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Skid trails are a major management‐induced disturbance in temperate forest ecosystems with considerable impact on soil ecological processes that are so far poorly understood. In German forests, skid trails comprise 10%–20% of the forest area that is potentially affected by soil compaction through heavy machinery. We systematically investigated the influence of skid trails on physical, chemical and microbiological soil parameters at 84 paired plots across four Central European forest types. In low mountain forests with steeper topography, skid trails had more drastic effects than in lowland forests. Skid trails in low mountain areas showed a decrease in the C to N ratio of microbial biomass (MBC/MBN), as well as increased microbial (MBC/SOC) and enzyme activities leading to faster carbon turnover (lower C/N, EOC/EN) and increased CO2 losses (CO2/SOC) from the soil. The overall effects of the skid trails in lowland forests were small. On base‐poor soils, we found an increase in the MBC/MBN ratio, while skid trails in base‐rich lowland soils showed a reduction in CO2/SOC, suggesting a proportional increase in soil carbon storage. Regardless of region‐specific effects, the relative increase in the bulk density of the fine soil was identified as a ‘golden trait’ that determined the effects of skid trails on many soil parameters, as shown by negative correlations with SOC, N, MBC, MBN, MBP, MBC/SOC and CO2/SOC and positive ones with the activities of certain hydrolytic enzymes. Synthesis and applications: Our data clearly showed that carbon conversion processes and soil respiration leading to significant carbon and nutrient losses increased significantly on skid trails in low mountain regions with relatively steep slopes, which was in sharp contrast to lowland sites. The strong context dependence of our findings suggests that the mapping of soil conditions in terms of slope, substrate and moisture with high spatial resolution is mandatory to assess the vulnerability of sites to soil compaction by heavy machinery. Based on such vulnerability analysis, negative impacts can be minimised through the designation of permanently fixed skid trails, technical adaptation of vehicles (e.g. wide base tyres) as well as careful planning and timing of management operations that should be restricted to dry weather and soil moisture conditions or periods of frost. [ABSTRACT FROM AUTHOR]

Experimental evidence shows that grassland plant diversity enhances ecosystem functioning. Yet, the transfer of results from controlled biodiversity experiments to naturally assembled 'real world' ecosystems remains challenging due to environmental variation among sites, confounding biodiversity ecosystem functioning relations in observational studies. To bridge the gap between classical biodiversity‐ecosystem functioning experiments and observational studies of naturally assembled and managed ecosystems, we created regionally replicated, within‐site gradients of species richness by seeding across agricultural grasslands differing in land‐use intensity (LUI) and abiotic site conditions.Within each of 73 grassland sites, we established a full‐factorial experiment with high‐diversity seeding and topsoil disturbance and measured 12 ecosystem functions related to productivity, and carbon and nutrient cycling after 4 years. We then analysed the effects of plant diversity (seeded richness as well as realized richness), functional community composition, land use and abiotic conditions on the ecosystem functions within (local scale) as well as among grassland sites (landscape scale).Despite the successful creation of a within‐site gradient in plant diversity (average increase in species richness in seeding treatments by 10%–35%), we found that only one to two of the 12 ecosystem functions responded to realized species richness, resulting in more closed nitrogen cycles in more diverse plant communities. Similar results were found when analysing the effect of the seeding treatment instead of realized species richness. Among sites, ecosystem functioning was mostly driven by environmental conditions and LUI. Also here, the only functions related to plant species richness were those associated with a more closed nitrogen cycle under increased diversity.The minor effects of species enrichment we found suggest that the functionally‐relevant niche space is largely saturated in naturally assembled grasslands, and that competitive, high‐functioning species are already present.Synthesis: While nature conservation and cultural ecosystem services can certainly benefit from plant species enrichment, our study indicates that restoration of plant diversity in naturally assembled communities may deliver only relatively weak increases in ecosystem functioning, such as a more closed nitrogen cycle, within the extensively to moderate intensively managed agricultural grasslands of our study. [ABSTRACT FROM AUTHOR]

Seed sourcing for restoration measures is a currently highly debated issue in conservation ecology. Where to take the seeds from, if reintroduction of plant species is necessary? In many countries, seed transfer zones have been defined to preserve genetic variability and to provide locally adapted plants. However, delineation of seed transfer zones mostly relies on climatic gradients, ignoring other abiotic factors, such as bedrock and soil conditions. One of the main soil properties is soil reaction (pH), yet it is still unclear whether pH is an important driver for local adaptation in plants. In this study, we tested whether plants are adapted to soil reaction across five common grassland species. For each species, we sampled seeds from two provenances, and within each provenance from two populations—one coming from basic and one from acidic soil. We grew the plants in a common garden in an artificial substrate with manipulated pH, which allowed us to test for the effect of soil reaction, isolated from other soil properties. All species produced more biomass on acidic substrate, in most cases independently of their original soil and provenance. Only one out of five species showed weak local adaptation to soil reaction. The experimental substrate by far explained most of the biomass production in all species. This suggests that adaptation to soil reaction is rare and of low importance in common species of temperate grasslands. [ABSTRACT FROM AUTHOR]

Questions: How does species composition of different vegetation types respond to translocation? How do they respond to encroachment of expansive native or alien species? Location: Meadow, heath and fen plots in Radzionków Habitat Botanical Garden, Poland. Methods: In 2013, between June and October, 16,500 pieces of turf blocks from three communities, each 80 × 120 cm in size and 40–50 cm deep, were transferred from a donor site to newly constructed artificial basins. Temporal changes of species composition were observed in 163 permanent plots 2 × 2 m from 2013 to 2016. To analyse compositional changes, we carried out constrained ordination with time as explanatory variable. For changes in species richness, diversity, herb and shrub layers, contribution of woody species, diagnostic taxa, archaeophytes, neophytes, native expansive taxa and ruderal plants, a one‐way ANOVA was applied. Results: We found that only 35%–39% of species had a positive correlation with time. The total number of species significantly decreased only within the meadow plots. The fen and heath only experienced a slight decrease in species number. Significant changes in abundance of diagnostic species were observed in all plant communities. The abundances of diagnostic taxa were maintained during the first 2 year, then dropped considerably. The highest decrease was noted in the heathland community. Conclusions: Turf translocation appeared to be only partially effective as a compensatory measure. Four years after the translocation, the three different habitats still maintained their specific structural features, however the number of diagnostic taxa considerably decreased, particularly in the heathland and the wet meadow. Given the high financial and logistical effort required, translocation measures are questionable and should only be applied as an exceptional last resort method. We analysed the changes in species composition in meadow, heath and fen plots after translocation to artificial basins in Habitat Botanical Garden. After 4 years of experiment we found that the most sensitive vegetation type in terms of species decrease was meadow. All habitats suffer from diagnostic species decline with heathland as the most impoverished. Despite the three plant communities still maintained their specific structural features, turf translocation appeared only partially to be an effective compensatory measure. Given the high financial and logistical effort translocations remain controversial and should only be applied as exceptional last chance method. [ABSTRACT FROM AUTHOR]

Highlights • Comparison of the effects of goat paddock grazing and migratory sheep herding on Gagea bohemica. • Species cover and individual numbers were higher in goat paddocks. • We found a negative relationship between litter layer and species performance. • Goat grazing should start in spring to restore shrub-encroached dry grasslands. Abstract Goat pasturing is often recommended for managing shrub-encroached dry grasslands, but entails higher grazing pressure. However, there have been few studies about the effects of goats on assumedly grazing sensitive geophytes. Therefore, in conservation practice, low-intensity migratory herding is still preferred in dry grasslands inhabited by threatened geophytes, even when shrub encroachment is already advanced. We compared the effects of restorative goat paddock grazing and low-intensity migratory sheep herding on the performance of Gagea bohemica (Liliaceae) a threatened spring geophyte. For this purpose, we recorded G. bohemica cover as well as numbers of flowering and non-flowering individuals on a total of 24 permanent plots in 2013, 2014 and 2016 in three study areas in Central Germany. In 2014, all flowering plants were monitored weekly for mature seeds. In addition, we sampled litter layer cover as a proxy for grazing intensity to analyse the effects of this habitat feature on the abundance of G. bohemica. Overall, G. bohemica cover and individual numbers were higher in paddocks than in migratory herding sites. The best performance was recorded in plots with low litter layer cover. Only 5.9% of the observed individuals flowered and only 0.3% produced visible seed sets in 2014. In abandoned dry grasslands, G. bohemica benefits from a relatively high grazing pressure, resulting in a lower litter cover and subsequently higher light availability at ground level. Due to its low seed set and ability to reproduce vegetatively by subterranean bulbils, ground disturbance by livestock trampling may also constitute an important factor supporting short-distance dispersal of G. bohemica. Goat grazing is a successful tool to restore shrub-encroached dry grasslands with existing remnant populations of spring geophytes. We recommend paddock grazing by goats with a high grazing pressure starting in April after above-ground parts of G. bohemica have already withered. [ABSTRACT FROM AUTHOR]

