Ecosystem Transformation
Ecological transformations, also known as state changes, regime shifts or vegetation type conversions, can be caused by many different disturbances including wildfire, climate change, and invasive species, as well as interactions between these drivers (Guiterman et al. 2022; Kerns et al. 2020; Gaertner et al. 2014). Examples of invasive species-mediated transformations in the western US can be seen via the spread of invasive grasses (e.g., cheatgrass, medusahead, ventenata, and bufflegrass) into sagebrush steppe and forest systems (Bradley et al. 2006; Kerns et al 2020). However, The carbon consequences of such transformations are not well documented. In this project, we will 1) generate novel, co-produced research on where in the North Central US ecosystems have experienced transformation due to invasive species and climate change, 2) quantify carbon consequences of this change, and 3) evaluate management practices that enhance carbon storage and improve resilience by engaging the NC RISCC network.
Effects of Ecological Transformation on Wildlife Communities
Many land managers and ecologists are watching terrestrial ecosystems rapidly transform under novel stressors like climate change, altered disturbance regimes, and biological invasions. Across woodlands, grasslands, and aridlands, transformations pose serious threats to biodiversity and human wellbeing. Although we know that higher trophic levels are affected by habitat change, most contemporary work on climate-mediated ecological transformation focuses on shifts in dominant vegetation, with animal communities receiving comparatively little attention for their roles in and responses to transformation. In an ongoing NC-RISCC project, we are assessing how transformation of sagebrush-steppe to exotic annual grasslands affects native songbirds across the sagebrush biome using biome-wide survey data for 40 species alongside remote sensing, occupancy modeling, and causal inference. We are seeing that transformation is driving an ongoing turnover of songbird communities, which is driven by differential impacts of annual grasses among species and guilds. We are also identifying possible regions for effective conservation of species affected by transformation. Our research thus provides evidence that animal communities are transforming alongside vegetation and offers insight into the approaches required to quantify nascent community turnover.