Asian tiger mosquito thrives in New York
Jul26

Asian tiger mosquito thrives in New York

The aggressive, day-biting Asian tiger mosquito, Aedes albopictus, has spread with global trade from its native home in the tropics and subtropics of Southeast Asia. First observed in Houston, Texas, in 1987, it rapidly spread through the interstate system in the the United States. Its range is pushing northward into New York and Pennsylvania. Does Ae. albopictus crowd out other mosquito species? Katz surveyed the mosquito species present at sites in southern New York State and will report on her results at the 2016 Annual Meeting of the Ecological Society of America this August. PS 2-24 -The community assemblage of tree-hole mosquitoes in southern New York State Monday, August 8, 2016, ESA Exhibit Hall, Ft Lauderdale Convention Center Marly B. Katz, Fordham University, New York City, NY Browse more presentations about mosquito ecology at the 2016 Annual...

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Forest dance on wires depicts a creeping fungal multitude blown back by a tornado
Nov11

Forest dance on wires depicts a creeping fungal multitude blown back by a tornado

Plant biology PhD student Uma Nagendra of the University of Georgia, Athens, wins the 2014 Dance Your PhD competion, sponsored by Science, AAAS, and HighWire Press. Floating on trapeze wires, young white pine seedlings unfurl and reach for light. But lurking in the roots of the parent tree are dangerous fungi that creep forth to strike at the young scions. The sprouts closest to the great tree falter and wilt, giving ground to other plants. But lo! a tornado approaches… Plant-soil feedbacks after severe tornado damage: Dance Your PhD 2014 from atinytornado on Vimeo. Nagendra tells the story of the dance in the video notes: The dance begins in an undisturbed forest. Because trees live for so long in one place, a mature pine tree accumulates a unique group of fungi around its roots—including pathogens that cause diseases in tree seedlings (in this case, Pythium and Rhizoctonia). White pine seedlings that are very close to a mature tree are more likely to be attacked by these pathogens—causing stunted growth, or even death. The farther away a seedling is from a mature tree, the less likely it is to get infected. These distant seedlings are more likely to survive to maturity. A pattern emerges where the mature pine trees are spaced far apart—leaving room for seedlings of other species to grow, and creating a diverse forest. In the middle of the dance, we witness the tornado—and how it changes the forest environment. The mature pine tree dies, and the forest floor is no longer shaded. The soil becomes hotter and drier. Without the living mature tree as a host, specialist pathogens are less active, and many die. Because of this, I am predicting that plant-soil relationships in recently tornado-damaged areas may be much weaker. In the last part of the dance, seedlings close to the (killed) mature tree are no longer at greater risk for disease; they grow and survive the same as their more distant siblings. The changing plant-soil relationships after disturbances might be one piece in the puzzle of how diverse ecosystems change over time. Read more about the competition and watch more science dancing...

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No love for the lady ginkgos