The break-up of the Soviet Union in 1991 triggered cropland abandonment on a continental scale, which in turn led to carbon accumulation on abandoned land across Eurasia. Previous studies have estimated carbon accumulation rates across Russia based on large-scale modelling. Studies that assess carbon sequestration on abandoned land based on robust field sampling are rare. We investigated soil organic carbon ( SOC) stocks using a randomized sampling design along a climatic gradient from forest steppe to Sub-Taiga in Western Siberia (Tyumen Province). In total, SOC contents were sampled on 470 plots across different soil and land-use types. The effect of land use on changes in SOC stock was evaluated, and carbon sequestration rates were calculated for different age stages of abandoned cropland. While land-use type had an effect on carbon accumulation in the topsoil (0-5 cm), no independent land-use effects were found for deeper SOC stocks. Topsoil carbon stocks of grasslands and forests were significantly higher than those of soils managed for crops and under abandoned cropland. SOC increased significantly with time since abandonment. The average carbon sequestration rate for soils of abandoned cropland was 0.66 Mg C ha−1 yr−1 (1-20 years old, 0-5 cm soil depth), which is at the lower end of published estimates for Russia and Siberia. There was a tendency towards SOC saturation on abandoned land as sequestration rates were much higher for recently abandoned (1-10 years old, 1.04 Mg C ha−1 yr−1) compared to earlier abandoned crop fields (11-20 years old, 0.26 Mg C ha−1 yr−1). Our study confirms the global significance of abandoned cropland in Russia for carbon sequestration. Our findings also suggest that robust regional surveys based on a large number of samples advance model-based continent-wide SOC prediction. [ABSTRACT FROM AUTHOR]

Year-round grazing by free-roaming herds of cattle and horses is increasingly applied for conservation management of grasslands. In such grazing schemes, periods of fodder shortage can occur in winter and early spring, but supplementary feeding is usually avoided. Hence, stocking rates have to be adjusted precisely to seasonal fodder availability for animal welfare reasons. We investigated the seasonal changes of biomass quantity and quality at four year-round pastures in northwest Germany, two on nutrient-rich and two on nutrient-poor soils. In total, 248 biomass samples were taken in spring, summer, fall and winter 2013 and 2014, and across different vegetation types. The samples were analyzed for fiber contents, calcium, magnesium, potassium and crude protein. Maximum grazing capacities for all pasture and vegetation types were calculated for each season and for cattle and horses separately. Overall, biomass quantity and nutrient contents were lower in nutrient-poor than nutrient-rich sites. Biomass quality varied less over the year at nutrient-rich compared to nutrient-poor sites. At nutrient-rich sites, a greater fluctuation in biomass quantity was measured over the year. In spring, biomass quantity was lowest in both pasture types, whereas nutrient values were lowest in spring at nutrient-poor and lowest in winter at nutrient-rich sites. Calculated grazing capacities were lowest in spring in both pasture types, but were limited by nutrient content at nutrient-poor sites and by biomass quantity at nutrient-rich sites. Hence, an adjustment of stocking rates simply to fodder quantity seems possible at nutrient-rich sites, whereas at nutrient-poor sites calculations under consideration of nutrient contents are recommendable. Especially for cattle, some nutrient contents of biomass were below requirements in winter and spring at nutrient-poor sites so that we rather propose grazing by horses or nutrient supplementation during the winter season. This study showed that adequate livestock nutrition under year-round grazing is possible, but that additional feeding or other measures might be necessary when pasturing very nutrient-poor habitats. [ABSTRACT FROM AUTHOR]

Restoring depleted soil organic carbon (SOC) stocks of arable land to remove carbon from the atmosphere and offset fossil fuel emissions is a promising strategy for the mitigation of climate change. In agroecosystems conservational tillage practices and the abandonment of formerly plowed fields (ex-arable land) are shown to have the highest potential to sequester SOC. Nevertheless reported sequestration rates vary and the effects of environmental site conditions remain poorly understood. Our results are based on a meta-analysis of 273 paired SOC estimates from 65 publications which included only mineral soils from the temperate zone. SOC stocks of ex-arable grasslands with an average of 14 years since abandonment were 18% larger compared to the SOC of arable land. Likewise, SOC stocks of never-plowed grassland plots were 11% larger than the SOC stocks of abandoned fields. The average sequestration rate was 0.72 t C ha − 1 yr − 1 . Semi-arid and sub-humid climate as well as low initial SOC stocks positively affected proportional SOC gains suggesting that the recovery of carbon stocks is not limited by low primary production. Therefore, the northward shift of cultivation areas in the temperate zone will lead to the abandonment of soils with high SOC recovery potential. However, if native soils are opened up elsewhere to compensate for yield losses due to abandonment the surplus of SOC in ex-arable land can easily be overcompensated by cultivation losses. [ABSTRACT FROM AUTHOR]

Land-use change and intensification play a key role in the current biodiversity crisis. The resulting species loss can have severe effects on ecosystem functions and services, thereby increasing ecosystem vulnerability to climate change. We explored whether land-use intensification (i.e. fertilization intensity), plant diversity and other potentially confounding environmental factors may be significantly related to water use (i.e. drought stress) of grassland plants. Drought stress was assessed using δ 13 C abundances in aboveground plant biomass of 150 grassland plots across a gradient of land-use intensity. Under water shortage, plants are forced to increasingly take up the heavier 13 C due to closing stomata leading to an enrichment of 13 C in biomass. Plants were sampled at the community level and for single species, which belong to three different functional groups (one grass, one herb, two legumes). Results show that plant diversity was significantly related to the δ 13 C signal in community, grass and legume biomass indicating that drought stress was lower under higher diversity, although this relation was not significant for the herb species under study. Fertilization, in turn, mostly increased drought stress as indicated by more positive δ 13 C values. This effect was mostly indirect by decreasing plant diversity. In line with these results, we found similar patterns in the δ 13 C signal of the organic matter in the topsoil, indicating a long history of these processes. Our study provided strong indication for a positive biodiversity-ecosystem functioning relationship with reduced drought stress at higher plant diversity. However, it also underlined a negative reinforcing situation: as land-use intensification decreases plant diversity in grasslands, this might subsequently increases drought sensitivity. Vice-versa, enhancing plant diversity in species-poor agricultural grasslands may moderate negative effects of future climate change. [ABSTRACT FROM AUTHOR]

Aim: Global‐scale maps of the environment are an important source of information for researchers and decision makers. Often, these maps are created by training machine learning algorithms on field‐sampled reference data using remote sensing information as predictors. Since field samples are often sparse and clustered in geographic space, model prediction requires a transfer of the trained model to regions where no reference data are available. However, recent studies question the feasibility of predictions far beyond the location of training data. Innovation: We propose a novel workflow for spatial predictive mapping that leverages recent developments in this field and combines them in innovative ways with the aim of improved model transferability and performance assessment. We demonstrate, evaluate and discuss the workflow with data from recently published global environmental maps. Main conclusions: Reducing predictors to those relevant for spatial prediction leads to an increase of model transferability and map accuracy without a decrease of prediction quality in areas with high sampling density. Still, reliable gap‐free global predictions were not possible, highlighting that global maps and their evaluation are hampered by limited availability of reference data. [ABSTRACT FROM AUTHOR]

