Interactions between global change components drive plant species richness patterns within communities in mountain grasslands independently of topography

Abstract

Questions How do interactions between global change factors (climate and land use, including livestock management) shape plant species richness patterns in mountain grassland communities? Does topography interact with global change factors to modulate their effect on within‐community plant diversity? Location Pyrenees, Spain. Methods We used an initial set of 20 predictors: climatic, biogeographic, livestock management and topographic. Our data set included a wide range of management and climatic conditions from mediterranean to alpine environments. After a variable selection procedure with random forest, we built GLM to explain species richness in plant communities through 100‐m2 plots (SR100), employing backward–forward selection with AIC and other techniques. Results The main filters of SR100 were the regional factors (climate and biogeography, with 23% and 17%, respectively, of the total contribution to SR100), followed by livestock management (14%) and topography (9%). Interactions between climatic and biogeographic variables were almost as important as the main effects (18%). Fragmentation effects were higher under low mean minimum temperatures and summer precipitation compared with other conditions. Connectivity interacted with most of the climatic variables. Moderately high stocking rates mitigated plant community species losses triggered by decreased connectivity. Sheep‐grazed grassland communities had lower SR100 than differently managed grasslands under low fragmentation scenarios; conversely, sheep grazing enhanced SR100 when fragmentation was high. Topographic predictors accounted for lower variability in SR100 than regional and management factors and were independent from these. Conclusions Several multi‐scale spatial filters determine SR100 of grassland communities in the Pyrenees, interacting through complex processes. Climate can enhance negative effects of fragmentation and lack of connectivity on SR100 under stressful conditions. Livestock management modified the impact of patch disaggregation and fragmentation on SR100.

Monitoring Plant Diversity to Support Agri-Environmental Schemes: Evaluating Statistical Models Informed by Satellite and Local Factors in Southern European Mountain Pastoral Systems

“…At Peneda-Gerês, with lower plant diversity than that registered in the Italian [40] and French Alps [52] or in the Spanish Pyrenees [53], this study identified a spatial pathway for the monitoring of species richness that may be of help for policy purposes. In fact, within the three main pathways established to monitor species richness, only the speciesenergy spatial pathway (P2) received statistical support.…”

Livestock species rather than grazing intensity shape plant guild proportions in interaction with multiple environmental drivers in grassland from the Pyrenees

“…Additionally, changes in grazing management in mountain grasslands are a manifestation of global change (Lasanta et al, 2017;Dibari et al, 2020), but are also a factor easy to manipulate, since it depends on human decisions (Komac et al, 2014;Muñoz-Ulecia et al, 2021). Consequently, they can contribute to the development of new management policies of grasslands in the Pyrenees, together with previous work that described the relationship of grazing management with plant diversity (Sebastià et al, 2008;Rodríguez et al, 2018) or ecosystem functions (Rodríguez et al, 2020(Rodríguez et al, , 2021.…”

“…The majority of the plant species in the grasslands are perennial (Sebastià, 2004), and both plants and environments are highly heterogeneous (Rodríguez et al, 2018). Most of the grasslands are grazed mainly in the summer season.…”

“…The data set used in this study was extracted from the PASTUS Database (https://ecofun.ctfc.cat/index.php/pastu s/), compiled by the Laboratory of Functional Ecology and Global Change (ECOFUN) of the Forest Sciences Centre of Catalonia (CTFC) and the University of Lleida (UdL). These data were already used in previous published articles to test other hypotheses (Rodríguez et al, 2018(Rodríguez et al, , 2020(Rodríguez et al, , 2021 Rodríguez et al, 2018Rodríguez et al, , 2020.…”

“…Management decisions will therefore influence simultaneously several ecosystem services and functions. Some authors have described management interactions with several multiscale filters to drive plant richness, for instance, interactions between livestock management and ecosystem fragmentation (Rodríguez et al, 2018); or interactions between grazing intensity and environmental conditions (Herrero-Jáuregui & Oesterheld, 2018). However, the studies addressing those management-environment interactions on the vegetation, have mainly focussed on those effects on taxonomic plant diversity (species richness), even though taxonomic plant diversity may not be fully accounting for the different ecosystem services and functions.…”