35,168 research outputs found

    The future of organic grassland farming in mountainous regions of Central Europe

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    8 % of the total EU population lives in mountainous areas which represent a particularly important eco-region in Central Europe. Because of ecological, climatic and economic reasons an increasing pressure is imposed upon agriculture. Hence in large parts of European mountainous areas drastic changes in agricultural structure and land use systems can be observed in terms of emigration and land abandonment. Due to disadvantaged production conditions, and the high ecological sensitivity, organic farming is an important option for a sound regional development. In alpine regions organic farming does not proceed in a homogeneous way. One essential reason for that could be seen in the differences of national and regional “traditions and orientations” and supporting tools. For a positive development it is necessary to work on further integration of organic farming in regional development concepts (e.g. organic regions) and on the development of the “quality leadership” through cross-regional production, marketing and merchandising concepts. Undisputedly, further positive development of organic farming in mountainous regions depends on ongoing financial, research and advisory support

    Changes in plant species richness distribution in Tibetan alpine grasslands under different precipitation scenarios

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    Species richness is the core of biodiversity-ecosystem functioning (BEF) research. Nevertheless, it is difficult to accurately predict changes in plant species richness under different climate scenarios, especially in alpine biomes. In this study, we surveyed plant species richness from 2009 to 2017 in 75 alpine meadows (AM), 199 alpine steppes (AS), and 71 desert steppes (DS) in the Tibetan Autonomous Region, China. Along with 20 environmental factors relevant to species settlement, development, and survival, we first simulated the spatial pattern of plant species richness under current climate conditions using random forest modelling. Our results showed that simulated species richness matched well with observed values in the field, showing an evident decrease from meadows to steppes and then to deserts. Summer precipitation, which ranked first among the 20 environmental factors, was further confirmed to be the most critical driver of species richness distribution. Next, we simulated and compared species richness patterns under four different precipitation scenarios, increasing and decreasing summer precipitation by 20% and 10%, relative to the current species richness pattern. Our findings showed that species richness in response to altered precipitation was grassland-type specific, with meadows being sensitive to decreasing precipitation, steppes being sensitive to increasing precipitation, and deserts remaining resistant. In addition, species richness at low elevations was more sensitive to decreasing precipitation than to increasing precipitation, implying that droughts might have stronger influences than wetting on species composition. In contrast, species richness at high elevations (also in deserts) changed slightly under different precipitation scenarios, likely due to harsh physical conditions and small species pools for plant recruitment and survival. Finally, we suggest that policymakers and herdsmen pay more attention to alpine grasslands in central Tibet and at low elevations where species richness is sensitive to precipitation changes

    Complex responses of spring vegetation growth to climate in a moisture-limited alpine meadow.

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    Since 2000, the phenology has advanced in some years and at some locations on the Qinghai-Tibetan Plateau, whereas it has been delayed in others. To understand the variations in spring vegetation growth in response to climate, we conducted both regional and experimental studies on the central Qinghai-Tibetan Plateau. We used the normalized difference vegetation index to identify correlations between climate and phenological greening, and found that greening correlated negatively with winter-spring time precipitation, but not with temperature. We used open top chambers to induce warming in an alpine meadow ecosystem from 2012 to 2014. Our results showed that in the early growing season, plant growth (represented by the net ecosystem CO2 exchange, NEE) was lower in the warmed plots than in the control plots. Late-season plant growth increased with warming relative to that under control conditions. These data suggest that the response of plant growth to warming is complex and non-intuitive in this system. Our results are consistent with the hypothesis that moisture limitation increases in early spring as temperature increases. The effects of moisture limitation on plant growth with increasing temperatures will have important ramifications for grazers in this system

    Effects of climate change on the dispersion of white grub damages in the Austrian grassland

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    Recent changes in occurrence of agricultural pests in Austria might already reflect climate change phenomena. In this study, an inventory of white grub (Melolontha melolontha, Amphimallon solstitiale and Phyllopertha horticola) damages in Austrian grassland including organic cultivation was performed by questioning plant protection consultants of 74 Agricultural County Chambers. Altogether, a cumulated 14.800 hectares of white grub damages were recorded. From 2000 onwards, a steady increase of white grub damages occurred with a climax in the year of heat and drought 2003. The infested fields extended along the alpine main ridge from Vorarlberg up to the alpine foreland. Additionally, southern slopes of the Danube valley in Upper and Lower Austria were affected. Very likely, the damages were mainly due to the garden chafer P. horticola. From 2004 to 2006, the extent of damages decreased again all over Austria. By studying meteorological data, it became obvious that the damaged areas were mainly situated in regions with a strong precipitation deficit. On-farm investigations performed in 2007 strengthened the hypothesis that drought and elevated soil temperatures might be the decisive factors for a strong development of grub populations and subsequent feeding damages. Additionally, drought can increase the effects of grub damage by delaying the regeneration of the damaged sward. A strongly damaged sward on slopes can be dangerous for the farmers e.g. by slipping machines

    A generalized framework for analyzing taxonomic, phylogenetic, and functional community structure based on presence-absence data

