OPS 2-9
NEON Aquatic Program: Tools for large river ecology
The National Ecological Observatory Network (NEON) is a national-scale research platform designed to assess the impacts of climate change, land-use change, and invasive species on ecosystem structure and function. The NEON Aquatic program will produce over 200 data products at each of its 36 sites for 30 years to facilitate spatiotemporal analysis of the drivers of ecosystem change using a combination of continuous in situ measurements and observational sampling. While the majority of aquatic sites are wadeable streams and lakes, four river sites will also be constructed. Two large river sites in Alabama were chosen to address the question of an eco-hydrologic gradient spanning the watershed from headwater stream to navigable river. Continuous measurements includes surface water physical, chemical and biological parameters (PAR, level, temperature, conductivity, pH, DO, nitrate, turbidity, Chl a, cDOM), groundwater level, temperature and conductivity and local meteorological parameters (air temperature, wind speed and direction, PAR, net radiation, barometric pressure). Observational sampling includes bathymetry, water chemistry and isotopes and a suite of organismal sampling from microbes to macroinvertebrates. We deployed an anchored buoy in July of 2013 to collect preliminary data as part of our site characterization process to guide our sampling and deployment strategy.
Results/Conclusions
Currently we have collected a 14-week time series of the temperature and light intensity profile in the Black Warrior River near Demopolis, AL. These data show strong diurnal fluctuations in temperature across the water column. A tenuous thermocline develops near 3 meters water depth over diurnal to subweekly timescales as a result of solar insolation and meteorological conditions. Temperature has a large effect on gas solubility as well as chemical and biological processes. The Black Warrior is highly turbid and light intensity is greatly diminished beyond 1 meter depth reducing primary productivity, which with increasing surface water temperature drive down the concentration of dissolved oxygen. These results help to guide the aquatic observational sampling strategy and placement of sensor installations. The long-term data collected by NEON will be freely available to the public allowing researchers to investigate the drivers of temporal and spatial variability in biogeochemistry and eco-hydrology in this river system. Additional data will be collected from nearby NEON terrestrial sites that will allow integration of data at the watershed level.