Constantine Alexander's blog

WSU researcher sees how forests thrive after fires and volcanoes

Forest succession helps rare plants and animals

WSU Pullman, WA.

Forests hammered by windstorms, avalanches and wildfires may appear blighted, but a Washington State University researcher says such disturbances can be key to maximizing an area's biological diversity.

In fact, says Mark Swanson, land managers can alter their practices to enhance such diversity, creating areas with a wide variety of species, including rare and endangered plants and animals.

"The 1980 eruption of Mt. St. Helens, for example, has created very diverse post-eruption conditions, and has some of the highest plant and animal diversity in the western Cascades range," says Mark Swanson, an assistant professor of landscape ecology and silviculture in Washington State University's School of the Environment.

Swanson, who has studied disturbed areas on Mount St. Helens and around western North America, presents his findings this week at the national convention of the Ecological Society of America in Portland.

His findings run counter to a widely held perception that most, if not all rare species tend to require older forests, not younger. In fact, he says, a substantial proportion of Washington's state-protected forest plants and animals spend some or all of their life cycle in areas rebounding from a major disturbance. That's because such habitats often include woody debris and snags, varied landscape patterns, and a rich diversity of plants that can be exploited for food and shelter.

"Severe fire in the northern Rockies creates conditions for some rare birds that depend on abundant dead trees, like the black-backed woodpecker," says Swanson. "It can benefit a host of other organisms, too, like elk, deer, bighorn sheep, some frog species, and many more."

Forest disturbances can be natural events, says Swanson, but they can also be the product of carefully designed forest harvests. In either case, he says, forest managers can help maximize biological diversity with practices that extend the time it takes the forest to return to a climax state with a closed canopy.

Clearcutting often leaves too little behind to provide habitat for a diversity of species, Swanson says. Also, clearcut areas are often reforested too quickly to allow open conditions and a diverse herb and shrub community to persist. By the same token, post-disturbance logging can hurt diversity by removing structures favored by plants and animals.

However, where maintaining biodiversity is an objective, like on federal lands, timber harvests can be designed to mimic natural disturbance and create habitat for some species that depend on a forest's recovery, or succession, says Swanson. Afterwards, he says, managers should avoid dense "recovery" plantings that can so shorten a forest's succession that they give short shrift to the ecological role of its early stages.

Contact: Eric Sorensen
eric.sorensen@wsu.edu
206-799-9186
Washington State University

 

 

Holy bat detector! Ecologists develop first Europe-wide bat ID tool

		This is a grey long-eared bat. Credit: Hugh Clark / Bat Conservation Trust

Just as differences in song can be used to distinguish one bird species from another, the pips and squeaks bats use to find prey can be used to identify different species of bat. Now, for the first time, ecologists have developed a Europe-wide tool capable of identifying bats from their echolocation calls.

The new free online tool – iBatsID – will be a major boost to conserving bats, whose numbers have declined significantly across Europe over the past 50 years. Details are published today in the British Ecological Society's Journal of Applied Ecology.

Working with an international team of ecologists, lead author and PhD student Charlotte Walters from the Zoological Society of London (ZSL) selected 1,350 calls of 34 different European bat species from EchoBank, a global echolocation library of more than 200,000 bat calls.

The calls were then analysed to find out which characteristics were most useful in distinguishing different bat species. According to Walters: "Lots of different measurements can be taken from an echolocation call, such as its maximum and minimum frequency, how quickly the frequency changes during the call, and how long the call lasts, but we didn't know which of these measurements are most useful for telling different species' calls apart."

The 12 most useful call parameters were then used to train artificial neural networks to produce the new identification tool, iBatsID, which can identify 34 different bat species across the whole of Europe. Most species can be identified correctly more than 80% of the time, although accuracy varies because some species are much harder to identify than others.

"iBatsID can identify 83-98% of calls from pipistrelle species correctly, but some species such as those in the Myotis genus are really hard to tell apart and even with iBatsID we can still only identify 49-81% of Myotis calls correctly," she explains.

iBatsID should have a major impact on European bat conservation, which until now has been hampered by the absence of a standardised, objective and continent-scale identification tool.

According to Professor Kate Jones, another of the paper's authors and chair of the Bat Conservation Trust: "Acoustic methods are really useful for surveying and monitoring bats, but without using the same identification methods everywhere, we can't form reliable conclusions about how bat populations are doing and whether their distributions are changing. Because many bats migrate between different European countries, we need to monitor bats at a European, as well as at country, scale. In iBatsID, we now have a free, online tool that works anywhere in Europe." Bat populations have declined significantly across Europe since the middle of the 20th century. As a result, all bats are now protected through the EU Habitats Directive. Bats face many pressures, including loss of roosting sites in trees and buildings; loss of feeding habitats in woodlands, meadows, parks and gardens; falling insect numbers; and habitat fragmentation resulting in the loss of green corridors such as hedges that provide connectivity in the landscape.

