Landscape connectivity explains interaction network patterns at multiple scales

SANTOS, MICAELA; CAGNOLO, LUCIANO; ROSLIN, TOMAS; MARRERO, HUGO J.; VÁZQUEZ, DIEGO

ECOLOGY

ECOLOGICAL SOC AMER

Año: 2019

0012-9658

Under a metacommunity framework, the spatial configuration of habitat fragments coulddetermine local community structure. Yet, quantifying fragment connectivity is challenging, as itdepends on multiple variables at several geographical scales. We assessed the extent to whichfragment connectivity and area explain patterns in interaction structure among four herbivoreguilds and their host plants in a metacommunity. We propose an integrative connectivity metricincluding geographic distance, neighbouring fragment area and similarity in resource compositionas an extension of Hanski?s classic metric. We then used non-linear models to assess whetherfragment connectivity and area predicted link richness and similarity in link composition. Wefound that link richness was always negatively related to connectivity but at different geographicscales depending on the herbivore guild. In contrast, while link composition was also related toconnectivity, the direction and strength of this relationship varied among herbivore guilds and typeof link composition (qualitative or quantitative). Furthermore, focal fragment area was not animportant determinant of interaction diversity in local communities. Our findings emphasizeresource similarity as a novel dimension of fragment connectivity relevant in explaininginteraction diversity patterns in natural trophic networks.