change, but also how people will respond to such change - the impact of adaptation. “This is a whole new dimension to the climate change adaptation debate.”

The research team looked at the interaction between agricultural land use and river water quality – both of which will be heavily impacted by climate change.

They studied land use and river quality from more than half a million records covering the whole of the UK and dating back to the early 1970s. They used computer models to predict not only how climate change would lead to agricultural changes, but how these agricultural changes would impact water quality.

“We found that a moderately warmer climate in the range of between 1oC and 3oC will be mainly beneficial for agriculture in Great Britain. Particularly in the eastern uplands and midlands, warmer temperatures will boots crop yield and allow for more livestock. But some localised losses can be expected - particularly in the east of England, where lower rainfall may increase the risk of drought.

“This intensification in agricultural practices in response to climate change, however, will also create new environmental pressures. For example changes in the agricultural sector will have a knock on effect for water quality – because they will cause increased amounts of nitrates and phosphates in streams and rivers....

A combine in a wheat field, shot by Dan Kollman, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

High seas fishing ban could boost global catches, equality

A press release from the University of British Columbia: Closing the high seas to commercial fishing could distribute fisheries income more equitably among the world’s maritime nations, according to research from the University of British Columbia (UBC).

The analysis of fisheries data indicates that if increased spillover of fish stocks from protected international waters were to boost coastal catches by 18 per cent, current global catches would be maintained. When the researchers modelled less conservative estimates of stock spillover, catches in coastal waters surpassed current global levels.

“We should use international waters as the world’s fish bank,” says Rashid Sumaila, director of the UBC Fisheries Economics Research Unit and lead author of the study. “Restricting fisheries activities to coastal waters is economically and environmentally sensible, particularly as the industry faces diminishing returns.”

...The study also indicates that a high-seas moratorium would improve fisheries income distribution among maritime nations. Currently, 10 high seas fishing nations capture 71 per cent of the landed value of catches in international waters.

Under all scenarios considered by the researchers, European Member States, Group of Eight nations, and least developed fishing nations would benefit the most from a closure. Under a catch-neutral scenario, the United States, Guam and the United Kingdom would benefit the most, each with potential increases in landed values of more than $250 million (USD) per year. Canada would see an increase of $125 million (USD) per year....

Map of gains and losses from the proposed plan from the University of British Columbia website

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 

Ebola a stark reminder of link between health of humans, animals, environment

Emily Caldwell at the Ohio State University News Room: For many, global public health seems like an abstract and distant problem – until the Ebola virus is diagnosed among people in our midst. Though no one would call the Ebola pandemic a good thing, it has presented an opportunity for scientists to alert the public about the dire need to halt the spread of infectious diseases, especially in developing and densely populated areas of the world.

“What often seems like an abstract notion becomes very concrete when a deadly virus previously contained in Western Africa infects people on American soil,” said Wondwossen Gebreyes, professor of veterinary preventive medicine at The Ohio State University. “It does create a certain sense of urgency and awareness that this world is much smaller than we think.”

Gebreyes is the lead author of an article published in the Nov. 13, 2014, issue of PLOS Neglected Tropical Diseases that makes the case for accelerating efforts to put “One Health” into action. One Health refers to a strategy to more fully understand and address the links between animal health, human health and the environment.

The paper emphasizes the danger of zoonotic infections – those transmitted from animals to humans – and the staggering damage they do, especially in developing nations that lack a variety of resources. These diseases don’t just kill people, but they cause tremendous economic harm in a variety of ways: killing livestock, reducing the ranks of qualified health and education providers, creating political unrest and stopping development in its tracks.

There is an urgent need for progress. Approximately 75 percent of emerging infectious diseases are those transmitted from animals to humans, and the world is on pace to experience at least one deadly disease outbreak each year.

...“To attain a true One Health approach, we need broad recognition of the interconnectivity among the health of humans, domestic or wild animals and the environment, which are all closely linked by the pathogens that they share,” he said....

The link between environmental degradation and Ebola

Peter Stoett and Catherine Machalaba in the Toronto Star:  The Ebola epidemic besieging West Africa is perhaps the starkest warning yet that as we tear down forests, we open ourselves up to new strains of virulent disease. Among the key lessons from the current outbreak is that human-created pressures such as intensified food production, rapid trade and travel, and climate change, are putting future generations at risk of further Ebola-like catastrophes.

