An evaluation of the sampling completeness in a mutualistic network

CHACOFF, NATACHA; VÁZQUEZ, DIEGO P.; LOMASCOLO, SILVIA; PADRÓN, BENIGNO; DORADO, JIMENA; STEVANI, ERICA

Avila

Congreso; 12th European Ecological Federation Congress; 2011

The study of plant-pollinator interactions in a network context needs to estimate community level interaction richness, relative abundance and species composition. Therefore, network studies are subject to the same sampling issues as any study of diversity. We analyzed the completeness of a plant-pollinator network from the Argentinean Monte desert using asymptotic species richness estimators. Our goal was to assess the extent to which the realized sampling effort allows for an accurate description of species interactions and to estimate the minimum number of additional censuses required to detect 90% of the interactions. We also evaluated whether sampling completeness was influenced by sampling effort and plant characteristics, such as flower abundance, flower life span, number of interspecific links (degree), and selectiveness of flower visitors. In spite of our high sampling effort, and although we sampled 80% of the pollinator fauna, we recorded only 55% of the interactions. Furthermore, although a 64% increase in sampling effort would suffice to detect 90% of the pollinator species, a 5-fold increase in sampling effort would be necessary to detect 90% of the interactions. Detection of interactions was incomplete for most plant species, particularly specialists with a long flowering season and high flower abundance, or generalists with short flowering span and fewer flowers. Our results suggest that equal sampling effort for all plant species in a network is inadequate to sample interactions. Our study contributes to the understanding of what affects sampling accuracy in a plant-pollinator community, one of the major challenges in the field of plant-animal interactions.