Dust intrusion from the Sahara Desert. Credit: NASA
Spanish and Portuguese researchers have analysed the composition and radiative effect of desert aerosols during two episodes which simultaneously affected Badajoz (Spain) and Évora (Portugal) in August 2012. Results show that the intrusion of dust from the Sahara Desert caused radiative cooling of the Earth's surface.
Atmospheric aerosols (solid or liquid particles suspended in the atmosphere) are difficult to examine for various reasons. Firstly, they remain in the atmosphere for a short time and secondly, their cause may be natural or anthropogenic.
Yet there is no doubt that research into atmospheric aerosols is becoming increasingly important due to the effects that they can have on the global temperature of the Earth, given that solar radiation is the main source of energy for the Earth-Atmosphere system. Aerosols also affect human health, ecosystems and the water cycle.
For this reason, a group of researchers from Extremadura (Spain) and Portugal has analysed the radiative effect of a type of natural aerosol (the dust from the desert areas), of great interest to the Iberian Peninsula due to the proximity of the Sahara desert.
The scientists focused their study, published in the journal 'Atmospheric Research', on two desert aerosol intrusions which occurred in August 2013 and that affected two monitoring stations in the south-west of the Iberian Peninsula, in Évora and Badajoz, which belong to the AErosol RObotic NETwork (AERONET) and are managed by NASA.
During these two significant events, "the amount of radiation that reached the surface was less than that which would done if these aerosols had not been there," Mª Ángeles Obregón, researcher in the Physics department of the University of Extremadura (UEx) and the University of Évora (Portugal) and lead author of this study, explains to SINC.
Presence of pollution causes greater impact
By studying the precise measurements of these intrusions, the team determined that although the second desert dust intrusion was more intense (with a greater concentration of PM10 particles), it was in fact the earlier one which caused a greater degree of radiative cooling in both places. As the study underlines, this is due to the presence of absorbent aerosols from anthropogenic pollution.
"It was not only a mix of desert aerosol and pollution but there were also surface and column measurements. This is not always possible, given that the measurements are often contaminated by cloud cover and are fragmented, or simply do not exist because the instruments are calibrating themselves," the researcher clarifies.
During this event, the aerosols stayed close to the surface due to the presence of a anticyclone hovering over the study region at sea-level, "reducing the amount of shortwave irradiance reaching the surface and causing greater radiative cooling," states Obregón, who likens the effects of desert dust with those resulting from certain forest fires or episodes of high pollution.
However, the expert indicates that it is important to bear in mind that the effects of each type of aerosol are different due to their "varying composition, size and properties," she concludes.
More than twice as many bird species avoided California Spotted Owl habitat reserves in the northern Sierra Nevada as favored them.
A study just published this week shows many bird species, including several of high conservation concern, aren't getting the habitat they need due to a focus on promoting California Spotted Owl habitat in the northern Sierra Nevada.
The study, published in the science journal, PLoS ONE, tracked different bird species' use of areas inside and outside Spotted Owl reserves for two years in Plumas and Lassen National Forests. The results show 17 species avoided the reserves, including species of conservation concern like Yellow Warblers and Olive-sided Flycatchers, compared with only seven species preferring the habitat inside the reserves.
Federal land managers have set aside reserves, or core areas, covering 1000 acres each of relatively mature and dense forest around historical or existing Spotted Owl nest locations. Unlike their cousin, the Northern Spotted Owl, California Spotted Owls currently are not federally listed as endangered.
"There is an absolutely clear need to continue to protect old growth forests," said Ryan Burnett, Sierra Nevada Group Director for Point Blue Conservation Science and the study's lead author. "However, we're at a stage now where it's time to re-evaluate our sometimes singular focus on old-growth forest management, and ensure we are balancing it with providing diverse forest habitats for the full range of species that rely on the Sierra ecosystem."
In the northern Sierra area of the study over 50 percent of the National Forest land base is designated to promote and protect mature, closed-canopy forest that supports less undergrowth, such as shrubs and grasses. Many bird species--and other wildlife--seek out undergrowth and the habitat provided in forest openings for food, shelter and nesting.
