Host range dynamics at different scales: host use by a hemiparasite across its geographical distribution

ATENCIO, N.O.; VIDAL RUSSELL, ROMINA; CHACOFF, N. P.; AMICO, GUILLERMO C.

PLANT BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021

1435-8603

? The complexity of natural communities is the result of interactions among species that coexist within them. Parasitic interactions are among the most common species interaction types, and analysis of parasite-host ranges can advance understanding of how host-parasite pairs structure community interactions across their geographic distributions. ? Using network analysis and host preference relative index we analyzed host-use by the South American mistletoe, Tristerix corymbosus (Loranthaceae), in 22 localities among two biomes: Chilean matorral and temperate forest.? The total number of host species recorded was 27, and 40% of species were non-native. The non-native species Populus sp. was shared between biomes. There was a positive relationship between host range and potential host species richness at the studied localities. On average, the mistletoe parasites each host species relative to its abundance. However, some host species in some localities are more parasitized than expected. Network structure showed a differentiable host use between the two biomes, Aristotelia chilensis was central in the temperate forest while Populus sp. in the Chilean matorral. Host use intensity in the Chilean matorral was higher for non-native species. ? Tristerix corymbosus has a wide host range and could be considered as a generalist parasite across its full geographic distribution, but at local scales, host preferences differed among localities and are related to host coverage. Alterations in community composition, due to natural events or human activities, can modify the availability of possible hosts. Hence, the mistletoe with the described characteristics may be able to change its infection preference maintaining the interaction functionality.