Land use change consistently reduces a- but not ß- and y-diversity of bees

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic a-diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., ¿-diversity), either due to reduced ß-diversity amplifying diversity loss or increased ß-diversity dampening diversity loss. Additionally, studies often focus on taxonomic diversity, while other important biodiversity components, including phylogenetic diversity, can exhibit differential responses. Here, we evaluated how agricultural and urban land use alters the taxonomic and phylogenetic a-, ß-, and ¿-diversity of an important pollinator taxon—bees. Using a multicontinental dataset of 3117 bee assemblages from 157 studies, we found that taxonomic a-diversity was reduced by 16%–18% in both agricultural and urban habitats relative to natural habitats. Phylogenetic a-diversity was decreased by 11%–12% in agricultural and urban habitats. Compared with natural habitats, taxonomic and phylogenetic ß-diversity increased by 11% and 6% in urban habitats, respectively, but exhibited no systematic change in agricultural habitats. We detected a 22% decline in taxonomic ¿-diversity and a 17% decline in phylogenetic ¿-diversity in agricultural habitats, but ¿-diversity of urban habitats was not significantly different from natural habitats. These findings highlight the threat of agricultural expansions to large-scale bee diversity due to systematic ¿-diversity decline. In addition, while both urbanization and agriculture lead to consistent declines in a-diversity, their impacts on ß- or ¿-diversity vary, highlighting the need to study the effects of land use change at multiple scales.

Objectius de Desenvolupament Sostenible::15 - Vida d'Ecosistemes Terrestres

Objectius de Desenvolupament Sostenible::15 - Vida d'Ecosistemes Terrestres::15.1 - Per a 2020, vetllar per la conservació, el restabliment i l’ús sostenible dels ecosis­temes terrestres i els ecosistemes interiors d’aigua dolça i els serveis que proporcionen, en particular els boscos, els aiguamolls, les muntanyes i les zones àrides, d’acord amb les obligacions marcades pels acords internacionals

Objectius de Desenvolupament Sostenible::2 - Fam zero::2.4 - Per a 2030, assegurar la sostenibilitat dels sistemes de producció d’aliments i aplicar pràctiques agrícoles resilients que augmentin la productivitat i la producció, contribueixin al manteniment dels ecosistemes, enfor­teixin la capacitat d’adaptació al canvi climàtic, fenòmens meteorològics extrems, sequeres, inundacions i altres desastres, i millorin progressivament la qualitat del sòl i la terra

Objectius de Desenvolupament Sostenible::2 - Fam zero

Postprint (author's final draft)