Washington DC Department of Urban Forestry nips stinky seeds in the bud By Liza Lester, ESA communications officer. A male Gingko biloba in Lafayette Park, flanking the White House. Credit, Liza Lester April, 2012. As an urban arboreal companion, the ginkgo has much to recommend it. Its tall branches bring welcome summer shade, the fans of its leaves turn a lovely gold in the fall, it copes well with city pollution, lives for thousands of years, and isn’t prone to disease or insect infestation. But it has a serious drawback. In the fall, mature female ginkos produce fleshy seeds (not a “fruit” in the parlance of botany, as the ginkgo is not an angiosperm, or flowering plant), and unlike cherry season, the height of ginko reproduction is not a time of celebration. The seeds drop all over city streets, smelling “like dirty socks and vomit.” Some city dwellers hate the trees so much that they are willing to cut them down rather that endure the annual mess. Rather than massacre female ginkgo trees all over the city, this week DC’s Urban Forestry Administration will spray the trees with “Shield EC” aka “Sprout Nip” aka “chlorpropham,” an herbicide that interferes with the division of plant cells during growth. Agricultural distributors typically use chlorpropham to discourage potatoes from sprouting after harvest. Buds and shoots  – anywhere the plant is actively growing – are hotspots of cell division, and the incipient ginko seed buds fall off before they can grow stinky. At least, that’s the idea. Not all customers are satisfied. Since only female trees are a problem, it would make sense to plant only male trees. But male and female trees look identical when their reproductive parts aren’t hanging out. It can be a good two decades before a tree matures and begins to produce either pollen cones or seeds. Botanist CL Lee’s argument for an X/Y sex determination scheme (like the human mechanism), pointing to a subtle chromosomal difference between the sexes, has not been confirmed in the fifty years since he proposed it. Genetics has not provided an easy solution. Although Chinese scientists have been looking for molecular signatures that would allow botanists to sex young saplings, there is no easy test as of yet. Instead, nurseries now take cuttings of mature male trees to create “clones” of the male tree, either inducing root growth, or grafting the cutting to the roots of a young tree (sometimes this backfires when the graft fails and the root stock turns out to be female, hence reports of male trees turning female). But in the meantime there are robust, mature female trees...

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Loveliest of Trees
Mar22

Loveliest of Trees

Project Budburst: Cherry Blossom Blitz kicks off in the midst of an unusually early bloom. by Liza Lester, ESA communications officer IT’S the first week of spring, and Washington DC’s Tidal Basin is rimmed with snowy petals. Thousands of cherry trees bloom along the water – a week ahead of schedule. Hurried along by a streak of 80 degree (F) days and warm nights, the trees are in full bloom, the earliest since 2000, and petals will be falling by the time the centennial Cherry Blossom Festival* starts on March 24th. Much to the distress of festival organizers. A gift from the City of Tokyo in 1912, the cherry trees have brought out their spring finery around the 4th of April, give or take a few weeks, for 100 years. But a few weeks’ give is often too much leeway for the coordination of major city events, planned months in advance. The Washingtonian reported earlier this month that the city is expecting 100s of thousands of tourists, bringing 100s of millions of dollars, to arrive for the festival. So predicting the bloom is no trivial matter. Unfortunately, predicting it more than ten days in advance is entirely luck, according the National Park Service. Cherry trees are exquisitely sensitive to the vagaries of early spring weather. “This has been a wonderful learning opportunity. If the cherry blossoms don’t show up for their very own parade, people take notice,” said Sandra Henderson, director of the National Ecological Observatory Network’s (NEON) Project BudBurst. Festival organizers have sounded considerably more morose about this lesson than Henderson in the flood of recent news reports. But they are interested in different things. Henderson doesn’t have a festival to run; she just wants to map the blossoming of your backyard cherry to latitude, longitude, and date, with the option to cross-reference it to weather and climate trends. Henderson co-founded the citizen science project in 2007 with Kayri Havens-Young of the Chicago Botanic Garden, and Carol Brewer, emeritus professor of biology at the University of Montana (and now on NEON’s board of directors, among other activities). The project collects data worldwide. They’re interested in “phenology”: the study of seasonal changes and their environmental cues. The eponymous “bud burst” of new leaves unfurling on the branches of deciduous trees is one such phenomenon, or phenophase, “but don’t let our name fool you; we’re interested in plants throughout the year,” said Henderson. It’s just that “project leaf dye-off” didn’t have quite the same enticing cache. BudBurst records the first unfolding of leaves, stages of bloom, the pale green new needles at the tips of fir trees, showers of pollen,...