Question Are optimal intervention levels in ecological restoration linked to disturbance severity or spatial and temporal scales of restoration activities in the studies included in this special feature? Methods Comparison of ten studies of restoration in the context of disturbance severity, regional biodiversity, and predictability of succession trajectories. Results The ten studies largely represent restoration of grasslands in Europe but also include restoration following disturbances by mining, invasive species, and trampling by tourists. Maximal intervention levels were used in studies with high or low disturbance severity, low regional biodiversity, and high predictability of successional trajectories. The spatial and temporal scales of restoration activities had little effect on intervention levels. Conclusions General guidelines on how to optimize intervention levels in restoration activities can be sought by comparing success rates across gradients of disturbance severity. [ABSTRACT FROM AUTHOR]

Complementarity that leads to more efficient resource use is presumed to be a key mechanism explaining positive biodiversity-productivity relationships but has been described solely for experimental set-ups with controlled environmental settings or for very short gradients of abiotic conditions, land-use intensity and biodiversity. Therefore, we analysed plant diversity effects on nitrogen dynamics across a broad range of Central European grasslands., The 15N natural abundance in soil and plant biomass reflects the net effect of processes affecting ecosystem N dynamics. This includes the mechanism of complementary resource utilization that causes a decrease in the 15N isotopic signal. We measured plant species richness, natural abundance of 15N in soil and plants, above-ground biomass of the community and three single species (an herb, grass and legume) and a variety of additional environmental variables in 150 grassland plots in three regions of Germany. To explore the drivers of the nitrogen dynamics, we performed several analyses of covariance treating the 15N isotopic signals as a function of plant diversity and a large set of covariates., Increasing plant diversity was consistently linked to decreased δ15N isotopic signals in soil, above-ground community biomass and the three single species. Even after accounting for multiple covariates, plant diversity remained the strongest predictor of δ15N isotopic signals suggesting that higher plant diversity leads to a more closed nitrogen cycle due to more efficient nitrogen use., Factors linked to increased δ15N values included the amount of nitrogen taken up, soil moisture and land-use intensity (particularly fertilization), all indicators of the openness of the nitrogen cycle due to enhanced N-turnover and subsequent losses. Study region was significantly related to the δ15N isotopic signals indicating that regional peculiarities such as former intensive land use could strongly affect nitrogen dynamics., Synthesis. Our results provide strong evidence that the mechanism of complementary resource utilization operates in real-world grasslands where multiple external factors affect nitrogen dynamics. Although single species may differ in effect size, actively increasing total plant diversity in grasslands could be an option to more effectively use nitrogen resources and to reduce the negative environmental impacts of nitrogen losses. [ABSTRACT FROM AUTHOR]

Distinguishing organic and conventional products is a major issue of food security and authenticity. Previous studies successfully used stable isotopes to separate organic and conventional products, but up to now, this approach was not tested for organic grassland hay and soil. Moreover, isotopic abundances could be a powerful tool to elucidate differences in ecosystem functioning and driving mechanisms of element cycling in organic and conventional management systems. Here, we studied the δ15N and δ13C isotopic composition of soil and hay samples of 21 organic and 34 conventional grasslands in two German regions. We also used Δδ15N (δ15N plant - δ15N soil) to characterize nitrogen dynamics. In order to detect temporal trends, isotopic abundances in organic grasslands were related to the time since certification. Furthermore, discriminant analysis was used to test whether the respective management type can be deduced from observed isotopic abundances. Isotopic analyses revealed no significant differences in δ13C in hay and δ15N in both soil and hay between management types, but showed that δ13C abundances were significantly lower in soil of organic compared to conventional grasslands. Δδ15N values implied that management types did not substantially differ in nitrogen cycling. Only δ13C in soil and hay showed significant negative relationships with the time since certification. Thus, our result suggest that organic grasslands suffered less from drought stress compared to conventional grasslands most likely due to a benefit of higher plant species richness, as previously shown by manipulative biodiversity experiments. Finally, it was possible to correctly classify about two third of the samples according to their management using isotopic abundances in soil and hay. However, as more than half of the organic samples were incorrectly classified, we infer that more research is needed to improve this approach before it can be efficiently used in practice. [ABSTRACT FROM AUTHOR]

Highlights: [•] Livestock use influenced soil salinity, above- and belowground biomass, and plant CSR-strategy types in prairie wetlands. [•] Soil salinity increased and biomass was reduced by livestock use. [•] Competitors were less and ruderals more abundant in more intensely used wetlands. [•] Salinity only favored stress tolerators at low levels of use. [Copyright &y& Elsevier]

Many north-hemispherical mires seemingly untouched by drainage and cultivation are influenced by a diffuse sum of man-made environmental changes, such as atmospherical nitrogen deposition that mask general patterns in species richness and functional group responses along resource gradients. To obtain insights into natural diversity-environment relationships, we studied the vegetation and the peat chemistry of pristine bog ecosystems in southern Patagonia along a west–east transect across the Andes. The studied bog ecosystems covered a floristic gradient from hyperoceanic blanket bogs dominated by cushion building vascular plants via a transitional mixed type to Sphagnum-dominated raised bogs east of the mountain range. To test the influence of resource availability on diversity patterns, species richness and functional groups were related to environmental variables by calculating general regression models and generalized additive models. Species richness showed strong linear correlations to peat chemical features and the general regression model resulted in three major environmental variables (water level, total nitrogen, NH4Cl soluble calcium), altogether explaining 76% of variance. Functional group response illustrated a clear separation along environmental gradients. Mosses dominated at the low end of a nitrogen gradient, whereas cushion plants had their optimum at intermediate levels, and graminoids dominated at high nitrogen contents. Further shifts were related to NH4Cl soluble calcium and water level. The models documented partly non-linear relationships between functional group response and trophical peat properties. Within the three bog types, the calculated models differed remarkably illustrating the scale-dependency of the explanatory factors. Our findings confirmed several general patterns of species richness and functional shifts along resource gradients in a surprisingly clear way and underpin the significance of undisturbed peatlands as reference systems for testing of ecological theory and for conservation and ecological restoration in landscapes with strong human impact. [ABSTRACT FROM AUTHOR]

Question: Which environmental variables affect the floristic composition of south Patagonian bog vegetation along a gradient of climate and biogeochemical changes with increasing distance from the Pacific ocean? Location: Trans-Andean transect (53° S), southern Patagonia Material and Methods: Floristic composition, peat characteristics (water level, decomposition, pH, total nitrogen, total carbon, ash content and plant available P, K, Na, Ca, Mg, Fe, Mn, Zn, and Al) and climatic constraints of ombrotrophic peatlands were measured at 82 plots along a gradient of increasing distance from the Pacific Ocean. Results: Climatic constraints and biogeochemical peat characteristics significantly change with increasing distance from the Pacific. Peatland vegetation shifted from hyperoceanic blanket bogs dominated by cushion forming vascular plants to the west to Sphagnum bogs to the east. Climatic and biogeochemical variables explained a large proportion of the floristic variation along the first DCA axis. The second axis represented a water level gradient. When 'distance to the Pacific' was defined as a covariable in partial CCA, the proportion of variance explained declined for most other variables, especially in the case of annual precipitation and exchangeable base cations and related traits. The differences in biogeochemical characteristics related to peat were mainly attributed to the input of sea-borne cations. Conclusions: While variation in vegetation composition along a longitudinal gradient crossing the southern Andes was attributed to climatic constraints as expected, vegetation composition was also strongly affected by the biogeochemical characteristics of peat. Sea spray was of high ecological importance to peat chemistry and, consequently, to floristic composition. Presumably, south Patagonian peat bogs represent a glimpse of pre-industrial environments, so that these peat bogs may act as reference systems with respect to atmospheric inputs in mire ecology research. [ABSTRACT FROM AUTHOR]

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. [Copyright &y& Elsevier]