Through some mix of travel control, medical advances, and humanitarian assistance, we can hopefully stop the current outbreak’s carnage. But what can we do to prevent future outbreaks of so-called exotic diseases?

Delegates at the recent UN conference on biodiversity in South Korea expressed particular concern that the long-term alteration of habitats (by, for example, logging, farming, mining) and speeding climate change will increase the chances of the spread of exotic diseases. They compellingly made the case that Guinea, Liberia, and Sierra Leone are all known for their high deforestation rates; and each has been affected by periods of civil strife that exacerbated population displacement and relocation.

It would be premature to conclude that deforestation or other causes of ecosystem change were the factors behind this outbreak, but they remain part of the equation for Ebola, other emerging illnesses and even established diseases like malaria.

Unsustainable policies designed to increase agricultural output for export, illegal logging, the mercurial rise of the palm oil industry and the hunt for oil and gold within tropical and boreal forests — all of these place humans in greater contact with wild species, in some cases for the first time, enabling more efficient transmission of diseases both known and unknown.

Indeed, scientists started linking infectious diseases with environmental alteration decades ago. Today, climate change complicates the issue: most predictions (many of them already realized) suggest the changing climate will allow for the spread of invasive species, degrade ecosystems’ resiliency and ultimately broaden the reach of some diseases....

CDC Disease detective Kari Yacisin (left) conducts contact tracing for Ebola in West Africa with a local health official. CDC photo via Wikimedia Commons, under the Creative Commons 2.0 license

The 1934 drought was worst of the last millennium

A press release from the American Geophysical Union: The 1934 drought was by far the most intense and far-reaching drought of the last 1,000 years in North America, and was caused in part by an atmospheric phenomenon that may have also led to the current drought in California, according to a new study.

New research finds that the extent of the 1934 drought was approximately seven times larger than droughts of comparable intensity that struck North America between 1000 A.D. and 2005, and nearly 30 percent worse than the next most severe drought that struck the continent in 1580.

“We noticed that 1934 really stuck out as not only the worst drou
ght but far outside the normal range of what we see in the record,” said Benjamin Cook, an environmental scientist at NASA’s Goddard Institute for Space Studies in New York City and lead author of a new paper that has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

The new study also finds that the same atmospheric pattern of a high pressure ridge over the West Coast deflecting away storms laden with rain last winter was also present over the area during the winter of 1933-34.

This ridging pattern has preceded some of the worst West Coast droughts, including the 1976 California drought—the beginning of a two-year dry spell which is widely regarded as one of the most severe droughts in the state’s history. The three-year drought currently crippling California will cost the state $2.2 billion in 2014 alone, and will likely continue through 2015, according to a recent report from the University of California, Davis.

Yet the current drought is nothing, so far, compared to what occurred in 1934, the start of a decade-spanning drought that would come to be known as the Dust Bowl and was one of the worst environmental disasters in the history of the United States.

The drought, which afflicted nearly 72 percent of the western United States, was likely made even worse by atmospheric effects from human-created dust storms, according to the new research. The new study suggests that such interactions between the land and the atmosphere may have an important role to play in drought severity, said Cook, who holds a joint appointment at Columbia University’s Lamont-Doherty Earth Observatory....

Arthur Rothstein's 1936 of a dust storm in the Texas Panhandle

Study measures steep coastal costs of China's GDP growth

Seed Daily via SPX: A new study by a team of Chinese and American conservation biologists quantifies the serious consequences of China's recent economic growth on its coastal ecosystems. By several measures, 1978 was the beginning of a hugely successful surge in the nation's ability to produce economic value, but that surge brought accelerated degradation in the vitality of its coastal ecosystems.

The combined analysis of economic growth, human activities and impacts, and environmental quality data appears in the journal Scientific Reports. It shows that after reforms declared in 1978, which liberalized the Chinese economy to spur growth, many human economic activities with deleterious environmental impacts increased markedly, even in the absence of significant population growth.

The economic reforms led to a shift from an inland agrarian economy to an industrial economy concentrated on the coast. In lockstep with that shift came environmental problems such as declines in fish size and diversity, damage to coral reefs, and a surge in harmful algal blooms.

"This study flags the problem and screams out this is a problem that has to be dealt with," said Mark Bertness, professor of ecology and evolutionary biology at Brown University and the paper's second author. "This has all happened within a generation."

