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This study compares diversity and abundance of birds plus abundance of butterflies, bumblebees and herbaceous plants between six small farms (<52 ha arable land) and six large farms (>135 ha arable land) in Roslagen in southeastern Sweden. Two of the large and four of the small farms were organic. Large-scale landscape mosaic and underlying bedrock were similar for all farms. Statistical analysis was performed using box-plots on medians and analysis of variance on mean values. More than twice as many bird species and territories, butterflies, and herbaceous plant species, and five times more bumblebees were found on the small compared to the large farms. The largest differences were found between small organic and large conventional farms. Differences were also noted between small and large organic farms: 56% more bird species were found on small organic than on large organic farms, although none of the farms used any pesticides. We therefore argue that the consideration of organic agriculture's effect on biodiversity should include factors affected by farm size.
The main source of human exposure to persistent organic pollutants (POPs) is, in general, food. In this study, 64 butter samples from 37 countries were analyzed to assess the global contamination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), hexachlorobenzene (HCB), and 2,2-bis (4-chlorophenyl)-1,1,1-trichloroethane (DDT) together with its major metabolites. The objectives of the study were to assess the presence of major organohalogen contaminants in butter, to trace geographical differences, and to determine toxic equivalents (TEQs) of PCDDs/Fs and dioxin-like PCBs in butter. The highest PCDD/F concentrations were found in butter from Korea with an average of 1.4 pg TEQ g−1 lipid weight (l.w.). from PCDD/F and an additional contribution from the non- and mono-ortho-PCBs of 0.55 pg TEQ g−1 l.w. Belgian butter showed average levels of 0.53 and 1.2 pg TEQ g−1 l.w. for PCDDs/Fs and PCBs, respectively, but one sample of Belgium butter had a total TEQ level as high as 4.0 pg TEQ g−1 l.w. Three out of five butter samples from Portugal showed similarly high PCDD/F TEQ levels. The ΣPCB levels in European butter appeared to be somewhat higher than in the samples from the rest of the world. The average contribution of CB-153 to the total PCB concentration was 22% (SD 6.4, coefficient of variation 29%). Generally, the PCBs contributed around 60% of the total TEQ value, with CB-126 contributing approximately half of this value. This shows the important TEQ contribution from dioxinlike PCBs to the total TEQs. The highest HCB levels were found in butter samples from Russia, Ukraine, Belgium, and Slovenia. Low levels of HCB in butter were generally found in the Southern Hemisphere. Butter samples from countries from Eastern Europe had elevated ΣDDT concentrations, with a particularly high concentration in Ukraine butter, followed by some Russian samples, Brazil, and the US.
Intensification of agriculture has been proposed as one way of minimizing emissions per unit of product, apparently legitimizing the ongoing structural changes in agriculture. We have investigated the relationship between the farming intensity and the nitrogen (N) dissipation by calculating the overall N emission factor (E: total N surplus per unit of N in the produce) from several studies of dairy farms, covering a wide range of environments and production intensities. Fundamental steps were 1) the distinction between trophic levels, mineral, plant and animal N; and 2) the inclusion of N losses related to bought feed. The results show that E increases significantly with the production intensity of the dairy farm. The tradition for separate optimization of the animal and crop sectors may be a reason. We suggest that the N pollution can be mitigated by more extensive farming, both by re-coupling crop and animal production side by side, and by keeping land under cultivation when production is reduced.
This study estimates the national-level annual volume and value of commercial medicinal plant harvest in Nepal. Data were collected using open-ended questionnaires administered to local medicinal plant traders (n = 149) in 15 districts in Nepal and regional wholesalers (n = 53) in India. The annual trade volume is estimated to range from 7000 to 27 000 tons, with 14 500 tons harvested in the case year 1997–1998. The corresponding annual export value, calculated using regional wholesaler purchasing prices in the main markets in India, is estimated at US$7–30 million, with a value of US$16 million in 1997–1998. Around 10% of rural households are involved in commercial harvesting. Lower ecological zones dominate supplies in both volume and value terms; herbs constitute the most important life form in value terms. Around 36% of volume and 51% of value derive from destructive harvesting. It is argued that annual volume and value figures are likely to be conservative estimates. The implications of findings for Himalayan medicinal plant conservation and trade are briefly discussed.
