The return of the giants: ecological effects of an increasing elephant population

Northern Botswana and adjacent areas, have the world's largest population of African elephant (Loxodonta africana). However, a 100 years ago elephants were rare following excessive hunting. Simultaneously, ungulate populations were severely reduced by decease. The ecological effects of the reduction in large herbivores must have been substantial, but are little known. Today, however, ecosystem changes following the increase in elephant numbers cause considerable concern in Botswana. This was the background for the "BONIC" project, investigating the interactions between the increasing elephant population and other ecosystem components and processes. Results confirm that the ecosystem is changing following the increase in elephant and ungulate populations, and, presumably, developing towards a situation resembling that before the reduction of large herbivores. We see no ecological reasons to artificially change elephant numbers. There are, however, economic and social reasons to control elephants, and their range in northern Botswana may have to be artificially restricted.     

The New England Air Quality Forecasting Pilot Program: development of an evaluation protocol and performance benchmark

The National Oceanic and Atmospheric Administration recently sponsored the New England Forecasting Pilot Program to serve as a "test bed" for chemical forecasting by providing all of the elements of a National Air Quality Forecasting System, including the development and implementation of an evaluation protocol. This Pilot Program enlisted three regional-scale air quality models, serving as prototypes, to forecast ozone (O3) concentrations across the northeastern United States during the summer of 2002. A suite of statistical metrics was identified as part of the protocol that facilitated evaluation of both discrete forecasts (observed versus modeled concentrations) and categorical forecasts (observed versus modeled exceedances/nonexceedances) for both the maximum 1-hr (125 ppb) and 8-hr (85 ppb) forecasts produced by each of the models. Implementation of the evaluation protocol took place during a 25-day period (August 5-29), utilizing hourly O3 concentration data obtained from over 450 monitors from the U.S. Environment Protection Agency's Air Quality System network.     

Butyltin contamination of sediments and benthic fish from the East,Gulf and Pacific coasts of the United States

Butyltin concentrations were determined in sediments, tissues and stomach contents of fish collected in 41 embayments on the East, Gulf and Pacific coasts of the U.S.A. between 1986 and 1991 as part of the National Oceanic and Atmospheric Administration's (NOAA) National Benthic Surveillance Project (NBSP). A total of 99 sediments, 108 fish liver samples from 11 fish species, and 10 composites of fish stomach contents were analyzed for tetrabutylin, tributylin, dibutylin and monobutylin. Tributyltin (TBT) was detected (i.e. > 10 ng/g) in 38 of the sediments samples analyzed and was generally the predominant bulytin present; concentrations of total butyltins ranged from 15 to 1600 ng/g wet weight. The highest concentrations were found in sediments from urban sites, especially sites on the West coast. Many of the fish liver and stomach contents samples also contained butyltins. Tributyltin represented 83 (7.1)% [mean (SEM); n=15], 64 (6.6)% (n=12) and 36 (7.8)% (n=12) of the total butyltins in livers from white croaker, winter flounder and Atlantic croaker, respectively, suggesting possible species differences in biotransformation of TBT. The concentrations of butyltins in stomach contents indicated that diet can be a significant route of exposure of fish to butyltins. Between 1986 and 1991 butyltin concentrations in sediments and fish generally appeared to be declining; however, no statistically significant temporal trends were observed at individual sites or for the sites overall.The U.S. government's right to retain a non-exclusive, royalty free license in and to any copyright is acknowledged.     

Using PM10 geochemical maps for defining the origin of atmospheric pollution in Andalusia (Southern Spain)