As part of the study, Burnett and colleagues monitored the bird community at 1,164 locations inside and outside Spotted Owl reserves. They found that they could conclusively determine the habitat preference for 24 bird species detected. Of those 24 species, 17 preferred habitat outside the reserves and only seven preferred habitat inside the reserves. Another 30 species were detected but it was unclear if those birds showed a preference or not.
"Our current forest management may be focusing too much on a handful of mature, dense forest-associated species at the expense of others, including several of high conservation concern," Burnett said. "The Sierra ecosystem evolved with disturbance, such as wildfire. It's important we manage the areas outside of the old growth reserves for the wide range of habitat types and conditions that support a substantial portion of the ecosystem's biological diversity, including early seral forest habitat."
According to Burnett, a combination of forest management actions could promote habitat for many other species outside the reserves. An increased use of managed fire coupled with selective logging to thin overly dense forest stands can benefit many of the species that avoid mature, dense forest habitat and promote an ecosystem more aligned with current and future climate conditions.
Point Blue Conservation Scienceconserves birds, other wildlife, and their ecosystems, through science, outreach, and partnerships. Founded in 1965 as Point Reyes Bird Observatory, our 140 scientists work to advance nature-based solutions to climate change, habitat loss and other environmental threats.
New research shows that parrotfish play a pivotal role in providing the sands necessary to build and maintain coral reef islands.
Parrot grind up coral during feeding and, after digesting the edible content, excrete the rest as sand, which can then be used in island building. Photo by Chris Perry, University of Exeter.
As well as being a beautiful species capable of changing its colour, shape and even gender, new research published today shows that parrotfish, commonly found on healthy coral reefs, can also play a pivotal role in providing the sands necessary to build and maintain coral reef islands.
The study, based on work in the Maldives and published in the journal Geology, found that parrotfish produced more than 85% of the new sand-grade sediment on the reefs around these reef islands.
Reef islands are unique landforms composed entirely of sediment produced on their surrounding coral reefs. Despite being of vital importance to island development and future maintenance, the sources of the sediment that are most important to island building, and the rates at which this sediment is produced, has remained very poorly examined.
Professor Chris Perry of the University of Exeter, lead author of the study said: "Previous research has highlighted how important parrotfish are for the general health of coral reefs, specifically because they help to control algal growth and promote coral recruitment. Our study quantifies another fascinating aspect of the species - the major role they can play in producing the sediment necessary to build and sustain reef islands."
The study, based on work in the Maldives and published in the journal Geology, found that parrotfish produced more than 85 percent of the new sand-grade sediment on the reefs around these reef islands. Photo by Chris Perry, University of Exeter.
Using survey and sedimentary data, the researchers explored the links between reef ecology and sediment production around the island of Vakkaru in the Maldives.
They identified parrotfish as the major sand producers, generating more than 85% of the new sand-grade sediment produced on the outer reef flat each year. The fish grind up coral during feeding and, after digesting the edible content, excrete the rest as sand, a proportion of which can then be transported to adjacent island shorelines.
Professor Perry added: "Coral reef islands are considered to be among the most vulnerable landforms to climate change and especially to future sea-level rise. This study demonstrates the critical links that exist between the ecology of the reefs that surround these islands and the processes of sand supply. We provide evidence that protecting parrotfish populations, and the habitats on which they depend, is likely to be vital to ensuring a continued supply of the sediment from which these Maldivian reef islands are built."
University of Sydney geoscientists have helped prove that some of the ocean's underwater volcanoes did not erupt from hot spots in the Earth's mantle but instead formed from cracks or fractures in the oceanic crust.
The discovery helps explain the spectacular bend in the famous underwater range, the Hawaiian-Emperor seamount chain, where the bottom half kinks at a sixty degree angle to the east of its top half.
"There has been speculation among geoscientists for decades that some underwater volcanoes form because of fracturing," said Professor Dietmar Muller, from the University of Sydney's School of Geosciences in Australia and an author on the research findings published in Nature Geoscience today.
