Ph.D. Candidate, University of Connecticut
Landscape-scale carbon biogeochemistry of beaver modification in New England
Conference Travel Grant Type 2
“Through their activity as ecosystem engineers, North American beavers (Castor canadensis) are anticipated to play an increasingly important role in the global carbon cycle as their populations expand. However, data on carbon gas dynamics from beaver-modified ecosystems is sparse, and broader trends in carbon dynamics across these spatially heterogeneous and seasonally variable ecosystems are poorly resolved. To examine trends in carbon biogeochemistry as water flows through beaver-modified habitat, we selected thirty beaver-modified ecosystems across southern New England to include in a spatial survey in late summer 2024, and chose a subset of five sites for twice-monthly temporal sampling from spring to early fall of 2025. At each beaver pond and associated inlet and outlet streams, we measured dissolved methane and carbon dioxide from surface water, alongside in situ surface water quality (temperature, pH, specific conductivity, and dissolved oxygen). In the spatial survey across all 30 sites, methane and carbon dioxide were highly variable, (ranging 5 and 3 orders of magnitude, respectively). Methane was seven times higher in ponds than inlets and slightly elevated in outlets. Likewise, carbon dioxide was twice as high in ponds than in inlets or outlets. Across both spatial survey and time series, water temperature tended to be higher in ponds and outlets, and dissolved oxygen was lower in ponds than inlets or outlets. Time series data show methane and carbon dioxide increasing as water temperature rises and as dissolved oxygen drops over the course of the growing season in beaver ponds. These results indicate that New England beaver ponds are active environments for anaerobic processes associated with carbon gas emissions, and next steps include investigating the underlying biotic processes involved in the carbon cycle within these ecosystems.”