Lab trip to Biosphere 2, Arizona (continued...)

Lab trip continued...

We’re hard at work down here at Biosphere 2 (while also enjoying the delights of an unseasonably warm Arizonan January). We have been spending some time analyzing soil moisture and water potential data from test-runs of ‘mini-LEO’ – a newly-built, 1 m3 sand box model of a hillslope. These results are helping us to fine-tune our questions for an experiment that will begin on Monday. The experiment will test the hypothesis that groundwater ridging causes rapid delivery of large volumes of old water from the hillslope subsurface to the stream. We also helped with measuring the spatial distribution of rainfall patterns over one of the three LEO hillslopes, to help guide the set-up of the rainfall sprinkler system (left photo).

Meanwhile, we are also devising some ideas for future ecohydrology research in the 25-year old rainforest biome here at Biosphere 2 with Joost van Haren. With Jaivime’s lead, we’re hoping to test for the existence of the ‘two water worlds’ hypothesis in this environment; and also, during a simulated drought in the biome, to determine how water-stressed conditions affects the depth of plant water uptake by roots. Next week, we will be taking preliminary rainfall and subsurface outflow samples, vegetation samples from the tree canopy, and soil samples from the three soil pits (right photo).

We’ve also had other visitors to Biosphere 2, including Scott Jasechko, a PhD student from the University of New Mexico. Scott gave a talk on his analysis of a global-scale compilation of river, lake and groundwater chemistry data. Specifically, his research focuses on separating evapotranspiration into fluxes of evaporation and transpiration using a global dataset of water isotope data. We’re looking forward to having Scott work with us in Saskatoon for three months from April 2014.

That’s all, for now. More updates to follow soon on our experimental goings-on (and maybe some photos of an upcoming lab trip to the Grand Canyon).

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