Cerrado in the Anthropocene: climate changes and anthropogenic pressure already influence plant diversity

Understanding how anthropogenic pressures are altering spatial patterns in plant diversity is essential to delineate public policies for biodiversity conservation. Here, we address the influence of climate and landscape changes, fire frequency and human footprint on the spatial patterns of plant taxonomic and phylogenetic alpha and beta diversity in the Brazilian Cerrado, at large and regional scales.

We accounted for historical environmental factors such as palaeoclimate and topography, and soil characteristics on plant diversity. At large scale, we analysed direct and indirect effects of all predictors on response variables using piecewise structural equation modelling. To address the effects of predictor variables at regional scale, we used geographically weighted regression.

We found that soil characteristics, climate stability, and current climate are the main drivers of savanna and forest taxonomic and phylogenetic alpha diversity at both large and regional spatial scales. We also found that fire frequency and %agriculture mainly explained savanna and forest taxonomic and phylogenetic alpha and beta diversity at regional scale. Thus, a range of variables influenced plant diversity in different ways across spatial distribution, and at varying spatial scales in Cerrado.

Our findings show that current climate and human pressure are already affecting plant diversity in Cerrado. For design conservation policies to maintain higher Cerrado's plant richness, it is remarkable to consider regional differences, restore habitats at rural properties and watershed levels, and include the different natural vegetation types. Conservation and management planning to mitigate and offset climate and landscape changes due to human influence should include restoration of habitats. Zero forest and savanna cut for agriculture expansion policy in Cerrado is urgent. Unproductive areas can give space for new sustainable production systems or habitat restoration to fill yield gaps and increase carbon stock, landscape connectivity, and wildlife diversity in the biome.