Mean - Variance Experiment sample archives

We designed novel field experimental infrastructure to resolve the relative importance and interactions among changes in precipitation mean and variance in regulating the structure and function of dryland populations, communities, and ecosystem processes. The Mean x Variance Experiment (MVE) adds three novel elements to prior designs (Gherardi & Sala 2013) that have manipulated interannual variance in climate in the field by (i) determining interactive effects of mean and variance in a factorial design that crosses a drier mean with increased (more) variance, (ii) studying multiple dryland ecosystem types to compare their susceptibility to transition under interactive climate drivers, and (iii) adding stochasticity to our treatments to permit the antecedent effects that occur under natural climate variability. This new infrastructure enables direct experimental tests of the hypothesis that interactions between the mean and variance of precipitation will have larger ecological impacts than either the mean or variance in precipitation alone.
We collected samples of soils, biological soil crusts, leaves of the foundation plant species, and roots of the two dominant grass species each year during peak productivity (September-October).
These samples enable us to address the question: How do interactions between the mean and variance of precipitation alter the biogeochemistry and microbiomes of plants and soils.
This data package includes accession numbers for all samples collected from the Mean x Variance Experiment at the Sevilleta National Wildlife Refuge, Socorro, NM.