The practice of integrated coastal management (ICM) has matured sufficiently since its beginnings in the early 1980s to suggest a set of principles that could be used to guide the massive investments that will be made over the next several years to rehabilitate and reconstruct the thousands of kilometers of coastlines devastated by the 26 December 2004 tsunami. We offer six principles to guide what can be done to make coastal communities less vulnerable, to improve the conditions of the poor, and to avoid repeating the mistaken judgements that have been made in the past about how shorelines are allocated and developed. We then offer a set of five principles to guide how action plans are formulated and implemented. These stress the critical importance of tailoring principles to the unique conditions and needs of each place. The roles of national government in setting policies to guide a decentralized planning and decision-making process are distinguished from a negotiation process that engages the people of the place in a bottom-up application of ICM good practices.
Surface sediment samples were collected from five stations along the Jordanian coast of the Gulf of Aqaba, Red Sea, during October and November over 2 years, 2000 and 2001. The monthly sedimentation rate also was estimated for the same stations. Collected sediments were analyzed for color, odor, redox potential, grain size, organic carbon, organic nitrogen, calcium carbonate, and total phosphorus. The Hotels area at the northernmost tip of the Gulf of Aqaba, characterized by sandy beaches and sea grass bottom habitat, exhibited the lowest values for redox potential and was associated with a black color. The Phosphate Port area exhibited the highest sedimentation rate, finest grain size, highest organic carbon content, and highest total phosphorus concentration. This is a deposition habitat that receives phosphate particles lost during shipment. The Marine Science Station and the Tourist Camp, typical coral reef habitats, had the highest calcium carbonate and organic nitrogen concentrations. This is directly attributed to the nature of the bottom habitat. Calcium carbonate deposits result from the erosion of hard corals, and organic nitrogen accumulates due to the rapid consumption and recycling of plankton in the coral reef framework. Comparison of the current records with old records from the 1970s and early 1980s indicates significant improvement in the environmental quality at the Phosphate Port. Tracking the coastal management practices over time shows that these improvements in the environmental quality can be attributed both to the zero discharge policy Jordan has followed since 1986 and to improvements in the phosphate handling system by the Ports Corporation.
An overview of the importance of fossil fuels in supplying the energy requirements of the 21st century, their future supply, and the impact of their use on global climate is presented. Current and potential alternative energy sources are considered. It is concluded that even with substantial increases in energy derived from other sources, fossil fuels will remain a major energy source for much of the 21st century and the sequestration of CO2 will be an increasingly important requirement.
The growing gray seal population in the Baltic Sea has led to increased conflicts with fisheries. Despite limited data on gray seal ecology, management measures, such as culling, have been implemented recently. We studied movements and site fidelity of Baltic gray seals using mark-recapture analysis based on photographic identification of individuals (photo-id). Seals were photographed at the major summer haul-out sites. Profile photographs of the head and neck were matched using purpose-written software to generate a database of capture histories from 1995–2000. The haul-outs were grouped into seven areas. Darroch's method (20) for a two-sample capture-recapture census was adapted to estimate rates of movement between the areas. The majority of seals were estimated to remain within the same area, suggesting that Baltic gray seals exhibit a high degree of site fidelity during the summer, and that fidelity to a site lasts for more than one season.
Over the course of the 20th century, fossil fuels became the dominant energy input to most of the world's fisheries. Although various analyses have quantified fuel inputs to individual fisheries, to date, no attempt has been made to quantify the global scale and to map the distribution of fuel consumed by fisheries. By integrating data representing more than 250 fisheries from around the world with spatially resolved catch statistics for 2000, we calculate that globally, fisheries burned almost 50 billion L of fuel in the process of landing just over 80 million t of marine fish and invertebrates for an average rate of 620 L t−1. Consequently, fisheries account for about 1.2% of global oil consumption, an amount equivalent to that burned by the Netherlands, the 18th-ranked oil consuming country globally, and directly emit more than 130 million t of CO2 into the atmosphere. From an efficiency perspective, the energy content of the fuel burned by global fisheries is 12.5 times greater than the edible-protein energy content of the resulting catch.
The complexity of development activities, in which the interactions between various forces often mean that outcomes are unpredictable and unanticipated, highlights the importance of objective and comprehensive evaluations. In the specific case of the evaluation of towns east and south of Colombo water supply projects, the findings have major implications for the implementation of the Millennium Development Goals, if the water-related objectives are to be fulfilled. The study found that 30% of the households of these towns that are receiving clean, piped water are not using it for drinking. Instead, they are continuing to drink contaminated well water. Whereas it is considered that the main beneficiaries of water supply projects have been women and people who are sick, elderly, or disabled, the general perception is that the health conditions of the families have not improved with the provision of clean water (in fact, many claim that their health conditions have deteriorated). In spite of the higher cost of the supplied water, people are willing to pay for it as long as the supply is reliable.