As well as providing vital ecosystem services, such as pollinating plants and controlling insect pests, bats are important indicators of biodiversity. "Bats are very sensitive to changes in their environment, so if bat populations are declining, we know that something bad is going on in their environment. Monitoring bats can therefore give us a good idea of what is going on with biodiversity in general," Walters adds.

• iBatsID is available free online.

Reference: Charlotte L Walters et al (2012). 'A continental-scale tool for acoustic identification of European bats', doi: 10.1111/j.1365-2664.2012.02182.x, is published in the Journal of Applied Ecology on Tuesday 7 August 2012.

Contact: Becky Allen
beckyallen@ntlworld.com
44-012-235-70016
Wiley

 

 

Birds do better in 'agroforests' than on farms

Study indicates growing coffee and cacao in shade helps birds

		The orange-billed nightingale-thrush is an insect-eating bird that lives on Costa Rican "shade " coffee plantations. A new University of Utah study indicates that, compared with open farmland, wooded "agroforests " like shade coffee and cacao plantations promote bird diversity and also the "ecosystem services" birds provide to human society, including insect control, spreading seeds and pollinating crops. Credit: Çağan Şekercioğlu, University of Utah

Compared with open farmland, wooded "shade" plantations that produce coffee and chocolate promote greater bird diversity, although a new University of Utah study says forests remain the best habitat for tropical birds.

The findings suggest that as open farmland replaces forests and "agroforests" – where crops are grown under trees – reduced number of bird species and shifts in the populations of various types of birds may hurt "ecosystem services" that birds provide to people, such as eating insect pests, spreading seeds and pollinating crops.

"We found that agroforests are better overall for bird biodiversity in the tropics than open farms," says study author Çağan H. Şekercioğlu (pronounced Cha-awn Shay-care-gee-oh-loo), an assistant professor of biology at the University of Utah.

"This doesn't mean people should farm in intact forests," the ornithologist adds. "But if you have the option of having agroforest versus open farmland, that is better for biodiversity, with shade coffee and shade cacao [the source of cocoa and chocolate] being the prime examples."

Şekercioğlu's new study, funded by the University of Utah, is being published this month in the Journal of Ornithology. He will present the findings Thursday, Aug. 9, at the Ecological Society of America's annual meeting in Portland, Ore.

If consumers wish to support bird diversity and agroforests, "a good way is by choosing certified, bird-friendly, shade coffee or shade chocolate," he says. While such coffee or chocolate often cost more because they are more labor-intensive to produce, the certification "is usually better for the farmers' income as well."

He adds: "There are trustworthy environmental organizations that certify shade coffee," including the Smithsonian Institution, the Rainforest Alliance and the Rainforest Action Network.

Other crops grown in shade include cardamom, which is a spice, and yerba mate, which is steeped in hot water to make a beverage popular in South America.

Study Focuses on Birds of Forests, Farms or Both

An agroforest "is a type of farm where the crops are grown under trees at a reasonable density," Şekercioğlu says. "Often, it's not like forest-forest – it feels more like a open park," although in Ethiopia "commercial coffee is grown under full-on forests in its original native habitat."

Şekercioğlu conducted the study in two steps. First, "I used my world bird database that has information on all the 10,000-plus bird species of the world," he says. "I sorted birds based on habitat choices and compared species that prefer forests to those that prefer agricultural areas and others that prefer both forests and agricultural areas."

		University of Utah ornithologist Çağan Şekercioğlu uses radio equipment to track an orange-billed nightingale-thrush in the Costa Rican countryside. A new study by Şekercioğlu indicates that wooded "shade " plantations where coffee and cacao (the source of chocolate) are grown are better for bird diversity than open farmlands, although forests still are the best habitat for tropical birds. Credit: Mauricio Paniagua Castro

Next, he reviewed about 40 previously published studies that examined bird communities in forests, agroforests and open agricultural areas.

"The global analysis of all the birds species mostly agrees with the findings of detailed local bird studies," Şekercioğlu says.

The study focused 6,093 tropical bird species, including migratory birds, in which their top three habitat choices (out of 14 possible habitats) included forests, farms or both, with the latter described as agroforest birds. So the study found 4,574 bird species that include forest but not farms in their top three habitats, 303 species that include farms but not forests in their top three habitat choices, and 1,216 agroforest species tha include both forests and farms among their top three habitats.

The findings suggest, but don't prove, that conversion of forest to farmland may reduce ecosystem services, which are services birds provide to people.