Abstract: As a response to the sharp decline in species-rich flood-meadows along the northern Upper Rhine during the past decades, large-scaled restoration projects have been started recently. For the implementation of restoration measures knowledge about the effects of topsoil disturbance, litter and simultaneously sown grasses on seedling recruitment are of special interest. This applies in particular to the role of sown of grasses that may accelerate sward development and ease the incorporation of newly created meadows into local farming systems. As study species we selected six typical, but rare or declining flood-meadow species which differed in seed size, since this may influence the impact of the applied treatments. We studied effects of simultaneously sown grasses on germination and recruitment success of these flood-meadow species in two former arable fields situated in the functional and fossil floodplain along the northern Upper Rhine. The effects of litter and topsoil disturbance in an existing grass sward on the recruitment of the six flood-meadow species were experimentally assessed in a species-poor grassland in the functional floodplain. The individual fate of emerging seedlings was followed over two years. The effects of the applied treatments were species-specific and rather inconsistent. Responses towards disturbance and litter application corresponded to differences in seed size, with large-seeded species showing a lower susceptibility to the influence of treatments. In addition, simultaneous sowing of grass did not hamper seedling recruitment in most cases, and thus seems to be a feasible measure to accelerate the integration of newly created flood-meadows into farming systems. [Copyright &y& Elsevier]

Question: Is the failure of establishment of rare flood-meadow species in habitat restoration primarily due to seed or microsite limitation? How do sown species respond to artificially created gaps and added litter at two neighbouring sites with similar physical conditions but contrasting vegetation matrix (young arable fallow field vs species-poor meadow sward)? Location: Upper Rhine valley, southwestern Germany, 85 m a.s.l. Methods: Seeds of six typical flood-meadow species were sown in four treatment combinations of the factors gap creation and litter addition. Seedling recruitment was monitored for three years. Results: Five of the six species established successfully at both sites largely irrespective of treatments, indicating seed limitation. Only in the small-seeded Arabis nemorensis, which was revealed to be strictly gap-dependent at the meadow site, could an obvious microsite limitation be shown. The non-significance of gap treatments in all other species at the relatively high productive meadow site is probably due to biomass removal by mowing in early summer. Only at the extremes of the seed size spectrum did the results meet predictions of plant ecological theory, such as the strict gap dependence of small-seeded species in closed swards or the positive to neutral response of large-seeded species to litter layers. Conclusions: Species identity was revealed to be the major factor influencing differences in recruitment. Due to the lack of a general trend in the response towards treatments the results support conceptual models that describe the interplay of facilitation and interference as a highly dynamic equilibrium, driven by variable abiotic and biotic marginal conditions. [ABSTRACT FROM AUTHOR]

Due to their high value for biodiversity preservation, flood mitigation and nutrient retention, the re-creation of flood-meadows is presently one of the main targets in restoration projects along large central European lowland rivers. Like other semi-natural grasslands, flood-meadows depend on adequate agricultural management to fulfil these important ecological functions. To achieve this in an ecologically and economically sensible way, the prospects for incorporating management and biomass utilisation in farming systems appears to be a key issue.Differences in yield and forage quality in extensively-managed flood-meadows were studied with respect to vegetation type, site conditions, management history, species-richness and nature conservation value. The study covers the most important alluvial grassland communities in the floodplain of the northern Upper Rhine (alliances Arrhenatherion, Cnidion, Magnocaricion), which are typically ordered along an elevational gradient of increasing flooding frequency.Gradients in flooding frequency between the different grassland communities and differences between classes were clearly reflected by floristic composition in Detrended Correspondence Analysis. In contrast, there were only minor differences in terms of soil nutrient status, which are consistent with relatively small differences in yield and forage quality, particularly in the drier Arrhenatherion-communities. In Cnidion meadows, yield and fodder quality were both raised in classes of higher nature conservation value, most likely due to a shift in functional groups towards sedges, herbs and legumes. However, in contrast to hypotheses recently made by several authors, no general relationship between species-richness and productivity was found. We discuss the implications of the results for restoration practice, management strategies and agricultural utilisation of species-rich flood-meadows. [Copyright &y& Elsevier]

Question: How does vegetation and management affect the population stage structure of Serratula tinctoria, a species indicative of highly endangered and species-rich flood-plain meadows? Are different management regimes suitable to support viable populations of S. tinctoria? Location: Flood-plain of the northern Upper Rhine, Germany. Methods: We analysed the population structure of S. tinctoria at 24 meadow sites which differed in vegetation and management. In this comparative study the investigated meadows were either (1) late mown in September; (2) early mown in June or (3) mown in June and then grazed by sheep. Results: The structure of the surrounding vegetation had a clear effect on the population structure of S. tinctoria. The percentage of bare soil, as well as the cover of bryophytes, were positively related, whereas the Ellenberg N-value of the established vegetation was negatively related to the density and proportion of seedlings. Generally, we found only slight differences between the population structure of S. tinctoria in early and late mown meadows. Both management regimes had high densities of seedlings. In contrast, the meadow pastures supported significantly lower densities of seedlings and generative adults but relatively high densities of juveniles and vegetative adults, indicating a greater importance of clonal propagation under grazing pressure. Conclusions: Our results clearly showed that viable populations of S. tinctoria may occur in all of the studied management regimes. Although S. tinctoria was considered to be highly sensitive to early mowing, our findings suggest a facilitation of the species at more nutrient-rich sites by mowing in June, which is also a benefit for the integration of management in farming systems. [ABSTRACT FROM AUTHOR]

Along the northern Upper Rhine, Germany, large-scaled restoration attempts aiming at the recovery of species-rich alluvial meadows from ex-arable fields were evaluated. We analysed floristic composition, soil nutrient status and biomass production of old and newly established meadows with respect to their position in both, the recent functional flood-plain and the fossil flood-plain compartment which is protected from flooding by a dyke. It is hypothesised that restoration in terms of species-enrichment will be more successful in the functional floodplain due to the input of propagules in the course of flooding events.Generally, we found great floristic differences between old and new meadows, independent of their position in the floodplain. After 15–20 years of restoration management, the floristic structure of new meadows was still dominated by sown grasses and a high proportion of ruderal and arable species, whereas target species of flood-meadows largely failed to establish in both compartments. Old and new meadows differed only slightly in the environmental variables, while measured significant differences in plant available phosphorus and biomass yield were revealed between floodplain compartments.The results indicated a minor effect of edaphic site conditions on the low restoration success and limited dispersal and recruitment were revealed to be the main constraints for restoration. We found no evidence that species enrichment is enhanced in the functional floodplain via the input of diaspores by flooding. Our results strongly suggest that dispersal limitation of target species is unlikely to be overcome merely by the restoration of more natural flooding conditions. [Copyright &y& Elsevier]

To assess seed bank persistence of target species in endangered flood-meadows (alliances Cnidion and Molinion ), we investigated established vegetation and soil seed bank of 46 plots for 3 yr and 2 yr, respectively. As traits of seed persistence we calculated various continuous indices that refer to the frequency and abundance of species in above-ground vegetation and at different soil depths.Furthermore, we tested the significance and soundness of easily observed traits such as maximum seed density per plot and seed attributes (mass, size and shape)as predictors of soil seed bank features. In linear regression, SAI, the seed accumulation index, showed the best agreement (R 2 =0.64) with the seed longevity index that was derived from the database by Thompson et al. (1997) for a set of 115 species. The second best predictor (R 2 =0.39) of the seed longevity index was maximum seed density per plot in the lower soil layer (5-10 cm). Depth distribution indices and seed attributes showed weaker but still significant relations.The dynamic character of flood-meadows was reflected by a large proportion of species with a strong tendency to accumulate seeds in the soil relative to their importance in above-ground vegetation. Most of these species have a ruderal strategy, exploiting gaps after flood disturbances, while the dominants of flood-meadows tended to have short-lived seed banks. Compared to other grassland types, a relatively large proportion of rare and endangered target species can be expected to form long-term persistent seed banks. However, only under marginal conditions that facilitate seed survival in the soil (e.g. fallow) are these persistent seed banks likely to contribute to restoration. We conclude that easily observed traits of persistence such as seed weight, size and shape do not meet the accuracy needed in scientific and practical applications. Thus, there is a crucial demand for further seed bank studies in poorly investigated habitats... [ABSTRACT FROM AUTHOR]

