Insects or Wind? New findings on the pollination system of Euterpe edulis (Arecaceae)

Abstract

The palm Euterpe edulis is an important palm species for the extraction of palm heart, a highly profitable consumable product. Due to its importance, much research has been conducted around the ecology of this palm species. Nevertheless, information available on its reproductive ecology is quality-deficient and fragmented, resulting in misleading views of the pollination and reproductive ecology of E. edulis. Here we conduct the first thorough study assessing the relative dependence on animal pollination of E. edulis in Argentina, and conduct parallel detailed observations on floral visitors. Also, we integrate our results with those available for the species in the literature. Here we found that E. edulis has an ambophilic pollination system. However, in our study system, there was a predominance of wind pollination over insect pollination and the species can also set seeds in the absence of pollen. Also, our study shows in great detail the large diversity of insects visiting E. edulis, indicating the generalist pollination system of the species, where Hymenoptera and Diptera stand out in richness and frequency of visits. The palm represents a key resource for a wide diversity of insect visitors, but the palm does not rely on their efficiency to act as pollinators. The varied levels of reproductive dependence on animal versus wind pollination of E. edulis may be shaped by climatic and landscape conditions. Such alternative versatile strategies allow the species to guarantee the reproductive success under different ecological contexts.