Changes in oxygen concentrations in our ocean can disrupt fundamental biological cycles

By: Thomas Schmitt Attorney on November 25, 2019 / comment : 0 Biodiversity, Climate Change, Ecosystems, Natural Heritage, Oceans, Wildlife

New research led by scientists at the University of Bristol has shown that the feedback mechanisms that were thought to keep the marine nitrogen cycle relatively stable over geological time can break down when oxygen levels in the ocean decline significantly.

On Aug. 11, 2015, a NASA satellite captured this false-color image of a large bloom of cyanobacteria (Nodularia) swirling in the Baltic Sea. These cyanobacteria fix inorganic atmospheric nitrogen (N2) into a form available to Life,  a process fundamental for marine ecosystems. In our paper we show that nitrogen fixation becomes even more important when the state of oxygenation of the ocean declines [Credit: NASA Earth Observatory/USGS]

The nitrogen cycle is essential to all forms of life on Earth - nitrogen is a basic building block of DNA.

The marine nitrogen cycle is strongly controlled by biology and small changes in the marine nitrogen cycle have major implications on life. It is thought that the marine nitrogen cycle has stayed relatively stable over geological time due to a range of different feedback mechanisms.

These feedback mechanisms are called 'the nitrostat'. However, exactly how the global marine nitrogen cycle and the associated feedback mechanisms responded to past severe changes in marine oxygenation is not well understood.

The team used a data-constrained earth system model to show show that under these deoxygenated conditions the ocean can become extremely depleted in nitrogen as the total bioavailable nitrogen inventory collapses relative to phosphorous.

At the same time the ocean transitions from an oxic-nitrate ocean to an anoxic ammonium ocean. The substantive reduction in the ocean bioavailable-N inventory in response to change in marine oxygenation may represent a key biogeochemical vulnerability.

Lead author Dr David Naafs from the University of Bristol's School of Earth Sciences, said: "Our results demonstrate that changing the amount of oxygen in the ocean can have disastrous effects on vital biogeochemical cycles such as the nitrogen cycle, which is essential for all forms of Life."

Co-author Dr Fanny Monteiro, from Bristol's School of Geographical Sciences, added: "Our modelling results are in agreement with the sparsely available proxy data from the geological past."

Co-author Professor Ann Pearson from Harvard University, said: "Our modelling results show the impact of changes in ocean oxygenation on the marine nitrogen cycle for places and time periods for which we do not (yet) have sufficient proxy data."

The strength and state of the marine nitrogen cycle and biological pump in the ocean are highly susceptible to disruptions in the level of oceanic oxygen.

As oxygen levels in the oceans are currently declining and expected to decline significantly more in the coming decades due to anthropogenic activities, the results indicate that the marine nitrogen cycle might be significantly disrupted in the future.

Their findings are published in the journal Proceedings of the National Academy of Sciences.

Source: University of Bristol [November 25, 2019]

Climate change is reshaping communities of ocean organisms

By: Thomas Schmitt Attorney on November 25, 2019 / comment : 0 Biodiversity, Climate Change, Ecosystems, Natural Heritage, Oceans, Wildlife

Climate change is reshaping communities of fish and other sea life, according to a pioneering study on how ocean warming is affecting the mix of species.

This is a black and yellow rockfish (Sebastes chrysomelas) in the Channel Islands National Marine Sanctuary off Southern California [Credit: Claire Fackler/CINMS, NOAA]

The study, published in the journal Nature Climate Change, covers species that are important for fisheries and that serve as food for fish, such as copepods and other zooplankton.

"The changes we're observing ripple throughout local and global economies all the way to our dinner plates," said co-author Malin Pinsky, an associate professor in the Department of Ecology, Evolution, and Natural Resources in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick.

"We found dramatic evidence that changing temperatures are already reshaping communities of ocean organisms," Pinsky said. "We found that warm-water species are rapidly increasing and cold-water marine species are decreasing as the global temperature rises. Changes like this are often disrupting our fisheries and ocean food chains."

An international team of scientists also found evidence that species in some places can avoid declines by seeking refuge in cooler, deeper water - like plants on land that move to higher elevations to avoid heat, Pinsky said.

The scientists compiled the most comprehensive assessment of how ocean warming is affecting the mix of species in our oceans. They looked at fishes, invertebrates such as crabs and other crustaceans and plankton in the North Atlantic and North Pacific, across two continents and two oceans. They analyzed three million records of thousands of species from 200 ecological communities across the globe from 1985 to 2014.

Regions with stable temperatures (the Northeast Pacific and Gulf of Mexico, for example) show little change in species dominance, while warming areas (the North Atlantic, for example) are experiencing strong shifts toward the dominance of warm-water species, the study says.

Temperature is a fundamental driver for change in marine systems, with restructuring of communities in the most rapidly warming areas. Still, the data "suggest a strong prognosis of resilience to climate change for these communities," the study says.

"We're now trying to understand how the changes we see in the ocean compare with those on land and in freshwater ecosystems," said Pinsky, who is also a sabbatical professor at the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig.

Source: Rutgers University [November 25, 2019]

Almost a third of tropical Africa's flora faces extinction

By: Thomas Schmitt Attorney on November 21, 2019 / comment : 0 Africa, Biodiversity, Ecosystems, Endangered Species, Natural Heritage

31.7% of tropical Africa’s vascular plant species could be threatened with extinction, reveals an international study coordinated by an IRD researcher, published in the journal Science Advances. Using a new approach based on the key elements of the assessment process used by the International Union for Conservation of Nature (IUCN), for the first time researchers have been able to assess the potential conservation status of tropical flora on the scale of a continent.

Mountains of the eastern arch of Tanzania. The flora of this region is threatened with extinction [Credit: IRD - Thomas Couvreur]

Given the anthropological and climate threats facing nature, the conservation of tropical biodiversity is a major challenge. To encourage the implementation of better biodiversity management practices, countries and international agreements on biodiversity refer to the assessments of species "at risk of extinction" performed by the IUCN as part of a standardised procedure (See Red List of Threatened Species). This approach remains the most comprehensive and objective means of identifying species in need of protection.