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 grass-land. However, high quality of plant material and suitable site conditions with low competition in early stages of succession seem to be essential... [ABSTRACT FROM AUTHOR]

We studied the restoration success of flood plain meadows in the northern Upper Rhine valley, where between 1988 and 1992, 35 ha of arable land was converted into grassland and subsequently managed for nature conservation. Remnant populations of typical alluvial meadow species were found in old meadows and along drainage ditches that dissect the whole area. We analysed the site conditions and phytosociological relevés in old and new meadows. Small differences in site parameters between old and new meadows contrasted with a clear floristic differentiation between the two meadow types. The vegetation of old meadows was much more differentiated along prevailing environmental gradients than the vegetation of new meadows. Despite the favourable site conditions for the re-establishment of species-rich meadows on the former arable land, restoration success was limited to the vicinity of remnant stands. In contrast to old meadows, indicator species of new grassland were still typical species of regularly disturbed ruderal and arable habitats, often capable of building up a persistent seed bank. The precise mapping of 23 target species revealed that even wind dispersal predominantly leads to re-establishment in the close circumference of parent plants. We found no indication that regular flooding, hay-making and autumnal grazing had an impact on recolonization of newly created grassland. Even under favourable conditions for the re-establishment of target species, restoration success in alluvial meadows proved to be strongly dispersal limited. We discuss the implications of our findings for future restoration management in grasslands. [ABSTRACT FROM AUTHOR]

The goal of this study was to evaluate to what extent wild ungulates (fallow deer) can contribute to the maintenance of semi‐natural calcareous grasslands, which are a threatened habitat type (natura 2000 code *6210).In a 10‐year exclosure experiment, we tested the effects of ungulate foraging using three treatments: (A) control with combined foraging of herded sheep and wild fallow deer, (B) sheep exclosure with only deer foraging and (C) total exclosure with no foraging.Treatments not grazed by sheep (B, C) were characterized by significantly declining species numbers, litter accumulation and shrub encroachment. Despite high population densities, the effect of fallow deer alone (B) was weak: Succession of woody species was only partly inhibited, while annuals, short‐growing and rosette‐building plant species were strongly suppressed by litter accumulation.Only the combination of sheep and fallow deer foraging preserved vegetation structure and species richness and led to a promotion of target species.Synthesis and applications. We conclude that we need to continue the traditional land‐use forms such as sheep grazing in order to maintain calcareous grasslands. However, we should also raise our awareness for wild animals and analyse more in depth their potential contribution to the conservation management of open habitats. [ABSTRACT FROM AUTHOR]

Restoring habitats degraded by intensive agriculture is challenging, and the resulting communities often have lower quality and host fewer species than reference ecosystems. To improve restoration outputs, we need to understand what limits both establishment and performance of target species in restored populations. In this study, we focused on grassland restoration with regional seeds and compared the performance of two target herbs, Betonica officinalis and Centaurea jacea, between restored and reference populations. We also measured plant functional traits and environmental characteristics to understand which parameters affect population performance. Individual plants of both species were smaller in restored populations, which indicates reduced performance. Leaves of plants from restored populations contained more δ15N and, in Betonica, also less nitrogen and higher C:N ratio, which suggests that the performance of the target species may be limited by nitrogen. Nitrogen limitation of all restored communities was further corroborated by the low N:P ratio of bulk biomass. In Centaurea, we also recorded massive herbivory damage in restored populations, which likely further reduced this species' performance in restored meadows. In summary, target plants in restored populations showed lower performance than conspecifics in reference sites, probably due to nutrient imbalance (low nitrogen availability) and excessive herbivory damage. [ABSTRACT FROM AUTHOR]

Plant below‐ground organs perform essential functions, including water and nutrient uptake, anchorage, vegetative reproduction and recruitment of mutualistic soil microbiota. Recently, multivariate analyses showed that root traits of species can largely be linked to a 'conservation' and a 'collaboration' gradient. Here, we tested whether this species‐level bidimensional below‐ground trait space also exists at the community level in grasslands. Furthermore, we tested whether the position of grassland communities in below‐ground trait space relates to environmental variables.For a total of 313 species, we collected data on eight below‐ground traits in greenhouse and common garden experiments and supplemented it with data on bud‐bank size and specific leaf area from databases. We calculated community weighted means (CWMs) of these 10 traits for 150 temperate grassland plots to investigate below‐ground plant‐trait dimensionality and its variation along 10 soil and land‐use parameters.Using PCA, we found that about 55% of variance in CWMs was explained by two main dimensions, corresponding to a mycorrhizal 'collaboration' and a resource 'conservation' gradient. Frequently overlooked traits such as rooting depth, bud‐bank size and root‐branching intensity were largely integrated in this trait space. The two plant‐strategy gradients were partially dependent on each other, with communities that do 'outsourcing' of resource uptake to mycorrhizal fungi along the collaboration gradient also being more 'slow' along the conservation gradient. (i.e. high root tissue density and high root weight ratio). 'Outsourcing' communities were also more often deep rooting and associated with soil parameters, such as low moisture and sand content, high topsoil pH, high C:N and low δ15N. 'Slow' communities had large bud banks and were associated with low land‐use intensity, high topsoil pH and low nitrate but high ammonium concentration in the soil. Surprisingly, we did not find an association of phosphorus availability with the mycorrhizal 'collaboration' gradient.Synthesis. The 'collaboration' and 'conservation' gradients previously identified among species scale up to the community level in grasslands, encompass more traits than previously described, and vary with the environment. [ABSTRACT FROM AUTHOR]

Wildflower strips established on arable fields or intensively used grassland are an important tool for supporting biodiversity in impoverished landscapes. They provide ecosystem services like resources for pollinators, and, if they are based on perennial native plants, also plant diversity as well as nesting and wintering habitats for insects. To successfully create such wildflower strips, it is important to understand parameters that restrain establishment of the target plant species. Here we studied initial plant establishment at 45 experimental plots located in recently established wildflower strips across a broad variety of environmental conditions, complemented by 32 control plots in adjacent intensively used grasslands. All strips were seeded with a nearly identical seed mixture of native species, and thus, differences in vegetation were largely driven by environmental factors. We recorded vegetation and related it to soil parameters, seeding season, and previous use. Establishment of wildflower strips nearly doubled plant species richness in comparison with adjacent grasslands. Seeded species established better on former arable land than in intensively used grasslands, but also in grasslands, nearly half of the species from the seed mixture established. Sown species were more abundant in wildflower strip seeded in fall. The success of the seeded species was largely independent of soil parameters. In summary, the initial establishment of perennial wildflower strips is likely to be successful in a wide range of soil conditions, but further monitoring is needed to understand the vegetation development over the whole time period these strips are supposed to persist for. [ABSTRACT FROM AUTHOR]

Wildflower strips established on arable fields or intensively used grassland are an important tool for supporting biodiversity in impoverished landscapes. They provide ecosystem services like resources for pollinators, and, if they are based on perennial native plants, also plant diversity as well as nesting and wintering habitats for insects. To successfully create such wildflower strips, it is important to understand parameters that restrain establishment of the target plant species. Here we studied initial plant establishment at 45 experimental plots located in recently established wildflower strips across a broad variety of environmental conditions, complemented by 32 control plots in adjacent intensively used grasslands. All strips were seeded with a nearly identical seed mixture of native species, and thus, differences in vegetation were largely driven by environmental factors. We recorded vegetation and related it to soil parameters, seeding season, and previous use. Establishment of wildflower strips nearly doubled plant species richness in comparison with adjacent grasslands. Seeded species established better on former arable land than in intensively used grasslands, but also in grasslands, nearly half of the species from the seed mixture established. Sown species were more abundant in wildflower strip seeded in fall. The success of the seeded species was largely independent of soil parameters. In summary, the initial establishment of perennial wildflower strips is likely to be successful in a wide range of soil conditions, but further monitoring is needed to understand the vegetation development over the whole time period these strips are supposed to persist for. [ABSTRACT FROM AUTHOR]

