| 1. |
- Allan, Eric, et al.
(author)
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Interannual variation in land-use intensity enhances grassland multidiversity
- 2014
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In: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 111:1, s. 308-313
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Journal article (peer-reviewed)abstract
- Although temporal heterogeneity is a well-accepted driver of biodiversity, effects of interannual variation in land-use intensity (LUI) have not been addressed yet. Additionally, responses to land use can differ greatly among different organisms; therefore, overall effects of land-use on total local biodiversity are hardly known. To test for effects of LUI (quantified as the combined intensity of fertilization, grazing, and mowing) and interannual variation in LUI (SD in LUI across time), we introduce a unique measure of whole-ecosystem biodiversity, multidiversity. This synthesizes individual diversity measures across up to 49 taxonomic groups of plants, animals, fungi, and bacteria from 150 grasslands. Multidiversity declined with increasing LUI among grasslands, particularly for rarer species and aboveground organisms, whereas common species and belowground groups were less sensitive. However, a high level of interannual variation in LUI increased overall multidiversity at low LUI and was even more beneficial for rarer species because it slowed the rate at which the multidiversity of rare species declined with increasing LUI. In more intensively managed grasslands, the diversity of rarer species was, on average, 18% of the maximum diversity across all grasslands when LUI was static over time but increased to 31% of the maximum when LUI changed maximally over time. In addition to decreasing overall LUI, we suggest varying LUI across years as a complementary strategy to promote biodiversity conservation.
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| 2. |
- Eckstein, Rolf Lutz, et al.
(author)
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Biological flora of central Europe : Viola elatior, V. pumila and V. stagnina
- 2006
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In: Perspectives in plant ecology, evolution and systematics. - : Elsevier BV. - 1433-8319 .- 1618-0437. ; 8:1, s. 45-66
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Research review (peer-reviewed)abstract
- Viola elatior, V pumila and V stagnina (syn. V persicifolia) are very rare in central and western Europe and red-listed in many central European countries. To improve their conservation and to base management efforts on sound scientific knowledge, we here review the available information on their biology. A comparative approach is adopted to identify similarities and differences between the species. Special emphasis will be on taxonomy, community ecology and population biology. All three species belong to the section Viola, subsection Rostratae. Since they are morphologically rather similar and have often been misidentified, we supply the most important characters for separating the three taxa. The species share a continental distribution with a centre of occurrence in the temperate zone of eastern Europe and western Siberia, and reach their western range margin in central and western Europe. They have become rare and endangered through melioration and fragmentation of their habitats. All three species are iteroparous hemicryptophytes with a complex life cycle, a mixed mating system with chasmogamous and cleistogamous flowers, and a persistent seed bank. Viola pumila and V. stagnina occur in floodplain meadows and wet grasslands, whereas V. elatior is a typical species of alluvial woodland fringes and other ecotonal habitats bordering floodplain meadows. Viola elatior and V pumila are confined to calcareous or at least base-rich substrates, whereas V stagnina may also occur on strongly acidic soils. The violets are able to occupy a broad range of site conditions in terms of soil nutrient status and productivity. However, on fertile sites the species depend on regular disturbances that weaken competitors and enhance the germination of dormant seeds. Current information about mycorrhizal colonisation, biochemical and physiological data, and herbivores and pathogens is scarce or lacking, probably due to the rarity of the three species in central Europe. (c) 2006 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved.
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| 3. |
- Teuber, Laurenz, et al.
(author)
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Livestock grazing in intermountain depressional wetlands-Effects on plant strategies, soil characteristics and biomass
- 2013
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In: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 175, s. 21-28
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Journal article (peer-reviewed)abstract
- Prairie wetlands are considered valuable habitat for plants, birds, and wildlife. Livestock use of these wetlands can create conflicts with conservation issues. To achieve proper management, patterns and processes induced by grazing livestock need to be understood. In this study, we examined interactions of livestock use, soil and vegetation of depressional prairie wetlands in British Columbia, Canada. Plant community composition; biomass, and soil properties (bulk density, salinity, nitrogen and carbon content) were sampled on transects in marsh and wet meadow vegetation zones of wetlands along a grazing intensity gradient. Grime's CSR-strategies were used to calibrate strategy signatures, which indicate the importance of competition, stress and disturbance. Heavily grazed sites had higher salinity, less biomass, and proportionally less belowground biomass. Differences concerning strategies between vegetation zones were only apparent in un/lightly grazed sites, where stress was higher in marsh and competition higher in wet meadow zones. Livestock use and nitrogen were positively correlated with ruderal abundance and negatively correlated with competitors and stress-tolerators. Livestock use was identified to be most influential on plant strategies. Our results indicate that heavy livestock use significantly alters vegetation patterns and processes in prairie wetlands and may have negative impact on valuable habitat. Management decisions should consider reduced livestock access and incorporate conservation issues in grazing schemes.
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