However, while the conservation status of the majority of vertebrate species has been assessed, the same cannot be said for plants, although they are critical to earth ecosystems. This is especially true in tropical regions where the flora is very diverse but remains poorly documented.

In this study, the researchers developed a new fast and automatic approach based on key elements of the conservation assessment process used by the IUCN. Their objective was to provide relevant information on the conservation status of a large number of plant species at broad scales, in the form of Preliminary Automated Conservation Assessments (PACA).

The researchers therefore applied this methodology to the RAINBIO database, which contains over 600,000 georeferenced occurrences of plants in tropical Africa across more than 20,000 vascular plant species.

Infographic of the main results [Credit: Thomas L.P. Couvreur]

After classifying these species into six categories - which include species that are "probably or potentially threatened", those that are "potentially rare" and those that are "potentially not threatened" - they reveal that almost a third (31.7%) of the 22,036 vascular plant species studied are potentially threatened with extinction, and an additional 33.2% are potentially rare (they could be threatened in the near future).

After determining the most endangered species, the researchers identified four regions in Africa that are particularly exposed: Ethiopia, central Tanzania, the south of the Democratic Republic of the Congo and the West African tropical rainforests.

They highlight the advantages of this approach, based on the preliminary automated conservation assessments, in terms of cost reduction, time saving and the potential to carry out large-scale assessments. "This study is the first large-scale assessment of the potential conservation status of the tropical African flora, explicitly using the IUCN's methodology", explains botanist Thomas Couvreur from the IRD who coordinated the study.

"These assessments could provide crucial information for improving biodiversity management and promoting sustainable economic development in Africa. They are, however, not intended to replace the comprehensive assessments carried out by the IUCN which lead to official statuses. The two approaches are complementary, and a significant international effort is still needed to assess all plant species in Africa", he urges.

"These results were possible because the partners involved agreed to share their data", says Bonaventure Sonke, Professor at the Laboratory of Systematic Botany and Ecology of the Ecole Normale Superieure (University Yaounde 1, Cameroon). "This is a strong signal to encourage researchers to share their data, in order to obtain results on a larger scale".

Source: Institut de recherche pour le developpement [November 21, 2019]

Melting Mongolian ice patches may threaten reindeer pastoralism, archaeological artefacts

By: Thomas Schmitt Attorney on November 20, 2019 / comment : 0 Climate Change, Ecosystems, Heritage, Indigenous Cultures, Mongolia, Natural Heritage

Northern Mongolian "eternal ice" is melting for the first time in memory, threatening the traditional reindeer-herding lifestyle and exposing fragile cultural artifacts to the elements, according to a study published in the open-access journal PLOS ONE by William Taylor from the Max Planck Institute, Germany, and the University of Colorado-Boulder, USA, and colleagues.

This is a domestic reindeer saddled for riding outside a Tsaatan summer camp in Khuvsgul province,  northern Mongolia [Credit: Julia Clark]

The mountainous tundra of the northern Mongolian steppes features "munkh mus" or "eternal ice", ice patches which remain intact even in the summer. For the reindeer-herding Tsaatan people, they provide a place for heat-stressed reindeer to cool down, as well as fresh water, useful plants, and a reprieve from summer insects for herders and reindeer alike.

The authors of the present study visited the Ulaan Taiga Special Protected Area of Mongolia to investigate the potential for cultural artifacts in the ice. They conducted an archaeological survey on foot and on horseback, and also held ethnographic interviews with eight local families over 2018.

(Left): Image of a persistent snow and ice patch in Mengebulag taken in 2006, showing domestic reindeer using the  patch, and (right): the same patch in 2018, which local residents indicated had melted for the very first time [Credit: Taylor et al, 2019]

The families interviewed described how many ice patches had melted for the first time in memory between 2016 and 2018, while stressing the importance of eternal ice for reindeer and herding families alike. Many herders complained that recent declines in pasture quality had led to reindeer sickness and death.

The archaeological survey revealed a number of wooden artifacts at one melted ice patch site which dated from the 1960s, when herders moved into the area - the first discovered artifacts from this region. Organic materials are preserved in ice but degrade rapidly upon exposure to the elements, meaning that melting ice could affect the archaeological record.

A domesticated reindeer from northern Mongolia [Credit: O. Batchuluun]

As Mongolia continues to warm at a higher rate than the global average, the authors note that the eternal ice appears to be melting due to the increasing summer temperatures--and stress this puts both cultural heritage and traditional reindeer herding at extreme risk in the years to come.

The authors add: "This study shows us that global climate change is an urgent threat in Inner Asia - melting ice is threatening both reindeer herding as a way of life, and the region's cultural heritage."

Source: Public Library of Science [November 20, 2019]

Amazon deforestation and number of fires show summer of 2019 not a ‘normal’ year

By: Thomas Schmitt Attorney on November 18, 2019 / comment : 0 Biodiversity, Brazil, Ecosystems, Natural Heritage, Rainforests

The fires that raged across the Brazilian Amazon this summer were not 'normal' and large increases in deforestation could explain why, scientists show.

Recently deforested land in the Amazon [Credit: Marizilda Cruppe/ Rede Amazonia Sustentavel]

The perceived scale of the Amazon blazes received global attention this summer. However, international concerns raised at the time were countered by the Brazilian Government, which claimed the fire situation in August was 'normal' and 'below the historical average'.

An international team of scientists writing in the journal Global Change Biology say the number of active fires in August was actually three times higher than in 2018 and the highest number since 2010.

Although fires in the Amazon can occur in a number of ways, the scientists show that there is strong evidence to link this year's increases to deforestation.

They have used evidence collected from the Brazilian Government's DETER-b deforestation detection system -- which calculates deforestation by interpreting images taken by NASA satellites.

This shows that deforestation in July this year was almost four times the average from the same period in the previous three years. This is important as deforestation is almost always followed by fire -- the cut vegetation is left to dry before being burned.

Professor Jos Barlow, lead author of the paper said: "The marked upturn in both active fire counts and deforestation in 2019 therefore refutes suggestions by the Brazilian Government that August 2019 was a normal fire month in the Amazon."

