Phenological synchrony between plants and pollinators and potential mismatches in response to climate changes in campo rupestre, a tropical mountain ecosystem

Abstract

Climate change is anticipated to induce alterations in phenological events among species, with varying responses to shifting environmental conditions. Consequently, species interactions may be disrupted due to phenological mismatches. Mutualistic systems, such as plant-pollinator interactions, are expected to be particularly vulnerable, as both partners benefit from the interaction and are likely to suffer from its disruption. In the short term, pollinators are expected to be more vulnerable than plants, especially obligate flower visitors like bees, which rely on floral resources for survival. Unlike most plants, which can mitigate the lack of pollinators through self-pollination, vegetative reproduction, seed banks, and iteroparity, pollinators are less adaptable.Phenological mismatches are also expected to affect specialist species of plants and pollinators more than opportunistic species, as specialists interact with a restricted group of partners, necessitating greater synchronization. The degree of phenological synchrony between interacting species relies on the similarity of the environmental cues governing their phenological events. In temperate areas, where research has been concentrated, both plants and pollinators exhibit synchronization with temperature seasonality. However, phenological desynchronization still arises due to variations in species' sensitivities to environmental cues, influenced by morphological, physiological, and behavioral traits.Our previous research revealed that phenological patterns in Brazilian tropical bees are also primarily thermoregulated, even in the face of milder temperature seasonality, and exhibit similar variations to those observed in temperate regions in response to comparable traits. However, direct comparisons with plant phenology, essential for analyzing phenological synchronization and potential mismatches caused by global warming, have yet to be conducted at the community scale.This proposal aims to analyze the phenological synchrony and the potential phenological mismatches between plants and pollinators in response to climate change in a tropical ecosystem. It will begin by identifying the environmental cues and traits driving plant flowering and pollinator foraging phenology, estimating the magnitude of phenological mismatches caused by climate variations, and determining if the level of phenological synchronization is higher among specialized species. The study will be conducted along an altitudinal gradient as a space-for-time substitution, given the lack of sufficiently long time series data. The Campo rupestre ecosystem at Serra do Cipó, located south of the Espinhaço Range, has been selected as the study site due to its great spatial heterogeneity, and the accumulated knowledge of the Morellato's group in the area.Sampling of plant-bee interactions will occur over one year along the altitudinal gradient at Serra do Cipó. Bee and plant species will be segregated based on different traits, with the spatiotemporal frequencies of trait groups correlated with climate variability to identify phenological drivers. Phenological synchronization and potential mismatches between plants and pollinators will be analyzed by calculating differences in their phenological peaks under the environmental gradient. We expect to find similar environmental cues driving bee foraging and plant flowering phenology, phenological differences between functional groups of bees and plants, and higher synchronization between bee specialist plants and their pollinators. (AU)