Excavating what looks like a giant shoe box was my first "field site" role at Biosphere 2. Today marked the end of the second phase of excavation of miniLEO. The miniLEO, easily put, is a lysimeter and a smaller scaled down version of the Landscape Evolution Observatory (LEO) hillslopes housed at Biosphere 2.
Using miniLEO as a system, an interdisciplinary team of microbiologists, hydrologists, and geochemists came together to understand landscape evolution, under alternate wetting and drying precipitation regimes. My role is to identify microbial community dynamics across the length and depth of the slope, as affected by hydrological flowpaths and geochemical weathering. The excavation was challenging to say the least. Sampling had to be done in a manner to ensure we did not compromise the quality of samples collected. Needless to say, team effort played a huge role. A hydrology and a geochemistry PhD student, and I, a soil microbial ecologist postdoc meticuluously planned out the excavation plan. We also periodically received helped from two undergraduates and two graduate studetns. And of course, there was lots of coffee. We essentially worked 12 hours on site each day and spent atleast an hour every night reviewing our work from that day and revising our excavation plans for the next day.
While for the first phase, we concentrated on getting the excavation technique right, the second phase got challenging due to the slope of miniLEO. Also, the deeper we went depth wise, the more challenging it got to retreive the samples. But we managed to get to the end of it (quite literally!). We sampled over a period of 10 days! Now the next thing is to analyze all the samples we have, and hold your breath...each one of us as 400 samples! So there are 400 each of microbio sample, geochemical sample, bulk density sample, and horizontal and vertical hydraulic conductivity samples. And while we plan out the best way to coordinate our data analyses steps, and work on a methods manuscript detailing our excavation, here are some pictures!