Saving 'half Earth' for nature would affect over a billion people

By: Thomas Schmitt Attorney on November 18, 2019 / comment : 0 Biodiversity, Climate Change, Ecosystems, Environment, Natural Heritage, Wildlife

As the extinction crisis escalates, and protest movements grow, some are calling for hugely ambitious conservation targets. Among the most prominent is sparing 50% of the Earth's surface for nature.

Credit: Kate Ter Haar

'Half Earth' and similar proposals have gained traction with conservationists and policy makers. However, little work has gone into identifying the social and economic implications for people.

Now, researchers have produced the first attempt to assess how many and who would be affected if half the planet was 'saved' in a way that secures the diversity of the world's habitats.

A team of scientists analysed global datasets to determine where conservation status could be added to provide 50% protection to every "ecoregion": large areas of distinct habitats such as Central African mangroves and Baltic mixed forests.

Even avoiding where possible "human footprints" such as cities and farmland, their findings suggest a "conservative" estimate for those directly affected by Half Earth would be over one billion people, primarily in middle-income countries.

Many wealthy and densely populated nations in the Global North would also need to see major expansions of land with conservation status to reach 50% - this could even include parts of London, for example.

The study's authors, led by University of Cambridge researchers, say that while radical action is urgently required for the future of life on Earth, issues of environmental justice and human wellbeing should be at the forefront of the conservation movement.

"People are the cause of the extinction crisis, but they are also the solution," said Dr. Judith Schleicher, who led the new study, published today in the journal Nature Sustainability. "Social issues must play a more prominent role if we want to deliver effective conservation that works for both the biosphere and the people who inhabit it."

Towards the end of next year, the leaders of most of the world's nations will aim to agree global targets for the future of conservation at the Convention on Biological Diversity in Beijing.

"Goals that emerge from the Convention on Biological Diversity could define conservation for a generation," said Schleicher, who conducted the research while at the University of Cambridge's Conservation Research Institute and its Department of Geography.

"We need to be ambitious given the environmental crises. But it is vital that social and economic implications at local levels are considered if the drivers of biodiversity loss are to be tackled. The lives of many people and the existence of diverse species hang in the balance."

The idea of a 'Half Earth' for nature was popularised by famed biologist E.O. Wilson in his 2017 book of the same name. More recently, a 'Global Deal for Nature' - aiming for 30% protection by 2030 and 50% by 2050—has been endorsed by a number of leading environmental organisations. However, these proposals have been ambiguous about "exact forms and location", say Schleicher and colleagues.

Based on their analyses, researchers cautiously estimate that an additional 760 million people would find themselves living in areas with new conservation status: a fourfold increase of the 247 million who currently reside inside protected areas.

The team call for proponents of Half Earth, and all supporters of area-based conservation, to "recognise and take seriously" the human consequences—both negative and positive—of their proposals.

"Living in areas rich in natural habitat can boost mental health and wellbeing. In some cases, protected areas can provide new jobs and income through ecotourism and sustainable production," said Schleicher.

"However, at the other extreme, certain forms of 'fortress' conservation can see people displaced from their ancestral home and denied access to resources they rely on for their survival."

While conservation coverage has been increasing, species numbers continue to plummet—suggesting a "disconnect" between international targets and implementation at local and regional levels, argue the team.

"Conservation needs strong action to protect life on earth, but this must be done in a way that takes account of people and their needs," said co-author Dr. Chris Sandbrook from Cambridge's Department of Geography.

"Failing to consider social issues will lead to conservation policy that is harmful to human wellbeing and less likely to be implemented in the first place."

Conservation is not just a problem for people of the Global South. Recent reports on UK wildlife revealed devastating declines in iconic species. Yet the study reveals that achieving 50% ecoregion coverage could even see parts of central London become protected. "It highlights the absurdity of hitting arbitrary targets," Sandbrook said.

Source: University of Cambridge [November 18, 2019]

Global climate change concerns for Africa's Lake Victoria

By: Thomas Schmitt Attorney on November 14, 2019 / comment : 0 Africa, Climate Change, Earth Science, Ecosystems, Natural Heritage

Global climate change could cause Africa's Lake Victoria, the world's largest tropical lake and source of the Nile River, to dry up in the next 500 years, according to new findings from a team of researchers led by the University of Houston. Even more imminent, the White Nile -- one of the two main tributaries of the Nile -- could lose its source waters in just a decade.

View of modern Lake Victoria from the Kenya shoreline where fishing is a vital part of economy and very  susceptible to changes in climate that affect the amount of rainfall and levels of the lake [Credit: Emily Beverly]

Using ancient sediment from outcrops along the edge of the lake, Emily Beverly, assistant professor of sedimentary geology at the UH College of Natural Sciences and Mathematics, along with researchers at Baylor University, generated a water-budget model to see how Lake Victoria's levels respond to changes in evaporation, temperature, rainfall and solar energy. Their findings, published in Earth and Planetary Science Letters, indicate a rapid lake level decline was very possible tens of thousands of years ago and could happen again in the future.

"Our model predicts that at current rates of temperature change and previous rates of lake level fall, Lake Victoria could have no outlet to the White Nile in as little as 10 years. Every major port in Lake Victoria could be landlocked within a century, and Kenya could lose access to the lake in 400 years," Beverly explained.

The result would significantly affect the economic resources supplied by the lake and the livelihoods of approximately 40 million people living in the Lake Victoria Basin.

- Kenya and Tanzania depend on the lake's freshwaters to support their fishing industries because the lake harvests more than one million tons of fish annually.

Members of the team explored outcrops along Lake Victoria in western Kenya. These sediments were used to understand the history of the lake over the past 100,000 years [Credit: Emily Beverly]

- Uganda would be deprived of its primary source of electricity via hydropower and the water that sustains the Nile during non-flood stages.

- The Kagera River basin, which is the main river that flows into Lake Victoria, feeds rainwater to Rwanda and Burundi which rely on agriculture and livestock production.

Lake Victoria gets most of its water from rain, and each year, the area gets about 55 inches of rainfall. The sediment analyzed from along the lake shows rainfall levels from 35,000 to 100,000 years ago were about 28 inches, or almost half of what they are today. The water-budget model in the study shows low amounts of rainfall caused the lake to dry up at least three times in the past 100,000 years and could happen again.