"But this is the first comprehensive analysis of the rocks that form in this setting that confirms their origins."
It has long been accepted that as the Earth's plates move over fixed hot spots in its underlying mantle, resulting eruptions create chains of now extinct underwater volcanoes or 'seamounts'.
One of the most famous is the Hawaiian-Emperor chain in the northern Pacific Ocean. The seamounts of that chain are composed mainly of ocean island basalts - the type of lava that erupts above hot spots.
But north of the Hawaiian chain, in a formation called the Musicians Ridge, researchers found samples from seamounts that were not made up of the ocean island basalts you would expect from plates moving over a hot spot.
"The oldest part of the Musicians Ridge formed approximately 90 million years ago from hot spots but these new samples are only about 50 million years old and have a different geochemistry," said Professor Muller.
"They did not form because of a hot spot but because of plates cracking open at their weakest point, allowing new magma to rise to the seabed and restart the formation of underwater volcanoes. They are near extinct hot spot volcanoes because that hot spot action millions of years earlier helped weaken the crust (the layer directly above the mantle) where new volcanoes now form."
Vulnerable spots in the Earth's plates crack when they are stressed, in this case due to movement of the Pacific Plate which started to dive or submerge back into the Earth's crust at its northern and western edges around 50 million years ago.
The formation of these younger seamounts caused by the deformation of the Pacific Plate at its margins suggests a link to the unique bend in the Hawaiian-Emperor chain.
"We believe tectonic changes along the margins of the Pacific Plate around 50 million years ago put the weakest points of the Pacific Ocean crust under tension and created the youngest Musicians Ridge seamounts," said Professor Muller.
"It also caused the flow in the slowly convecting mantle under the Pacific to change dramatically, to the point that the Hawaiian hot spot in the Earth's mantle changed its position.
"The resulting seamounts along the Hawaii-Emperor chain changed their position accordingly and the bend was born."
This work provides a solid foundation for understanding other 'non-hot spot' volcanism seen elsewhere, for example the Puka Puka Ridge in the South Pacific.
Study reveals similar genetic, geographic patterns in monk parakeet.
The two independent invasions of monk parakeets that have occurred in the United States and in Europe over the last 40-50 years appear to have originated from the same small area in the native range in South America. Photo by Steve Baldwin.
The monk parakeets that have invaded Europe and North America over the last 40-50 years fortifying their massive communal nests atop utility poles in many urban areas appear to have originated from the same small area in South America, according to a new study.
Considered one of the best speaking parrots, thousands of these bright green birds have been imported for the pet trade, and feral populations began appearing in the United States in the 1960s and in Europe in the 1980s. And yet, these two independent invasions--in the United States and in Europe--appear to have originated from the same small area in the native range, likely located in Uruguay, according to the new study, which appears online in the journal Molecular Ecology.
The study, which unravels the global invasion history of the monk parakeet, also found that that the North American and European monk parakeets have lower genetic diversity in their invasive populations compared to the genetic diversity in native populations. This is unusual because invasive species with greater genetic diversity often have a greater chance at survival--a more diverse gene pool means more variety in traits of individuals for natural selection to act upon and allow the species to survive and thrive in a new area.
Until now, very little has been known about the genetic processes linked to successful establishment of invasive parrots. Yet, a better understanding of the genetic linkages could shed light on the potential success of an invasion.
For the study, an international team of researchers based at institutions in Spain, the United States, Canada and Australia used mitochondrial DNA and microsatellite genotypic data to investigate the levels of genetic variation and to reconstruct the history of the invasions.
The study raises interesting questions about why the two separate invasions show such similar genetic patterns.
"One possibility is that these invasive populations may be under similar selection pressures. Most of the invasive populations are restricted to urban and suburban habitats, which may be selecting for some key traits that increase fitness of individuals in those environments," said co-author Elizabeth Hobson, a postdoctoral fellow at the National Institute for Mathematical and Biological Synthesis, which helped support the research.
Social behavior may also affect invasion success, Hobson said. "It could make it easier for a species to invade a new area and survive, or it could inhibit invasions in other circumstances," she said.
