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Ellis et al 1931.pdf
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Ellis Keim 1918.pdf
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Elowe, Ken
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Emergence of a mid-season period of low floral resources in a montane meadow ecosystem associated with climate change
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Summary. 1. Shifts in the spatial and temporal patterns of flowering could affect the resources available to pollinators, and such shifts might become more common as climate change progresses. 2. As mid-summer temperatures have warmed,we found that a montane meadow ecosystem in the southern Rocky Mountains of the United States exhibits a trend toward a bimodal distribution of flower abundance, characterized by a mid-season reduction in total flower number, instead of a broad, unimodal flowering peak lasting most of the summer season. 3. We examined the shapes of community-level flowering curves in this system and found that the typical unimodal peak results from a pattern of complementary peaks in flowering among three distinct meadow types (dry, mesic and wet) within the larger ecosystem. However, high mid-summer temperatures were associated with divergent shifts in the flowering curves of these individual meadow types. Specifically, warmer summers appeared to cause increasing bimodality in mesic habitats, and a longer interval between early and late flowering peaks in wet and dry habitats. 4. Together, these habitat-specific shifts produced a longer mid-season valley in floral abundance across the larger ecosystem in warmer years. Because of these warming-induced changes in flowering patterns, and the significant increase in summer temperatures in our study area, there has been a trend toward non-normality of flowering curves over the period 1974–2009. This trend reflects increasing bimodality in total community-wide flowering. 5. The resulting longer periods of low flowering abundance in the middle of the summer season could negatively affect pollinators that are active throughout the season, and shifts in flowering peaks within habitats might create mismatches between floral resources and demand by pollinators with limited foraging ranges. 6. Synthesis. Early-season climate conditions are getting warmer and drier in the high altitudes of the southern Rocky Mountains. We present evidence that this climate change is disrupting flowering phenology within and among different moisture habitats in a sub-alpine meadow ecosystem, causing a mid-season decline in floral resources that might negatively affect mutualists, especially pollinators. Our findings suggest that climate change can have complex effects on phenology at small spatial scales, depending on patch-level habitat differences.
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Emerging Techniques for Soil Carbon measurements
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Soil carbon sequestration is one approach to mitigate greenhouse gases. However, to reliably
assess the quantities sequestered as well as the chemical structure of the soil carbon, new
methods and equipment are needed. These methods and equipment must allow large scale
measurements and the construction of dynamic maps. This paper presents results from some
emerging techniques to measure carbon quantity and stability. Each methodology has specific
capabilities and their combined use along with other analytical tools will improve soil organic
matter research. New opportunities arise with the development and application of portable
equipment, based on spectroscopic methods, as laser-induced fluorescence, laser-induced
breakdown spectroscopy and near infrared, for in situ carbon measurements in different
ecosystems. These apparatus could provide faster and lower cost field analyses thus
improving soil carbon contents and quality databases. Improved databases are essential to
model carbon balance, thus reducing the uncertainties generated through the extrapolation of
limited data.
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Endangered Mussels Released into the Clinch River, Largest Release in Eastern US
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Biologists from the Virginia Department of Game and Inland Fisheries (VDGIF), and partners from Virginia Tech, the Nature Conservancy, and the U.S. Fish and Wildlife Service stocked thousands of mussels into the Clinch River, Russell County. The Clinch River has more species of endangered freshwater mussels than any other river in North America. Elementary school students from Cleveland, VA, participated in the event, and learned about the many functions of mussels, including providing habitat for fish, becoming food for many other animals, and filtering and cleaning the water in our streams and rivers. Over 3,500 federally-endangered mussels were produced at the Department's Aquatic Wildlife Conservation Center in Marion, Virginia.
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Endries, Mark
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Energetic and biomechanical constraints on animal migration distance
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Animal migration is one of the great wonders of nature, but the factors that determine how far migrants travel remain poorly understood. We present a new quantitative model of animal migration and use it to describe the maximum migration distance of walking, swimming and flying migrants. The model combines biomechanics and metabolic scaling to show how maximum migration distance is constrained by body size for each mode of travel. The model also indicates that the number of body lengths travelled by walking and swimming migrants should be approximately invariant of body size. Data from over 200 species of migratory birds, mammals, fish, and invertebrates support the central conclusion of the model – that body size drives variation in maximum migration distance among species through its effects on metabolism and the cost of locomotion. The model provides a new tool to enhance general understanding of the ecology and evolution of migration.
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Energy
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The Appalachians have and still are a hotspot for America's energy needs. Forests provided early settlers with a ready supply of wood fuel. As the nation industrialized, the region became the center for coal, oil, and recently natural gas extraction and wind. Though essential for society, the extraction of these resources has altered the Appalachian landscape, impacting biodiversity and natural places that make the Appalachians unique. As wind, natural gas, and oil development expand along with traditional coal, there is an increasing need for research to inform discussions on how to meet immediate and future energy needs while sustaining the health of natural systems.
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Energy consumption and the unexplained winter warming over northern Asia and North America
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The worldwide energy consumption in 2006 was close to 498 exajoules. This is equivalent to an energy convergence of 15.8 TW into the populated regions, where energy is consumed and dissipated into the atmosphere as heat. Although energy consumption is sparsely distributed over the vast Earth surface and is only about 0.3% of the total energy transport to the extratropics by atmospheric and oceanic circulations, this anthropogenic heating could disrupt the normal atmospheric circulation pattern and produce a far-reaching effect on surface air temperature. We identify the plausible climate impacts of energy consumption using a global climate model. The results show that the inclusion of energy use at 86 model grid points where it exceeds 0.4 W m−2 can lead to remote surface temperature changes by as much as 1K in mid- and high latitudes in winter and autumn over North America and Eurasia. These regions correspond well to areas with large differences in surface temperature trends between observations and global warming simulations forced by all natural and anthropogenic forcings 1. We conclude that energy consumption is probably a missing forcing for the additional winter warming trends in observations.
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