"It's so warm there and the sun is so strong because you are at the equator that evaporation is very high," said Beverly. "If the water balance is thrown off, the lake can dry up very quickly. It doesn't take much of a drop in precipitation to change it."

Author: Sara Tubbs | Source: University of Houston [November 14, 2019]

Last Arctic ice refuge is disappearing

By: Thomas Schmitt Attorney on November 12, 2019 / comment : 0 Arctic, Climate Change, Earth Science, Ecosystems, Environment, Natural Heritage

The oldest and thickest Arctic sea ice is disappearing twice as fast as ice in the rest of the Arctic Ocean, according to new research.

New research finds the Arctic’s oldest and thickest ice is more mobile and is vanishing twice as fast as ice in the rest of the Arctic [Credit: NOAA]

A new study in AGU's journal Geophysical Research Letters finds ice in the Arctic Ocean north of Greenland is more mobile than previously thought, as ocean currents and atmospheric winds are likely transporting the old, thick ice found there to other parts of the Arctic. As a result, ice mass in the area - the last place researchers think will lose its year-round ice cover - is declining twice as fast as ice in the rest of the Arctic, according to the new findings.

Climate models predict Arctic summers will soon be ice-free - perhaps as early as 2030 - meaning less than 1 million square kilometers (386,000 square miles) of summer sea ice will blanket the Arctic Ocean. Arctic warming has already created an environment which leads to younger sea ice. Watch a visualization of the age of Arctic sea ice over time here.

Most ice covering the Arctic is only one to four years old, according to the National Snow and Ice Data Center. As thin, young ice melts in future summers, only a 2,000-kilometer (1,240-mile) arc of ice will remain, stretching from the western Canadian Arctic Archipelago to Greenland's northern coast. In this slice of the Arctic, which experts call the Last Ice Area, sea ice is more than five years old and can measure more than four meters (13 feet) thick.

The new research suggests the Last Ice Area is a dynamic place encompassing two sub-regions where ice thickness fluctuates by 1.2 meters (4 feet) from year to year. Ice is becoming thinner in two distinct subregions, which are losing 0.4 meters (1.3 feet) of ice thickness per decade, amounting to a 1.5-meter (5 foot) loss of ice since the late 1970s, according to the new study.

Annual mean sea ice thickness (m) over the Arctic Ocean from 1979 – 2018. The black line  surrounds the area where the ice thickness exceeds 3 m and can be considered as the  region known as the Last Ice Area. The white lines surround the two areas where the ice thickness exceeds 4m [Credit: Kent Moore/University of Toronto]

"We can't treat the Last Ice Area as a monolithic area of ice which is going to last a long time," said Kent Moore, an atmospheric physicist at the University of Toronto in Canada and lead author of the new study. "There's actually lots of regional variability."

For wildlife who rely on sea ice for survival, the Last Ice Area offers a sanctuary, and is the final place they can retreat to in a warming world. Understanding how the Last Ice Area changes throughout the year could help pinpoint which spots are best suited to provide a refuge for wildlife who are dependent on sea ice, according to the study's authors.

Places with less ice movement, for example, may provide more suitable conditions for a wildlife sanctuary, as the ice will remain longer. The new study presents context for policymakers to consider when they establish protected areas in the Arctic, Moore said.

"Eventually the Last Ice Area will be the region that will repopulate the Arctic with wildlife," Moore said. "If we lose all the ice, we lose those species. This area will be a refuge where species can survive and hopefully expand their regions once the ice starts returning."

A dynamic zone

The Last Ice Area is home to the Arctic's oldest and thickest ice because ocean currents and atmospheric winds carry patches of floating ice in a circular pattern. These blocks of ice crash into each other and pile up along the northern edges of Greenland and Canada. Researchers, however, know little about how ice in this region moves and melts during the year.


This lack of knowledge prompted Moore and his colleagues to track changes in the Last Ice Area. In the new study, the team modeled sea ice cover, thickness and motion across the zone from 1979 to 2018. Their model, based on satellite observations and atmospheric data, revealed two regions with distinct seasonal and inter-annual fluctuations - one to the east and one to the west.

In both regions, sea ice was thinner and covered less area in the summer and early fall than in the Arctic winter, though ice thickness in the west tended to hit its minimum earlier in the season. Ice motion in the eastern portion of the Last Ice Area appeared to be more stable. Western ice - controlled by winds blowing clockwise - has begun moving faster, which could be the result of thinning ice.

According to Moore, the loss of ice in the Last Ice Area is likely due to ice movement out of the region, particularly in the west. If sea ice is thinner and moving faster, pieces at the margins will flow first into the open ocean, followed by larger bits from the center, like a big traffic jam.

"Historically, we thought of this place as an area that just receives ice," said David Barber, an Arctic climatologist from the University of Manitoba in Canada who was not involved in the new study. "But these results are teaching us that this is a dynamic area."

Source: American Geophysical Union [November 12, 2019]

Evolutionary diversity is associated with Amazon forest productivity

By: Thomas Schmitt Attorney on November 11, 2019 / comment : 0 Biodiversity, Ecosystems, Evolution, Genetics, Rainforests, South America

An international team of researchers led by the University of Leeds have revealed for the first time that Amazon forests with the greatest evolutionary diversity are the most productive.

The Amazon canopy [Credit: Fernanda Coelho,  University of Leeds]

The team used long term-records from 90 plots as part of the Amazon Forest Inventory Network (RAINFOR) and ForestPlots.net to track the lives and productivity of individual trees across the Amazon region. By combining these records with DNA sequence data - which identified the evolutionary relationships among all the species - the team was able to investigate the links between how fast different forests grow and their diversity.

Their study demonstrated that the plots with the greatest evolutionary diversity were a third more productive compared to areas with the least evolutionary diversity.

The finding suggest that evolutionary diversity should be an important consideration when identifying priority areas for conservation.

