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Semi‐natural grasslands in Western Europe are degrading and declining. Their plant species diversity and associated fauna, such as arthropods, are decreasing fast making restoration crucial.Carabid beetles are an essential link in ecosystem functioning (e.g., through herbivory and predation) and provide important ecosystem services (e.g., pest control). As a diverse group from different trophic levels, they occupy a variety of ecological niches, making them good indicators of restoration success and habitat quality.To study how different aspects of carabid diversity change along a restoration gradient from degraded grasslands to restored semi‐natural Nardus grasslands, we sampled carabid beetles in grasslands in Northern Belgium. We analysed differences in abundance, diversity and community composition and investigated carabid traits potentially influencing carabids' response to grassland restoration.Species richness did not change along the restoration gradient, but number of individuals decreased as grassland restoration time and effort increased and species composition changed, mostly caused by species turnover. As grassland restoration time and effort increased, carabid body size decreased and the proportion of day‐active carabids increased. Predators and habitat generalists were dominant along the entire gradient.Even though the target vegetation was restored, the carabid communities were not, or at least, did not possess yet traits to be expected from a restored community. The landscape in Northern Belgium might be too fragmented for larger species with low dispersal ability to recolonize restored grasslands. However, restored species‐rich grasslands are beneficial for conservation of meadow birds as day‐active beetles thriving in restored grasslands are an important food source. [ABSTRACT FROM AUTHOR]

Biodiversity is declining at a rapid pace and, with it, the ecosystem functions that support ecosystem services. To counter this, ecosystem restoration is necessary. While the relationship between biodiversity and ecosystem functioning has been studied in depth, the relationship between ecosystem restoration and ecosystem functioning is studied less. We performed an observational study in grasslands undergoing restoration management toward Nardus grassland. Eight ecosystem functions, representing flows of energy, matter or information between functional compartments, were measured across five successive restoration phases along the restoration gradient. The levels of functioning were then compared along the gradient for both the individual functions and a multifunctionality index. We hypothesized that plant richness increases when grasslands are more restored and this increase in biodiversity is paralleled by an increase in ecosystem functioning. In our study, the degraded grasslands, generally occurring on more nutrient‐rich soils, were dominated by competitive fast‐growing species, resulting in higher process rates and thus in higher, faster functioning. Likewise, more restored grasslands exhibited slower process rates and, thus, lower functioning. When studying ecosystem functioning, value judgments are easily made. Especially in a restoration context, high functioning does not necessarily equals well functioning, as this depends on the stakeholder perspective. We need to ask ourselves if a high functioning ecosystem is most desirable, especially in a restoration or conservation context. Policy frameworks will need to balance these goals. [ABSTRACT FROM AUTHOR]

Questions: Effective and successful restoration of species-rich semi-natural grasslands requires knowledge of the soil nutrient status, including soil phosphorus availability. Plants are solid indicators of soil nutrient status, because their growth reflects nutrient availability integrated over a certain period. The use of reflectance spectroscopy to estimate vegetation nutrient content has the potential to offer a fast and efficient approach to provide information about soil nutrient availability for plants. Here, we investigated the effect and relative importance of vegetation phosphorus content compared with vegetation nitrogen content and species identity in explaining variation in vegetation reflectance. Location: Pot experiment mimicking Western European grassland communities on a restoration trajectory. Methods: We combined a pot experiment with a broad range of mesotrophic grassland species growing along a soil phosphorus gradient with a multivariate modelling approach. We measured vegetation spectra and vegetation phosphorus and nitrogen content in monocultures and mixtures. Results: Although vegetation biochemistry explained a considerable part of the variation in vegetation reflectance, we found no pronounced absorption features for vegetation nitrogen and phosphorus content across the reflectance spectrum. The relatively large effect of species and community identity suggest that other drivers, for example vegetation architecture, overruled the effect of vegetation biochemistry on the reflectance spectrum. Our findings indicate that species detection and indirect case-specific estimation of nutrients is possible, especially in structurally less-complex canopies such as monospecific grass swards. Conclusions: Disentangling the specific drivers of variation in spectral reflectance is challenging. Many studies confound the effect of species identity on the vegetation reflectance spectrum with the effect of vegetation biochemistry. Here, we showed the importance of explicitly taking species identity into account. Gaining insight into light-vegetation interactions and the in-depth integration of ecological theory in remote sensing are the way forward. [ABSTRACT FROM AUTHOR]