In their native range in South America, monk parakeets have become notorious crop pests devouring cereal grain and citrus fruits, and they have the potential to become the same especially in Florida with its citrus crops, although so far they have had minimal impacts. In their invasive range, monk parakeet activities can cause problems for electrical companies. Their massive nests of sticks atop utility poles can disrupt power and damage equipment.
In the late 1960s and early 1970s, tens of thousands of parakeets were imported to the United States as pets. Many birds have been released either deliberately or by accident by their owners, and some may have also escaped during transport. The monk parakeet has now been documented in at least 14 US states with the highest concentrations in Florida and Texas. They also roost in urbanized areas such as New York City and Chicago where they form large, noisy flocks that can be heard for great distances. Some people still keep the birds as pets, although ownership is illegal in some US states.
The National Institute for Mathematical and Biological Synthesis is an NSF-supported center that brings together researchers from around the world to collaborate across disciplinary boundaries to investigate solutions to basic and applied problems in the life sciences.
Young researcher discovers new factors impacting the fate of sinking carbon.
The researchers found that sinking particles of stressed and dying phytoplankton release chemicals that have a jolting, steroid-like effect on marine bacteria feeding on the particles. The chemicals juice up the bacteria's metabolism causing them to more rapidly convert organic carbon in the particles back into CO2 before they can sink to the deep ocean.Photo by Dawn Moran, Woods Hole Oceanographic Institution.
The ocean has been sucking up heat-trapping carbon dioxide (CO2) building up in our atmosphere--with a little help from tiny plankton. Like plants on land, these plankton convert CO2 into organic carbon via photosynthesis. But unlike land plants that are held fast to terra firma, plankton can sink into the deep ocean, carrying carbon with them. Along the way they decompose when bacteria convert their remains back into CO2.
It's called the "biological pump," and if it operated 100 percent efficiently, nearly every atom of carbon drawn into the ocean would be converted to organic carbon, sink into the deep ocean, and remain sequestered from the atmosphere for millennia. But like hail stones that melt before reaching the ground, some carbon never makes it to the deep ocean, allowing CO2 to leak back into the upper ocean and ultimately exchange with the atmosphere.
In a new study published April 27 in the Proceedings of the National Academy of Sciences, scientists at Woods Hole Oceanographic Institution (WHOI) and their colleague from Rutgers University discovered a surprising new short-circuit to the biological pump. They found that sinking particles of stressed and dying phytoplankton release chemicals that have a jolting, steroid-like effect on marine bacteria feeding on the particles. The chemicals juice up the bacteria's metabolism causing them to more rapidly convert organic carbon in the particles back into CO2 before they can sink to the deep ocean.
"We think these compounds are acting as signals to the bacterial community to let them know phytoplankton are dying, lots of 'free' food on the way, and to ramp up their metabolisms," said Bethanie Edwards, lead author of the study and a graduate student in the MIT/WHOI Joint Program in Oceanography. "When the bacteria consume phytoplankton faster, more CO2 is given off in the shallow depths, where it can return to the surface of the ocean and the atmosphere more quickly."
Typically, the detritus of phytoplankton have no special effect on bacteria; they are simply a food source. But the phytoplankton in this study--diatoms--are different. When stressed, some diatoms release bioactive molecules known as polyunsaturated aldehydes (PUAs). The researchers found that these molecules kick the bacteria's metabolism and CO2 respiration rates into hyperdrive -- like skinny weightlifters after a steroid shot. The bacteria start devouring the falling particles like they are at an all-you-can-eat buffet, and significantly reduce the amount of sinking detritus while releasing CO2.
Lead author Bethanie Edwards, a graduate student in the MIT/WHOI Joint Program in Oceanography, with her advisor, Ben Van Mooy, a co-author of the study and a marine chemist at WHOI. Working with colleague Kay Bidle of Rutgers University, the team's research is the first to show how molecular compounds affect what happens to CO2 in the ocean. Photo by Tom Kleindinst, Woods Hole Oceanographic Institution.
