Research in the Albertson Lab investigates interactions between freshwater organism ecology and physical stream geomorphology. Using experiments, field surveys, and theoretical models, we study feedbacks between animals, sediment erosion, and flow regimes. We are also interested in the impacts of changing hydrology and species invasions on ecogeomorphic linkages.
Animals that influence erosion
Ecosystem engineers are organisms that modify or maintain their physical environment. We study the mechanisms that regulate where and when ecosystem engineers influence physical processes in stream habitats. We focus our research on aquatic animal engineers such as net-spinning hydropsychid caddisfly larvae (Trichoptera:Hydropsychidae). These insects weave silk threads together into a web that they use to filter-feed, much like a spider does in the air. The silk threads are attached to rocks on the riverbed and can bind together and stabilize sediment during floods. We seek to identify the biological (organism density, community composition, and species traits) and physical (grain size, discharge) thresholds where these types of biotic engineering effects are strongest.
Biotic interactions and physical processes
We investigate how interactions among individuals and species influence ecosystem
engineering effects of aquatic organisms on sediment erosion. Currently, we focus
on the role of competition, body size, and territorial behaviors in regulating how
strongly biotic engineers control processes related to erosion. The goal of this work
is to incorporate more realistic biological communities and species diversity into
predictive sediment transport models.
Changing flow regimes and aquatic communities
Hydrologic regimes are shifting worldwide due to a variety of factors related to climate change, damming, and agricultural diversions. As a result, many streams are experiencing low- or no-flow periods, particularly in the summer months. We are studying the impact of these low-flow periods on stream communities. Projects include the impact of drying on algal community recovery, architecture and silk properties of net-spinning caddisfly larvae (Hydropsychidae), and population dynamics of stoneflies (Pteronarcyidae).
Introduction of non-native species is one of the world's most pressing environmental problems. Many invasive species are ecosystem engineers, which are organisms that have a strong influence on the formation of their physical environment. Crayfish are one of the most widespread freshwater invaders that are known to engineer riverbeds through their foraging and burrowing activities. We are investigating how invasive Rusty crayfish (Orconectes rusticus) influence gravel sorting, fine sediment suspension, and riverbed topography using field and laboratory experiments.
Although a growing number of projects seek to restore degraded freshwater ecosystems, the biological and geomorphological factors driving the successful recovery of ecosystem functions in restoration sites remain unknown. We are investigating how the quality of woody debris added to streams during restoration projects influences aquatic macroinvertebrate recovery and community composition in areas that have historically been grazed by cattle. We also study how riparian land-use changes relate to stream temperature, food resource availability, and the phenology of aquatic organisms.
Stroud Water Research Center Film on Caddisfly Ecosystem Engineers
Montana State University Graduate Student Film on American Dippers
Montana State University Undergraduate Student Film on Microplastics in Rivers