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Andreas Gigon 《应用植被学》1999,2(1):89-94
Abstract. Sustainability is an important quality of the types of agriculture nowadays promoted in central Europe, notably ‘biological agriculture’ and ‘integrated production’. Agronomists, decision-makers and the public generally assume that this agricultural sustainability implies the maintenance of species diversity. However, this assumption often does not hold true. This is shown in a case study of moderately ferti-lized Arrhenatheretum meadows in northern Switzerland. Earlier and more frequent mowing, simultaneous harvesting of all the grasslands in a region, and ecological changes in surrounding arable fields, hedges and other ecosystems often cause a decline in plant and animal species richness, while agricultural yield does not noticeably change. To emphasize the distinction the concept of biocenotic sustainability is proposed for describing the capability of a community to maintain its species composition and structure. For maintaining or attaining biocenotic sustainability. results of modern ecology have to be taken into account, e.g. the theories of island biogeography, minimum viable populations, dispersal, and metapopulations. There is evidence that biocenotic sustainability always implies sustainability of agricultural yield. 相似文献
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N. Erik Sjödin 《Biodiversity and Conservation》2007,16(7):2103-2121
It has been suggested that intensive grazing management, aimed at maintaining plant diversity, might not be the optimal choice to preserve diversity of insects in semi-natural pastures. In the present study the behaviour of flower visiting insects was studied in two semi-natural pastures in central Sweden. Two grazing treatments were established with one grazed from mid-May, “continuous”, and one grazed from mid-July, “late”. Flower visitors were followed for 9 weeks in summer 2003 in 7 pairs of 5 × 5 m plots on two sides of a fence dividing the two grazing treatments. Visitor behaviour was studied on three decision levels between: (1) habitats, (2) flowers and (3) activities on flowers. The pattern varied between decision levels: More species and individual visitors chose to forage in the late grazing treatment. Visitation rate and flower constancy did not differ between treatments and was related, to a large extent, to plant species richness. In relation to flowers, insects utilized a broader diversity of activities in the late grazing treatment. All patterns were consistent across sites and during the whole study period. The differences in pollinator abundance and activities on flowers were best explained by the higher abundance of flowers. It is suggested that studies of insect behaviour may be a useful tool when deciding on management recommendations. Late grazing is recommended as a useful management regime and might potentially function as a substitute for mowing in the future. 相似文献
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Regeneration patterns in a Central European dry heathland: effects of burning,sod-cutting and cutting 总被引:2,自引:0,他引:2
Vegetation development in dry heathlands was studied during a six-year period following experimental burning, sod-cutting and cutting in a continental area in the southern part of the Czech Republic (Podyjí National Park). Calluna vulgaris-dominated heathlands in the area were composed of uneven-aged stands and had been unmanaged for several decades. The aim of the study was testing the applicability of Western European management systems to nature conservation in a continental area. Species composition was recorded in 8 permanent plots using 25×25 cm grids, and vegetation recovery following different treatments was analysed. Calluna recovered successfully after burning. Burning dense heathlands, which contained a large amount of woody fuel, resulted in a medium-intensity fire that destroyed moss mats and litter and exposed patches of bare ground to facilitate Calluna regeneration by seed, in addition to vegetative regrowth. On the contrary, in open heathlands with patches of herbaceous vegetation, low-intensity fires which failed to expose mineral soil were more typical. Almost all Calluna regeneration was vegetative in this case, and regrowth was slower. Heathland recovery after sod-cutting to mineral soil depended on whether or not Calluna seed germination occurred in the plot. With germination, the community developed towards heathland; without towards grassland. Cutting promoted a striking increase in grass cover, which was followed by the slow recovery of Calluna. The experiments suggest that of these management systems, burning is perhaps the most appropriate in the study area. A nature conservation management system is proposed, based on sheep grazing combined with rotational burning of restricted patches. 相似文献
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Gerald Louette Dries Adriaens Peter Adriaens Anny Anselin Koen Devos Kurt Sannen Wouter Van Landuyt Desiré Paelinckx Maurice Hoffmann 《Journal for Nature Conservation》2011,19(4):224-235
Natura 2000 targets the sustainable conservation of Europe's biodiversity. An important cornerstone of Natura 2000 is the Habitats Directive, which is currently implemented across European member states. However, straightforward implementation is not obvious since the favourable conservation status of habitats and species needs to be achieved at the member state level, while conservation objectives need to be formulated at the protected site level. To bridge this gap, we propose to start from regional conservation objectives before site level objectives are formulated. These regional conservation objectives have the advantage of providing a framework according to which conservation objectives can be allocated both within and outside the protected sites of the Natura 2000 network. Especially since they all contribute to the national or regional conservation status. Recently, Flanders (northern Belgium) has adopted this approach and has quantified conservation objectives at the regional scale. As the current regional conservation status of habitats and species is mostly unfavourable, regional conservation objectives entail a drastic increase in area (42%) for habitats, and active conservation measures for 78% of the species. We are convinced that the method outlined here, may substantially contribute to a helpful discussion about implementing and streamlining Natura 2000 across European member states. 相似文献
