Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litter and methodologies, adding major uncertainty to syntheses, comparisons and meta-analyses across different experiments and sites. In the TeaComposition initiative, the potential litter decomposition is investigated by using standardized substrates (Rooibos and Green tea) for comparison of litter mass loss at 336 sites (ranging from -9 to +26 °C MAT and from 60 to 3113 mm MAP) across different ecosystems. In this study we tested the effect of climate (temperature and moisture), litter type and land-use on early stage decomposition (3 months) across nine biomes. We show that litter quality was the predominant controlling factor in early stage litter decomposition, which explained about 65% of the variability in litter decomposition at a global scale. The effect of climate, on the other hand, was not litter specific and explained <0.5% of the variation for Green tea and 5% for Rooibos tea, and was of significance only under unfavorable decomposition conditions (i.e. xeric versus mesic environments). When the data were aggregated at the biome scale, climate played a significant role on decomposition of both litter types (explaining 64% of the variation for Green tea and 72% for Rooibos tea). No significant effect of land-use on early stage litter decomposition was noted within the temperate biome. Our results indicate that multiple drivers are affecting early stage litter mass loss with litter quality being dominant. In order to be able to quantify the relative importance of the different drivers over time, long-term studies combined with experimental trials are needed.

Summary1. Disturbance is one of the most important factors structuring the taxonomic and functional composition of vegetation. Vegetation resistance or resilience to disturbance depends on local environmental conditions, further modifying the pool of species and traits. This paper aims to understand how disturbance and local environment combine to affect the resistance and resilience of vegetation. 2. A functional-trait approach was used to detect traits related to vegetation resistance and resilience, and trait attributes of individual species responding to disturbance. Trait approaches enable comparison of vegetation responses across biogeographic regions containing different species pools. 3. At 35 European forest and grassland sites, experimental disturbance (human trampling) was applied at five intensities. Indices for resistance and resilience were calculated, based on total vegetation cover, and related to climate and local site factors. Additional indices were calculated for the most common species to demonstrate traits that confer resistance and resilience to disturbance. Resistance depends on the functional composition of predominant species in the assemblage, which is strongly affected by land-use history; resilience is directly connected to growth rates affected by climate. We argue for the inclusion of land-use history and climate into the planning process for visitor management, especially in areas of high conservation interest.

Changes in traditional agricultural systems in Europe in recent decades have led to widespread abandonment and colonization of various habitats by shrubs and trees. We combined several vegetation databases to test whether patterns of changes in plant diversity after land abandonment in different habitats followed similar pathways. The impacts of land abandonment and subsequent woody colonization on vegetation composition and plant traits were studied in five semi-natural open habitats and two arable habitats in six regions of Europe. For each habitat, vegetation surveys were Folia Geobot (2011) 46:303-325 carried out in different stages of succession using either permanent or non-permanent plots. Consecutive stages of succession were defined on a physiognomic basis from initial open stages to late woody stages. Changes in vegetation composition, species richness, numbers of species on Red Lists, plant strategy types, Ellenberg indicator values of the vegetation, Grime CSR strategy types and seven ecological traits were assessed for each stage of the successional pathway. Abandonment of agro-pastoral land-use and subsequent woody colonization were associated with changes in floristic composition. Plant richness varied according to the different habitats and stages of succession, but semi-natural habitats differed from arable fields in several ecological traits and vegetation responses. Nevertheless, succession occurred along broadly predictable pathways. Vegetation in abandoned arable fields was characterized by a decreasing importance of R-strategists, annuals, seed plants with overwintering green leaves, insect-pollinated plants with hemi-rosette morphology and plants thriving in nutrient-rich conditions, but an increase in species considered as endangered according to the Red Lists. Conversely, changes in plant traits with succession within the initiallyopen semi-natural habitats showed an increase in plants thriving in nutrient-rich conditions, stress-tolerant plants and plants with sexual and vegetative reproduction, but a sharp decrease in protected species. In conclusion, our study showed a set of similarities in responses of the vegetation in plant traits after land abandonment, but we also highlighted differences between arable fields and semi-natural habitats, emphasizing the importance of land-use legacy.

Context Abandonment of extensively managed meadows is an ongoing global challenge in recent decades, particularly in mountain regions, and directly affects plant diversity. However, the extent to which plant diversity further affects associated insect pollinators or herbivores is little investigated. Objectives We focused on the effects of abandonment of mountain meadows on species richness and assemblages of bumblebees, bugs and grasshoppers. Specifically, we investigated the influence of vegetation cover, flower cover, plant richness and surrounding landscape on the three insect groups.Methods Species richness, abundance and species assemblages of bumblebees, bugs and grasshoppers were surveyed in one Swiss and two Austrian regions: three meadows which had been abandoned for 15-60 years, and three extensively managed meadows (mown once a year, no use of fertilizers). We surveyed bumblebees and bugs by sweep net, and grasshoppers using the time-effective soundscape approach. Results Bumblebee species richness and abundance were significantly higher in managed meadows, whereas bug and grasshopper richness and abundance showed no differences between both management types. Managed and abandoned meadows harboured significantly different species assemblages of bugs and grasshoppers, but not of bumblebees. Increasing flower cover and plant richness increased bumblebee 123Landscape Ecol (2017) 32:1937-1951 DOI 10.1007 richness, but correlated negatively with richness of bugs. Surrounding open landscape positively affected bugs. Caelifera positively correlated with surrounding forest cover and negatively with vegetation cover. Vegetation cover positively affected Ensifera. Conclusions Abandoned and extensively managed meadows are important habitat types for the conservation of the three insect groups, thus suggesting the maintenance of both habitat types within mountain landscapes.

