Caracterização da diversidade de interações planta-morcego polinizador em fragmentos de floresta tropical seca (Colômbia)

Abstract

Despite the large number of research on plant-pollinator interactions, studies at the community level still represent a strand that lacks empirical data for understanding processes in tropical communities, especially for chiropterophilous interactions. In this study, the objective was to identify some determinants of the pattern and robustness of pollination interactions between plants and bats in different fragments of tropical dry forest, as well as to evaluate the connectivity and species roles in the network and in the ecosystem. For this, interaction networks analysis was used, such as: modularity, specialization, the core decomposition index (k-core decomposition) and its k-core, k-degree and k-risk components, and beta diversity analysis of species and their interactions, which were related to the distance between the fragments. The role of species (degree, specialization, interaction strength, role in module formation - CZ values) was related to their attributes (bats: body condition index - BCI, rostrum; plants: floral size, plant height, number of stamens, flower type and anthesis). Additionally, robustness analyzes were performed with different simulations. As a result, a modular and specialized network was found, in which plant species showed greater partition than bat species, similar in the beta analysis, where the dissimilarity of the bat community was lower, indicating their role as habitat connectors. Species β-variation was independent of the distance between fragments, and plants had higher values of species dissimilarity (βST - turnover), which was the main component of the total beta diversity of interactions. In addition, plant species occupied the external k-core, as peripheral species, and bats were located in the internal k-core (core), corresponding to their activity as connectors, a role played mainly by the species Glossophaga soricina and Phyllostomus hastatus. The body condition and rostral size of the bats was an important attribute of the role played in the network, as module connectors. However, some plant species also acted as important network connectors such as Ceiba pentandra and Crescentia cujete (plants), with height, anthesis and number of stamens being important attributes. Finally, the secondary extinction simulations allowed us to observe that the network was more robust against the loss of less linked nodes, and for the plant community, showing less stability due to the removal of generalist species, mainly bats. In general, these results allowed us to understand the structure of a plant-bat pollination network and may represent an important basis for articulating other studies that allow clarifying the factors that induce changes in the interaction networks in fragmented systems.