Canopy volume:aboveground biomass relationships of desert perennials and the effects of elevated CO2

We measured canopy volume and aboveground biomass for 22 species of perennial plants in the Mojave Desert, USA, at the Nevada Desert FACE Facility (NDFF): four species before treatment and 22 species after ten years (1997-2007) of elevated [CO2]. Canopy volume to aboveground biomass allometry was estimated for each of the nine most common species individually; the remaining 13 species, unidentifiable living plants, and unidentified dead shrubs combined to form a single ‘other’ group. The resulting slopes and intercepts, which were estimated using a robust version of major axis regression, were compared across treatments and time points. None of the species had altered allometry in elevated [CO2] compared to ambient [CO2] treatments, nor did the relationships change over time. Data for each species were therefore combined across treatments and time points to provide the best available predictive equations relating canopy volume and aboveground biomass. The data set contains the canopy volume and aboveground biomass for all 3,702 individual plants which were measured. We provide the regression coefficients relating canopy volume to aboveground biomass for both treatment and time comparisons and a single equation which predicts aboveground biomass from canopy volume for each species group. The most notable limitation of this data set is that the maximum plant size at this site may be smaller than at other locations with the same species. Our results suggest that aboveground biomass for desert perennial plants in elevated [CO2] conditions may be reasonably estimated from the allometry of plants under ambient [CO2]. This data set is associated with Vanier et al. 2013. Ecology 94:2656 and Ecological Archives E094-246.