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M. E. DUNCAN POORE 《Biological journal of the Linnean Society. Linnean Society of London》1987,32(2):179-187
An official organization responsible for ecological research and nature conservation was formed in 1949. This paper traces its development and vicissitudes, first as an independent Nature Conservancy, then as a part of the Natural Environment Research Council, and finally as the Nature Conservancy Council. Much has been achieved: ecology is now a household word; there is a strong voluntary tide for nature conservation in the country; and there have been notable achievements in practical conservation. But the dangers to nature in Britain have proved to be much greater than anticipated. 相似文献
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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
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Abstract. In previous studies, limited dispersal was revealed to be the main obstacle to restoration of species‐rich flood‐meadows along the northern Upper Rhine in Germany. To overcome dispersal limitation we transferred freshly mown plant material from species‐rich sources to a restoration site on a former arable field. Before plant material application, topsoil was removed to accelerate nutrient impoverishment and create favourable conditions for seedling recruitment. Topsoil removal led to a drastic reduction in organic matter and essential mineral nutrients to the level of target communities (P) or even below (N, K). At a removal depth of 30 cm content of the soil seed bank that comprised exclusively of annual arable weeds, ruderals and some common grassland species, declined by 60 ‐ 80%, while at a removal depth of 50 cm the seed bank was almost completely eliminated. With few exceptions, all species recorded in source plant material were found established at the restoration site. However, the overall correlation between seed content in plant material and establishment success was not very high. Vegetation development at the restoration site was characterized by a rapid decline in arable weeds and ruderals, while resident grassland species and species transferred with plant material increased rapidly from the third year onwards. After four years as many as 102 species were established that could be exclusively attributed to plant material transfer, among them many rare and highly endangered plants. Establishment of species from plant material was most successful in regularly flooded plots, due to the suppression of competitors as well as the creation of favourable moisture conditions for seedling emergence. Diaspore transfer with plant material proved to be an extremely successful method in restoring species‐rich grassland. However, high quality of plant material and suitable site conditions with low competition in early stages of succession seem to be essential prerequisites. 相似文献
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Eef Arnolds 《Plant biosystems》2013,147(6):779-795
Abstract The motives for the conservation of fungi are briefly outlined. The data and methods needed for successful use of fungi in environmental conservation are mentioned. A survey is given of the main habitats of threatened fungi in Western and Central Europe, including data on the significance of their mycoflora, the causes of decrease and possible measures to improve the situation. The value of macrofungi as bio-indicators for environmental quality is discussed and demonstrated with three examples: the indicator value of wood-inhabiting fungi for undisturbed forest sites; of ectomycorrhizal fungi for air pollution stress in forests and of saprotrophic fungi for the duration of undisturbed grassland use. Lists of indicator species with different indicator values for air pollution stress and grassland use are provided. 相似文献
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G.W.W. Wamelink J.J. de Jong H.F. van Dobben M.N. van Wijk 《Journal for Nature Conservation》2007,15(2):131-143
In this paper, we present a method to estimate the additional costs made by nature reserve managers to mitigate the effects of atmospheric deposition. Theoretically, these extra costs may be saved when deposition levels drop. The costs were calculated per Nature Target Type (NTT) and management intensity for both the current (high) and reduced deposition levels. The resulting ecological quality was estimated in both cases. We calculated the difference in costs based on the management intensities required to maintain ecological quality at the current and reduced nitrogen deposition levels. For the NTTs within the clusters grassland, reed and rough land, and heathland we used dynamic simulation models. For forests and moorland pools we used expert knowledge to estimate the reduction in management costs due to a decrease in deposition. The total amount of money that may be saved because of the reduction of deposition rates is estimated at 42 million euro per year for the period from 2000 to 2020 for the assessed NTTs. The highest savings can be made in grasslands; 28 million euro. On average the savings were 80 €/ha/yr, which ranged from 5 €/ha/yr for forest to 299 €/ha/yr for reed and rough land. 相似文献
