Wildfires and Lake Characteristics May Influence Zooplankton Communities in the Yukon-Kuskokwim Delta, Alaska
Abstract
Tundra ecosystems, which are vital to global carbon budgets, are experiencing increasingly frequent wildfires. Wildfires can substantially alter terrestrial ecosystem nutrient dynamics through combustion of vegetation and organic soils as well as through fire-induced permafrost thaw. Growing evidence suggests that aquatic systems can also be heavily impacted by tundra wildfire through the solute-rich runoff from recently burned and thawed areas. It remains unclear, however, what impact fires will have on the biodiversity of these environments and the interplay between carbon and nutrient cycling. To understand these impacts we characterized the pelagic communities of lakes in burned and unburned areas to assess how water quality may affect food webs in Alaska's Yukon-Kuskokwim Delta. Zooplankton (small heterotrophs mostly made up of crustacea) function as an essential link between primary producers and higher trophic levels, and changes in their abundance and diversity can be seen as a key indicator for environmental changes. We sampled zooplankton from 11 lakes in the Yukon-Kuskokwim Delta within watersheds that burned in 2015 (n= 4), 1972 (n= 3) and in unburned areas (n= 4). We used multivariate analyses to correlate zooplankton community composition to environmental factors including inorganic phosphorus and nitrogen concentrations, total dissolved nitrogen, dissolved organic carbon, chlorophyll concentrations, dissolved oxygen, pH and lake temperature. Although we detected no differences in zooplankton abundance across burn histories, there were distinct clusters of zooplankton communities from lakes with different burn histories. Zooplankton are highly susceptible to changes in environmental conditions and understanding potential responses to disturbances like tundra wildfires will allow us to extrapolate effects to the larger tundra ecosystem and other drivers of landscape change.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.B52I0977F