Carlos Martínez-Núñez, Antonio J. Manzaneda, Sandra Lendínez, Antonio J. Pérez, Luis Ruiz-Valenzuela & Pedro J. Rey
The promotion of sustainable agriculture is a key challenge in biodiversity conservation and the development of human societies. To achieve sustainability, we need to understand how agricultural management and landscape characteristics affect natural communities and their functions. For instance, does organic/intensive farming affect wild pollinators and the pollination services they provide? Does the amount of semi-natural habitat that surrounds a farm matter? In recent years, scientists have begun to pay greater attention to the interplay between local agricultural practices and landscape characteristics. It is thought that landscape modulates the effects that agricultural practices have on biodiversity, although this idea has never been tested using pollination networks (networks of interactions that reveal who pollinates whom and how often), a very powerful tool in ecology.
In this study, we used bee hotels (bee trap nests) to analyze pollination networks involving above-ground nesting solitary bees and wild herbs in one of the world’s most important permanent agroecosystems, olive groves. Particularly, we addressed the effects of management-landscape interplay on network stability, complexity, and spatial homogenization.
We found that pollination networks were more complex, stable, and heterogeneous in organic farms, which suggests that organic farming is better for bees and the wild plants they pollinate. Moreover, we found that differences between organic and intensively managed farms were maximized in landscapes with an intermediate amount of natural areas. Thus, biodiversity-friendly management in olive groves is especially important in the case of farms located in intermediate landscapes, as the Intermediate Landscape Complexity Hypothesis predicts.
This study sheds light on the foundations of a currently highly important aspect of the conservation of nature in agroecosystems.