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Questions: Semi-natural habitats are threatened by shifts in management with worrying effects on multiple facets of biodiversity. We revisited sites once representing a reference for a calcareous semi-natural grassland habitat aiming to: (a) identify the drivers of taxonomic, functional and phylogenetic diversity, and habitat conservation state; (b) assess the role of characteristic and derived diversity in determining these patterns; and (c) discuss the possibility of reconciling the goals of habitat conservation and enhancement of different facets of plant diversity. Location: Seven sites along the Apennines (Italy), from Mt. Catria (43.46206° N, 12.70397° E) to Mt. Alpi (40.11768° N, 15.98341° E). Methods: For 132 revisited plots, we calculated vascular plant taxonomic, functional and phylogenetic diversity using Hill numbers, and used boosted regression trees to investigate their response to the compositional dissimilarity from historical plots, to grazing intensity and to environmental variables. We identified characteristic and derived diversity and summarized them in an index of habitat conservation state whose drivers were investigated using the same approach. Results: Plant diversity was influenced by the site, whereas the habitat conservation state responded more markedly to vegetation type. Grazing intensity, slope and soil variables drove taxonomic and functional diversity, and the habitat conservation state, with some differences in their relative importance. Phylogenetic diversity responded only partly to grazing intensity, while it showed a major response to increasing temperatures. Conclusions: Patterns and drivers of different facets of plant diversity partially differ from those of the habitat conservation state, suggesting that the management of semi-natural habitats should be carefully tailored on specific conservation objectives. Generalized actions on grazing regimes and litter removal can promote habitat conservation, whereas the outcomes of these actions for plant diversity may differ across sites. Identifying areas particularly subjected to land-use changes and/or climate warming may drive conservation actions. [ABSTRACT FROM AUTHOR]

The European biodiversity and forest strategies rely on forest sustainable management (SFM) to conserve forest biodiversity. However, current sustainability assessments hardly account for direct biodiversity indicators. We focused on forest multi-taxon biodiversity to: i) gather and map the existing information; ii) identify knowledge and research gaps; iii) discuss its research potential. We established a research network to fit data on species, standing trees, lying deadwood and sampling unit description from 34 local datasets across 3591 sampling units. A total of 8724 species were represented, with the share of common and rare species varying across taxonomic classes: some included many species with several rare ones (e.g., Insecta); others (e.g., Bryopsida) were represented by few common species. Tree-related structural attributes were sampled in a subset of sampling units (2889; 2356; 2309 and 1388 respectively for diameter, height, deadwood and microhabitats). Overall, multi-taxon studies are biased towards mature forests and may underrepresent the species related to other developmental phases. European forest compositional categories were all represented, but beech forests were over-represented as compared to thermophilous and boreal forests. Most sampling units (94%) were referred to a habitat type of conservation concern. Existing information may support European conservation and SFM strategies in: (i) methodological harmonization and coordinated monitoring; (ii) definition and testing of SFM indicators and thresholds; (iii) data-driven assessment of the effects of environmental and management drivers on multi-taxon forest biological and functional diversity, (iv) multi-scale forest monitoring integrating in-situ and remotely sensed information. • Through a Europe-wide research network we harmonized and merged 34 datasets on forest biodiversity • Multi-taxon biodiversity information is available for studied across 3,591 sampling units • Available data unevenly cover the European forest compositional categories • Knowledge gaps are boreal, Mediterranean, thermophilous and floodplain forests • The available information has the potential to inform conservation and management strategies for European forests [ABSTRACT FROM AUTHOR]

Monitoring semi-natural grasslands is difficult and costly because they occur in highly dynamic and extremely complex habitat mosaics. We combined the use of a low-cost unmanned aerial vehicle (UAV) and Structure from Motion (SfM) photogrammetry to acquire high spatial resolution (∼1.5 cm pixel) RGB imagery. After image classification through Object-Based Image Analysis (OBIA), we accurately were able to distinguish three semi-natural grassland types, one of which is a habitat of conservation concern. The use of orthomosaics, digital elevation models (DEMs), and canopy height models (CHMs) yielded excellent overall classification accuracies (>89%) assessed through both remotely validated and ground-truthed points. We identified two layers of woody vegetation with a user's (UA) and producer's (PA) accuracies >73% and three grassland types: closed grassland (UA = 94%; PA = 97%), open grassland habitat (UA = 97%; PA = 93%) and open grasslands with soil erosion (UA = 96%; PA = 98%). The grassland types differed substantially in the cover of vegetation, rocks, stones, and bare soil measured in the field, as well as in the number and relative cover of the habitat diagnostic species. The proposed methodology is highly promising for mapping and monitoring semi-natural grassland of conservation concern in support of tailored management actions. [Display omitted] • Fine-scale mapping identifies three different semi-natural grassland classes. • High-resolution imagery and dense point clouds improve vegetation classification. • A useful tool for monitoring habitats of conservation concern. • Cost-effective and time-saving tool for frequent monitoring programs. [ABSTRACT FROM AUTHOR]

In Europe, the conservation of extensively grazed semi-natural grasslands is addressed by agricultural policies whose effectiveness is questioned. We studied sub-xerophilous Bromus erectus semi-natural grasslands to analyse the interactions among: i) agri-environmental payments, ii) grazing regimes, iii) environmental conditions, iv) habitat conservation state, and v) forage yield and quality. We sampled 98 plots across 19 farms and unmanaged control areas in five regions encompassing Italy and Switzerland. We fitted two piecewise structural equation models (SEM) to infer direct and indirect effects of agri-environmental payments, grazing regimes and environmental conditions on proxies of habitat conservation state, (i.e., the number and cover of diagnostic species), and forage yield and quality (i.e., specific leaf area - SLA, leaf dry-matter content - LDMC, sward height and pastoral value). Agri-environmental payments contributed to maintain grazing management and in turn to preserve the habitat biodiversity and functions. Payments did not affect stocking rates, but determined a more even distribution of grazing intensity, with positive effects on habitat conservation state and negative outcomes for LDMC. Conversely, LDMC increased with stocking rates. Among environmental condition, elevation and soil carbonates content had a positive effect on the habitat conservation state, while slope exerted only indirect effects on forage quality and diagnostic species by reducing fine-scale grazing intensity. Overall, the effectiveness of payments largely depended on the scale of measures' implementation. Farm-level grazing contracts and periodic field monitoring would allow to influence the fine-scale grazing intensity and to implement a result-oriented approach towards the objectives of the post-2020 CAP. • Payments do not influence stocking rates, but fine-scale grazing intensity. • Fine-scale grazing intensity affects habitat conservation and forage provision. • Stocking rates affect forage yield and quality, but not habitat conservation state. • Elevation, soil carbonates and slope influence habitat conservation state. • Payments should include farm specific grazing contracts and habitat monitoring. [ABSTRACT FROM AUTHOR]