Habitat conservation state and plant diversity respond to different drivers in semi‐natural grasslands

Abstract

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.

Proposals for improvement of Annex I of Directive 92/43/EEC: Sardinia

“…Motivation: The conservation value of the European traditional farming systems has been recognized for several decades because of the biodiversity levels they support and the socio-ecological values they provide (Bignal and McCracken 2000). Among traditional farming systems, semi-natural grasslands host high levels of plant diversity and habitat richness at different spatial scales (Biurrún et al 2021), responding to different drivers such as grazing intensity, soil and topographical variables (Napoleone et al 2021). Moreover, they support several ecosystem services (Bagella et al 2020a).…”

Both management practices and landscape influence plant communities in urban grasslands

“…Among seminatural habitats in Europe, grasslands present important challenges for biodiversity conservation (Lindborg et al, 2008;Napoleone et al, 2021), especially due to their high species richness (Habel et al, 2013). In contrast to agricultural grasslands, urban grasslands remain understudied (Cochard et al, 2019) in spite of their contribution to urban biodiversity (McKinney, 2002;Fischer et al, 2013;Vega and Küffer, 2021;Mugnai et al, 2023).…”

Site dependence of local-scale variations in taxonomic and functional diversity of semi-natural dry grasslands

“…Semi-natural dry grasslands and scrubland facies on calcareous substrates (habitat 6210*, where * indicates that the habitat is an important site for orchids; see CEC 2003b), are an important habitat for orchids and other species (Gheza et al 2020). In Italy, this habitat is found across the Apennines where its cover has been rapidly declining (Burrascano et al 2013;Lazzaro et al 2020;Napoleone et al 2021).…”