Anthropogenic and Naturally-Occurring Ecosystem Subsidies

Anthropogenic activities and changes in land-use and landcover play critical roles in the terrestrial-aquatic linkages associated with the abundance and transport of ecosystem subsidies (e.g., leaf litter, woody debris) to river systems. Anthropogenic litter (e.g., human trash) has been documented in terrestrial, aquatic, and atmospheric systems, as well as in the animal food web, suggesting that these materials could be moving through ecosystems similarly to naturally-occurring ecosystem subsidies. Previous research in the literature has focused specifically on anthropogenic chemical contaminant subsidies; however, the ecological context of anthropogenic litter subsidies is understudied in the field. The McNeish lab aims to develop the predictive framework for understanding how environmental conditions and anthropogenic activities affect freshwaters and anthropogenic cross-system subsidies associated with ecosystem health and function ​

Restoration Ecology

Restoration ecology is the scientific study of understanding how to restore ecosystems. This requires conducting research at multiple ecological scales to develop our understanding of the ecological connections. The science of restoration ecology can be used to guide ecological restoration activities, the practice of restoring ecological systems. Several projects include efforts linked with invasive species removal, riparian restoration, and freshwater restoration.

Riparian Plant Invasion Impacts Terrestrial-Aquatic Linkages

Streams and adjacent terrestrial habitats (riparian zones) are interlinked by the transfer of resources between these two systems; hence, riparian forests are crucial interfaces between terrestrial and aquatic ecosystems. Changes in the quality and quantity of resources (e.g., leaf litter) moving between habitats can influence in-stream habitat availability, food resources, and nutrient dynamics that shape aquatic communities. Many riparian zones throughout the Midwest, USA are near-monocultures of the invasive Amur honeysuckle shrub, which creates dense canopies overarching headwater streams. This project focuses on characterizing how riparian invasion of Amur honeysuckle impacts terrestrial-aquatic connections in headwater streams via 1) the availability of plant organic matter that serves as habitat and food resources for aquatic organisms, 2) nutrient availability, and 3) aquatic macroinvertebrate community dynamics and functional trait patterns. This research uses riparian plant invasion to create a predictive framework for understanding how alterations in the terrestrial environment shape aquatic ecosystems and communities.  

Leaf Litter Influences Crayfish Behavior and Growth

Leaf litter from riparian forests serves as a critical habitat and food resource for fish and aquatic macroinvertebrates.  Plants produce chemical compounds that can suppress the growth and survivorship of competing plants and macroinvertebrates. Invasive plants tend to produce more of these chemicals compared to native plants, which can impact organisms that utilize leaves as a resource.  This project focuses on understanding how invasive leaf litter from Tree-of-Heaven (Ailanthus altissima) influences the invasive rusty crayfish (Orconectes rusticus) and the native Appalachian brook crayfish (Cambarus bartonii) antagonistic behavior and growth.

Rusty crayfish (Orconectes rusticus)