Metacommunity structure reveals that temperature affects the landscape compositional patterns of avian malaria and related haemosporidian parasites across elevations

Abstract

Metacommunity ecology studies how species compositional patterns and their distributions vary across local and regional scales and provides insights on processes driving the distribution of communities. Avian haemosporidians comprise a diverse and widely distributed parasite taxon; some studies have analyzed their alpha and beta diversity patterns. Yet, metacommunity structures of avian haemosporidians and thus relevant biotic and abiotic variables explaining such structures at the landscape scale (i.e., 10–200 km) have not been assessed. We studied the metacommunity structure of avian haemosporidian mtDNA cyt b lineages and the infected avian host assemblage across four different elevations in Central Veracruz, Mexico. We performed variation-partitioning analyses to evaluate the contribution of host-related traits and climatic variables to the metacommunity. We found a richness of 78 lineages within 38 infected species of birds. At the component community level, we observed that bird species infected with a lower number of parasite lineages (e.g., <3) represented a nested subset of those with a higher number of parasite lineages (e.g., >8) (i.e., nested structure). However, this nested pattern was due to the restricted spatiotemporal co-occurrence of hosts and parasites, given the high degree of turnover across elevations. Host-related traits (functional, transmission-associated, and phylogenetic relationships) only explained a small fraction of the variation (4.4%) in parasite lineage composition across avian hosts. At the habitat level, there was a group turnover by parasite genera across elevation (i.e., quasi-Clementsian structure), which was partly explained by climatic variables (mean annual temperature and annual diurnal range; 27.6%) that may constrain parasite reproduction and vector distribution across the environmental gradient. At the scale of our study, environmental conditions represented a more important driver of avian haemosporidian metacommunity structure than host-related traits, suggesting an important role of environmental filtering structuring parasite assemblages at the landscape level.