In this work we present a detailed study of atmospheric PM₁₀ pollution in Andalusia (Southern Spain) based on geochemical maps. The study includes determination of PM₁₀ levels and bulk chemical composition with samples from 17 representative monitoring stations (rural, urban background, traffic hot spot, and urban zones with industrial influence) during 2007. The knowledge of background levels and concentrations of relevant chemical compounds and elements allows the quantification of the main sources of pollution in relevant cities and sites of ecological interest.In comparison to other stations in Spain and mainland Europe, PM₁₀ in Andalusia is characterized by high levels of crustal matter and secondary inorganic components (SIC). This has been attributed to the following causes: 1) High road traffic and industrial emissions, 2) High frequency of North African air mass outbreaks contributing between 3 and 4 μg m^?3 in western Andalusia and 4–7 μg m^?3 in eastern Andalusia, and 3) Climate factors such as low rainfall, dry soils favouring resuspension, and high photochemical activity.Atmospheric particulate matter in urban areas located in the vicinity of industrial estates is enriched in secondary inorganic compounds and metals. Three main hot spots have been identified according their high trace element concentrations: Huelva (As, Cu, Zn, Se, and Bi), Strait of Gibraltar (V, Ni, Cr, and Co) and Bailén (V and Ni). The transport of pollutants from cities and industrial estates to areas of ecological interest (e.g. Doñana National Park) has been found to cause the increase in background levels in a number of trace elements (e.g. As) in the air. An important outcome of this study is that geochemical maps of atmospheric matter are a powerful tool for illustrating spatial variation patterns of geochemical components and identifying specific pollution hot spots.     

Photochemical model evaluation of the surface ozone impact of a power plant in a heavily industrialized area of southwestern Spain

The characterization and evaluation of the impact that an industry is likely to have on the surrounding ozone levels is one of many problems confronting air quality managers and should be taken into consideration when authorizing its installation. The correct management of an environment, in terms of monitoring existing industries and planning new activities, requires adequate knowledge of the processes sustained by the industrial emissions therein.This paper explores the improvements in air quality management arising from taking into account the uncertainties involved in the photochemical modeling of the impact of an industry on surface ozone levels.For this, we evaluate the impact on ozone levels of a power plant located in an industrial area of southwestern Spain (Huelva). The evaluation takes into account the effects of both emissions' uncertainty and the non-linear chemistry between ozone and its precursors, thus providing a probable range of increase over the normative values (hourly and 8-hourly maximums) defined in the European Directive. The proposed methodology is easily applicable by air quality managers.Advanced modeling techniques were used for the power plant assessment, MM5 atmospheric modeling system, and air quality model CAMx. The results from meteorology and ozone forecasts have shown acceptable agreement with the observations.The spatial distribution of the impact is found to be strongly determined by mesoscale meteorological processes, which are reinforced by the local orography; there is also a marked temporal evolution. The industrial plume is observed to induce a decrease (or maintenance) of the ozone levels near the emission source (0–10 km), and an increase in the ozone concentrations farther away (with maximums between 10 and 50 km). In fact, in the meteorological episodes with a predominance of local breeze circulations, impacts have been detected at distances of more than 100 km from the emission source.Sensitivity of the power plant impact to variations in ozone precursor emissions is described, and the scenarios and the points in the domain presenting higher sensitivity and registering larger impacts are also identified. The results show that the largest impacts take place in emission scenarios where the NO_x has been reduced with respect to the base case scenario. In contrast, in scenarios where the VOC emissions are reduced with respect to the base case scenario, the impact is smaller or remains unchanged. This is important in areas like the study case, where there is a high percentage of biogenic VOC emissions and the industrial areas are close to natural protected areas and agricultural fields.     

Study of poverty alleviation strategy based on labor force quality improvement and ecological protection in Western China

Fragile ecological environment and poverty correlate to and reinforce each other closely in Western China.At the same time,Western China is also the most prominent area of the knowledge and human poverty with very low labor force quality.On the basis of analyzing the characteristics of poverty in Western China,this paper studies the coupling relationship between fragile ecological environment and poverty in Western China,including the impacts of fragile environment on poverty occurrence and the effects of ecological construction on poverty alleviation.It also analyzed how low labor quality causes persistent poverty in the western region.At the end of the paper,strategies of diversity poverty alleviation in Western China are suggested based on sustainable development,including education improvement,ecological construction,industries development,infrastructure construction,planning institution innovation,and so on.     

Kodymirus and the case for convergence of raptorial appendages in Cambrian arthropods

The Science of Nature - Kodymirus vagans Chlupá? and Havlí?ek in Sb Geol Ved Paleontol 6:7–20, 1965 is redescribed as an aglaspidid-like arthropod bearing a single pair of...