Agricultural intensification drives changes in hybrid network robustness by modifying network structure. (8th December 2019)

• Record Type: Journal Article
• Authors: Morrison, Beth M. L.; Brosi, Berry J.; Dirzo, Rodolfo
• Editors: Gomez, José Marìa
• Is Part Of: Ecology letters. Volume 23:Number 2(2020)
• Page Start: 359
• Page End: 369
• Publication Date: 2019-12-08
• Subjects: Agroecology -- biodiversity -- community ecology -- plant‐insect interactions -- robustness -- species interaction networks -- stability; Ecology -- Periodicals; 577
• DOI: 10.1111/ele.13440
• Languages: English
• ISSNs: 1461-023X

Abstract

Abstract: Within ecological communities, species engage in myriad interaction types, yet empirical examples of hybrid species interaction networks composed of multiple types of interactions are still scarce. A key knowledge gap is understanding how the structure and stability of such hybrid networks are affected by anthropogenic disturbance. Using 15, 169 interaction observations, we constructed 16 hybrid herbivore‐plant‐pollinator networks along an agricultural intensification gradient to explore changes in network structure and robustness to local extinctions. We found that agricultural intensification led to declines in modularity but increases in nestedness and connectance. Notably, network connectance, a structural feature typically thought to increase robustness, caused declines in hybrid network robustness, but the directionality of changes in robustness along the gradient depended on the order of local species extinctions. Our results not only demonstrate the impacts of anthropogenic disturbance on hybrid network structure, but they also provide unexpected insights into the structure‐stability relationship of hybrid networks. Abstract : A key gap in our understanding of the effects of anthropogenic disturbance on species interactions and communities is how disturbance alters hybrid species interaction networks. We constructed 16 hybrid herbivore‐plant‐pollinator networks along an agricultural intensification gradient to explore changes in network structure and robustness to local extinctions, which is a critical component of stability. We found that agricultural intensification led to declines in modularity but increases in nestedness and connectance but, unexpectedly, network connectance, a structural feature typically thought to increase robustness, caused declines in hybrid network robustness.