Edwards, her advisor, WHOI scientist Ben Van Mooy, and co-author Kay Bidle from Rutgers University went to sea to collect and analyze particle samples from several locations across the North Atlantic, including the Sargasso Sea, the subarctic North Atlantic near Iceland, and the western North Atlantic near Massachusetts. The spatial coverage was important, Van Mooy said.
"We know that there's more sinking carbon in some places and less in others, so we wanted to better understand the distribution across different ocean regions," he said.
To collect the particles, 6-foot-wide, funnel-shaped sediment traps were submerged 150 meters down (picture huge traffic cones dunked upside down in the ocean) for 24 hours. Once the traps were brought back to surface, the scientists incubated collected particles with PUAs and analyzed changes in bacterial metabolism over a 24-hour period.
"Very rarely do you see organisms respond positively to PUAs. In fact, in higher concentrations, they often have a toxic effect, causing a decrease in phytoplankton growth rates and mutations," Edwards said. "But our results were very surprising. We saw an increase in CO2 production rates, enzyme activity, and bacterial cell growth."
The scientists also found much higher concentrations of PUAs within the sinking particles than had been previously been observed in the water column. "This suggests that sinking particles are 'hotspots' for PUA production," Edwards said.
"This study shows that when it comes to long-term biological sequestration of atmospheric carbon dioxide in the ocean, not all species of phytoplankton are created equal," said Don Rice, program director for the National Science Foundation (NSF)'s Chemical Oceanography Program, which partially funded the research.
"These scientists have uncovered yet another nuance that may affect the efficiency of the biological pump to remove carbon from surface waters," added David Garrison, program director for NSF's Biological Oceanography Program, which also contributed funds for the project.
To collect the particles of sinking phytoplankton, the scientific team used 6-foot-wide, funnel-shaped sediment traps at several locations across the North Atlantic, including the Sargasso Sea, the subarctic North Atlantic near Iceland, and the western North Atlantic near Massachusetts. The traps were submerged at depths of 150 meters for 24 hours and then the collected particles were analyzed in the lab. Photo by Suni Shah, Woods Hole Oceanographic Institution.
Small compounds, big implications
Scientists investigating what controls the fate of carbon in the ocean have explored factors such as how easily phytoplankton particles break down, how much carbon they contain, and how fast they sink. According to Van Mooy, this research is the first to show how molecular compounds affect what happens to CO2 in the ocean.
"The depth of organic carbon sinking is important, as about a quarter of CO2 from burning fossil fuels ends up in the deep ocean because of these mechanisms," said Van Mooy. "For over half a century people have been trying to understand why carbon sinks more here and less there. These molecules [PUAs] are telling us they have a role to play in all this."
"We typically think of temperature and other physiochemical factors as being critically important in determining the bacterial processing of diatom detritus and how deep it sinks in the ocean, but this work shows that the molecular composition of 'infochemicals' really matters," said Bidle.
"The team makes a strong case that the growth of microbes and the consequent flow of carbon in the sea can be influenced not only by predation and nutrient limitation, but also by unique chemicals that have an effect on microbial behavior -- an important new idea for the field," said Jon Kaye, program director of the Marine Microbiology Initiative at the Gordon and Betty Moore Foundation, the study's major funder.
Edwards sees the research as a steppingstone toward a clearer understanding of CO2 absorption in the ocean and the efficiency of the biological pump in the vast planetary cycle that circulates carbon through air, land, ocean, and living things.
"By gaining more detailed knowledge about the intricate interactions of marine microbes," she said, "we can paint a more complete picture of how the carbon cycle works, the positive and negative feedbacks, and the implications for global climate."
The research was funded by the Gordon and Betty Moore Foundation, with additional support from the National Science Foundation and the Office of Naval Research.
The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.
An Australian Giant Cuttlefish crosses a seagrass bed. Credit: Richard Ling
By Science for Environment Policy
Damage caused by boats anchoring in seagrass meadows off the coast of Sardinia continues despite restrictions, new research shows. The study's authors provide a number of recommendations to help protect seagrass. These include creating special anchoring areas in seagrass-free locations, and limiting the number of boats that enter a marine protected area.