Restoration of terrestrial ecosystems often requires re‐introduction of plants. In restored sites, the plants often face environments that differ from those of natural populations. This can affect plant traits, reduce performance and impose novel selection pressures. As a response, restored populations might rapidly evolve and adapt to the novel conditions. This may enhance population survival and contribute to restoration success, but has been rarely tested so far.Here, we focused on populations of three grassland species restored 20 years ago (Galium wirtgenii, Inula salicina and Centaurea jacea) by the transfer of green hay, and compared them with donor populations that were the source of the hay. We measured plants both in situ, and in a common garden under control and three stress conditions.In situ, plants in restored sites flowered earlier than plants in donor sites in two out of the three species. In the common garden, plants from the restored populations flowered earlier (in Galium) or showed increased plasticity of clonal propagation in response to clipping (in Inula). Both these traits suggest rapid adaptation to the contrasting mowing regimes in restored in comparison with the donor sites. In Centaurea, we detected no differentiation, neither in situ, nor in the common garden.Synthesis and applications. Grassland plants introduced into degraded habitats within the framework of ecological restoration may quite commonly evolve in response to novel selection pressures at restored sites. This rapid evolution likely increases the plant's adaptation to the new conditions of the restored grassland and thus enhances the likelihood of survival of the population and ultimately restoration success. While most practitioners do not consider evolution to be part of restoration, our finding highlights that restored populations of grassland species can be systems with considerable eco‐evolutionary dynamics. [ABSTRACT FROM AUTHOR]

The dramatic decline in the once superabundant Yellow‐breasted Bunting Emberiza aureola, a widely distributed Eurasian songbird, triggered worldwide media interest. Five years after the initial publication, we set out to give an update on the status of this critically endangered species, the conservation actions that followed, and the lessons that can be learned from this exceptional case for the conservation of migratory land birds in Asia and beyond. While there are signs of possible population recovery in the Yellow‐breasted Bunting, other migratory songbird species were recently observed to be trapped in huge numbers, which could lead to further declines. We argue that the Yellow‐breasted Bunting can be used as a flagship species to promote the conservation of East Asian land bird migrants. [ABSTRACT FROM AUTHOR]

The transition from a command to a market economy resulted in widespread cropland abandonment across the former Soviet Union during the 1990s. Spatial patterns and determinants of abandonment are comparatively well understood for European Russia, but have not yet been assessed for the vast grain belt of Western Siberia, situated in the Eurasian forest steppe. This is unfortunate, as land-use change in Western Siberia is of global significance: Fertile black earth soils and vast mires store large amounts of organic carbon, and both undisturbed and traditional cultural landscapes harbor threatened biodiversity. We compared Landsat images from ca. 1990 (before the break-up of the Soviet Union) and ca. 2015 (current situation) with a supervised classification to estimate the extent and spatial distribution of abandoned cropland. We used logistic regression models to reveal important determinants of cropland abandonment. Ca. 135,000 ha classified as cropland around 1990 were classified as grassland around 2015. This suggests that ca. 20% of all cropland remain abandoned ca. 25 years after the end of the Soviet Union. Abandonment occurred mostly at poorly drained sites. The likelihood of cropland abandonment increased with decreasing soil quality, and increasing distance to medium-sized settlements, roads and railroads. We conclude that soil suitability, access to transport infrastructure and availability of workforce are key determinants of cropland abandonment in Western Siberia. [ABSTRACT FROM AUTHOR]

European inner-alpine dry grasslands face substantial threats within the increasingly human-altered landscape, endangering their persistence. To understand changes in dry grassland communities, we revisited historical vegetation plots of Josias Braun-Blanquet after 70 years in Val Venosta, Italy, hosting rare steppe-like grassland vegetation. By disentangling the key environmental factors encompassing climate, land use and human management, and ecological site preferences, we aimed at explaining changes in dry grassland communities with implications for future conservation. By extending our analysis beyond conventional dissimilarity metrics and adopting a landscape-ecological perspective accounting for species-environment interactions, we assessed how environmental changes affect dissimilarity patterns among historical sites, recent non-protected sites, and recent protected sites with generalized additive modelling. Moreover, we examined ecologically significant species changes to evaluate their contribution to community variation within and between sites, discerning their consequences at the landscape scale. Our results revealed significant changes in dry grassland sites, both on non-protected and protected sites. The encroachment of shrubs was associated with a significant increase in generalist species, including various woody species on sites where grazing had ceased. Furthermore, we observed a higher abundance of nutrient-demanding species on sites next to intensive agriculture. These trends were consistent regardless of the protection status, implying that current conservation measures may be insufficient to guarantee their future persistence. To ensure the long-term conservation of typical inner-alpine dry grasslands, interdisciplinary conservation efforts are essential to address adverse environmental impacts across the entire landscape. [Display omitted] • Inner-alpine dry grasslands harbor a specialized flora important for biodiversity. • Resurveying historical Braun-Blanquet relevés (>70 years) reveals striking changes. • Nutrient tolerant- and non-specialized species characterize community changes. • Species-environment analyses reveal intensive agriculture and abandonment as key change drivers. • Protected areas alone may not suffice for long-term conservation of dry grasslands. [ABSTRACT FROM AUTHOR]

Biodiversity typically increases multiple ecosystem functions simultaneously (multifunctionality) but variation in the strength and direction of biodiversity effects between studies suggests context dependency. To determine how different factors modulate the diversity effect on multifunctionality, we established a large grassland experiment manipulating plant species richness, resource addition, functional composition (exploitative vs. conservative species), functional diversity and enemy abundance. We measured ten above‐ and belowground functions and calculated ecosystem multifunctionality. Species richness and functional diversity both increased multifunctionality, but their effects were context dependent. Richness increased multifunctionality when communities were assembled with fast‐growing species. This was because slow species were more redundant in their functional effects, whereas different fast species promoted different functions. Functional diversity also increased multifunctionality but this effect was dampened by nitrogen enrichment and enemy presence. Our study suggests that a shift towards fast‐growing communities will not only alter ecosystem functioning but also the strength of biodiversity‐functioning relationships. [ABSTRACT FROM AUTHOR]

Many grassland ecosystems and their associated biodiversity depend on the interactions between fire and land‐use, both of which are shaped by socioeconomic conditions. The Eurasian steppe biome, much of it situated in Kazakhstan, contains 10% of the world's remaining grasslands. The break‐up of the Soviet Union in 1991, widespread land abandonment and massive declines in wild and domestic ungulates led to biomass accumulation over millions of hectares. This rapid fuel increase made the steppes a global fire hotspot, with major changes in vegetation structure. Yet, the response of steppe biodiversity to these changes remains unexplored. We utilized a unique bird abundance dataset covering the entire Kazakh steppe and semi‐desert regions together with the MODIS burned area product. We modeled the response of bird species richness and abundance as a function of fire disturbance variables—fire extent, cumulative burned area, fire frequency—at varying grazing intensity. Bird species richness was impacted negatively by large fire extent, cumulative burned area, and high fire frequency in moderately grazed and ungrazed steppe. Similarly, overall bird abundance was impacted negatively by large fire extent, cumulative burned area and higher fire frequency in the moderately grazed steppe, ungrazed steppe, and ungrazed semi‐deserts. At the species level, the effect of high fire disturbance was negative for more species than positive. There were considerable fire legacy effects, detectable for at least 8 years. We conclude that the increase in fire disturbance across the post‐Soviet Eurasian steppe has led to strong declines in bird abundance and pronounced changes in community assembly. To gain back control over wildfires and prevent further biodiversity loss, restoration of wild herbivore populations and traditional domestic ungulate grazing systems seems much needed. [ABSTRACT FROM AUTHOR]

