Summary

Launched in 2006 with support from the National Science Foundation and leveraged by CAP LTER, the Carbon and Nitrogen deposition project sought to answer 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 this 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 five locations based in desert preserves within the urban core. 

In addition to the gradient of atmospheric deposition in and around the urban core, select study plots at each of the15 desert locations receive amendments of nitrogen, phosphorus or a nitrogen and 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, CAP LTER assumed responsibility for the project. It was renamed the desert fertilization experiment and provides a remarkable platform to study the long-term effects of nutrient enrichment on ecosystem properties.

Map tiles by Stamen Design, under CC BY 3.0. Data by OpenStreetMap, under ODbL.

Publications

  • Wheeler, M. M., S. L. Collins, N. B. Grimm, E. M. Cook, C. Clark, R. A. Sponseller and S. J. Hall. 2021. Water and nitrogen shape winter annual plant diversity and community composition in near-urban Sonoran Desert preserves. Ecological Monographs 91(3):e01459. DOI: 10.1002/ecm.1450.
  • Ball, B. A., M. P. Christman and S. J. Hall. 2019. Nutrient dynamics during photodegradation of plant litter in the Sonoran Desert. Journal of Arid Environments 160(Jan):1-10. DOI: 10.1016/j.jaridenv.2018.09.004.
  • Cook, E. M., R. A. Sponseller, N. B. Grimm and S. J. Hall. 2018. Mixed method approach to assess atmospheric nitrogen deposition in arid and semi-arid ecosystems. Environmental Pollution 239(Aug):617-630. DOI: 10.1016/j.envpol.2018.04.013.
  • Marusenko, Y. Y., F. Garcia-Pichel and S. J. Hall. 2015. Ammonia-oxidizing archaea respond positively to inorganic nitrogen addition in desert soils. FEMS Microbiology Ecology 91(2):1-11. DOI: 10.1093/femsec/fiu023.
  • Ball, B. A. and J. Alvarez Guevara. 2015. The nutrient plasticity of moss-dominated crust in the urbanized Sonoran Desert. Plant and Soil 389(1):225-235. DOI: 10.1007/s11104-014-2355-7.
  • Davis, M. K., E. M. Cook, S. L. Collins and S. J. Hall. 2015. Top-down vs. bottom-up regulation of herbaceous primary production and composition in an arid, urbanizing ecosystem. Journal of Arid Environments 116:103-114. DOI: 10.1016/j.jaridenv.2015.01.018.
  • Sponseller, R. A., S. J. Hall, D. P. Huber, N. B. Grimm, J. P. Kaye, C. M. Clark and S. L. Collins. 2012. Variation in monsoon precipitation drives spatial and temporal patterns of Larrea tridentata growth in the Sonoran Desert. Functional Ecology 26(3):750-758. DOI: 10.1111/j.1365-2435.2012.01979.x.
  • Hall, S. J., R. A. Sponseller, N. B. Grimm, D. P. Huber, J. P. Kaye, C. F. Clark and S. L. Collins. 2011. Ecosystem response to nutrient enrichment across an urban airshed in the Sonoran Desert. Ecological Applications 21(3):640-660. DOI: 10.1890/10-0758.1
  • Kaye, J. P., S. E. Eckert, D. A. Gonzales, J. O. Allen, S. J. Hall, R. A. Sponseller and N. B. Grimm. 2011. Decomposition of urban atmospheric carbon in Sonoran Desert soils. Urban Ecosystems 4:737-754. DOI: 10.1007/s11252-011-0173-8.
  • Hall, S. J., B. Ahmed, P. Ortiz, R. C. Davies, R. A. Sponseller and N. B. Grimm. 2009. Urbanization alters soil microbial functioning in the Sonoran Desert. Ecosystems 12(4):654-671. DOI: 10.1007/s10021-009-9249-1.
  • McCrackin, M. L., T. K. Harms, N. B. Grimm, S. J. Hall and J. P. Kaye. 2008. Responses of soil microorganisms to resource availability in urban, desert soils. Biogeochemistry 87(2):143-155. DOI: 10.1007/s10533-007-9173-4.