Why mistletoes are more aggregated in disturbed forests? The role of differential host mortality

Abstract

© 2017 Elsevier B.V. Mistletoes rely on biotic seed dispersal to ensure their recruitment on appropriate host plants, as their seeds must be deposited on safe sites to allow attachment. As most host-parasite systems, mistletoe's spatial distribution depends on the spatial arrangement of the hosts and on the seed disperser's behavior. We used the mistletoe Tristerix corymbosus, which is solely dispersed by the arboreal marsupial Dromiciops gliroides, and it is capable to parasitize a wide range of hosts. We previously found T. corymbosus mistletoes to be more abundant and densely aggregated in disturbed habitats, compared to neighboring native forests, at similar levels of disperser abundance and host availability. To explain this pattern, we tested two non-mutually exclusive hypotheses(1) the larger resource availability in disturbed habitats modify the disperser behavior reducing its home range, and (2) plant species in disturbed habitats are better hosts and offer higher survival pro