Study lead author Fernanda Coelho from the School of Geography at Leeds said: "Understanding how biodiversity affects productivity in tropical forests is important because it allows us to understand how conservation strategies can best be designed to maximise protection of species and the services that these ecosystems provide.

"Our results indicate that we should include evolutionary history in conservation priorities - because ecosystem function may be higher in areas where species come from right across the tree of life'.

The paper is published in Nature Ecology & Evolution.

Source: University of Leeds [November 11, 2019]

Unless warming is slowed, emperor penguins will be marching towards extinction

By: Thomas Schmitt Attorney on November 07, 2019 / comment : 0 Antarctic, Climate Change, Ecosystems, Endangered Species, Natural Heritage, Wildlife

Emperor penguins are some of the most striking and charismatic animals on Earth, but a new study from the Woods Hole Oceanographic Institution (WHOI) has found that a warming climate may render them extinct by the end of this century. The study, which was part of an international collaboration between scientists, published in the journal Global Change Biology.

The fate of emperor penguins is largely tied to sea ice, making them particulary vulnerable to warming [Credit: Stephanie Jenouvrier, Woods Hole Oceanographic Institution]

"If global climate keeps warming at the current rate, we expect emperor penguins in Antarctica to experience an 86 percent decline by the year 2100," says Stephanie Jenouvrier, a seabird ecologist at WHOI and lead author on the paper. "At that point, it is very unlikely for them to bounce back."

The fate of the penguins is largely tied to the fate of sea ice, which the animals use as a home base for breeding and molting, she notes. Emperor penguins tend to build their colonies on ice with extremely specific conditions -- it must be locked in to the shoreline of the Antarctic continent, but close enough to open seawater to give the birds access to food for themselves and their young. As climate warms, however, that sea ice will gradually disappear, robbing the birds of their habitat, food sources, and ability to hatch chicks.

Jenouvrier and her team conducted the study by combining two existing computer models. The first, a global climate model created by the National Center for Atmospheric Research (NCAR), offered projections of where and when sea ice would form under different climate scenarios. The second, a model of the penguin population itself, calculated how colonies might react to changes in that ice habitat.


"We've been developing that penguin model for 10 years," says Jenouvrier. "It can give a very detailed account of how sea ice affects the life cycle of emperor penguins, their reproduction, and their mortality. When we feed the results of the NCAR climate model into it, we can start to see how different global temperature targets may affect the emperor penguin population as a whole."

The researchers ran the model on three different scenarios: a future where global temperature increases by only 1.5 degrees Celsius (the goal set out by the Paris climate accord), one where temperatures increase by 2 degrees Celsius, and one where no action is taken to reduce climate change, causing to a temperature increase of 5 to 6 degrees Celsius.

Under the 1.5 degree scenario, the study found that only 5 percent of sea ice would be lost by 2100, causing a 19 percent drop in the number of penguin colonies. If the planet warms by 2 degrees, however, those numbers increase dramatically: the loss of sea ice nearly triples, and more than a third of existing colonies disappear. The 'business as usual' scenario is even more dire, Jenouvrier adds, with an almost complete loss of the colonies ensured.

"Under that scenario, the penguins will effectively be marching towards extinction over the next century," she says.

Source: Woods Hole Oceanographic Institution [November 07, 2019]

Human activities drying out the Amazon: NASA study

By: Thomas Schmitt Attorney on November 06, 2019 / comment : 0 Amazonia, Biodiversity, Brazil, Ecosystems, Environment, Natural Heritage, Rainforests, South America

A new NASA study shows that over the last 20 years, the atmosphere above the Amazon rainforest has been drying out, increasing the demand for water and leaving ecosystems vulnerable to fires and drought. It also shows that this increase in dryness is primarily the result of human activities.

The Amazon rainforest [Credit: Marcio Isensee e Sa/Adobe Stock]

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, analyzed decades of ground and satellite data over the Amazon rainforest to track both how much moisture was in the atmosphere and how much moisture was needed to maintain the rainforest system.

"We observed that in the last two decades, there has been a significant increase in dryness in the atmosphere as well as in the atmospheric demand for water above the rainforest," said JPL's Armineh Barkhordarian, lead author of the study. "In comparing this trend to data from models that estimate climate variability over thousands of years, we determined that the change in atmospheric aridity is well beyond what would be expected from natural climate variability."

So if it's not natural, what's causing it?

Barkhordarian said that elevated greenhouse gas levels are responsible for approximately half of the increased aridity. The rest is the result of ongoing human activity, most significantly, the burning of forests to clear land for agriculture and grazing. The combination of these activities is causing the Amazon's climate to warm.

When a forest burns, it releases particles called aerosols into the atmosphere—among them, black carbon, commonly referred to as soot. While bright-colored or translucent aerosols reflect radiation, darker aerosols absorb it. When the black carbon absorbs heat from the sun, it causes the atmosphere to warm; it can also interfere with cloud formation and, consequently, rainfall.

Why It Matters

The Amazon is the largest rainforest on Earth. When healthy, it absorbs billions of tons of carbon dioxide (CO2) a year through photosynthesis—the process plants use to convert CO2, energy and water into food. By removing CO2 from the atmosphere, the Amazon helps to keep temperatures down and regulate climate. But it's a delicate system that's highly sensitive to drying and warming trends.

The image shows the decline of moisture in the air over the Amazon rainforest, particularly across the south  and southeastern Amazon, during the dry season months - August through October - from 1987 to 2016. The measurements are shown in millibars [Credit: NASA/JPL-Caltech, NASA Earth Observatory]

Trees and plants need water for photosynthesis and to cool themselves down when they get too warm. They pull in water from the soil through their roots and release water vapor through pores on their leaves into the atmosphere, where it cools the air and eventually rises to form clouds. The clouds produce rain that replenishes the water in the soil, allowing the cycle to continue. Rainforests generate as much as 80% of their own rain, especially during the dry season.

But when this cycle is disrupted by an increase in dry air, for instance, a new cycle is set into motion—one with significant implications, particularly in the southeastern Amazon, where trees can experience more than four to five months of dry season.