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    Community structure as summarized by presence–absence data is often evaluated via diversity measures by incorporating taxonomic, phylogenetic and functional information on the constituting species. Most commonly, various dissimilarity coefficients are used to express these aspects simultaneously such that the results are not comparable due to the lack of common conceptual basis behind index definitions. A new framework is needed which allows such comparisons, thus facilitating evaluation of the importance of the three sources of extra information in relation to conventional species-based representations. We define taxonomic, phylogenetic and functional beta diversity of species assemblages based on the generalized Jaccard dissimilarity index. This coefficient does not give equal weight to species, because traditional site dissimilarities are lowered by taking into account the taxonomic, phylogenetic or functional similarity of differential species in one site to the species in the other. These, together with the traditional, taxon- (species-) based beta diversity are decomposed into two additive fractions, one due to taxonomic, phylogenetic or functional excess and the other to replacement. In addition to numerical results, taxonomic, phylogenetic and functional community structure is visualized by 2D simplex or ternary plots. Redundancy with respect to taxon-based structure is expressed in terms of centroid distances between point clouds in these diagrams. The approach is illustrated by examples coming from vegetation surveys representing different ecological conditions. We found that beta diversity decreases in the following order: taxon-based, taxonomic (Linnaean), phylogenetic and functional. Therefore, we put forward the beta-redundancy hypothesis suggesting that this ordering may be most often the case in ecological communities, and discuss potential reasons and possible exceptions to this supposed rule. Whereas the pattern of change in diversity may be indicative of fundamental features of the particular community being studied, the effect of the choice of functional traits—a more or less subjective element of the framework—remains to be investigated

    The permafrost carbon inventory on the Tibetan Plateau : a new evaluation using deep sediment cores

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    Acknowledgements We are grateful for Dr. Jens Strauss and the other two anonymous reviewers for their insightful comments on an earlier version of this MS, and appreciate members of the IBCAS Sampling Campaign Teams for their assistance in field investigation. This work was supported by the National Basic Research Program of China on Global Change (2014CB954001 and 2015CB954201), National Natural Science Foundation of China (31322011 and 41371213), and the Thousand Young Talents Program.Peer reviewedPostprin

    Developing a panarchy model of landscape conservation and management of alpine-mountain grassland in Northern Italy.

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    This paper explores methods of applying resilience theory to a case study of natural resource management and the cultural landscape of upland and alpine pasture in northern Italy. We identify that the close interaction between alpine pastures and its managers offers a strong fit with the concept of a social-ecological system that maintains the cultural landscape. We first considered a descriptive approach looking historically at socio-economic development in the study area. We explored whether this can be related to resilience phenomena such as regime shifts, thresholds and/or regime stability through adaptive processes. However, we found it difficult at this overarching level to conceptually combine natural and social capital of alpine pastures and their managers in any quantitative way. We also interpreted our data through considering economic, social and ecological information as acting within separate but interacting domains. This led us to construct conceptual models of adaptive cycles to describe the alpine mountain grassland ecosystem of our study site and to conclude that a panarchy model can offer a powerful metaphor for its ecological dynamics. This has practical implications both for the management of Natura 2000 interest and the maintenance of the cultural landscape in which this Alpine interest occurs. We suggest that Resilience theory through its dynamic approach of interacting scales of adaptive cycles offers useful insights into the resource management (of valued cultural and natural attributes) but that care is needed in distinguishing between descriptive metaphor and predictive model or "real" system.natural resource management, natural and social capital

    Changes in species composition in alpine snowbeds with climate change inferred from small-scale spatial patterns

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    Alpine snowbeds are characterised by a very short growing season. However, the length of the snow-free period is increasingly prolonged due to climate change, so that snowbeds become susceptible to invasions from neighbouring alpine meadow communities. We hypothesised that spatial distribution of species generated by plant interactions may indicate whether snowbed species will coexist with or will be out-competed by invading alpine species – spatial aggregation or segregation will point to coexistence or competitive exclusion, respectively. We tested this hypothesis in snowbeds of the Swiss Alps using the variance ratio statistics. We focused on the relationships between dominant snowbed species, subordinate snowbed species, and potentially invading alpine grassland species. Subordinate snowbed species were generally spatially aggregated with each other, but were segregated from alpine grassland species. <br><br> Competition between alpine grassland and subordinate snowbed species may have caused this segregation. Segregation between these species groups increased with earlier snowmelt, suggesting an increasing importance of competition with climate change. Further, a dominant snowbed species (<i>Alchemilla pentaphyllea</i>) was spatially aggregated with subordinate snowbed species, while two other dominants (<i>Gnaphalium supinum</i> and <i>Salix herbacea</i>) showed aggregated patterns with alpine grassland species. These dominant species are known to show distinct microhabitat preferences suggesting the existence of hidden microhabitats with different susceptibility to invaders. <br><br> These results allow us to suggest that alpine snowbed areas are likely to be reduced as a consequence of climate change and that invading species from nearby alpine grasslands could outcompete subordinate snowbed species. On the other hand, microhabitats dominated by <i>Gnaphalium</i> or <i>Salix</i> seem to be particularly prone to invasions by non-snowbed species

    Critical review of the impacts of grazing intensity on soil organic carbon storage and other soil quality indicators in extensively managed grasslands

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    Acknowledgements This work contributes to the N-Circle project (grant number BB/N013484/1), and CINAg (BB/N013468/1) Virtual Joint Centres on Agricultural Nitrogen (funded by the Newton Fund via UK BBSRC/NERC), U-GRASS (grant number NE/M016900/1), the Belmont Forum/FACCE-JPI DEVIL project (grant number NE/M021327/1), Soils-R-GGREAT (grant number NE/P019455/1), ADVENT (grant number NE/M019713/1), Sêr Cymru LCEE-NRN project, Climate-Smart Grass and the Scottish Government’s Strategic Research Programme.Peer reviewedPublisher PD
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