Lead author Qiang He of Beijing Normal University, who led the research while a visiting scholar in the Bertness lab at Brown, said the research shows that economic growth alone can generate environmental impacts. "We show that in a country with a relatively constant coastal population growth rate, economic growth rather than population growth is the major driver of coastal degradation, while previous science often addresses how increasing human population degrades the coastal and marine environment," He said....

Shanghai's Bund viewed from the Oriental Pearl Tower in Pudong, Shanghai, shot by Bobak, Wikimedia Commons, under the Creative Commons 2.5 license

Call for ‘ecohealth’ approach to tackling climate change

Marco Boscolo in SciDev.net: If researchers are to effectively address the profound challenges that climate change will have on human health, they will have to work across disciplines and with local communities, says a declaration from the 5th Biennial Conference of the International Association For Ecology & Health held last week (11-15 August).

The declaration “is an endorsement and a call to action on climate change”, said Maya Gislason, a member of the conference’s international advisory committee from the University of Northern British Columbia, Canada.

“Ecohealth is a field of research, education and practice that integrates scientific evidence, professional expertise and community experience with a view to improving the health of humans, animals and ecosystems,” the declaration says. “A focus on health — across humans, animals and other species — offers new opportunities to harness synergies across disparate efforts to address climate change.”

It is not the first time a call has been made to break boundaries between disciplines but previously there has been little follow-up action, Jean Lebel, the president of the International Development Research Centre, a Canadian public corporation that supports research in developing nations and which co-organised the conference, told SciDev.Net.

...The declaration says it is intended to push more researchers to address climate change issues through concrete actions such as working directly with communities most affected by climate change, for example, those on small island states....

The alleged location of the Garden of Eden, at the mouth of the Tigris River, from Underwood's "Sacred Books and Literature of the East"

World's primary forests on the brink

Terra Daily via SPX: An international team of conservationist scientists and practitioners has published new research showing the precarious state of the world's primary forests. The global analysis and map are featured in a paper appearing in the esteemed journal Conservation Letters and reveals that only five percent of the world's pre-agricultural primary forest cover is now found in protected areas.

...Representing organisations such as the US-based Wildlife Conservation Society, the Zoological Society of London, the Geos Institute and Australian National University, they conclude that primary forest protection is the joint responsibility of developed as well as developing countries and is a matter of global concern.

Primary forests - largely ignored by policy makers and under increasing land use threats - are forests where there are no visible indications of human activities, especially industrial-scale land use, and ecological processes have not been significantly disrupted.

These forests are home to an extraordinary richness of biodiversity, with up to 57 percent of all tropical forest species dependent on primary forest habitat and the ecological processes they provide. The analysis shows that almost 98 per cent of primary forest is found within 25 countries, with around half of that located in five developed countries: the U.S., Canada, Russia, Australia and New Zealand.

Professor Mackey warns that industrial logging, mining and agriculture gravely threaten primary forests, and those outside of protected areas are especially vulnerable. He adds that policies are urgently needed to reduce pressure to open up primary forests for industrial land use....

Abraham Govaerts, "Het eeuwige Woud"

'Peak soil' threatens future global food security

Nigel Hunt and Sarah Mcfarlane in Reuters: The challenge of ensuring future food security as populations grow and diets change has its roots in soil, but the increasing degradation of the earth's thin skin is threatening to push up food prices and increase deforestation.

 While the worries about peaking oil production have been eased by fresh sources released by hydraulic fracturing, concern about the depletion of the vital resource of soil is moving center stage.  "We know far more about the amount of oil there is globally and how long those stocks will last than we know about how much soil there is," said John Crawford, Director of the Sustainable Systems Program in Rothamsted Research in England.  "Under business as usual, the current soils that are in agricultural production will yield about 30 percent less than they would do otherwise by around 2050."

Surging food consumption has led to more intensive production, overgrazing and deforestation, all of which can strip soil of vital nutrients and beneficial micro-organisms, reduce its ability to hold water and make it more vulnerable to erosion.

Such factors, exacerbated by climate change, can ultimately lead to desertification, which in parts of China is partly blamed for the yellow dust storms that can cause hazardous pollution in Asia, sometimes even severe enough to cross the Pacific Ocean and reduce visibility in the western United States....