"It's a matter of supply and demand. With the increase in temperature and drying of the air above the trees, the trees need to transpire to cool themselves and to add more water vapor into the atmosphere. But the soil doesn't have extra water for the trees to pull in," said JPL's Sassan Saatchi, co-author of the study. "Our study shows that the demand is increasing, the supply is decreasing and if this continues, the forest may no longer be able to sustain itself."

Scientists observed that the most significant and systematic drying of the atmosphere is in the southeast region, where the bulk of deforestation and agricultural expansion is happening. But they also found episodic drying in the northwest Amazon, an area that typically has no dry season. Normally always wet, the northwest has suffered severe droughts over the past two decades, a further indication of the entire forest's vulnerability to increasing temperatures and dry air.

If this trend continues over the long term and the rainforest reaches the point where it can no longer function properly, many of the trees and the species that live within the rainforest ecosystem may not be able to survive. As the trees die, particularly the larger and older ones, they release CO2 into the atmosphere; and the fewer trees there are, the less CO2 the Amazon region would be able to absorb—meaning we'd essentially lose an important element of climate regulation.

The study was published in Scientific Reports.

Author: Esprit Smith | Source: NASA [November 06, 2019]

The importance of Madagascar's lowland rainforest for lemur conservation

By: Thomas Schmitt Attorney on November 06, 2019 / comment : 0 Ecosystems, Endangered Species, Environment, Madagascar, Natural Heritage, Wildlife

Throughout their evolutionary history, animals in regions with limited lowland habitat have evolved to adapt to higher elevations. Although lemurs--among the most endangered mammals on earth--are flexible and can persist at intermediate and high elevations in the Madagascar's eastern rainforest, a new Mammal Review study shows that the few remaining patches of lowland rainforest host the highest levels of lemur abundance for several species.

A new study shows that the few remaining patches of lowland rainforest host the highest levels of lemur abundance for several species [Credit: Marco Campera]

The findings suggest that the rapid human encroachment occurring in Madagascar's coastal areas has disproportionately threatened these primates.

"Very few lowland forests remain in Madagascar, and most of them have been poorly studied compared with areas at mid-elevations," said lead author Marco Campera, PhD, of Oxford Brookes University, in the UK. "Our research group found that the few remaining forests at low elevations host the highest abundance of lemurs,"

"It is crucial to promote research and conservation management in the few remaining patches of lowland rainforests to reconstruct the evolutionary history of the lemurs and to ensure the best possible protection of these unique primates," added senior author Giuseppe Donati, PhD, of Oxford Brookes University, in the UK.

Source: Wiley [November 06, 2019]

Figuring out the total human impacts on biodiversity

By: Thomas Schmitt Attorney on November 05, 2019 / comment : 0 Biodiversity, Ecosystems, Environment, Natural Heritage, Wildlife

How much have humans affected the population of other species on the planet? A new methodology for documenting the cumulative human impacts on biodiversity aims to answer this question.

Gulf grouper [Credit: Alfredo Barroso, Flickr/Sea Around Us]

Dubbed EPOCH -for Evaluation of Population Change- the methodology was developed by a group of scientists from universities in Europe, Asia, and North America. It provides a standardized framework for organizing disperse data on individual species or populations of animals and plants that have been affected by urbanization, pollution, fishing, hunting, over-harvesting, and other anthropogenic activities.

Assessing impact requires contrasting the status of current populations with a reference state or baseline. However, the experts were faced with the challenge that for many species the baseline is not known because they have been impacted for a long time and those impacts have been forgotten. This phenomenon responds to the concept of 'Shifting Baseline Syndrome' developed by the Sea Around Us' principal investigator and University of British Columbia professor Daniel Pauly.

"So we decided to define baseline not as a particular date but as a reference state, that is, the population size expected today in the absence of human actions," said Ana Rodrigues, lead author of the study from the University of Montpellier. "This means that any changes in relation to this baseline reveal the cumulative extent of human impacts."

Rodrigues explained that the flexible definition allows for the baseline to be tailored to each population being studied and to be estimated from historical data, by comparing with an area where a species is still relatively intact, or by relating a less-known to a better-known species.

"For example, for Gulf grouper, we set the baseline in the 1940s, before industrial exploitation kicked off. Back then, it was considered a fish commonly present in the Gulf of California, according to historical records and interviews with old fishers. However, as time passed, data shows that it has been depleted through past overfishing and that in more recent years it is considered rare by new generations," Rodrigues said. "This is an example of a relatively recent temporal baseline but for the bowhead whales in the Barents Sea we went back 400 years, prior to industrial whaling."

Credit: Valentina Ruiz Leotaud

Each assessed species is classified into one of 11 EPOCH categories, based on the extent to which humans have affected their population numbers. Species can have experienced little change, their numbers may have moderately or severely increased or decreased, they may have been extirpated, or they may be newly present in a certain area.

"The advantage of going back in time and establishing these categories is that we can see the whole picture of how much more we have lost over hundreds of years," said Deng Palomares, a co-author of the study and the Sea Around Us project manager at UBC's Institute for the Oceans and Fisheries.

According to Palomares, her own experience setting an as-early-as-possible baseline, as it is done with the Sea Around Us' fisheries data, has already been useful to establish the reality of how much has been lost.

"Now, imagine going back hundreds of years, when explorers describe codfish as being so abundant in the coastal waters off Newfoundland that one could walk on their backs. With this framework, we bring the baseline nearer to a population's 'virgin biomass,' that is, the biomass that was there before humans invented powerful machines to harvest these resources and in the process destroy them."

For Rodrigues, Palomares, and their colleagues, these assessments that show the cumulative level of population change through time should help set realistic targets for the recovery of affected populations. "With the United Nations having just declared 2021-2030 the Decade of Ecosystem Restoration, ensuring future conservation efforts take into account the history of past change is more pertinent than ever," they wrote in their paper.

The paper was published in Philosophical Transactions B.

Author: Valentina Ruiz Leotaud | Source: Sea Around Us [November 05, 2019]

11,000 scientists declare climate emergency

By: Thomas Schmitt Attorney on November 05, 2019 / comment : 0 Biodiversity, Climate Change, Ecosystems, Endangered Species, Environment, Natural Heritage

A global team of scientists including Dr Thomas Newsome at the University of Sydney and international colleagues has warned that "untold human suffering" is unavoidable without deep and lasting shifts in human activities that contribute to greenhouse gas emissions and other factors related to climate change.

