TY - JOUR

T1 - Habitat fragmentation increases specialization of multi-trophic interactions by high species turnover

AU - Zhang, Xue

AU - Dalsgaard, Bo

AU - Staab, Michael

AU - Zhu, Chen

AU - Zhao, Yuhao

AU - Gonçalves, Fernando

AU - Ren, Peng

AU - Cai, Chang

AU - Qiao, Gexia

AU - Ding, Ping

AU - Si, Xingfeng

PY - 2023

Y1 - 2023

N2 - Habitat fragmentation is altering species interactions worldwide. However, the mechanisms underlying the response of network specialization to habitat fragmentation remain unknown, especially for multi-trophic interactions. We here collected a large dataset consisting of 2670 observations of tri-trophic interactions among plants, sap-sucking aphids and honeydew-collecting ants on 18 forested islands in the Thousand Island Lake, China. For each island, we constructed an antagonistic plant-aphid and a mutualistic aphid-ant network, and tested how network specialization varied with island area and isolation. We found that both networks exhibited higher specialization on smaller islands, while only aphid-ant networks had increased specialization on more isolated islands. Variations in network specialization among islands was primarily driven by species turnover, which was interlinked across trophic levels as fragmentation increased the specialization of both antagonistic and mutualistic networks through bottom-up effects via plant and aphid communities. These findings reveal that species on small and isolated islands display higher specialization mainly due to effects of fragmentation on species turnover, with behavioural changes causing interaction rewiring playing only a minor role. Our study highlights the significance of adopting a multi-trophic perspective when exploring patterns and processes in structuring ecological networks in fragmented landscapes.

AB - Habitat fragmentation is altering species interactions worldwide. However, the mechanisms underlying the response of network specialization to habitat fragmentation remain unknown, especially for multi-trophic interactions. We here collected a large dataset consisting of 2670 observations of tri-trophic interactions among plants, sap-sucking aphids and honeydew-collecting ants on 18 forested islands in the Thousand Island Lake, China. For each island, we constructed an antagonistic plant-aphid and a mutualistic aphid-ant network, and tested how network specialization varied with island area and isolation. We found that both networks exhibited higher specialization on smaller islands, while only aphid-ant networks had increased specialization on more isolated islands. Variations in network specialization among islands was primarily driven by species turnover, which was interlinked across trophic levels as fragmentation increased the specialization of both antagonistic and mutualistic networks through bottom-up effects via plant and aphid communities. These findings reveal that species on small and isolated islands display higher specialization mainly due to effects of fragmentation on species turnover, with behavioural changes causing interaction rewiring playing only a minor role. Our study highlights the significance of adopting a multi-trophic perspective when exploring patterns and processes in structuring ecological networks in fragmented landscapes.

KW - antagonistic network

KW - bottom-up effect

KW - interaction rewiring

KW - mutualistic network

KW - plant–aphid–ant interaction

U2 - 10.1098/rspb.2023.1372

DO - 10.1098/rspb.2023.1372

M3 - Journal article

C2 - 37876189

AN - SCOPUS:85175271169

VL - 290

JO - Proceedings of the Royal Society B: Biological Sciences

JF - Proceedings of the Royal Society B: Biological Sciences

SN - 0962-8452

IS - 2009

M1 - 20231372

ER -