"As you go to more and more open agriculture, you lose some bird groups that provide important ecosystem services like insect control [insect eaters], seed dispersal [fruit eaters] and pollination [nectar eaters], while you get higher numbers of granivores [seed and grain eaters] that actually can be crop pests," Şekercioğlu says. Specifically:

• Insectivores or insect-eating birds do best in forests – especially those that live near the ground in the understory, the layer of plants below the tree canopy and above the ground cover. But small and medium insect-eating birds, especially migrant and canopy species, do well in agroforests. The number of insect-eating species declines on open farms, where they help control pests.
• Frugivores or fruit-eating birds, especially larger ones, "do best in forest because they have more habitat and more food, and the large ones often are hunted outside forests in agricultural settings. Overall, frugivores – especially smaller ones – do OK in agroforests, but the number of fruit-eating species decline significantly on open farms." Frugivores help spread the seeds of the fruits they eat.
• Nectarivores or nectar-eating birds help pollinate many plants. They "tend to increase in agroforests compared with forests. A lot of nectar-eating birds obviously like flowers, and many plants flower when there's some light. When you have extensive forest its often pretty shady so not many things are in flower at any given time." The nectar eaters are less common on open farms.
• Omnivores, which are birds that eat many things, "tend to do better in agroforests and especially on open farms" than in forests, because their diet is so generalized instead of specialized in certain foods.
• Granivores, or grain- and seed-eating birds are "the only group that significantly increases in open agricultural areas. A lot of the seeds they eat are grass seeds, but also from crops. Some of these seed-eating bird species are major agricultural pests, and that's another reason for encouraging agroforests. In completely open agricultural systems, you have more seed-eating birds that can cause significant crop losses."

		An orange-collared manakin, a fruit-eating bird that lives in wooded "shade " coffee plantations in Costa Rica. It is an example of a bird that does better living in such "agroforests " than on open farms. A new University of Utah study indicates that while tropical forests are best, agroforests are better than open farms for many birds. Credit: Çağan Şekercioğlu, University of Utah

While the study found fewer species on farms than in agroforests, and fewer on agroforests than in forests, Şekercioğlu says it doesn't answer a key question: "Does the decline in the number species translate into a decline in individuals providing a given ecosystem service?" If so, farms and agroforests have lost birds that provide important insect-control, pollination and seed-dispersal services.

"It is possible you may lose a lot of species, but some of the remaining species increase in number and compensate and for the decline in ecosystem services by the lost species," he adds. "It's one of the biggest questions in ecology."

The Trend toward Sun Coffee

Noting that the study found forests have more tropical bird species than agroforests, which in turn have more bird species that open farms, Şekercioğlu says: "A lot of threatened species globally are found only in forests, and most of them disappear from agroforests and open agricultural areas."

He says many migratory birds that breed in the United States are in decline – even though the nation has a law to protect them – and not just because of U.S. environmental problems, "but due to problems in their wintering grounds in Latin America, such as loss of habitat and intensification of agriculture."

"Coffee was originally a mid- to high-elevation African forest understory plant," he adds. "For centuries in Ethiopia and parts of Central and South America, coffee has been grown as an understory plant with shade traditionally provided by native trees."

But fungi can be a problem in humid shade coffee plantations, and growers have come up with varieties that grow well in the sun with less fungus and bigger yields, so in recent decades, there has been a trend toward converting Central and South American shade-coffee forests to open farms, Şekercioğlu says.

"As tropical forest is converted to increasingly open types of agriculture, hundreds of endangered bird species are being lost," he says. "Tropical forest is the only refuge for thousands of bird species and hundreds of endangered bird species. Although agroforest is better than open farmland, at the end of the day intact tropical forest is the only suitable habitat for thousands of bird species."

Contact: Lee Siegel
lee.siegel@utah.edu
801-581-8993
University of Utah

 

 

UMass Amherst, national team define limits of microbial life in an undersea volcano

A third of Earth's organisms by mass live in rock and sediments, yet their lives and ecology are a mystery - This week, a report in PNAS offers the first detailed data about a group of methane-exhaling microbes in undersea volcanoes

		The research submarine Alvin reaches with its mechanical arm to a high-temperature black smoker at the Endeavour Segment, Juan de Fuca Ridge, to study methanogenic microbes. Credit: Bruce Strickrott of WHOI

By some estimates, a third of the Earth's organisms by mass live in our planet's rocks and sediments, yet their lives and ecology are almost a complete mystery. This week, microbiologist James Holden at the University of Massachusetts Amherst and others report in Proceedings of the National Academy of Sciences the first detailed data about a group of methane-exhaling microbes that live deep in the cracks of hot undersea volcanoes.

Holden says, "Evidence has built over the past 20 years that there's an incredible amount of biomass in the Earth's subsurface, in the crust and marine sediments, perhaps as much as all the plants and animals on the surface. We're interested in the microbes in the deep rock, and the best place to study them is at hydrothermal vents at undersea volcanoes. Warm water flows bring the nutrient and energy sources they need."

"Just as biologists studied the different habitats and life requirements for giraffes and penguins when they were new to science, for the first time we're studying these subsurface microorganisms, defining their habitat requirements and determining how those differ among species. It's very exciting, and will advance our understanding of biogeochemical cycles in the deep ocean."