Credit: Rui Vieira/PA

The declaration is based on scientific analysis of more than 40 years of publicly available data covering a broad range of measures, including energy use, surface temperature, population growth, land clearing, deforestation, polar ice mass, fertility rates, gross domestic product and carbon emissions.

"Scientists have a moral obligation to warn humanity of any great threat," said Dr Newsome from the School of Life and Environment Sciences. "From the data we have, it is clear we are facing a climate emergency."

In a paper published in BioScience, the authors from the University of Sydney, Oregon State University, University of Cape Town and Tufts University, along with more than 11,000 scientist signatories from 153 countries, declare a climate emergency, present data showing trends as benchmarks against which to measure progress and outline six areas of action to mitigate the worst effects of a human-induced climate change.

"Despite 40 years of major global negotiations, we have generally conducted business as usual and are essentially failing to address this crisis," said Professor William Ripple, distinguished professor of ecology in the Oregon State University College of Forestry and co-lead author of the paper. "Climate change has arrived and is accelerating faster than many scientists expected."

Dr Newsome said that measuring global surface temperatures will continue to remain important. However, he said that a "broader set of indicators should be monitored, including human population growth, meat consumption, tree-cover loss, energy consumption, fossil-fuel subsidies and annual economic losses to extreme weather events".

He said the indicators are intended to be useful for the public, policymakers and the business community to track progress over time.

"While things are bad, all is not hopeless. We can take steps to address the climate emergency," Dr Newsome said.

The scientists point to six areas in which humanity should take immediate steps to slow down the effects of a warming planet:

1. Energy. Implement massive conservation practices; replace fossil fuels with clean renewables; leave remaining stocks of fossil fuels in the ground; eliminate subsidies to fossil fuel companies; and impose carbon fees that are high enough to restrain the use of fossil fuels.

2. Short-lived pollutants. Swiftly cut emissions of methane, hydrofluorocarbons, soot and other short-lived climate pollutants. This has the potential to reduce the short-term warming trend by more than 50 percent over the next few decades.

3. Nature. Restrain massive land clearing. Restore and protect ecosystems such as forests, grasslands and mangroves, which would greatly contribute to the sequestration of atmospheric carbon dioxide, a key greenhouse gas.

4. Food. Eat mostly plants and consume fewer animal products. This dietary shift would significantly reduce emissions of methane and other greenhouse gases and free up agricultural lands for growing human food rather than livestock feed. Reducing food waste is also critical - the scientists say at least one-third of all food produced ends up as garbage.

5. Economy. Convert the economy's reliance on carbon fuels to address human dependence on the biosphere. Shift goals away from the growth of gross domestic product and the pursuit of affluence. Curtail the extraction of materials and exploitation of ecosystems to maintain long-term biosphere sustainability.

6. Population. Stabilise global population, which is increasing by more than 200,000 people a day, using approaches that ensure social and economic justice.

The paper states: "Mitigating and adapting to climate change means transforming the ways we govern, manage, eat, and fulfil material and energy requirements.

"We are encouraged by a recent global surge of concern - governments adopting new policies; schoolchildren striking; lawsuits proceeding; and grassroots citizen movements demanding change.

"As scientists, we urge widespread use of the vital signs and hope the graphical indicators will better allow policymakers and the public to understand the magnitude of the crisis, realign priorities and track progress."

The graphs illustrate how climate-change indicators and factors have changed over the past 40 years, since scientists from 50 nations met at the First World Climate Conference in Geneva in 1979.

In the ensuing decades, multiple other global assemblies have agreed that urgent action is necessary, but greenhouse gas emissions are still rapidly rising. Other ominous signs from human activities include sustained increases in per-capita meat production, global tree cover loss and number of airline passengers.

There are also some encouraging signs - including decreases in global birth rates and decelerated forest loss in the Brazilian Amazon and increases in wind and solar power - but even those are tinged with worry.

The decline in birth rates has slowed over the last 20 years, for example, and the pace of Amazon forest loss may be starting to increase again.

"Global surface temperature, ocean heat content, extreme weather and its costs, sea level, ocean acidity and land area are all rising," Professor Ripple said.

"Ice is rapidly disappearing as shown by declining trends in minimum summer Arctic sea ice, Greenland and Antarctic ice sheets, and glacier thickness. All of these rapid changes highlight the urgent need for action."

Source: University of Sydney [November 05, 2019]

To save biodiversity, scientists suggest 'mega-conservation'

By: Thomas Schmitt Attorney on November 05, 2019 / comment : 0 Biodiversity, Ecosystems, Endangered Species, Natural Heritage

While the conservation of charismatic creatures like pandas, elephants and snow leopards are important in their own right, there may be no better ecological bang-for-our-buck than a sound, science-based effort to save widespread keystone systems. And the majestic aspens could be a perfect start for such an endeavor.

Hairy Woodpecker (Leuconotopicus villosus) at the famed Pando aspen clone, Fishlake National Forest, Utah, USA [Credit: Paul C. Rogers, Western Aspen Alliance]

That's the conclusion of the researchers behind the first-ever compendium of world aspen communities. In their new publication, the researchers advance the idea of "mega-conservation," where the conservation of widespread, common, species -- like aspen -- may have a strategic advantage over traditional, single-species conservation.

"The significance of aspen is that they support large numbers of dependent species, meaning aspen are truly keystone species," said Paul Rogers, the director of the Western Aspen Alliance at Utah State University and a co-author of the report. "There are six species of aspen that span much of the northern hemisphere and similarities in these aspen ecosystems allow us to employ continental conservation practices with enormous benefits to world biodiversity."

Aspen forests have been directly and indirectly impacted by human actions, including forest management favoring high-value timber trees, domestic and wild herbivore mismanagement, fire suppression, land development and mining, and extended droughts related to climate warming. A vast array of species depend on intact aspen forests; as aspen thrive or decline, so do those species dependent on their status.

