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111.
In order to characterise current and historical pattern of heavy metal (HM) pollution in Estonia, this article will compare the concentrations and stocks of Cd, Cr, Cu, Ni, Pb and Zn represented in current deposition (data from 18 local precipitation stations) with natural media of three different ages: 1–3-year-old moss carpet (ICP Vegetation moss survey data from 99 open area plots), 3–5-year-old litter layer, and several-decades-old organic layer (mor humus) of coniferous forest, in mostly podzolic soils (ICP Forest soil survey data, 75 stands).Objectives of this study are (1) to assess differences in HM retention and accumulation in various aged media of coniferous stands (2) to estimate territorial differences in current HM distribution and previously accumulated concentrations and stores of HM (3) to compare territorial distribution of HM concentration in Estonia between five different regions: N-W; N-E; S-W; S-E and Western insular region, whereas the local oil shale industry in N-E part of Estonia has been the main source of HM pollution over a long period of time and therefore may have an effect on HM regional distribution.Comparing the studied media, three types of HM retention patterns were detected: (1) for Cu, Ni, Cr (2) for Cd, Pb, (3) for Zn. The mean current level of HM deposition in Estonia is low comparison to previous decades, especially the 1980s. The effect of the previously significantly higher exposure of HM emissions and deposition is preserved in older part of soil organics (OF), where the highest stocks and concentrations of HMs (with the exception of Zn) are currently found. The HM proportions in fly ash of oil shale and in OF layer of soil were very similar with regards to Ni and Cr—indicating their origin from the oil shale industry in the N-E region. According to spatial distribution analysis, the greatest accumulated storages of Ni and Cr in OF layer of coniferous forest soils are characteristic to S-W Estonia. 相似文献
112.
113.
Military training areas (MTAs) host high numbers of endangered habitats and species due to their large area, generally low fertilizer and biocide exposure, and a high dynamic of disturbances caused by military training activities. Since the end of the Cold War in the 1990s, thousands of former military properties have been closed due to international disarmament agreements. Based on a literature review, we present the importance of decommissioned MTAs in Germany for nature conservation, their number, area, and status, as well as the German approaches and experiences managing these sites. More than 119,000 ha of former military areas of high conservation value were transferred by the Federal Government to German Federal States, the German Federal Environmental Foundation, and other nature conservation organizations as part of the so-called National Nature Heritage (NNH), and an additional 60,000 ha were saved in other ways. It is a big challenge in nature conservation to establish appropriate management systems to maintain the endangered habitats and species on these sites, most of which are contaminated with unexploded ordnance (UXO). Several projects have been implemented in Germany to develop strategies to deal with UXO contamination. We discuss management options, from prescribed burning on UXO contaminated sites to the establishment of wilderness, in the light of the requirements of the European Union’s Natura 2000 network of protected areas. 相似文献
114.
The role of the surface polymer brush of nonionic surfactant vesicles (NSV) in inhibiting interactions with small membrane-perturbing molecules was investigated using the bee venom peptide melittin as a probe. The interaction between melittin and NSV was compared with that of distearoylphosphatidylcholine (DSPC) vesicles and sterically stabilised liposomes (SSL) containing 5 mol% pegylated distearoylphosphatidylethanolamine (DSPE.E44). The degree of melittin interaction with the various vesicles was determined by measuring peptide binding and folding, using intrinsic tryptophan fluorescence and circular dichroism respectively, in addition to monitoring the release of encapsulated carboxyfluorescein dye. NSV composed of 1,2-di-O-octadecyl-rac-glyceryl-3-(ω-dodecaethylene glycol) (2C18E12) showed a strong affinity for melittin, whilst exhibiting ~ 50% less bound peptide than SSL. 2C18E12:Chol vesicles showed reduced melittin interaction, in a manner consistent with Chol incorporation into DSPC vesicles. These results are discussed with respect to the effect of Chol on the in-plane order of 2C18E12 bilayers and consequent attenuation of hydrophobic interactions with the peptide. NSV formed from equimolar mixtures of polyoxyethylene-n-stearoyl ethers C18E2 and C18E20 showed a greater interaction with melittin than 2C18E12. However, replacing C18E20 with C18E10 was sufficient to achieve an attenuation of melittin interaction similar to that observed in 2C18E12:Chol vesicles. This indicates that the presence of surface polymer brush alone may confer resistance to melittin, provided hydrophobic interactions between the peptide and the vesicles can be minimised, through improved in-plane bilayer order. 相似文献
115.
内蒙古不同类型草地叶面积指数遥感估算 总被引:5,自引:0,他引:5
叶面积指数(Leaf Area Index,LAI)是重要的植被结构参数,反演LAI是植被遥感的重要研究内容之一。根据在内蒙古呼伦贝尔和锡林浩特草原利用LAI 2000观测的草地LAI,比较了不同植被指数(SR、RSR、EVI、NDVI、SAVI和ARVI)估算不同类型草地LAI的能力,建立了基于Landsat-5 TM遥感数据的LAI估算模型,并利用LAI观测数据对模型进行了检验,生成了研究区内草地LAI分布图,据此对MODIS LAI产品一致性进行了评价。结果表明,在呼伦贝尔和锡林浩特两个研究区,RSR与LAI的相关性最高(R2分别为0.628、0.728,RMSE分别为0.512、0.490),在低密度草地,RSR的优势更为明显;验证表明,根据RSR建立的LAI估算模型的精度可达70%;利用TM数据生成的两个地区的LAI(TM LAI)空间变化明显,锡林浩特草地的LAI值整体上低于呼伦贝尔草地;在呼伦贝尔和锡林浩特,MODIS LAI产品与TM LAI一致性分别为0.566,0.323,MODIS LAI产品高估了呼伦贝尔草地LAI值,而在锡林浩特研究区则存在低估现象。 相似文献
116.