Fire is an important disturbance in grassland ecosystems. Anthropogenic factors, especially land use, have drastically altered fire regimes in many regions, but how changing land-use intensity affects fire patterns remains weakly understood. Here, we reconstruct changes in fire regimes between 1989 and 2016 for the understudied Eurasian steppes, where major land-use changes happened after the dissolution of the Soviet Union in 1991. We mapped burned areas in a 540,000 km2 study region in northern Kazakhstan for 3-year periods centered on 1990, 2000, and 2015, based on all available Landsat imagery. We then used these maps to assess changes in the extent, number, and size of fires over time, and to explore links between changes in fire regimes and agriculture. We found a sevenfold increase in total burned area and an eightfold increase in fire numbers between 1990 and 2000. After 2000, burned area and fire numbers declined slightly, while fire size remained stable. Most of the observed increase in fires in the 1990s occurred on cropland, most likely due to the agricultural burning. The abandonment of cropland and pastures was also associated with intensified fire regimes, likely due to increased aboveground biomass and thus higher fuel loads. Overall, our results suggest that intensifying fire regimes on the Eurasian steppe are clearly linked to post-Soviet changes in agriculture. Given that fires on Eurasia's steppes have wide-ranging consequences, affecting regions as far away as the Arctic, better regulation of agricultural practices, better fire monitoring, and more proactive fire management are needed. [ABSTRACT FROM AUTHOR]

Questions: It is frequently reported that overstocking of camels, cattle and goats is degrading the Anogeissus cloud forest, which is endemic to a 200‐km stretch of coastal mountains in southern Arabia. However, livestock impacts on the vegetation have not been assessed. Furthermore, we have a limited understanding of the impacts of large‐bodied browsing livestock, such as camels, in woodland and forest rangelands. Therefore, in this study, we examine the effects of livestock browsing on the species composition, density, and phytomorphology of woody vegetation in the Anogeissus cloud forests in the Dhofar Mountains of Oman. Location: Data were collected at 30 sites in the Jabal Qamar mountain range in western Dhofar, Oman. Methods: The point‐centred quarter method was used to sample the composition, density and structure of woody vegetation. Constrained correspondence analysis was used to quantify the effects of livestock browsing on woody plant species composition, whilst effects on plant density were analysed using mixed‐effects models. Standardised major axis regression was used to examine differences in height–diameter allometry (stunting) under different stocking rates. Results: Fog density, topographic position and long‐term stocking rates were found to be important factors affecting woody species composition. We found lower species diversity and plant density, and higher frequencies of unpalatable species, under higher stocking rates. Juveniles showed a stronger response to stocking rates than adults, and several common species exhibited stunted morphology under high stocking rates. Conclusions: Browsing by large‐bodied livestock, such as camels and cattle, can substantially alter the species composition, structure, and phytomorphology of woody vegetation in semi‐arid woodlands and forests. Juveniles are particularly susceptible to browsing which alters woody vegetation demography and inhibits regeneration potential. Our results support previous suggestions of overstocking in Dhofar and highlight the importance of swift measures to reduce livestock browsing pressure in the Anogeissus cloud forests. [ABSTRACT FROM AUTHOR]

The UN Decade on Ecosystem Restoration calls for upscaling restoration efforts, but many terrestrial restoration projects are constrained by seed availability. To overcome these constraints, wild plants are increasingly propagated on farms to produce seeds for restoration projects. During on-farm propagation, the plants face non-natural conditions with different selection pressures, and they might evolve adaptations to cultivation that parallel those of agricultural crops, which could be detrimental to restoration success. To test this, we compared traits of 19 species grown from wild-collected seeds to those from their farm-propagated offspring of up to four cultivation generations, produced by two European seed growers, in a common garden experiment. We found that some plants rapidly evolved across cultivated generations towards increased size and reproduction, lower within-species variability, and more synchronized flowering. In one species, we found evolution towards less seed shattering. These trait changes are typical signs of the crop domestication syndrome, and our study demonstrates that it can also occur during cultivation of wild plants, within only few cultivated generations. However, there was large variability between cultivation lineages, and the observed effect sizes were generally rather moderate, which suggests that the detected evolutionary changes are unlikely to compromise farm-propagated seeds for ecosystem restoration. To mitigate the potential negative effects of unintended selection, we recommend to limit the maximum number of generations the plants can be cultivated without replenishing the seed stock from new wild collections. [ABSTRACT FROM AUTHOR]

Invertebrate herbivory is a crucial process contributing to the cycling of nutrients and energy in terrestrial ecosystems. While the function of herbivory can decrease with land‐use intensification, the underlying mechanisms remain unclear. We hypothesize that land‐use intensification impacts invertebrate leaf herbivory rates mainly through changes in characteristics of plants and insect herbivores. We investigated herbivory rates (i.e., damaged leaf area) on the most abundant plant species in forests and grasslands and along land‐use intensity gradients on 297 plots in three regions of Germany. To evaluate the contribution of shifts in plant community composition, we quantified herbivory rates at plant species level and aggregated at plant community level. We analyzed pathways linking land‐use intensity, plant and insect herbivore characteristics, and herbivory rates. Herbivory rates at plant species and community level decreased with increasing land‐use intensity in forests and grasslands. Path analysis revealed strong direct links between land‐use intensity and herbivory rates. Particularly at the plant community level, differences in plant and herbivore composition also contributed to changes in herbivory rates along land‐use intensity gradients. In forests, high land‐use intensity was characterized by a larger proportion of coniferous trees, which was linked to reduced herbivory rates. In grasslands, changes in the proportion of grasses, plant fiber content, as well as the taxonomic composition of herbivore assemblages contributed to reduced herbivory rates. Our study highlights the potential of land‐use intensification to impair ecosystem functioning across ecosystems via shifts in plant and herbivore characteristics. De‐intensifying land use in grasslands and reducing the share of coniferous trees in temperate forests can help to restore ecosystem functionality in these systems. [ABSTRACT FROM AUTHOR]

Land-use intensification, nutrient enrichment and enhanced productivity levels are major drivers of the current biodiversity loss in agricultural grasslands. Although these drivers are potentially strongly causally linked, their potential to explain changes in biodiversity can enhance each other and often varies over time. Here, we explored the explanatory power of different abiotic drivers and the Ellenberg indicator value for nutrient availability to predict plant species richness using data of 150 grassland plots over seven years. The approach also allows to assess the temporal robustness of many of these drivers. Our results revealed the Ellenberg indicator value for nutrients to be the best and temporally most consistent predictor of plant species richness. Unweighted mean Ellenberg values showed an even stronger negative relationship to plant species richness than abundance weighted mean values. Direct measurements of soil and plant biomass nutrients, aboveground biomass and land-use intensity predicted plant species richness less well and showed considerable temporal variability in the respective association. In case of biomass nitrogen and phosphorus concentrations, current year weather conditions are assumed to strongly affect the strength of the relationship by shifting the phenological development considerable among sampling years. Although mainly driven by aboveground biomass, a combination of biomass nutrient concentrations with productivity, i.e. the nutrient stock in the aboveground biomass, turned out to better predict plant species richness than its single components and inter-annual variability in the relationship was markedly lower. Especially for aboveground biomass and the intensity of land-use, long-term mean values significantly improved the explanatory power compared to single year measurements. We conclude that studies explaining biodiversity changes should carefully take into account temporal variability in the drivers under study before judging the strength of a particular mechanistic relationship. [ABSTRACT FROM AUTHOR]