Excess soil phosphorus often constrains ecological restoration of degraded semi-natural grasslands in Western-Europe. Slow-growing species, often target of restoration (measures), are at a disadvantage because they are outcompeted by fast-growing species. Gaining insight into the responses of plant species and communities to soil phosphorus availability will help understanding restoration trajectories of grassland ecosystems. We set up two pot experiments using twenty grassland species with contrasting growth forms (i.e. grasses versus forbs) and nutrient use strategies (i.e. acquisitive versus conservative nutrient use). We quantified the nutrient use strategy of a species based on the stress-tolerance value of the CSR framework (StrateFy et al. 2017). We grew these species (1) as monocultures and (2) in mixtures along a soil phosphorus gradient and measured the aboveground biomass and plant phosphorus concentrations. Plant phosphorus concentration generally increased with soil phosphorus supply and biomass increased with soil phosphorus supply only in conservative communities. Forbs had higher plant phosphorus concentrations compared to grasses both in monocultures and mixtures. The species' nutrient use strategy had contrasting effects on plant tissue phosphorus concentrations, depending on soil phosphorus supply (interaction effect) and vegetation biomass (dilution effect). Our findings contribute to the knowledge required for successful ecological restoration of species-rich grasslands. Our results suggest that under specific conditions (i.e. nitrogen limitation, no dispersal limitation, no light limitation), slow-growing species can survive and even thrive under excess soil phosphorus availability. In the field, competition by fast-growing species may be reduced by increased mowing or grazing management. [Display omitted] • Understanding plant responses to soil P is key for restoring species-rich grasslands. • Species with contrasting nutrient use strategies were grown along a soil P gradient. • Plants mainly responded by increasing tissue P concentrations, and showed only a limited biomass response. • The nature of this tissue P response depended on the nutrient use strategy. • Surprisingly, conservative species survived and even thrived under excess soil P supply. [ABSTRACT FROM AUTHOR]

Aims: The restoration of degraded ecosystems typically focuses on establishing assemblages of target species, but successful recovery should also be evaluated by the ecosystem's functioning to guarantee long‐term persistence. We investigated how the processes underlying community assembly (i.e. species loss, species gain and changes in abundance of resident species) influenced ecosystem functioning in experimental grassland communities in different states of restoration. Location: A greenhouse experiment in northern Flanders, Belgium. Methods: We set up a mesocosm experiment with communities of 19 planted species, ranging from slow‐growing species from poorly productive Nardus grasslands to fast‐growing species from highly productive Lolium perenne grasslands. We categorised the mesocosms into different grassland restoration states based on known abiotic and biotic restoration barriers for semi‐natural grassland restoration: soil phosphorus levels and soil biota communities. After two growing seasons, we used the CAFE approach, an ecological application of the Price equation, to partition the effects of plant community assembly on ecosystem functioning (here community productivity) for the different restoration states. Results: Adding soil biota communities sampled from reference Nardus grasslands vs more intensively managed grasslands did not have a significant effect on either plant species richness or biomass productivity. Lower soil phosphorus concentrations (i.e. abiotic restoration) resulted in a higher plant species richness. However, the net effect on productivity was close to zero. The increase in productivity caused by species gains was compensated through decreases in productivity caused by species loss and by decreases in the abundance or functioning of species that are present in both abiotically degraded and abiotically restored states. Conclusions: Not only species richness but also species identity resulted in changes in ecosystem functioning (i.e. productivity), even though the net functional effects were close to zero. More specifically, we found that species richness‐driven increases in productivity were counterbalanced by resource‐driven and species identity‐driven reductions in productivity. [ABSTRACT FROM AUTHOR]