Dissipation and effect of chlorophenoxy herbicide on plant pigments and carbohydrates of sunflower (Helianthus annuus L.)

The dissipation pattern of the chlorophenoxy herbicides (2,4‐D and 2,4,5‐T) residues in sunflower plants (Helianthus annuus L.) has been studied along with its effect on the changes of plant pigments (chlorophyll‐a,b, total chlorophyll, carotene and anthocyanin), sugar and starch in different parts of the plant. The residues of 2,4‐D and 2,4,5‐T remained for larger period of time (10 days) at higher concentrations than the lower concentration. The concentrations of chlorophylls and carotene were found to be reduced with the application of both 2,4‐D and 2,4,5‐T. But the chlorophyll concentrations were slowly normalized accompanied with the reduction of the herbicide residues. For anthocyanin, there was no significant effect. In case of carbohydrate, the sugar concentration was found to be raised by all doses in leaf and stem. The change in starch content in different plant parts did not follow an uniform pattern at different doses of herbicides.     

Ecological aspects of rodent population control in natural plague foci on the territory of the Russian Federation

A concept of population control is proposed as applied to rodent carriers of plague and other infections with natural focality. The concept is based on the generalization of long-term experience gained in natural plague foci, differentiation of the enzootic territory with respect to the level of epidemic risk, analysis of the current state of rodent populations, and the necessity of biodiversity conservation in natural biocenoses.     

Developmental Instability in Fragmented Populations of Prairie Phlox: A Cautionary Tale

Abstract: Considerable attention has recently been focused on using levels of developmental instability among members of a population to detect environmental or genetic stresses on animals or plants. It is not yet clear, however, that high developmental instability in a sample of individuals always indicates environmental stress or poor genetic quality. We studied 13 fragmented populations of prairie phlox (   Phlox pilosa L.) to test the hypothesis that developmental instability should decrease with increasing population size—as expected if small populations suffer genetic problems associated with inbreeding or are exposed to more environmental stress than larger populations. We used two different measures of developmental instability, each calculated for two different traits: radial asymmetry of flowers (for petal width and petal length) and modular fluctuating asymmetry of leaves (  for leaf widths at two points along the leaf  ). There were weak but significant correlations among individuals for four of six pairwise combinations of these measures. Surprisingly, three of our four measures of developmental instability showed strong population size effects that were opposite to those expected: developmental instability increased with population size. We conclude that measures of developmental instability cannot be applied uncritically for biomonitoring without considerable knowledge of developmental mechanisms, natural history, and population biology of the species in question.     

Using expert opinion to prioritize impacts of climate change on sea turtles’ nesting grounds

Managers and conservationists often need to prioritize which impacts from climate change to deal with from a long list of threats. However, data which allows comparison of the relative impact from climatic threats for decision-making is often unavailable. This is the case for the management of sea turtles in the face of climate change. The terrestrial life stages of sea turtles can be negatively impacted by various climatic processes, such as sea level rise, altered cyclonic activity, and increased sand temperatures. However, no study has systematically investigated the relative impact of each of these climatic processes, making it challenging for managers to prioritize their decisions and resources. To address this we offer a systematic method for eliciting expert knowledge to estimate the relative impact of climatic processes on sea turtles’ terrestrial reproductive phase. For this we used as an example the world’s largest population of green sea turtles and asked 22 scientists and managers to answer a paper based survey with a series of pair-wise comparison matrices that compared the anticipated impacts from each climatic process. Both scientists and managers agreed that increased sand temperature will likely cause the most threat to the reproductive output of the nGBR green turtle population followed by sea level rise, then altered cyclonic activity. The methodology used proved useful to determine the relative impact of the selected climatic processes on sea turtles’ reproductive output and provided valuable information for decision-making. Thus, the methodological approach can potentially be applied to other species and ecosystems of management concern.     

Environmental Damage,Abandoned Treaties,and Fossil-Fuel Dependence: The Coming Costs of Oil-and-Gas Exploration in the “1002 Area” of the Arctic National Wildlife Refuge

Contrary to claims from American politicians, lobbyists, and oil and gas executives, allowing energy development in the Alaskan Arctic National Wildlife Refuge (ANWR) will harm the environment, compromise international law, erode the social significance of wilderness protection, and ultimately fail to␣increase the energy security of the United States. After exploring a brief history of the ANWR controversy, this piece argues that the operation of oil and gas refineries in ANWR will release discharged solids, drilling waste, and dirty diesel fuel into the ecosystem’s food-chain, as they have from oil operations in Prudhoe Bay. Less obvious but equally important, oil and gas exploration in ANWR will violate a number of international treaties on biodiversity protection. In the end, development in ANWR will threaten the concept of wilderness protection, and will do little to end US dependence on foreign sources of energy. About the Author: Benjamin K. Sovacool is a doctoral candidate in the Department of Science and Technology Studies at the Virginia Polytechnic Institute & State University in Blacksburg, Virginia. He works as a research analyst for the Consortium on Energy Restructuring and is a Senior Research Fellow for the Virginia Center for Coal and Energy Research. He also just completed a Graduate Fellowship in Energy Policy at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.