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111.
Young forests can be manipulated in diverse ways to enhance their ecological values. We used stem maps from two dense, second-growth stands in western Washington and a spatially explicit light model (tRAYci) to simulate effects of five silvicultural manipulations on diameter distribution, species composition, spatial patterning, and light availability. Each treatment removed 30% of the basal area, but differed in how trees were selected for removal. Three primary treatments were thin from below (removing the smallest trees), random thin (removing trees randomly), and gap creation (removing all trees in circles ∼1 tree height in diameter). Two additional treatments combined elements of these approaches: random ecological thin (a mixture of thin from below and random thin) and structured ecological thin (a mixture of thin from below and gap creation).  相似文献   
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This study presents an assessment of the potential impact of geological contamination of the environment on the health of the population in Spišsko-Gemerské rudohorie Mts. (SGR Mts.). The concentration levels of potentially toxic elements (mainly As, Cd, Cu, Hg, Pb, Sb, and Zn) were determined in soils, groundwater, surface water, and stream sediments as well as in the food chain (locally grown vegetables). A medical study included some 30 health indicators for all 98 municipalities of the study area. The As and Sb contents in human fluids and tissues were analyzed in one municipality identified to be at the highest risk. Based on element content, environmental and health risks were calculated for respective municipalities. Out of 98 municipalities 14 were characterized with extremely high environmental risk and 10 were characterized with very high carcinogenic risk from arsenic (groundwater). Extensive statistical analysis of geochemical data (element contents in soils, groundwater, surface water, and stream sediments) and health indicators was performed. Significant correlations between element contents in the geological environment and health indicators, mainly cancer and cardiovascular diseases, were identified. Biological monitoring has confirmed the transfer of elements from the geological environment to human fluids and tissues as well as to the local food chain.  相似文献   
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This investigation assesses the feasibility of calculating and visualizing health risk estimates from exposure to groundwater contaminated with arsenic (As) using data from national geochemical databases. The potential health risk associated with As-contaminated groundwater was assessed based on an elaboration of existing geochemical data in accordance with accepted methodological procedures established for human health risk assessment (U.S. Environmental Protection Agency methodology). A screening analysis approach was used for estimating the contribution of As to the total chronic health risk from exposure to groundwater contaminated with potentially toxic elements, including As, Ba, Cd, Cu, Hg, Pb, Sb, Se and Zn, and the results indicate that As contributes significantly (>50%) to this total health chronic risk in about 10% of Slovak territory. Based on the calculation of the potential risk level by exposure modelling, increased chronic as well as carcinogenic risk levels (medium to high) were documented in approximately 0.2 and 11% of the total Slovak area, respectively. The areas characterized by high health risk levels are mainly those geogenically contaminated. High and very high carcinogenic risk was determined in 34 of 79 districts and in 528 of 2924 municipalities.  相似文献   
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The agri-environmental programme (AEP) is the European Union policy instrument used for the delivery of environmental services expected by the society, but societal expectations for these environmental services are insufficiently assessed. In order to realistically meet the expectations of AEP, this research utilises analytical hierarchy process based web survey to assess the importance that various societal stakeholders in the European countries of Slovenia and Croatia give to specific environmental services and to also identify the agricultural practices that have the greatest potential to realise the expectations that society values the most. All stakeholders (overall group) from Slovenia and Croatia ranked water quality and availability as the first most important environmental service, and reduction of pesticides as the most important agricultural practice to deliver societal expectations. The results indicate that there is similar demand for environmental services in these two countries that differ in their agricultural settings.  相似文献   
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Environmental Science and Pollution Research - Highly time-resolved particle number size distributions (PNSDs) were evaluated during 5 years (2013–2017) at four background stations in the...  相似文献   
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