Climate and land‐use change jointly affect the future of biodiversity. Yet, biodiversity scenarios have so far concentrated on climatic effects because forecasts of land use are rarely available at appropriate spatial and thematic scales. Agent‐based models (ABMs) represent a potentially powerful but little explored tool for establishing thematically and spatially fine‐grained land‐use scenarios. Here, we use an ABM parameterized for 1,329 agents, mostly farmers, in a Central European model region, and simulate the changes to land‐use patterns resulting from their response to three scenarios of changing socio‐economic conditions and three scenarios of climate change until the mid of the century. Subsequently, we use species distribution models to, first, analyse relationships between the realized niches of 832 plant species and climatic gradients or land‐use types, respectively, and, second, to project consequent changes in potential regional ranges of these species as triggered by changes in both the altered land‐use patterns and the changing climate. We find that both drivers determine the realized niches of the studied plants, with land use having a stronger effect than any single climatic variable in the model. Nevertheless, the plants' future distributions appear much more responsive to climate than to land‐use changes because alternative future socio‐economic backgrounds have only modest impact on land‐use decisions in the model region. However, relative effects of climate and land‐use changes on biodiversity may differ drastically in other regions, especially where landscapes are still dominated by natural or semi‐natural habitat. We conclude that agent‐based modelling of land use is able to provide scenarios at scales relevant to individual species distribution and suggest that coupling ABMs with models of species' range change should be intensified to provide more realistic biodiversity forecasts.

In protected areas maintaining existing phytodiversity is an important conservation target. In this study we analysed the effects of abandonment on plant species composition and species richness over a period of nine years in a montane grassland in the Long-term Ecosystem Research (LTER) region Eisenwurzen (Styria, Austria). Additional investigations concerned the number of Red Data List species, plant strategy types, Ellenberg indicator values, indicator values for mowing, grazing and trampling tolerance, temporal sequence of phenological phases and seven plant traits. We differentiated two topography-related habitat types: an initially species-rich sheep pasture on a steep, south-facing slope and a less species-rich meadow on a flat site immediately below, with a comparatively higher nutrient and water supply in the topsoil. Testing a possible management alternative, the effects of continued low-intensity sheep grazing on the slope were also analysed. In spring 2001, one permanent plot of 50 m² was established in the centre of each habitat type and treatment. Our results show that the long-term effects of abandonment on grassland vegetation depend largely on local site conditions. Nutrient availability in the soil seems to be an especially important factor. On the abandoned flat site, floristic composition and physiognomy changed dramatically within four years; a high species turnover and a decline in phytodiversity could be observed. In contrast, we found only minor effects on the abandoned slope site even nine years after abandonment. If the maintenance of existing phytodiversity is a conservation target, suitable management operations have to be carried out at shorter intervals (at least every 3 years) in habitats with nutrient-rich soils than in nutrient-poor habitats (approx. 5 to 10 years). From a nature conservation point of view, low-intensity sheep grazing may be a suitable management alternative to mowing.

Semi-natural, extensively managed, grasslands are among the most species-rich agroecosystems in Europe. However, they are threatened by abandonment. We investigated the response of semi-natural grasslands to cessation of mowing at ten sites in three UNESCO Biosphere Reserves in Switzerland and Austria. We assessed vegetation characteristics, topsoil properties and microbially mediated soil processes by comparing once-a-year mowed with adjacent long-term abandoned grasslands on semi-dry, nutrient-poor, baserich soils. Plant litter decomposition was determined using standardized substrates (Tea Bag Index). Soil microbial community composition was assessed by phospholipid fatty acid analysis. Abandonment altered floristic composition by replacing shade-intolerant or low-growing grassland species, in particular character species of the alliance Bromion erecti, with medium-to tall-sized grasses (e.g. Brachypodium pinnatum) and tall herbs (e.g. Laserpitium latifolium). Time since abandonment had an influence on the magnitude of successional changes after abandonment. Cessation of mowing increased above-ground phytomass but decreased plant species richness and evenness. Abandonment increased soil microbial biomass, promoted litter decomposition and led to an increased soil organic carbon, C:N ratio, and inorganic N supply. Our findings also showed that abandoned grasslands dominated by grasses remained shrub-and treeless for several decades.

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