One of the key questions in ecosystem restoration is the choice of the seed material for restoring plant communities. The most common strategy is to use local seed sources, based on the argument that many plants are locally adapted and thus local seed sources should provide the best restoration success. However, the evidence for local adaptation is inconsistent, and some of these inconsistencies may be due to different experimental approaches that have been used to test for local adaptation. We illustrate how conclusions about local adaptation depend on the experimental design and in particular on the method of data analysis. We used data from a multispecies reciprocal transplant experiment and analyzed them in three different ways: (1) comparing local vs. foreign plants within species and sites, corresponding to tests of the 'local is best' paradigm in ecological restoration, (2) comparing sympatric vs. allopatric populations across sites but within species, and (3) comparing sympatric and allopatric populations across multiple species. These approaches reflect different experimental designs: While a local vs. foreign comparison can be done even in small experiments with a single species and site, the other two approaches require a reciprocal transplant experiment with one or multiple species, respectively. The three different analyses led to contrasting results. While the local/foreign approach indicated lack of local adaptation or even maladaptation, the more general sympatric/allopatric approach rather suggested local adaptation, and the most general cross-species sympatric/allopatric test provided significant evidence for local adaptation. The analyses demonstrate how the design of experiments and methods of data analysis impact conclusions on the presence or absence of local adaptation. While small-scale, single-species experiments may be useful for identifying the appropriate seed material for a specific restoration project, general patterns can only be detected in reciprocal transplant experiments with multiple species and sites. [ABSTRACT FROM AUTHOR]

Aim: Grazing intensity and fire patterns across the Eurasian steppes have changed dramatically over the past decades due to the collapse of the Soviet Union in 1991, and Kazakhstan is now a global fire hotspot. The implications of these changes for ecosystem functioning are largely unclear. We aimed to understand the effects of changed grazing intensity and fire frequency on a key ecosystem engineer, the yellow ground squirrel Spermophilus fulvus, on a very large scale. Location: Kazakhstan. Methods: Ground squirrels were surveyed in an area of ca. 100,000 ha in the dry steppe of central Kazakhstan, using hierarchical distance sampling at more than 200 random points, stratified by fire frequency and livestock grazing intensity. We modelled abundance as a function of different variables, grouped at the landscape scale (fire and grazing), meso‐scale (soil and vegetation structure) and at burrow scale (plant traits such as palatability, digestibility and nutrient content). Results: Ground squirrels prefer areas of a high wormwood cover (Artemisia spp.) and high plant species richness, which are moderately grazed, preferably by cattle, with only rare fire occurrence. High squirrel densities were also related to the availability of nitrogen‐rich plants of high nutritional value for herbivores. Main Conclusions: Yellow ground squirrels seem to reach their density optima by balancing trade‐offs between optimal foraging in areas of short, nutrient‐rich vegetation and a good visibility of approaching predators. Post‐Soviet changes in grazing pressure, resulting in higher fire recurrence rates due to grass encroachment and litter accumulation (i.e. fuel for wildfire), have likely affected the abundance of burrowing mammals and associated biodiversity across huge parts of the Eurasian steppes and semideserts. [ABSTRACT FROM AUTHOR]

Question Restoration of channelized streams increases geomorphic complexity but it remains unclear how this interacts with processes that drive future vegetation changes (dispersal, germination and establishment). This study asks if increased geomorphic complexity increases recruitment conditions of sown seeds or affects post-dispersal natural seedling densities. Location Vindel River catchment, northern Sweden. Methods We selected seven study streams with paired reaches that differed in the degree to which geomorphic complexity was restored. Basic reaches used simple restoration methods while enhanced reaches additionally added large boulders and woody debris. We sowed seeds of six species at ten locations in each reach in 2014 and counted the number of seedlings after 8 wk and the number of naturally occurring seedlings in a plot adjacent to the sowing locations in 2013 and 2014. Using factor analysis based on 34 complexity measurements, overall geomorphic complexity was quantified for eight of the 14 reaches. Results Total numbers of sown (2014) and natural seedlings (2013 and 2014) summed per reach did not differ between restoration types when tested pair-wise. Enhanced restoration did not always significantly increase geomorphic complexity, which differed considerably between the streams. More complex reaches were steeper, had larger size sediment and more nutrient-poor soils. Total recruitment of sown species significantly decreased with increasing complexity. Numbers of natural seedlings differed considerably from 2013 to 2014, but were not related to complexity. In 2014, a potential parent plant of the same species occurred within the same plot for 71.8% of the natural seedlings that could be identified. Conclusions The recruitment of sown seeds was affected by overall geomorphic complexity rather than by the enhanced restoration. The absence of a correlation between geomorphic complexity and natural seedlings could indicate that natural seedling dynamics are not solely determined by recruitment conditions, but also by dispersal. [ABSTRACT FROM AUTHOR]

Year-round grazing by cattle and horses has recently become a common practice in conservation management in north-western Europe. Though many projects claim positive effects on vegetation development, evidence is still largely anecdotal. There are no comprehensive regional surveys allowing the detection of general patterns beyond single case studies. This applies even more to nutrient-poor sites where year-round grazing systems were only recently established and concerns about potentially negative effects on plant diversity are still prevalent. Hence, this study investigates the impacts of year-round grazing on plant species richness, species composition, and vegetation structure on nutrient-poor sites using a regional multi-site approach. Surveys were carried out at five different study sites in the diluvial plain of northwestern Germany and the Netherlands comprising sand grasslands, dry grasslands, and heathlands. Results show overall positive effects of grazing: Plant species richness, the number of endangered plant species, and the proportion of open soil were increased significantly. Contrary, green biomass, litter cover, vegetation height, and the cover of woody species significantly decreased. At grazed sites there were more small, light-demanding species than taller, mesophilic species. A distinct decrease of ruderal species and an increase of species following a competitive strategy was observed at abandoned sites. Based on broad regional evidence, we conclude that year-round grazing is a suitable tool for the restoration and management of open habitats on nutrient-poor sandy sites. Low sward biomass and poor nutritional quality raise, however, concerns about adequate fodder supply and animal welfare. [ABSTRACT FROM AUTHOR]

Since 2019 the 'Floristisch-soziologische Arbeitsgemeinschaft' (FlorSoz) has annually nominated the 'plant community of the year', to draw attention to Germany's endangered plant communities in need of protection. This campaign specifically aims at supporting the conservation of plant communities and their habitats as well as at promoting political and administrative decisions and implementation processes that serve to protect and restore these ecosystems. Calthion palustris meadows will be the plant community of the year 2024. Formerly common in cultural landscapes throughout western and Central Europe, wet meadows with marsh-marigold (Caltha palustris) have become rare in most regions. Large-scale drainage and other measures of agricultural intensification, including the conversion of wetlands to intensive grassland and arable land, are responsible for the strong decline of this valuable meadow type in recent decades. Increased fertilization on the one hand and abandonment of marginal sites on the other led to changes in species composition and species loss. As an essential part of our cultural landscape, wet meadows are endangered and in some regions even threatened with extinction. Here, we outline the phytosociology of Calthion plant communities, their ecological characteristics, biodiversity and species composition. We provide an overview of the ecology, distribution and conservation status of the communities. Calthion wet meadows support a variety of mostly widely distributed, but locally rare and endangered plant species. They offer habitat to numerous vulnerable animal species, especially invertebrates and birds. With the decline of wet meadows, numerous groundnesting bird species typical of this habitat, especially waders, have also declined. As marsh-marigold wet meadows are of high ecological and functional importance and deserve prioritised protection, the causes of their decline are explained in detail. Furthermore, we discuss the ecological context of preservation, suitable conservation measures and options for restoration. Reclamation of abandoned wetlands can be considered a promising path for restoration. However, nutrient removal and rewetting of agriculturally improved grasslands, are often more difficult to implement. Diaspores have to be actively introduced and costly measures to raise groundwater levels such as sealing ditches or removing drainage systems are necessary. The short-term reduction of excessive nutrient levels is often impossible. Approaches promoting non-intensive use of wet meadows are discussed and suggestions are made to actively optimising the financial and advisory framework. For this purpose, better programs for nature conservation contracts, higher funding and other supporting instruments are essential. With the proclamation of Calthion wet meadows as plant community of the year and the publication of this paper, we intend to support conservationists and people committed to improving the general political conditions for the implementation of measures on local, regional, national and international levels. Those farmers who have managed wet meadows sustainably for decades despite adverse trends towards increased production growth deserve recognition and encouragement to maintain the traditional management. Successful measures to protect and restore species-rich wetlands are urgently needed. [ABSTRACT FROM AUTHOR]