I headed down to sunny Ft. Lauderdale last week in blistering heat, poster tube in hand, excited to attend the 101st Ecological Society of America conference. The theme, Novel Ecosystems in the Anthropocene, is critical to understand at this point in human history. Overall, the sessions focused on the impacts of human activity on ecosystems, including altered species distribution and pollution, in the context of a rapidly changing climate.
This conference was a nice fit for presenting the first results from our current MItacs-funded research project, which is a study about the integration of soil respiration measurements using Forced Diffusion (FD) at eddy covariance sites. Ten eosFD soil respiration chambers are currently co-installed and measuring CO2 flux at Howland Forest (Maine, USA) alongside automated chambers. Please refer to a previous blog post for background details and some photos.
I presented during Friday morning’s Latebreaking poster session (Biogeochemistry), entitled: Economical, scalable measurements of soil respiration in eddy covariance footprints using forced diffusion. Our preliminary data demonstrated that the eosFD chambers were measuring fluxes on that matched the variability of the existing automated chambers.
During my poster session, I had the opportunity to speak with several ecologists who study soil respiration and organic matter decomposition, who asked some thoughtful questions about scaling soil respiration to the canopy spatial scale. These individuals were interested in the deployability of the eosFD and recognized the advantages of the low cost and potential for year-round measurements.
My favorite part of conferences are the potential for information exchange and invigorating conversations at conferences and my time at ESA certainly did not disappoint. On Thursday, I had the pleasure to attend a full day of sessions and posters. Especially interesting to me were the Biogeochemistry sessions. Here are two interesting ones that feature soil respiration measurements:
Daniel Potts, Torri Ivancic, Kelly Delp, Robert Warren
Soil moisture dynamics and carbon metabolism in a greenroof ecosystem
Ever wondered about the ecosystem functioning of greenroof systems that control stormwater flow, constructed from lightweight “soil” and resilient stonecrop vegetation? At the SUNY (Buffalo), they took advantage of this novel ecosystem to carefully determine the effect of moisture on carbon cycling. With a carefully controlled setup, they measured photosynthesis and soil respiration using automated chambers in this novel ecosystem and calculated GEE (difference between the C uptake and C release). They found that a wide range of soil moisture produced predictable increases in soil respiration, with a consistent temperature optimum, and that C metabolism was highly responsive to rainfall events in this novel ecosystem.
Whendee Silver and Christine O’Connell
Drought in the rainforest: Biogeochemical responses and feedbacks to climate change
What happens when the rainforest dries? As we face a more variable climate, it is important to consider the effects of changing typical precipitation patterns in areas like rainforests, which are critical ecosystems to consider: they exchange vast quantities of C (and are known as the lungs of our planet). Whendee Silver and colleagues took advantage of an historic drought in 2015 to ask questions about how the system responds to a reduction in moisture, in a study area set up to examine changes to C cycling. This research setup also houses several of Eosense’s eosAC automated chambers which measure C exchange with high temporal resolution. Soil moisture and soil O2 altered soil respiration, and exhibited a threshold response to recovery from drought (i.e. responded only when the soil was wet enough), with a long recovery back to pre-drought conditions (known as hysteresis). They noticed that rainforests also responded to drought with changes in soil Fe which has impacts on soil nutrient availability – and with switches in CH4 fluxes that depended on moisture. These results are important to integrate into our understanding about ecosystems as they are being pushed beyond the typical climate regime.
I had a great time at ESA 2016 conference in Ft. Lauderdale, and was exposed to some new ideas, new faces, and new scenery. Thanks to all who came by to ask me about our research – it was my pleasure.
In several months we’ll be heading back down South to the West coast to AGU in December. We will have more data to present, so please watch for our poster!