Seagrass meadows are important marine habitats that provide ecosystem services such as nursery habitats for fish, coastal protection and water purification. The EU'sHabitats Directive and the Water Framework Directive recognise the importance of seagrass meadows, and marine protected areas (MPAs) have been set up to help ensure their protection.
Many meadows face increasing pressures from human activities. These include boat anchors or moorings, which can uproot seagrass or expose its delicate roots.
The study used underwater surveys by divers to evaluate the effect of anchoring damage, the impact of traditional mooring systems and the effectiveness of mooring fields (designated areas for boat mooring where mooring systems, such as dump weights, are provided) on the conservation of meadows of the seagrass Posidonia oceanica.
The study area was the La Maddalena Archipelago National Park, Italy, a 50km2 MPA off the coast of Sardinia. Despite its protected status, seagrasses in the area are still threatened by boat anchoring. The researchers focused on two areas of the park, Cala Portese and Porto Madonna, which are most frequented by boats and equipped with mooring fields.
In general, the researchers found disturbed or very disturbed seagrass in all investigated areas, including 'control areas', where mooring is not allowed, at distances of 300–500 m from the edge of mooring fields.
Seagrass covered 50–60% of the seafloor, on average, within mooring fields compared with 80–90% in the control areas. Seagrass meadows within mooring fields were also more fragmented than in control areas. This, the researchers say, suggests that mooring fields and 12 years of restrictions (on the amount and locations of anchoring in the MPA) have been an ineffective tool for protecting seagrass.
At each area studied, the researchers found an increase of up to 34% in anchoring damage following the tourist season. In control areas, anchor damage increased by 18% and 70% at Cala Portese and Porto Madonna, respectively. This shows that current anchoring restrictions are often ignored. Additionally, the researchers found that there was a lower density of seagrass around traditional mooring systems, such as dump weights. This suggests that such moorings can become dislodged, due to wave action or misuse, and move along the seafloor, damaging seagrass.
These findings led the study's authors to suggest a number of possible actions, both practical and legislative, to improve the protection of P. oceanica from anchoring damage. These are as follows:
Establish free zones for anchoring in areas where seagrass is not present, such as sandy bottoms.
Establish a maximum number of boats permitted in the park based on the number of mooring buoys available and the capacity of the designated anchoring sites on sandy bottoms.
Replace current mooring systems with 'seagrass-friendly' systems.
Better enforce anchoring restrictions, for example, by using surveillance technologies and co-operating closely with law enforcement.
Implement educational programmes or campaigns to change boaters' attitudes and behaviours to anchoring in coastal areas.
Design and use a long-term monitoring plan to measure the effects of any management strategy.
Citation: La Manna, G., Donno, Y., Sarà, G. & Ceccherelli, G. (2015). The detrimental consequences for seagrass of ineffective marine park management related to boat anchoring. Marine Pollution Bulletin 90(1-2): 160–166. DOI:10.1016/j.marpolbul.2014.11.001.
Hunting has obvious impacts on wild populations. However, new research concludes that for Scandinavian brown bears (Ursus arctos), it also contributes to the killing of cubs by adult males to increase the male's chances of mating with the cubs' mother. The researchers say that this indirect effect of hunting should be considered when developing sustainable hunting quotas and management plans.
Hunting is believed to lead to increases in sexually selected infanticide (SSI) among some species. SSI occurs when mating opportunities are limited and it becomes advantageous for one sex (usually males) to kill the offspring of another individual.
In the case of Scandinavian brown bears, infanticide can benefit adult males because females can mate again shortly after losing their young during the mating season. Hunting may promote SSI in this species because where a resident male is killed, his replacement will probably be unrelated to the cubs in the area.
This study aimed to quantify the impact of hunting and SSI on a Scandinavian brown bear population. The researchers monitored the survival of 180 adult females and their young (a total of 466 cubs) over the period 1990–2011 in a 13 000 km2 forested area of south-central Sweden.