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New grants promote greater understanding of infectious disease

This post contributed by Lindsay Deel, a Ph.D. student in geography at West Virginia University and Intern with ESA’s journal Frontiers in Ecology and the Environment Infectious diseases won’t know what hit them. A massive new collaborative effort between funding sources in the United States (US) and United Kingdom (UK) takes aim at infectious diseases from ecological and social perspectives, reported the National Science Foundation (NSF) in a recent press release. The overall goal of the suite of eight projects is to improve understanding of the factors affecting disease transmission, said NSF, but a major focus will also be on building models to help predict and control outbreaks. Each of these projects examines different themes within the global context of infectious disease. For example, Tony Goldberg (Professor of Epidemiology, University of Wisconsin–Madison) and colleagues will investigate the spread of HIV from its origin in monkeys to humans by examining similar viruses that are currently impacting wild monkeys in Uganda. This project will also study human social factors – such as awareness, beliefs, and behaviors – surrounding the transmission of such diseases. Another project helmed by David Rizzo (Professor of Plant Pathology, University of California–Davis) will explore how interacting forest disturbances – such as fire and drought – may control the emergence, persistence, and spread of invasive pathogens using the case of sudden oak death – a disease caused by a non-native pathogen, Phytophthora ramorum. “Over the past 10 years, potentially millions of trees in California and Oregon coastal forests have died as a result of this emerging disease,” explains Rizzo. “The goal of this new grant is [to] link this new disturbance agent (sudden oak death) with pre-existing disturbance agents (fire, drought) in coastal forests.” Samantha Forde (Professor of Ecology and Evolutionary Biology, University of California – Santa Cruz) will lead a project using a simplified laboratory system of E. coli bacteria and its viruses as a model to study why some viruses have evolved the ability to infect multiple host species, while others can only infect one.  “This will further a general understanding of the dynamics of disease in natural systems and help to improve public health initiatives,” she says. From the modeling perspective, Armand Kuris (Professor of Biological Sciences, University of California at Santa Barbara) and colleagues will delve into the complexity of ecological systems and how the level of complexity might influence disease dynamics.  Kuris and colleagues hope to bring the role of infectious diseases into the core of ecological thinking, comparable to the roles of predation, competition, disturbance and resource quality. Joseph Tien (Professor of Mathematics, Ohio State University) will examine the recent cholera epidemic in Haiti. ...

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A new addition to the terrestrial nitrogen cycle

This post contributed by Lindsay Deel, a Ph.D. student in geography at West Virginia University and Intern with ESA’s journal Frontiers in Ecology and the Environment Memorizing diagrams of the nitrogen cycle – complete with all the little arrows flowing between atmospheric sources to uptake by vegetation – is a rite of passage for most undergraduate ecology students.  Now, following a new study published in the journal Nature, the diagrams will need to include a new little arrow flowing from bedrock sources to vegetation.  This could have dramatic implications for understanding the growth potential – and therefore, the carbon sequestration potential – of forested ecosystems. Nitrogen is often cited as the most limiting nutrient for the growth of trees, so if forests can access more nitrogen, there is greater growth potential – and more growth means more carbon storage. “We were really shocked; everything we’ve ever thought about the nitrogen cycle and all of the textbook theories have been turned on their heads by these data,” said Benjamin Houlton, Assistant Professor of Terrestrial Biogeochemistry, in a UC Davis press release about the study.  “Findings from this study suggest that our climate-change models should not only consider the importance of nitrogen from the atmosphere, but now we also have to start thinking about how rocks may affect climate change.” Scientists have long thought that nitrogen could only enter forest ecosystems through the atmosphere – by deposition or biological fixation.  Based on this assumption, the UC Davis scientists expected to find, at most, the same nitrogen contribution from rocks. “To put it in perspective, there is enough nitrogen contained in one inch of the rocks at our study site to completely support the growth of a typical coniferous forest for about 25 years,” explained Randy Dahlgren, a biogeochemist and study co-author, in the UC Davis press release.  “This nitrogen is released slowly over time and helps to maintain the long-term fertility of many California forests. It is also interesting to consider that the nitrogen in the rocks from our study site originates from the time of the dinosaurs, when plant and animal remains were incorporated into the sediments that eventually formed the rocks.” The discovery of such a substantial pool of stored nitrogen that is directly accessible to plants also sheds new light on the infamous “missing carbon sink,” which is assumed to be terrestrial.  Indeed, research related to nitrogen cycling will change because of this finding – as will the diagrams of nitrogen cycling in undergraduate ecology textbooks.   Photo: Mountain deep forest by Paolo...