Previous research, for example, has demonstrated localized declines in bird species, insects, lichens, and small mammals when aspen forests are denuded. A healthy aspen forest, on the other hand, can support thousands of other species, forming a "protective bubble," of sorts, around many vulnerable or endangered species at once.

Major world aspen species and ranges. Coloured polygons represent range extent and should not be construed  as tree species coverage densities (i.e., species may be very dense or extremely sparse within colored polygons). Aspen in all regions are known to support relatively high biodiversity of plants and animals [Credit: Paul Rogers]

"While we don't advocate choosing one strategy only, we do suggest considering the broader benefits inherent in preserving world biodiversity by using keystone ecosystems, or mega-conservation," said Bradley Pinno (Univ. Alberta, Canada), another co-author of the paper, which uses regional experts to synthesize the best-available aspen science for use by government, commercial, and non-profit research and restoration institutions.

Fourteen leading aspen ecologists from eight countries across North America and Eurasia were assembled to review aspen science, threats, and restoration practices, including an examination of 200 published papers in the field. In all regions, the group found healthy aspen enhance biodiversity, facilitate rapid recolonization in natural and damaged settings like abandoned mines, and provide adaptability in changing environments.

A key take-home message is that shared cross-border science for widespread keystone systems can facilitate effective, global-scale, biodiversity. "Moving forward, we hope to expand our burgeoning Aspen Conservation Consortium will include more national experts and will continually improve the quality of world aspen science and management," Jan Sebesta (Mendel Univ., Czechia) said, "Using aspen forests as a proxy for a mega-conservation approach, we believe that an internationally focused research and conservation management approach may be the most effective way to preserve total species numbers."

Aspen forests aren't the only potential "keystone communities," Rogers suggests. Other potential widespread keystone communities are sage-steppe lands in Europe and North America, vast taiga forests of Eurasia, or Eucalypt forests across Australia.

The study is published in Global Ecology and Conservation.

Source: Utah State University [November 05, 2019]

Carbon bomb: Study says climate impact from loss of intact tropical forests grossly underreported

By: Thomas Schmitt Attorney on October 30, 2019 / comment : 0 Biodiversity, Climate Change, Ecosystems, Endangered Species, Environment, Natural Heritage, Rainforests, Wildlife

A new study in the journal Science Advances says that carbon impacts from the loss of intact tropical forests has been grossly underreported.

Road for oil palm plantations in West Kalimantan, Indonesia [Credit: Rainforest Action Network]

The study calculates new figures relating to intact tropical forest lost between 2000-2013 that show a staggering increase of 626 percent in the long-term net carbon impacts through 2050. The revised total equals two years' worth of all global land-use change emissions.

The authors of the study, from WCS, University of Queensland, University of Oxford, Zoological Society of London, World Resources Institute, University of Maryland, and University of Northern British Columbia, found that direct clearance of intact tropical forests resulted in just 3.2 percent of gross carbon emissions from all deforestation across the pan-tropics. However, when they factored in full carbon accounting, which considers forgone carbon removals (carbon sequestration that would occur annually into the future if cleared or degraded forest had remained intact after year 2000), selective logging, edge effects and declines of carbon-dense tree species due to overhunting of seed-dispersing animals, they discovered that the figure skyrocketed by a factor of more than six times.

Said the study's lead author Sean Maxwell of WCS and the University of Queensland: "Our results revealed that continued destruction of intact tropical forests is a ticking time bomb for carbon emissions. There is an urgent need to safeguard these landscapes because they play an indispensable role in stabilizing the climate."

According to 2013 estimates, 549 million acres of intact tropical forests remain. Only 20 percent of tropical forests can be considered "intact," but those areas store some 40 percent of the above-ground carbon found in all tropical forests.

The authors say that intact forest retention rarely attracts funding from schemes designed to avoid land-use and land cover change emissions in developing nations.

Notably, the Reducing Emissions from Deforestation and Forest Degradation (REDD+) approach enables developing countries to receive financial incentives for enhancing carbon stocks, or avoiding the loss of carbon that would otherwise be emitted due to land-use and land cover change. Among other activities, REDD+ covers support for conservation of forests not under immediate threat, and was formally adopted by parties to the United Nations Framework Convention on Climate Change in 2008 at the 14th Conference of the Parties in Poland. Since then, however, financial support and implementation has predominantly focused on areas with high historical rates of deforestation (i.e. 'deforestation frontiers'). This is widely believed to deliver more immediate and more clearly demonstrable emission reductions than conserving intact forest areas. The latter tend to be treated as negligible sources of emissions as a result of the short timescales and conservative assumptions under which REDD+ operates - assumptions which the present study suggests are causing key opportunities to be missed.

Said WCS's Tom Evans, a co-author of the study: "The relative value of retaining intact tropical forest areas increases if one takes a longer-term view and considers the likely state of the world's forests by mid-century - a milestone date in the Paris Agreement. Agricultural expansion, logging, infrastructure and fires reduced the global extent of intact forests by 7.2 percent between 2000 and 2013 alone, yet the eventual carbon emissions locked in by these losses have not been comprehensively estimated."

The authors go on to say that a comparable analysis is needed for intact forests outside of the tropics such as the boreal forests of Canada and Russia, given that approximately half to two-thirds of carbon removals on earth's intact ecosystems occur outside the tropics. Without this global clean-up service, CO2 from human activities would accumulate in the atmosphere markedly faster than it does at present.

Said co-author James Watson of WCS and the University of Queensland: "Clearly, the climate mitigation potential of retaining intact forests is significant, but without proactive conservation action by national governments, supported by the global community, this potential will continue to dwindle.

At least 35 percent of the intact forests studied are home to, and protected by, Indigenous Peoples. Intact forests also provide exceptional levels of many other environmental services - for example they protect watersheds much better than degraded forests, return moisture to the air that falls in distant regions as rain, and help to keep vast numbers of species safe from extinction. When compared to forests that have been degraded by large-scale human activities, intact forests are more resistant to shocks such as fire and drought and usually less accessible to logging and agriculture conversion, making them one of our best conservation bets in the face of a rapidly changing climate.

Source: Wildlife Conservation Society [October 30, 2019]