The study also addresses such questions as what metabolic processes may have looked like on Earth 3 billion years ago and what alien microbial life might look like on other planets. Further, because the study involves methanogens, microbes that inhale hydrogen and carbon dioxide to produce methane as waste, it may also shed light on terrestrial natural gas formation.

One major goal was to test results of predictive computer models and establish the first environmental hydrogen threshold for hyperthermophilic (super-heat-loving) methanogenic (methane-producing) microbes in hydrothermal fluids. "Models have predicted the habitability of the rocky environments that we're most interested in, but we wanted to ground truth into these models and refine them," Holden explains.

In a 2-liter bioreactor at UMass Amherst where she could control hydrogen levels, graduate student Helene Ver Eecke grew pure cultures of hyperthermophilic methanogens from their study site alongside a commercially available hyperthermophilic methanogen species as a control. She found growth kinetics for the three organisms were about the same. That is, all grew at the same rate when given equal amounts of hydrogen and had the same minimum growth requirements. "These experiments established for the first time that these methanogens need at least 17 micromolar of hydrogen to grow," Holden says.

Investigators from several institutions brought an unusually rich mix of expertise to this work. Holden and Ver Eecke at UMass Amherst used culturing techniques to look for organisms in nature and then study their growth kinetics in the lab. Co-investigators Julie Huber at the Marine Biological Laboratory on Cape Cod provided molecular analyses of the microbes while David Butterfield and Marvin Lilley at the University of Washington contributed geochemical fluid analyses.

Using the research submarine Alvin, they collected samples of hydrothermal fluids flowing from black smokers up to 350 degrees C (662 degrees F) and seeping out of ocean floor cracks at lower temperatures. Samples were from Axial Volcano and the Endeavour Segment, both long-term observatory sites along an undersea mountain range about 200 miles off the coast of Washington and Oregon and 1-1.5 miles below the surface.

"We use specialized sampling instruments to measure both the chemical and microbial composition of hydrothermal fluids," says Butterfield. "This is an effort to understand the biological and chemical factors that determine microbial community structure and growth rates." At the Axial site, they found hydrogen above their methanogen threshold for growth and molecular, organismal and geochemical evidence of on-going methanogenesis, while at Endeavour hydrogen levels were below their threshold and evidence for methanogenesis was largely absent. Others have taken culture and fluid samples around the world, so Holden and colleagues analyzed these as well and confirmed the lower threshold of hydrogen concentration needed by these methanogens.

There was a final happy twist awaiting the researchers as they pieced together a picture of how these methanogens live and work. At the low-hydrogen Endeavour site, they found that a few hyperthermophilic methanogens can eke out a living by feeding on the hydrogen waste produced by other hyperthermophiles.

"This was extremely exciting," says Holden. "We hypothesized that the methanogens grow syntrophically with the hydrogen producing microbes, and it worked out that way in the lab with a strain from the site. So we have described a methanogen ecosystem that includes a symbiotic relationship between microbes, which in my mind highlights the strength of our multi-pronged team approach. It really paid off. We feel that more research coupling broad field measurements with laboratory experiments will be really fruitful in the future."

Support for this research was from the National Science Foundation, NASA Astrobiology Institute, and the National Oceanographic and Atmospheric Administration.

Contact: Janet Lathrop
jlathrop@admin.umass.edu
413-545-0444
University of Massachusetts at Amherst

 

 

Microbes, sponges, and worms add to coral reef woes

Study by Wildlife Conservation Society and University of the Azores identifies additional risks to reefs stemming from pollution and heavy fishing

		This is a coral sample that shows a large borehole created by a sponge. Sponges proliferate in reefs with high levels of pollution, according to a new study. Credit: M. Carreiro-Silva

Microbes, sponges, and worms—the side effects of pollution and heavy fishing—are adding insult to injury in Kenya's imperiled reef systems, according to a recent study by the Wildlife Conservation Society and the University of Azores.

The authors of the study have found that pollution and overfishing on reef systems have an ecological cascading effect—the proliferation of microbes, sponges, and worms—that further degrade corals, a discovery that underlines the complexity of reefs and possible solutions.

The study appears in the online edition of Marine Ecology Progress Series. The authors include M. Carreiro-Silva of the Center of IMAR of the University of Azores and Tim McClanahan of the Wildlife Conservation Society.

The paper examines how human activities can create unexpected complications in coral reef recovery and management. For instance, recent experimental studies by Carreiro-Silva and colleagues in Belize and Kenya demonstrated that a higher nutrient content in coral reefs associated with growing agriculture activity and urbanization increased the rate at which reefs eroded from microbes such as bacteria, fungi, and algae, as well as larger animals like sponges and worms. While the study cites previous work suggesting a faster erosion of reef calcium carbonate with high pollution levels, the experimental manipulations and use of reefs experiencing different levels of fishing and pollution strongly supports those previous conclusions.