An archive shot of the Dust Bowl in the Texas Panhandle, original date not given, processed by Capmo, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

European Environment Agency urges for ‘systemic’ approach to environment, health concerns

EurActiv: Governments need to study the connections between health and environmental concerns, which could save them money and improve societal well-being over the longer term, according to the European Environment Agency.

...The EEA is also seeking to promote this kind of thinking in relation to climate change and other complex problems.

Noxious emissions can damage the environment, as seen in acid rain or reduced crop yields, or human health, with higher incidences of respiratory diseases, with the costs falling on governments and taxpayers.

"It may seem there is nothing new about considering different policy areas together – air pollution, for instance, has often been considered in terms of its health implications. But the report argues that research should further incorporate these areas, allowing us to gain a system-wide understanding of multiple causes and effects," the EEA says, referring to a report it released in February on the environment, health and well-being.

By failing to address the source of the problem, government costs can mount up, particularly in healthcare. Many European countries had to cut their healthcare budgets during the economic crisis, leaving citizens unable to receive treatment, such as medicines.

However, with many problems being inter-linked, the potential for governments to reduce their costs is great. “It is difficult to measure the effects of our environment on our health,” said Lode Godderis, a researcher on health and the environment with KU Leuven, in Belgium. However, sometimes the scientific evidence does reveal connections, he said....

Paris at night, shot by Benh LIEU SONG, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license 

Kenya needs to mitigate against the causes of desertification

AllAfrica. com via the Star (Kenya): There are plans to expand land under rice irrigation in Kirinyaga County as consumption of the product continues to rise in Kenya with the current consumption rate at 300,000 tonnes annually.

Njenga Mwaura, National Irrigation Board in Mwea said the area earns Sh 3 billion per year from rice production, and small-scale farmers who largely depend on the crop stand to benefit. " There are plans to expand 800 acres of land in Kiangungu and Kiamanyeki areas and 25 hectares in Mutithi area," said Mwaura.

...National Environment Management Authority (Nema) director general, prof Geoffrey Wahungu said climate variability and extremes are a major threat to sustainable development of the county, with rising temperatures contributing to increase of malaria, erratic rainfall resulting to drying up of some rivers and also flooding especially on the lower parts of Mwea.

Wahungu added that the major contributors to the degradation of the environment in the county are deforestation, poor solid waste disposal, cultivation along river banks by the community, and pollution from industries and farmers....

Tracks in the Chalbi Desert in northern Kenya, shot by Filiberto Strazzari, Wikimedia Commons via Flickr,  under the Creative Commons Attribution 2.0 Generic license

Climate change devastates Antarctic seabed ecosystems

Blue & Green Tomorrow: Climate change is decimating populations of tiny species that live on the seabed of the Antarctic shore, threatening ecosystem stability and life higher up the food chain, scientists have warned.  In a paper published on Monday in the journal Current Biology, scientists describe how the warming of Antarctic waters over the last two decades has al
lowed icebergs to drift more freely, battering the seabed as they do.

This has made it harder for most species to prosper on the seabed – where most forms of Antarctic life actually live. One species – fenestrulina rugula, a kind of sea moss – has thrived, the researchers found, filling the gap thanks to its remarkably fast growth and reproduction rate. “It’s a quite inconspicuous, really quite a weedy little thing”, the study’s lead author David Barnes, of the British Antarctic Survey, told the BBC.

“Now if you go there and picked up a boulder, 99 out of every 100 beasts that you would find on it would be that.” While this is good news for fenestrulina rugula, it’s bad news for the biodiversity of the region. The study notes that what was once an intricate ecosystem, made up of many competing species, is now lost.

“Now it all revolves around a single species”, Barnes said. “This means specialist predators will now have less food and the biological system is less stable, and thus more susceptible to environmental change.”

One survey, conducted in 2013, at a spot close to the area studied by Barnes and his colleagues, even found large areas where no life at all could be found. This was the first time that had ever been reported, despite frequent surveys of the area, scientists say. Such findings should concern us all, because the Antarctic Peninsula ”is like a canary in a coal mine”, Barnes said in a statement....

Port Lockroy, Antarctica, shot by Liam Quinn, Wikimedia Commons via Flickr, under the Creative Commons 2.0 license 

Wondering about the state of the environment? Just eavesdrop on the bees

EurekAlert via Cell Press: Researchers have devised a simple way to monitor wide swaths of the landscape without breaking a sweat: by listening in on the "conversations" honeybees have with each other. The scientists' analyses of honeybee waggle dances reported in the Cell Press journal Current Biology on May 22 suggest that costly measures to set aside agricultural lands and let the wildflowers grow can be very beneficial to bees.