Biodiversity and stakeholder participation 总被引:1,自引:0,他引:1
Consensus building through stakeholder participation is a promising new trend that takes into account the interactive character of the communication process. There is a growing realisation that stakeholder participation has a significant role to play in the development and delivery of biodiversity policy and practice. Experience and best practice from activities such as the designation and management of Natura 2000 and Integrated Coastal Zone Management shows that problem solving and conflict management are significantly enhanced through participative processes. There is therefore the potential for a change to take place in the way that biodiversity policy is developed and implemented. This brings challenges to the biodiversity community in terms of developing new skills and processes and in engaging with new agendas and sectors. 相似文献
117.
Jozef Keulartz 《Restoration Ecology》2009,17(4):446-450
The implementation of Natura 2000 has met with considerable resistance from farmers, fishermen, foresters, and other local residents in most European Union Member States. In response to the rural protest, the majority of governments have gradually abandoned their centralist, top-down approach and increasingly switched over to methods of participatory and interactive policy-making. However, this "democratisation" of European nature conservation policy is not without its problems and pitfalls. The inclusion of an ever-growing group of stakeholders with different and often diverging interests, ideas, views, and values will more often than not lead to conflicts over the future of nature and the landscape. The causes and consequences of these conflicts need to be examined to improve the policy process. 相似文献
118.
The abandonment of traditional anthropogenic activities is an important driver shaping landscape patterns. Therefore, multi-scale pattern analysis over time is needed to identify appropriate scales for biodiversity conservation and monitoring of abandoned landscapes. We compared spatial and temporal changes in a pair of alpine watersheds in Italy (Cajada and Tovanella), which are similar in size, geo-climatic conditions, and land-use histories; but have had divergent anthropogenic abandonment processes since the 1950s. We hypothesize that this divergence has led to corresponding dissimilarities in multi-scale patterns of landscape change. To examine this hypothesis, we analyzed land cover maps from three years (1954, 1980/83, 2006) and described the changes using transition matrices. For each year and watershed, landscape heterogeneity and a set of class-level metrics (i.e. percentage of the landscape, area-weighted mean patch size, patch density, area-weighted mean shape index, edge density, and aggregation index) were also measured at different scales using random sampling techniques, and the results were summarized by using scalograms. Woodland expansion occurred mainly at the expenses of grasslands, meadows, and shrublands. These changes were greater during the first time-period (1954-80/83) than in the more recent period (1980/83-2006), with a mean annual value that decreased from +5.18 to +1.33 ha/year and from +4.08 to +1.96 ha/year in the abandoned and managed watersheds, respectively. Landscape heterogeneity decreased over time with a similar pattern in both watersheds, which indicates a general process of homogenization. Management regime affected the spatial-scale response of class-level metrics; these metrics showed a variety of multi-scalar responses, which were not always consistent over time and under different management regimes. When considering the response of the indices across spatial-scales for both watersheds, certain historical curves showed a scale break, representing a significant change in the shape and slope of the curve (i.e. scale divergence). The presence of scale breaks in the scalograms can potentially reveal important thresholds for biodiversity. For example, grassland and meadow patch density at small spatial scales (<200 m radius), which was found to be important for protected butterfly species, had a greater reduction over time in the managed watershed when compared to the abandoned watershed. In conclusion, the findings of this study indicate that there is good potential for understanding changes in landscape patterns under different management abandonment regimes by combining spatial and temporal analysis of class-level metrics. 相似文献
119.
120.
Antonios D. Mazaris Joseph Tzanopoulos Athanasios S. Kallimanis Yiannis G. Matsinos Stephanos P. Sgardelis John D. Pantis 《Biodiversity and Conservation》2008,17(14):3567-3577
Understanding how overall patterns of spatial variation in species richness are affected by distributional patterns of species
has been an area of growing concern. In the present study, we investigated the relative importance of common and rare species
as contributors in overall plant species richness. We further examined if the effects of common or rare species in richness
patterns are affected by the size of the sampling units and if the observed patterns hold at different habitats. We used a
dataset of 5,148 higher plant species distributed across 16,114 sampling plots located in 240 sites of the NATURA 2000 network
of Greece. We ranked all species based on the number of sites they occupied and we developed a common to rare and a rare to
common sequence. We correlated those sequences with cumulative species distributions. We performed this analysis in nine different
sizes of sampling units and in three different datasets referring to (a) all habitat types together, (b) coniferous habitats
only and (c) alpine habitats only. Our analysis showed that despite the proportionally higher numbers of restricted species,
widespread species make a greater contribution to overall richness patterns and that this observed pattern does not depend
on the size of the sampling units. Moreover, the observed pattern stands for different habitat types. Our findings support
the generality of this pattern and highlight the importance of widespread species as adequate indicators of biodiversity patterns
at various habitat types.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献