An entirely new finding from this research is that worms are major eroders of reefs where fishing is heavy, while sponges play this same role in unfished reefs of the kind found in marine parks. This suggests that it is not only nutrients and pollution that are eroding the reef substratum. Marine consumers like fish and sea-urchins also appear to be influencing species that erode the reef substratum.

In heavily fished reefs, sea-urchins are the dominant grazers, and their grazing activity is so intense that only fast-growing early colonist species such as worms are able to grow inside the reef substratum. The lack of fish may also make these holes a safe haven for worms. In this scenario, worms then take over the role that sponges usually play.

"This change in the roles of worms and sponges shows how the affects of fishing can cascade down even into the hidden crevices of coral reefs," said Dr. Carreiro-Silva of the Department of Oceanography and Fisheries at the University of the Azores in Portugal and the lead author of the study.

In areas impacted with high levels of runoff and drainage from land, such as some of the oldest marine parks in Kenya, researchers have found the highest levels of reef decay; in these instances, the increased pollution produces an abundance of sponges that live in and erode reef cavities.

Dr. Tim McClanahan, senior conservationist for the Wildlife Conservation Society and co-author of the study added: "This problem is outside of the usual control of park managers and shows the importance of maintaining clean waters if reefs are to grow and keep up with the rise in sea levels."

The study authors are concerned about the cascading effects of pollution and overfishing on already stressed coral reef systems. Intensive erosion of carbonates has the potential to undermine reef growth and diminish reef structure over time, an increasing challenge as ocean temperatures and sea levels rise. The authors point out that reducing pollution, the influence of run-off, drainage of highlands and wetlands, and other sources of non-point pollution and land development in coastal areas are critical in conserving the ecological services provided by coral reefs.

Dr. Carreiro-Silva speculates that one unstudied but looming problem is the increased acidification of the ocean that will add to the growing intensity of impacts. Acidification created by increased emissions of carbon dioxide weakens coral skeletons and creates opportunities for species that like to live in hidden crevices and further dissolve the reef structure.

"Ultimately, the synergy between these different impacts may lead to the deterioration and eventual collapse of the reefs unless greater efforts are made to reduce the many sources of pollution and excessive use of coral reefs as fisheries," she added.

Contact: John Delaney
jdelaney@wcs.org
718-220-3275
Wildlife Conservation Society

 

 

Forensic tools for catching poachers

The trade in ivory was largely outlawed in 1989, but poaching continues and remains a serious threat to the African elephant. Seizures of large amounts of ivory, sometimes over a ton, continue to occur. Research by Alfred Roca, an assistant professor at the university, could be the basis for the development of new law enforcement tools.

Roca has found a way to determine where the ivory comes from. With funding from the Division of International Conservation of the U.S. Fish and Wildlife Service, he and his collaborators have sampled elephants at 22 locations in 13 African countries to get sequences of their mitochondrial DNA (mtDNA).

mtDNA is the DNA located in mitochondria, structures within cells that convert the chemical energy from food into a form the cells can use. Most DNA is "nuclear," found in the cell nucleus. What makes mtDNA a good marker for tracing the origin of ivory is first, that it is transmitted only by females and second, the fact that female elephants do not migrate between herds.

Other researchers have found that it is possible to get fragments of mtDNA from ivory and that is possible to amplify those fragments. Roca and his collaborators wanted to match these fragments to elephants from a specific location.

To do this, Nicholas Georgiadis, a researcher who was in Kenya and is now at Washington State, used a rifle to shoot a biopsy dart, which would hit the side of the elephant and scrape a small piece (less than a centimeter square) of skin from the elephant and fall off.

"It's like a biting insect," said Roca. "The hardest part was finding the dart after it fell off. Georgiadis never had a problem with an elephant unless it was already predisposed to be hostile to humans."

Georgiadis collected 653 samples that Yasuko Ishida, a researcher in Roca's lab, then sequenced and analyzed. She found eight distinct subclades, or subdivisions, of mtDNA – previous research had detected only two to five -- seven of which had limited geographical distribution.

They identified 108 unique mtDNA sequences, which provided fine-scale information about the origin of the ivory. Among the sequences, 72 percent were found in only one locality and 84 percent of them were country-specific. Although many elephants can have the same sequence, 44 percent of the individual elephants carried a sequence detected only at their sampling locality.

Roca and his team combined these results with five earlier trans-national surveys, which allowed them to examine a shorter region of elephant mtDNA in 81 locations in 22 African countries. Among the 101 unique short sequences detected, 62 percent were present in only one country.

More importantly, the phylogeographic signal (the geographic information provided by mtDNA) was different from the signal provided by nuclear DNA markers used in previous studies. Nuclear markers distinguished between forest and savanna elephants; the mtDNA marker indicated a precise location. The best method would be to combine both types of markers.

