Ecological Networks

We are broadly interested in how the structure of ecological networks affects their stability and functioning, how networks respond to perturbations, and more generally their dynamics and evolution. Most of our work focuses on mutualistic networks, particularly pollination networks, but we are interested in all kinds of ecological interactions, and especially in combining multiple interaction types in the same network. A particular goal is to better integrate theory and empirical data, an integration that remains rare in mutualistic network studies.

Key Papers

Bell KL, Fowler J, Burgess KS, Dobbs EK, Gruenewald D, Lawley B, Morozumi C, Brosi BJ. Applying pollen DNA metabarcoding to the study of plant-pollinator interactions. Applications in Plant Sciences, 2017. 5(6): 1600124

This work shows the integration between our DNA metabarcoding work and our network studies—demonstrating for the first time that highly-resolved pollination networks can be constructed by metabarcoding pollen carried by flower visitors. We highlight a number of suggestions for using this technique for network studies.

Brosi, BJ, Niezgoda K, Briggs HM.. Experimental species removals impact the architecture of pollination networks. Biology Letters, 13: 20170243

Most network simulation studies exploring the consequences of species losses assume that network structure stays fixed after species losses. In these replicated field experiments we show that network structure is altered, in ways that can be predicted from basic ecological theory.

Valdovinos, F.S., B.J. Brosi, H.M. Briggs, P. Moisset de Espanés, R. Ramos-Jiliberto, N.D. Martinez.. Adaptive foraging interacts with network structure to stabilize mutualistic networks. Ecology Letters, 2016. 19: 1277–1286.

This paper integrates modeling and our field data from Colorado, and shows that “adaptive foraging”—behavioral plasticity in foraging intensity on different resources—is key for stabilizing pollination networks, but has different effects in networks with different structures.

Bewick, S, BJ Brosi, and PR Armsworth. Competition causes secondary extinctions in plant-pollinator networks.. Oikos, 2013. 122: 1710–1719

Most models of mutualistic networks assume that mutualisms across groups are the only interactions occurring. Here, we show that integrating plant-plant competition in pollination-network models decreases network robustness to secondary extinctions.

networks

Projects

Balancing Stability and Functioning in Ecological Networks

A key conundrum in ecological network science is how networks balance efficient functioning with the redundancy needed for stability. In collaboration with Fernanda Valdovinos (U. Michigan) and Phillip Staniczenko (SESYNC), we are investigating how qualitative network topology (presence or absence of links) interacts with quantitative network structure (interaction intensity) to achieve this balancing act. Our ongoing work integrates mathematical modeling (led by post-doc Alva Curtsdotter) and field work at the Rocky Mountain Biological Laboratory (involving graduate students Xingwen Loy and Connor Morozumi).

Effects of accelerated snowmelt on pollination network structure and functioning

How environmental changes will affect ecological network structure and functioning is a key question in the Anthropocene. Led by graduate students Xingwen Loy and Connor Morozumi, we are investigating the effects of accelerated snowmelt—a key predicted effect of global climate change in montane systems—on pollination network structure and plant reproductive functioning, based at the Rocky Mountain Biological Laboratory. Climate change is particularly expected to lead to mismatches in the timing (phenology) of plants and pollinators, but whether and how these changes will affect structure and function of ecological systems is unknown. We are conducting this work with mathematical modeling and manipulative snowmelt experiments, using black shade cloth to speed up snowmelt in multiple replicate plots. Pilot work in spring / summer 2017 at RMBL showed proof-of-concept for our experimental approach.

Effects of Accelerated Snowmelt on Pollination Network Structure and Functioning

How environmental changes will affect ecological network structure and functioning is a key question in the Anthropocene. Led by graduate students Xingwen Loy [internal link] and Connor Morozumi [internal link], we are investigating the effects of accelerated snowmelt—a key predicted effect of global climate change in montane systems—on pollination network structure and plant reproductive functioning, based at the Rocky Mountain Biological Laboratory. Climate change is particularly expected to lead to mismatches in the timing (phenology) of plants and pollinators, but whether and how these changes will affect structure and function of ecological systems is unknown. We are conducting this work with mathematical modeling and manipulative snowmelt experiments, using black shade cloth to speed up snowmelt in multiple replicate plots. Pilot work in spring / summer 2017 at RMBL showed proof-of-concept for our experimental approach.