Anthropogenic disturbance causes changes in species composition relative to adjacent natural patches and reduces their biotic heterogeneity. Furthermore, land use management can influence changes in biodiversity beyond the targeted species. In the last decades, management practices in coffee plantations have transitioned from practices where coffee plants grow below accompanying (shade) trees, to monocultures in which coffee plants grow exposed to the sun. Previous studies have shown that the latter is a major driver of biodiversity loss and associated ecosystem services. On the other hand, shade trees can act as potential shelters and facilitate dispersal of organisms, mitigating biodiversity and ecosystem service loss. In our study, we assessed the impact of coffee plantation management practices on the taxonomical, phylogenetic and functional composition of ant communities, an ecologically dominant group and crucial biological pest controller in these agroecosystems. We specifically asked if shade-grown plantations harbour ant communities that better resemble nearby forest patches compared to sun-grown plantations. Through a combination of active and passive sampling methods, we surveyed ant communities found in eight sun-grown plantations and eight shade-grown plantations with eight nearby forest patches in the mountains of southern Colombia.
Results/Conclusions
Our results show that sun-grown coffee plantations change taxonomic, phylogenetic and functional composition of ant communities when compared to forest patches or shade-grown plantations. Additionally, we find that sun-grown plantations taxonomically and functionally homogenize ant communities, however not phylogenetically. Changes in community composition and heterogeneity can lead to disruptions in ant-provided services such as pest control. Overall, our findings provide evidence for shaded coffee buffering the impoverishment of multiple diversity facets after forest conversion. Studies assessing changes in multiple dimensions of biodiversity are increasingly necessary, given the misleading nature of unidimensional studies. Our results indicate that pluralistic approaches for characterizing the changes of biodiversity in agroecosystems can be used to better inform land management strategies focusing on minimizing biodiversity and ecosystem service loss.