Roca hopes that the method developed in this research will be used by conservationists to determine the provenance of confiscated ivory. "It is often hard to trace ivory back to where it came from," he said. "A ship may have left from a certain port in Africa, but that's not necessarily the country where the elephants were poached."

Sequencing the mtDNA can give a good indication of where the ivory is being poached. "Then steps can be taken by that particular country to prevent the poaching from taking place," said Roca.

The research has just been published in Evolutionary Applications.

Reference: Ishida, Y., N. J. Georgiadis, T. Hondo, and A. L. Roca. "Triangulating the provenance of African elephants using mitochondrial DNA." Evolutionary Applications. Published online http://onlinelibrary.wiley.com/doi/10.1111/j.1752-4571.2012.00286.x/full

Contact: Susan Jongeneel
sjongene@illinois.edu
217-333-3291
University of Illinois College of Agricultural, Consumer and Environmental Sciences

 

 

Seafood, wild or farmed? The answer may be both

		This is a seafood market in Borneo. Credit: Mary Turnipseed

Most people think of seafood as either wild or farmed, but in fact both categories may apply to the fish you pick up from your grocery store. In recent years, for example, as much as 40 percent of the Alaskan salmon catch originated in fish hatcheries, although it may be labeled "all wild, never farmed."

An article produced by a working group of UC Santa Barbara's National Center for Ecological Analysis and Synthesis (NCEAS) recommends that when a combination of seafood production techniques are used, this be acknowledged in the marketplace. The group calls on national and international organizations and governmental agencies to use the term "hybrid," when applicable. The article is in press with Marine Policy, and is currently available online.

"Farming fish and shellfish is generally a different way to produce seafood than fishing," said Dane Klinger, first author and a Ph.D. student at Stanford University. "While fisheries traditionally interact with their target population only at the time of capture, aquaculture, in its 'purest' state, controls the entire lifecycle of the organism, from egg to harvest. However, many common types of seafood are produced using techniques from both fisheries and aquaculture."

		These are parrotfish. Credit: Mary Turnipseed

Mary Turnipseed, second author and a former postdoctoral fellow at NCEAS, commented: "Seafood production is a critical part of global food security, but the way we study and talk about it often obscures how to achieve the thing we care the most about: increasing the supply of sustainably produced seafood to feed a rapidly growing human population. We need to start collecting more accurate data on how seafood is really produced in today's world, and a first step will be through replacing the old farmed-fished dichotomy with a farmed-fished-hybrid classification scheme."

The article reveals how the strictly traditional categories of seafood production –– fisheries and aquaculture –– are insufficient to account for the growth potential and environmental impacts of the seafood sector. The authors examine several popular seafood products that are harvested using a combination of techniques generally ascribed to either fisheries or aquaculture.

The authors reviewed several cases of fisheries that are augmented by aquaculture. In addition to the example of hatcheries stocking Pacific salmon in Alaskan fisheries, hatcheries also stock scallops in New Zealand waters, and eastern oysters in the Chesapeake Bay, according to the authors. And American lobsters are fed by bait placed in traps until they reach legal catch size. In fact, the amount of bait provided to lobsters in one season is often greater than the volume of lobster catch in the same season, by a factor of two.

		These are farmed salmon from Australia in the Gadong wet (seafood) market, Brunei. Credit: Mary Turnipseed

In aquaculture, the lines are often blurred –– fishing may be involved in production. For example, Bluefin tuna farms obtain their stock by fishing. These farms also fish for feed, and use 10 to 20 kilograms of fish for every kilogram of tuna they produce.

The primary source of information about the world's fisheries and aquaculture enterprises is the United Nation's Food and Agriculture Organization (FAO). However, the authors explain that the reporting of data from many developing and developed countries to the FAO is incomplete. They note that for the 52 percent of countries that do submit adequate data, "adding a hybrid production category would help elucidate their national understanding of domestic seafood production, as well as enhance global understanding of an important food sector."

The authors conclude by stating the urgency of adding the hybrid category: "Without these data, transformations in the market for a critical food and livelihood source for billions of people could occur, with global analysts and policymakers being the last to know."

The team responsible for the article, the NCEAS Working Group on Envisioning a Sustainable Global Seafood Market and Restored Marine Ecosystems, includes ecologists, economists, policy analysts, members of the seafood industry, and marine conservation organizations.

In addition to Klinger and Turnipseed, the authors are Benjamin S. Halpern, NCEAS; Kimberly A. Selkoe, NCEAS and the Hawaii Institute of Marine Biology; James L Anderson, University of Rhode Island; Frank Asche, the University of Stavanger, Stavanger, Norway; Larry Crowder, the Center for Ocean Solutions, Monterey, Calif.; Atle G. Guttormsen, Norwegian University of Life Sciences, Aas, Norway; Mary I. O'Connor, University of British Columbia; Raphael Sagarin, University of Arizona; Geoff Shester, Oceana, Monterey, Calif.; Martin D. Smith, Duke University; and Peter Tyedmers, Dalhousie University, Halifax, Nova Scotia.