They assessed survival rates of these bears in relation to the level of 'hunting pressure' at any one time. Hunting pressure was calculated as the number of bears legally killed divided by the number of bears legally available for hunting and monitored by the researchers. Hunters are allowed to kill any bear except 'family groups', i.e. females and their dependent young.
The researchers noted that there were two distinct periods of hunting pressure during 1990–2011. During 1990–2005, average pressure was low at 0.073. However, it rose to 0.199 during 2006–2011. These two periods provided a useful way to compare the effects of low and high hunting pressure on the bears.
They found that the population growth rate of the bears was positive during the low hunting pressure period: each year the population was estimated to be 1.082 times bigger than the previous year. The growth rate dropped during the high pressure period, to 0.975. This means that the local population would progressively get smaller, by 2.5% every year if hunting pressure stays at this level.
However, this reduction in growth rate cannot be explained by the number of bears directly killed by hunters alone. The researchers also found that 80.9% of cub deaths occur during the mating season. They attribute 'most, if not all' of these deaths to SSI. Without SSI, they expect that nearly all cubs (96.8%) would have survived their first year during 2006–2011, instead of the 53.5% that they actually observed.
The study also noted that fewer cubs were born during the high hunting pressure period, which also contributed to the negative population growth rate. Some mothers may have actively avoided males during mating season in order to protect their young from SSI. This would have possibly reduced the quality of their diet and future opportunities for reproduction.
Without SSI's effects, the population growth rate would have been 1.055. This means that the population would grow even with the direct effects of high hunting pressure.
Researchers have designed and proposed a new organic waste management plan for Catalonia, Spain, and presented it in a recent study. They say that the plan would reduce a number of environmental impacts that arise from landfilling biodegradable waste, including natural resource depletion, acidification and eutrophication.
To reduce the negative environmental effects of landfilling and to promote the sustainable management of biodegradable municipal waste, the EU Landfill Directive has set targets for EU Member States to limit the amount of landfilled biodegradable municipal waste to no more than 35% of the amount produced in 1995, by 2020.
For this study, the researchers proposed a new biowaste management plan. They used model simulations to examine the outcomes of using the plan to treat the annual amount of organic municipal solid waste produced in Catalonia in 2012 (1218 gigagrams (Gg)). In particular, they looked at the impact of using anaerobic digestion for recycling biowaste to produce biogas, adding sludge to soil, and various forms of industrial and home composting treatments.
They compared this new plan with those of actual waste management in 2012 in terms of impacts on abiotic (non-living) natural resource depletion, acidification, eutrophication, global warming, ozone layer depletion and summer smog.
The proposed management model meets the requirements of the Landfill Directive, as well as the new Catalan waste management plan (2013–2020). As incineration or disposal to landfill of untreated municipal solid waste is banned, the new plan is designed to cope with the increased volume of organic waste (food and green waste) collected by local authorities.
Under the plan, waste would be preferentially treated in anaerobic digestion plants, as well as in existing composting plants. To reduce ammonia and volatile organic compound (VOC) emissions from composting, biofilters would be installed in composting plants. The organic fraction of the municipal solid waste that had not been collected separately would be composted before being landfilled. Levels of home composting would also increase.
The results show that the new waste management plan would have caused less environmental damage across all impacts considered, compared with the actual 2012 management. The impact on summer smog was the only one to increase (by 23%) under the proposed scheme, mainly because more VOCs are emitted from composting processes than from landfill.
Under the new waste plan, global warming impacts would be reduced by 36%, the model predicts. Eutrophication impact would be cut by 49%, mainly through avoided nitrogen and phosphorus compounds leaching from landfill sites. Abiotic resource depletion would fall by 16%, largely the result of energy recovery from anaerobic digestion, but also through reduced transport to landfill sites. Furthermore, the ozone layer depletion impact would be reduced by 9%.
The researchers also highlight uncertainties related to modelling waste management systems. They found, for example, that if methane emissions escaping from the anaerobic digestion process are not controlled or collected, the climate change impact of this plan could actually increase by up to 31%.