"In the past two decades, the European Union has spent €41 billion on agri-environment schemes, which aim to improve the rural landscape health and are required for all EU-member states," says Margaret Couvillon of the Laboratory of Apiculture and Social Insects at the University of Sussex. "However, there is little evidence evaluating these schemes. Our work uses a novel source of data—the honeybee, an organism that itself can benefit from a healthy rural landscape—to evaluate not only the environment, but also the schemes used to manage that environment."

Couvillon and her colleagues, led by Francis Ratnieks, recorded and decoded the waggle dances of bees in three hives over a two-year period. Bees dance to tell their fellow bees where to find the good stuff: the best nectar and pollen. The angle of their dances conveys information about the direction of resources while the duration conveys distance. Researchers can measure those dance characteristics in a matter of minutes with a protractor and timer.

...The researchers were surprised to find that Organic Entry Level agri-environment schemes were the least frequented by bees. According to Couvillon, it may be that the regular mowing required initially to discourage certain plants from growing in those plots might leave few wildflowers for bees.

The study shows that honeybees can serve as bioindicators to monitor large land areas and provide information relevant to better environmental management, the researchers say. It also gives new meaning to the term "worker bee."...

Shot of a honey bee by Rebhu, Wikimedia Commons, under the Creative Commons 3.0 license

Devastating human impact on the Amazon rainforest revealed

A press release from Lancaster University: The human impact on the Amazon rainforest has been grossly underestimated according to an international team of researchers led by Lancaster University. They found that selective logging and surface wildfires can result in an annual loss of 54 billion tonnes of carbon from the Brazilian Amazon, increasing greenhouse gas emissions. This is equivalent to 40% of the yearly carbon loss from deforestation - when entire forests are chopped down.

This is the largest ever study estimating above and belowground carbon loss from selective logging and ground level forest fires in the tropics, based on data from 70,000 sampled trees and thousands of soil, litter and dead wood samples from 225 sites in the eastern Brazilian Amazon.

The forest degradation often starts with logging of prized trees such as mahogany and ipe. The felling and removal of these large trees often damages dozens of neighbouring trees. Once the forest has been logged, the many gaps in the canopy means it becomes much drier due to exposure to the wind and sun, increasing the risk of wildfires spreading inside the forest. The combination of selective logging and wildfires damages turns primary forests into a thick scrub full of smaller trees and vines, which stores 40% less carbon than undisturbed forests.

So far, climate change policies on the tropics have effectively been focusing on reducing carbon emissions from deforestation only, not accounting for emissions coming from forest degradation.

Lead researcher Dr Erika Berenguer from Lancaster University said: “The impacts of fire and logging in tropical forests have always been largely overlooked by both the scientific community and policy makers who are primarily concerned with deforestation. Yet our results show how these disturbances can severely degrade the forest, with huge amounts of carbon being transferred from plant matter straight into the atmosphere.”...

Logging in Amazonia, shot by Pediboi, Wikimedia Commons, under the Creative Commons 3.0 license

Light pollution impairs rainforest regeneration

A press release from the Leibniz Institute for Zoo and Wildlife Research: Increasing light pollution in tropical habitats could be hampering regeneration of rainforests because of its impact on nocturnal seed-dispersers. These new findings were reported by scientists from the German Leibniz Institute for Zoo and Wildlife Research Berlin (IZW). The study – published in the British Ecological Society's Journal of Applied Ecology – is the first to show that seed-dispersing bats avoid feeding in light-polluted areas.

Working with Sowell's short-tailed bats (Carollia sowelli), Daniel Lewanzik from the IZW gave the bats a simple choice. He divided a flight cage into two compartments. One was naturally dark and the other was illuminated by a sodium street lamp, the most common form of street lighting in the world. Inside both parts of the cage the bats were offered their favourite fruits to harvest: pepper plants, nightshade and figs.

The results revealed that bats flew into the dark compartment twice as often as the compartment lit by a street lamp. The bats also harvested fruits almost twice as often in the dark compartment.