Contact: Gail Gallessich
gail.g@ia.ucsb.edu
805-893-7220
University of California - Santa Barbara

 

 

New bird species discovered in 'cloud forest' of Peru

The Sira Barbet, Capito fitzpatricki, has been discovered and named by Cornell University graduates following an expedition to the remote Peruvian Andes. Credit: Cornell University

A colorful, fruit-eating bird with a black mask, pale belly and scarlet breast – never before described by science – has been discovered and named by Cornell University graduates following an expedition to the remote Peruvian Andes.

The Sira Barbet, Capito fitzpatricki, is described in a paper published in the July 2012 issue of The Auk, the official publication of the American Ornithologists' Union.

The new species was discovered during a 2008 expedition led by Michael G. Harvey (currently pursuing a doctorate at Louisiana State University), Glenn Seeholzer (currently pursuing a doctorate at Louisiana State University) and Ben Winger (currently pursuing a doctorate at University of Chcago), young ornithologists who had recently graduated from Cornell at the time. They were accompanied by co-author Daniel Cáceres, a graduate of the Universidad Nacional de San Agustín in Arequipa, Peru, and local Ashéninka guides. The team discovered the barbet on a ridge of montane cloud forest in the Cerros del Sira range in the eastern Andes. Steep ridges and deep river gorges in the Andes produce many isolated habitats and microclimates that give rise to uniquely evolved species.

Though clearly a sister species of the Scarlet-banded Barbet, the Sira Barbet is readily distinguished by differences in color on the bird's flanks, lower back and thighs, and a wider, darker scarlet breast band. By comparing mitochondrial DNA sequences of the new barbet to DNA sequences of its close relatives in the genus Capito, the team secured genetic evidence that this is a new species in the barbet family. The genetic work was done by co-author Jason Weckstein at The Field Museum in Chicago.

The team chose the scientific name of the new species Capito fitzpatricki in honor of Cornell Lab of Ornithology executive director John W. Fitzpatrick, who discovered and named seven new bird species in Peru during the 1970s and '80s.

"Fitz has inspired generations of young ornithologists in scientific discovery and conservation," said Winger. "He was behind us all the way when we presented our plan for this expedition."

The 2008 expedition was made possible by funding from a special gift to the Cornell Lab of Ornithology and donations to the Lab's student World Series of Birding team, Rawlings Cornell Presidential Research Scholars, National Geographic Young Explorers' Grant, and the Explorers Club.

Reference: A new species of barbet (Capitonidae: Capito) from the Cerros del Sira, Ucayali, Peru, Glenn F. Seeholzer, Benjamin M. Winger, Michael G. Harvey, Daniel Cáceres A. and Jason D. Weckstein.

• Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, New York 14850, USA
• Museum of Natural Science, 119 Foster Hall, Louisiana State University, Baton Rouge, Louisiana 70803, USA
• Committee on Evolutionary Biology, University of Chicago, 1025 E. 57th Street, Culver Hall 402, Chicago, Illinois 60637, USA
• Department of Zoology, Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, Illinois 60605, USA
• Museo de Historia Natural, Universidad Nacional de San Agustín, Avenida Daniel Alcides Carrión s/n, Arequipa, Perú

Contact: John Carberry
johncarberry@cornell.edu
607-255-5353
Cornell University

 

 

Airborne technology helps manage elephants

For years, scientists have debated how big a role elephants play in toppling trees in South African savannas. Tree loss is a natural process, but it is increasing in some regions, with cascading effects on the habitat for many other species. Using high resolution 3-D mapping, Carnegie scientists have for the first time quantitatively determined tree losses across savannas of Kruger National Park. They found that elephants are the primary agents—their browsing habits knock trees over at a rate averaging 6 times higher than in areas inaccessible to them. The research also found that elephants prefer toppling trees in the 16-to-30 foot (5-8 m) range, with annual losses of up to 20% in these height classes. The findings, published in Ecology Letters, bolster our understanding of elephant conservation needs and their impacts, and the results could help to improve savanna management practices.

"Previous field studies gave us important clues that elephants are a key driver of tree losses, but our airborne 3-D mapping approach was the only way to fully understand the impacts of elephants across a wide range of environmental conditions found in savannas," commented lead author Greg Asner of Carnegie's Department of Global Ecology. "Our maps show that elephants clearly toppled medium-sized trees, creating an "elephant trap" for the vegetation. These elephant-driven tree losses have a ripple effect across the ecosystem, including how much carbon is sequestered from the atmosphere."