This work can help similar European regions that need to change their biowaste management with the aim of implementing Landfill Directive recommendations in the mid-term future, say the researchers.
Citation: Colón, J., Cadena, E., Belen Colazo, A.B., Quiros, R., Sanchez, A., Font, X. & Artola, A. (2015). Toward the implementation of new regional biowaste management plans: Environmental assessment of different waste management scenarios in Catalonia. Resources, Conservation and Recycling. 95: 143–155. DOI:10.1016/j.resconrec.2014.12.012.
Prize honors Tom Graedel, pioneering figure in the field of industrial ecology.
The Kroon Hall is home to Yale School of Forestry & Environmental Studies. It features rooftop photovoltaic panel providing 25% of the building’s electricity. Architects: Hopkins Architects with Centerbrook Architects and Planners.
The Journal of Industrial Ecology (JIE) has introduced a new prize, the Graedel Prize, honoring the best papers by a junior and senior author published in the journal. The prize is named for Yale Professor Thomas E. Graedel in recognition of his vital contributions and pioneering work in the development of the field of industrial ecology.
The annual prizes are being awarded to one paper written by a junior single author or first author and one paper written by a senior single author or first author. The winners of the 2015 Graedel Prize are:
Junior Author Best Paper: "Comparative Environmental Life Cycle Assessment of Conventional and Electric Vehicles," written by Troy R. Hawkins, Bhawna Singh, Guillaume Majeau-Bettez, and Anders Hammer Strømman.
Senior Author Best Paper: "An Exploration of the Relationship between Socioeconomic and Well-Being Variables and Household Greenhouse Gas Emissions," written by Jeffrey Wilson, Peter Tyedmers, and Jamie E.L. Spinney.
The Journal of Industrial Ecology is a peer-reviewed, international scientific journal on industry and the environment owned by Yale University, headquartered at its School of Forestry & Environmental Studies (F&ES) and published by Wiley-Blackwell.
Prof. Graedel, who has served as professor of industrial ecology and director of the Center for Industrial Ecology at F&ES since 1996, will retire in June. Under his visionary guidance, Yale took a leadership role in developing and institutionalizing industrial ecology, including establishing the Journal of Industrial Ecology to become the primary scholarly journal in the field. Prof. Graedel published seminal articles and the first textbook on industrial ecology, served as the first president of the International Society for Industrial Ecology (ISIE), and established the Gordon Research Conference on Industrial Ecology.
The winners of the inaugural Graedel Prizes will receive $750 and a free membership in the ISIE. Funding for the prize has been provided by the Raw Materials Group Stockholm, A-1 Recycling, GE, AT&T, and the Nickel Institute.
The paper by Hawkins and colleagues compared conventional vehicles and electrical vehicles (EVs). They compiled new data on the greenhouse gas emissions originating from the production of EVs and provided an especially transparent data set in a research field where key data are often proprietary. The authors found that the relative life cycle benefits of EVs are very sensitive to the carbon intensity of the electricity that is used. The paper generated a global debate over the carbon footprint of EVs and, during the month of its release, it was the most downloaded scientific article published by Wiley, the journal's publisher.
The authors are affiliated with the Industrial Ecology Programme (IndEcol) at the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway. Troy R. Hawkins, director of Life Cycle Assessment at Enviance in Cincinnati, Ohio, was a postdoctoral researcher with IndEcol when the paper was written. Other authors are Bhawna Singh, Guillaume Majeau-Bettez, and Anders H. Strømman.
The paper by Wilson and colleagues examines the relationship between direct greenhouse gas (GHG) emissions and socioeconomic and well-being variables, with an unprecedented level of specificity based on household energy use survey data and personal travel data verified by geographic positioning systems. The findings challenge hoped-for linkages between emissions and well-being, and between emissions and environmental attitudes -- important for public policy.
The authors are collaborators based in Halifax, Nova Scotia, Canada. Jeffrey Wilson is an assistant professor at Dalhousie University. The other authors are Peter Tyedmers at Dalhousie University and Jamie Spinney at Saint Mary's University.
