The disruption of a keystone interaction erodes pollination and seed dispersal networks

VITALI, AGUSTIN; SASAL, YAMILA; VÁZQUEZ, DIEGO P.; MIGUEL, M. FLORENCIA; RODRÍGUEZ CABAL, MARIANO A.

ECOLOGY

ECOLOGICAL SOC AMER

Año: 2022

0012-9658

Understanding the impacts of global change on ecological communities is a major challenge inmodern ecology. The gain or loss of particular species and the disruption of key interactions are bothconsequences and drivers of global change that can lead to the disassembly of ecological networks.We examined whether the disruption of a hummingbird-mistletoe-marsupial mutualism by theinvasion of non-native species can have cascading effects on both pollination and seed dispersalnetworks in the temperate forest of Patagonia, Argentina. We focused on network motifs, subnetworkscomposed of a small number of species exhibiting particular patterns of interaction, toexamine the structure and diversity of mutualistic networks. We found that the hummingbirdmistletoe-marsupial mutualism plays a critical role in the community by increasing the complexity ofpollination and seed dispersal networks through supporting a high diversity of interactions. Moreover,we found that the disruption of this tripartite mutualism by non-native ungulates resulted in diverseindirect effects that led to less complex pollination and seed dispersal networks. Our resultsdemonstrate that the gains and losses of particular species and the alteration of key interactions canlead to cascading effects in the community through the disassembly of mutualistic networks.