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Seeing (less) red: Bark beetles and global warming

This post contributed by Jesse A. Logan, retired research entomologist living in Emigrant, Montana. The Greater Yellowstone Ecosystem (GYE) is an ecological reserve of regional, national and international significance. This collection of National Parks, National Forests, wildlife reserves and tribal lands is generally recognized as one of the last remaining large, nearly intact, ecosystems of the Earth’s northern temperate region. Climax whitebark pine (Pinus albicalus Engelman) forests comprise the majority of forested habitat above 2,750 meters and extend to the highest elevation as a crooked krumholtz growth form. By functioning as both a foundation and a keystone species, whitebark pine is an important ecological component of the GYE. Unfortunately, the foundation whitebark forests of the GYE are facing catastrophic collapse due to a combination of an introduced pathogen, unprecedented attack by a native bark beetle and climate change. Whitepine blister rust is a pathogen introduced near the turn of the past century, and its effect is to first compromise the reproductive capacity of the tree, eventually (requiring an average of twenty years in the GYE) leading to the tree’s death. On the other hand, attack by the native mountain pine beetle either immediately leads to the  tree’s deaths, or the tree successfully defends itself and repulses the attacking beetles. The seriousness of these threats to the integrity of high-elevation forests is indicated by the recent finding by the US Fish & Wildlife Service that whitebark meets the criteria for a threatened or endangered species; in addition, despite their risk of extinction, the FWS did not add whitebark to the endangered species list due to lack of sufficient funding. Under historic climate regimes, these high elevation forests were simply too cold for the mountain pine beetle (MPB) (Dendroctonus ponderosae) to thrive. Although, past MPB-caused whitebark pine mortality did occur during periods of unusually warm weather—for example, in the 1930s—these outbreaks were short-lived and limited in scale. With the publication of the first Interngovernmental Panel on Climate Change report in 1990, research on the potential for increased MPB activity in whitebark pine began to occur. Model predictions of high intensity MPB outbreaks began to be realized across the southern range of whitebark pine by the early 2000s. By 2005, USDA Forest Service Aerial Detection Survey (ADS) data showed significant MPB caused mortality across large areas of GYE whitebark pine. This mortality is first evident by large numbers of red trees (symptomatic of trees killed the previous summer), subsequently followed by vast areas of gray trees — the residual ghost forest — is shown in the photos above. In those photos of Hoyt Peak from Avalanche Peak near Sylvan Pass, Yellowstone National...

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Ecological research in images

(Click the below image to view the photo gallery.) This week, the American Museum of Natural History launched the exhibit “Picturing Science: Museum Scientists and Imaging Technologies” which explores the images produced by scientists while performing research. The images range from bug genitalia to staghorn coral (see video at the end of this post). As quoted in a recent Wired Science article, “‘A lot of people come to the museum under [the] impression that we just look at stuff in dusty jars, but that couldn’t be further from the truth,’ said zoologist Mark Siddall, curator of the museum’s new exhibit. ‘There’s a lot of solid, cutting-edge research going on here with incredibly advanced technology.’” Dave Mosher explained in the Wired Science article that images like these are a large part of any scientific endeavor, but often times, these images are filed away—never to be seen by the public. Of course, there are journals that publish images alongside the research articles. While they are all accessible through searches, these images are not typically displayed like those that are being featured in the AMNH’s new exhibit. The above photo gallery presents only some of the images that have been featured in the Ecological Society of America’s journals over the last decade or so. Click on the image to scroll through and learn a bit about the research corresponding with each image. Many of the images featured in ESA journals are taken by the researchers themselves. Browse all of the cover images on ESA’s journals...

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