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Trends and status of species and habitats need to be measured to assess whether global biodiversity policy targets have been achieved. However, it is impossible to monitor all species and habitats with a justifiable effort. Therefore, it is critical to prioritize the monitoring of specific biodiversity components. Priorities must be linked to key nature conservation policies to ensure that monitoring efforts are relevant to policy needs, achieve maximum impact, and obtain governmental support. Here we discuss priority setting in biodiversity monitoring in view of monitoring obligations and priorities in supranational biodiversity legislation and policies in Europe and assess overlaps in priorities among policies. While most supranational biodiversity regulations require monitoring of biodiversity, obligations are legally enforceable only for the Nature Directives, the Water Framework Directive, and the Marine Strategy Framework Directive of the European Union. Of the assessed international conventions and other relevant policy instruments about 50% explicitly designate priority species and most focus on vertebrates. Lower emphasis is given to habitats and geographical priorities are even less pronounced. Also, an overarching system for monitoring prioritization is still missing. Our prioritization system is based on three main criteria: (1) legal requirement for reporting, (2) wording used to define priority or importance, and (3) inclusion in lists that indicate importance of monitoring due to e.g. threats or relevance of a region for a species. Our system contains five main priority levels, within which an additional division differentiates priorities according to national/European responsibility criteria. Based on this system, we provide recommendations for allocating species and habitats enlisted by the reviewed policy tools to explicit non-overlapping priority levels. Our approach will facilitate synergies between monitoring activities for different policy needs, and contribute to alleviate the notorious resource shortage for biodiversity monitoring. 相似文献
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The Pampas deer is a medium-sized neotropical cervid whose population has been affected by the advancement of the agricultural frontier, poaching and depredation by introduced species. As a consequence, the population of the deer has dramatically decreased and its distribution has contracted. At present, Samborombón Bay remains one of the last populations of this deer in Argentina. The management of natural pastures to improve forage quality is one of the policies adopted by authorities at this site for the conservation of this cervid species. In this study, we assessed the efficacy of grassland management practices (burning and cutting) to promote better forage quality for Pampas deer. The work was carried out in the Campos del Tuyú National Park where two plots were managed to improve the available natural pastures. These plots were burned at the beginning of autumn and intensely defoliated at the end of spring, followed by mechanical cuts in the following autumn and late spring. Multivariate analyses revealed that structure and composition varied between treatments. Green biomass, total plant cover, and forage quality of grasses increased in the plots under management for winter pastures, although no significant differences were detected between summer pastures. The results indicate that grassland management would be a useful tool to improve habitat quality for Pampas deer; however, managed grassland also lost structural heterogeneity. Despite the fact that this study reveals a short-time response of grassland to management, our study shows promising results to continue and expand this practice for the improvement of the habitat quality for Pampas deers. 相似文献
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植物是人类和动物生活所必需,由于缺乏长远规划的目标,无计划的滥用已导致许多植物灭绝或陷入濒临灭绝的境地。为此,IUCN—WWF联合建立了“植物保护研究计划”,并把其列入他们各自工作的重点。主要工作内容有下列各项:1)传播信息宣传群众;2)建立必要的植物保护的工作条件:3)植物遗传资源的保护:4)野生经济植物的保护:5)加强植物园开展植物保护的工作条件:6)促进植物丰富的国家开展植物保护工作。 相似文献
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Abstract. The consequences of extensification on grassland invasion by weeds was studied in French Pyrenean hay-meadows through a survey of the population dynamics of one very successful colonizer: Chaerophyllum aureum. Experiments established in natural permanent grasslands allow us to test the effect of different intensities of cutting on the demography of adult and seedling populations and on the production of seeds and their survival in soil. Although an early cut can control population density by drastically reducing invasion by new genotypes, the results reveal a positive effect of early cutting on adult and seedling survival probably by decreasing intra-specific competition. Allocation of resources to sexual reproduction in response to cutting is limited, affecting especially the seed viability in soil. Nevertheless, the invasive ability of this species is due largely to a strategy whereby those adults showing a high survival rate tend to be perennial. 相似文献
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Establishing national parks should result from a desire to protect natural or near natural landscapes with the lowest degree of anthropogenic transformation. This paper tries to ascertain whether national parks in Poland protect the most natural landscapes and how far they have been affected by humans. The level of anthropogenic transformation of natural landscapes was assessed based on an analysis of the percentage of natural, semi-natural and anthropogenic land cover. The vast majority of national parks in Poland (21 out of 23) protect landscapes which have been minimally transformed by humans (RATTNP ranges from 1.01 to 1.16). Only two kinds of natural landscapes, those that are the most transformed by humans, are not represented within the set of the Polish national parks. Hence, the distribution of national parks reflects the degree of anthropogenic landscape transformation. The proposed method could be applied to any type of spatial unit and thus be the basis for designating areas that should be protected. 相似文献