Desert Fertilization Experiment: ecosystem response to nutrient enrichment across an urban airshed in the Sonoran desert

Launched in 2006 with support from the National Science Foundation (NSF) and leveraged by the CAP LTER, the Carbon and Nitrogen deposition (CNdep) project sought to answer the fundamental question of whether elemental cycles in urban ecosystems are qualitatively different from those in non-urban ecosystems. Ecosystem scientists, atmospheric chemists, and biogeochemists tested the hypothesis that distinct biogeochemical pathways result from elevated inorganic nitrogen and organic carbon deposition from the atmosphere to the land. To test the hypothesis, scientists examined the responsiveness of Sonoran desert ecosystems to nutrient enrichment by capitalizing on a gradient of atmospheric deposition in and around the greater Phoenix metropolitan area. Fifteen desert study sites were established, with five locations each west and east of the urban core, and in the urban core in desert preserves. In addition to the gradient of atmospheric deposition in and around the urban core, select study plots at each of the fifteen desert locations receive amendments of nitrogen, phosphorus, or nitrogen + phosphorus fertilizer. Measured variables include soil properties, perennial and annual plant growth, and atmospheric deposition of nitrogen. At the close of the initial grant period, the CAP LTER assumed responsibility for the project, renamed the Desert Fertilization Experiment, which provides a remarkable platform to study the long-term effects of nutrient enrichment on ecosystem properties. This data set features an amalgamation of data from the CAP LTER's long-term Desert Fertilization Experiment. The data presented here bring together many aspects of the project, and are featured in several papers, notably Hall et al. 2009 and 2011, and Sponseller et al. 2012. Investigators interested in other and more recent data from the CAP LTER's long-term Desert Fertilization Experiment should search the data repository for 'desert fertilization experiment'. Citations: Hall, S. J., B. Ahmed, P. Ortiz, R. Davies, R. A. Sponseller, and N. B. Grimm. 2009. Urbanization alters soil microbial functioning in the Sonoran Desert. Ecosystems 12:654.671. https://doi.org/10.1007/s10021-009-9249-1 Hall, S. J., R. A. Sponseller, N. B. Grimm, D. Huber, J. P. Kaye, C. Clark, and S. L. Collins. 2011. Ecosystem response to nutrient enrichment across an urban airshed in the Sonoran Desert. Ecological Applications 21:640-660. doi:10.1890/10-0758.1 Sponseller, R. A., S. J. Hall, D. Huber, N. B. Grimm, J. P. Kaye, C. Clark, and S. Collins. 2012. Variation in monsoon precipitation drives spatial and temporal patterns of Larrea tridentata growth in the Sonoran Desert. Functional Ecology, DOI 10.1111/j.1365-2435.2012.01979.x.