In a second experiment Lewanzik illuminated pepper plants growing in the wild with a street light and measured the percentage of ripe fruit which bats harvested from plants in a dark location and from lit plants. While bats harvested 100 per cent of the marked, ripe fruit from the plants in the dark, only 78 per cent were taken from the lit plants. Although insect-eating bats have been shown to avoid foraging in light-polluted areas, this is the first study to show that fruit-eating bats also avoid lit areas.

This has important implications for forest regeneration in the tropics. Bats play a key role in pollinating plants and spreading their seeds, especially the seeds of species that are first to recolonise cleared land. “In tropical habitats bat-mediated seed dispersal is necessary for the rapid succession of deforested land because few other animals than bats disperse seeds into open habitats”, says Daniel Lewanzik, doctoral candidate at the IZW and first author of the study. Under naturally dark conditions, bats produce a copious 'seed rain' when defecating seeds while flying. By reducing foraging of fruit-eating bats in lit areas, light pollution is likely to reduce seed rain, he commented....

Ernst Haekel's 1904 Kunstformen der Natur, Plate 67

Deer proliferation disrupts a forest’s natural growth

A press release by Joe Schwartz from Cornell University: By literally looking below the surface and digging up the dirt, Cornell researchers have discovered that a burgeoning deer population forever alters the progression of a forest’s natural future by creating environmental havoc in the soil and disrupting the soil’s natural seed banks. The study, “Deer Browsing Delays Succession by Altering Aboveground Vegetation and Belowground Seed Banks,” was published online March 7 in PLOS ONE.

“Deer are slowing down forest succession or natural establishment. In fact, the deer are preventing forests from establishing,” says Anurag Agrawal, Cornell professor of ecology and evolutionary biology, a co-author on the paper. Deer typically prefer to eat native, woody plants and rebuff invasive species. The study showed that when deer consume native plants, the non-native species are left to flourish, dropping seed in the soil.

As forests normally mature, their grasses give way to herbs and shrubs, and then new trees eventually take root. Expanding deer populations in the Northeast, however, stall forest development and promote the growth of thorny thickets of buckthorn, viburnum and multiflora rose bushes. If deer leave the forests alone, such trees as cottonwood, locust and sumac can sprout and grow unimpeded.

The researchers found that the impacts of deer grazing on vegetation were severe and resulted in bare soil and reduced plant biomass, less recruitment of woody species and relatively fewer native species. And the deer’s negative impact on seed banks resulted in significantly decreased overall species richness and relatively more short-lived species of both annual and biennial plants.

...“It’s obvious that the deer are affecting the above-ground species, but it’s like an iceberg. There are major effects below the soil surface. We are seeing a divergence of seeds contained within the soil from what should be there,” says DiTommaso. “We are not seeing the seeds of woody plants. Instead, we’re seeing an escalation of non-native seed and the virtual elimination of woody plant seeds.”...

A deer in Raleigh, North Carolina, shot by Clay Heaton, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Study shows less snowpack will harm ecosystem

Newswise via Boston University: A new Boston University study shows that the consequences of milder winters – a smaller snowpack leaving the ground to freeze harder and longer – can have a negative impact on trees and water quality of nearby aquatic ecosystems far into the warmer growing season.

In a paper in the journal Global Change Biology, BU biology Prof. Pamela Templer and her co-authors show that soil freezing due to diminishing snowpack damages the roots of sugar maple trees and limits their ability to absorb essential nitrogen and other nutrients in the spring. This leads to greater run off of nitrogen into ground water and nearby streams, which could deteriorate water quality and trigger widespread harmful consequences to humans and the environment.

“Most people think that climate change means hot, sweltering summer months, but it affects the winter as well,” said ecologist Templer, currently on fellowship at Harvard University, noting that winter snowpack has been shrinking over the past 50 years due to climate change and is likely to continue diminishing over time.

Templer and her colleagues discovered that a thick layer of snow acts as an insulating blanket. When snowpack was shoveled off sections of New Hampshire’s Hubbard Brook Experimental Forest to simulate the effects of a warm winter, the soil was much colder – a much as 10 degrees less -- than when it was when covered with deep snow. This means the ground could be frozen solid longer into the spring.

Templer is following up her winter research with a new National Science Foundation funded project that uses warming cables in the ground to determine the combined effects of warmer winters and summer on the trees....

A NASA image of Kings Canyon National Park in the Sierras of California