The technology used for monitoring trees is Light Detection and Ranging (LiDAR), mounted on the fixed-wing Carnegie Airborne Observatory (CAO). It provides detailed 3-D images of the vegetation canopy at tree-level resolution using laser pulses that sweep across the African savanna. The CAO's lasers can detect even small changes in each tree's height, and its vast coverage is far superior to previous field-based and aerial photographic evaluations.

The scientists considered an array of environmental variables spread over four study landscapes within Kruger and in very large areas fenced off to prevent herbivore entry. For years, four of these exclosures have kept out all herbivores larger than a rabbit. Two other partial enclosures have permitted entry of herbivores other than elephants. The scientists identified and monitored 58,000 individual trees from the air, inside and outside of these exclosures and across the landscape in 2008 and again in 2010. They found that nearly 9% of the trees decreased in height in two years, and that the mapped changes in treefall were linked to different climate and terrain conditions. Most tree losses occurred in lowland areas with more moisture and on soils high in nutrients that harbor trees preferred by elephants for browsing. Critically, the partial exclosures definitively identified elephants, as opposed to other herbivores and fire, as the major agent of tree losses over the two-year period.

"These spatially explicit patterns of treefall highlight the challenges faced by conservation area managers in Africa, who must know where and how their decisions impact ecosystem health and biodiversity. They should rely on rigorous science to evaluate alternative scenarios and management options, and the CAO helps provide the necessary quantification," commented co-author Shaun Levick.

Danie Pienaar, head of scientific services of the South African National Parks remarked, "This collaboration between external scientists and conservation managers has led to exciting and ground-breaking new insights to long-standing questions and challenges. Knowing where increasing elephant impacts occur in sensitive landscapes allows park managers to take appropriate and focused action. These questions have been difficult to assess with conventional ground-based field approaches over large scales such as those in Kruger National Park."

The Carnegie Airborne Observatory and this study are made possible by the Andrew Mellon Foundation, Gordon and Betty Moore Foundation, W. M. Keck Foundation, Grantham Foundation for the Protection of the Environment, Mary Anne Nyburg Baker and G. Leonard Baker Jr., and William R. Hearst III.

The Department of Global Ecology was established in 2002 to help build the scientific foundations for a sustainable future. The department is located on the campus of Stanford University, but is an independent research organization funded by the Carnegie Institution. Its scientists conduct basic research on a wide range of large-scale environmental issues, including climate change, ocean acidification, biological invasions, and changes in biodiversity.

The Carnegie Institution for Science  has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

Contact: Greg Asner
gpa@carnegiescience.edu
650-380-2828
Carnegie Institution

 

 

 

New Hampshire leads the US in percent tree cover

Urban tree cover highest in Connecticut

Mystic, Southeastern Connecticut, USA

Tree cover in the nation's Lower 48 states covers 659 million acres, more than one-third of the nation, according to a U.S. Forest Service study of national tree cover and impervious surfaces. New Hampshire leads the nation in percent tree cover (89 percent), followed by Maine (83 percent) and Vermont (82 percent). On the other end of the spectrum, North Dakota has the lowest percent tree cover (3 percent), followed by Nebraska (4 percent) and South Dakota (6 percent).

Using aerial photograph interpretation of circa 2005 imagery, U.S. Forest Service researchers Dave Nowak and Eric Greenfield found that in urban and community areas, percent tree cover is highest in Connecticut (67 percent) and lowest in Nevada (10 percent). The study, "Tree and impervious cover in the United States," was recently published in the journal Landscape and Urban Planning.

"Urban forests are a vital part of the nation's landscape," said Michael T. Rains, director of the Forest Service's Northern Research Station. "Forest Service science is supporting stewardship of urban forests with tools that communities, organizations and home owners can use to better understand the environmental benefits of trees."

Impervious cover in the conterminous United States is estimated at 2 percent, or 46 million acres. That percent goes up in urban areas, where impervious cover accounts for 25 percent of land cover. New Jersey leads the nation in impervious cover (12 percent) and Wyoming has the least statewide impervious cover (0.5 percent).

Both people and nature play a role in urban forestry, according to Nowak. "This research demonstrates how natural environments in concert with how we develop and manage communities significantly impacts tree cover in urban areas," Nowak said. "Cover data of a city or region can provide a baseline for developing management plans, setting tree cover goals, and for monitoring change through time, all of which are essential to sustaining urban forests."

The mission of the U.S. Forest Service is to sustain the health, diversity, and productivity of the nation's forests and grasslands to meet the needs of present and future generations. The agency manages 193 million acres of public land, provides assistance to state and private landowners, and maintains the largest forestry research organization in the world. The mission of the Forest Service's Northern Research Station is to improve people's lives and help sustain the natural resources in the Northeast and Midwest through leading-edge science and effective information delivery.

Contact: Jane Hodgins
jmhodgins@fs.fed.us
651-649-5281
USDA Forest Service - Northern Research Station