Biology subjects

Brosi, B.

Publications and source records attributed to Brosi, B..

3 recordsLinked to original sources

bioRxiv2020

Plant-pollinator interaction linkage rules are altered by agricultural intensification

Determining linkage rules that govern the formation of species interactions is a critical goal of ecologists, especially considering that biodiversity, species interactions, and the ecosystem processes they maintain are changing at rapid rate worldwide. Species traits and abundance play a role in determining plant-pollinator interactions, but we illustrate here that linkage rules of plant-pollinator interactions change with disturbance context, switching from predominantly trait-based linkage rules in undisturbed, natural habitats, to abundance-based linkage rules in intensive agricultural habitats. The transition from trait-based to abundance-based linkage rules corresponds with a decline in floral trait diversity and an increase in opportunistic interaction behavior as agricultural intensification increases. These findings suggest that agricultural intensification is changing the very rules determining the realization of interactions and the formation of communities, making it challenging to use the structure of undisturbed systems to predict interactions within disturbed communities.

ecology↗

bioRxiv2019

Not all interactions are positive: testing how antagonistic interactions impact the robustness of plant-pollinator networks.

Given ongoing pollinator declines, it is important to understand the dynamics of linked extinctions of plants driven by pollinator extinctions. Topological robustness models focused on this question suggest relatively high robustness of plant species to pollinator species extinctions. Still, existing robustness models typically assume that all interactions in plant-pollinator networks are positive, which is clearly not always the case. For example, many pollinators remove floral resources with-out transferring pollen, or even damage floral structures in the case of nectar robbing. Here we introduce antagonistic interactions into plant-pollinator networks and assess the resilience of plant communities to pollinator species losses. Incorporating antagonistic interactions leads to lower network robustness, i.e. an increased rate of plant species loss (as compared to networks with only mutualistic interactions) in empirical plant-pollinator networks. In conjunction with extinction order, the addition of increasingly antagonistic interactions was idiosyncratic in that it did not always magnify the effects of extinction order across the three networks. These results underscore the importance of considering the full spectrum of interaction outcomes when assessing robustness to coextinctions in plant-pollinator networks, as well as other ecological systems.

animal behavior and cognition↗

bioRxiv2017

Pollinator traits and competitive context shape dynamic foraging behavior in bee communities.

Interspecific interactions (e.g. competition) can dynamically shape individual and species-level resource use within communities. Understanding how interspecific competition between pollinators species shapes resource use is of particular interest because pollinator foraging behavior (\"floral fidelity\") is directly linked to plant reproductive function through the movement of conspecific pollen. Through targeted species removals, this study aims to gain a predictive understanding of how interspecific competition can influence pollinator foraging behavior. We explore how traits--specifically pollinator tongue length, known to dictate pollinator resource partitioning--influence behavioral plasticity and drive dynamic interspecific interactions. Our results demonstrate that bee species vary in their floral fidelity and that tongue length explains a large part of this variation. Bees with shorter tongues move between plant species (floral infidelity) more often than bees with longer tongues. We did not find significant variation in the response of bee species to a reduction in interspecific competition, but rather saw a guild-wide reduction in floral fidelity in response to the removal of the dominant bee species Finally, our results suggest that tongue length of the most abundant bee species, a site-level attribute, explains much of the site-to-site variation in pollinator foraging behavior. In particular, we found that as the tongue length of the most abundant bee in the site increases, the site level foraging fidelity decreases. With global pollinator populations on the decline, novel interactions between plants and pollinators are likely to occur. Exploring how the competitive landscape shapes foraging plasticity will help us generalize to other plant pollinator systems and begin to better predict the functional implications of competitive interactions.

ecology↗