, Volume 9, Issue 5, pp 711–724 | Cite as

Soil Characteristics and the Accumulation of Inorganic Nitrogen in an Arid Urban Ecosystem

  • Wei-Xing ZhuEmail author
  • Diane Hope
  • Corinna Gries
  • Nancy B. Grimm


Urbanization represents the extreme case of human influence on an ecosystem. Biogeochemical cycling of nitrogen (N) in cities is very different from that of non-urban landscapes due to the large input of reactive forms of N and the heterogeneous distribution of various land uses that alters landscape connections. To quantify the likely effects of human activities on soil N and other soil properties in urban ecosystems, we conducted a probability-based study to sample 203 plots randomly distributed over the 6,400 km2 Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) area, which encompasses metropolitan Phoenix with its 3.5 million inhabitants. Soil inorganic N concentrations were significantly higher in urban residential, non-residential, agricultural, transportation, and mixed sites than in the desert sites. Soil water content and organic matter were both significantly higher under urban and agricultural land uses, whereas bulk density was lower compared to undeveloped desert. We calculated that farming and urbanization on average had caused an accumulation of 7.23 g m−2 in soil inorganic N across the CAP study area. Average soil inorganic N of the sampled desert sites (3.23 g m−2) was much higher than the natural background level reported in the literature. Laboratory incubation studies showed that many urban soils exhibited net immobilization of inorganic N, whereas desert and agricultural soils showed small, but positive, net N mineralization. The large accumulation of inorganic N in soils (mostly as nitrate) was highly unusual in terrestrial ecosystems, suggesting that in this arid urban ecosystem, N is likely no longer the primary limiting resource affecting plants, but instead poses a threat to surface and groundwater contamination, and influences other N cycling processes such as denitrification.


urban land use soil nitrogen nitrate Central Arizona-Phoenix LTER 



This project is supported by the National Science Foundation Grant nos. DEB-9714833 and DEB-0423704. We are grateful to the entire 2000 sampling crew for their dedicated work both in the field and in the laboratory. We are indebted to the editors and reviewers for their constructive comments and suggestions. We thank Dr. Doug Green for providing consultation on soil sampling and soil processing and Dr. Jason Kaye for comments on writing. This paper is a contribution from the Central Arizona-Phoenix Long-Term Ecological Research Program.


  1. Aber J, McDowell W, Nadelhoffer K, Magill A, Berntson G, Kamakea M, McNulty S, Currie W, Rustad L, Fernandez I. 1998. Nitrogen saturation in temperate forest ecosystems: hypotheses revisited. Bioscience 48:921–34CrossRefGoogle Scholar
  2. Baker LA, Hope D, Xu Y, Edmonds J, Lauver L. 2001. Nitrogen balance for the central Arizona-Phoenix (CAP) ecosystem. Ecosystems 4:582–602CrossRefGoogle Scholar
  3. Boyle CA, Lavkulich L, Schreier H, Kiss E. 1997. Changes in land cover and subsequent effects on lower Fraser basin ecosystems from 1827 to 1990. Environ Manage 21:185–96PubMedCrossRefGoogle Scholar
  4. Collins JP, Kinzig AP, Grimm NB, Fagan WB, Hope D, Wu J, Borer ET. 2000. A new urban ecology. Am Sci 88:416–25CrossRefGoogle Scholar
  5. Effland WR, Pouyat RV. 1997. The genesis, classification, and mapping of soils in urban areas. Urban Ecosys 1:217–28CrossRefGoogle Scholar
  6. Elliott ET, Heill JW, Kelly EF, Monger HC. 1999. Soil structural and other physical properties. In: Robertson GP, Coleman DC, Bledsoe CS, Sollins P, Eds. Standard soil methods for long-term ecological research. New York: Oxford University PressGoogle Scholar
  7. Ellis AW, Hildebrandt ML, Fernando HJS. 1999. Evidence of lower-atmospheric ozone “sloshing” in an urbanized valley. Phys Geogr 20:520–36Google Scholar
  8. Ellis BA, Verfaillie JR, Kummerow J. 1983. Nutrient gain from wet and dry atmospheric deposition and rainfall acidity in southern California chaparral. Oecologia 60:118–21CrossRefGoogle Scholar
  9. Fenn ME, Haebuer R, Tonnesen GS, Baron JS, Grossman-Clarke S, Hope D, Jaffe DA, Copeland S, Geiser L, Rueth HM, Sickman JO. 2003a. Nitrogen emissions, deposition and monitoring in the Western United States. Bioscience 53:391–403CrossRefGoogle Scholar
  10. Fenn ME, Baron JS, Allen EB, Rueth HM, Nydick KR, Geiser L, Bowman WD, Sickman JO, Meixner T, Johnson DW, Neitlich P. 2003b. Ecological effects of nitrogen deposition in the western United States. Bioscience 53:404–20CrossRefGoogle Scholar
  11. Fisher SG, Grimm NB. 1985. Hydrologic and material budgets for a small Sonoran Desert watershed during three consecutive cloudburst floods. J Arid Environ 9:105–118Google Scholar
  12. Folke C, Jansson A, Larsson J, Costanza R. 1997. Ecosystem appropriation by cities. Ambio 26:167–72Google Scholar
  13. Grimm NB, Grove JM, Pickett STA, Redman CL. 2000. Integrated approaches to long-term studies of urban ecological systems. Bioscience 50:571–84CrossRefGoogle Scholar
  14. Hope D, Gries C, Zhu W, Fagan WF, Redman CL, Grimm NB, Nelson AL, Martin C, Kinzig A. 2003. Socioeconomics drive urban plant diversity. Proc Nat Acad Sci 100:8788–92PubMedCrossRefGoogle Scholar
  15. Hope D, Zhu W, Gries C, Oleson J, Kaye J, Grimm NB, Baker LA. 2005. Spatial variation in soil inorganic nitrogen across an arid urban ecosystem. Urban Ecosyst 8:251–273CrossRefGoogle Scholar
  16. Howarth RW, Billen G, Swaney D, Townsend A, Jaworski N, Lajtha K, Downing JA, Elmgren R, Caroco N, Jordan T, Berendse F, Freney J, Kudeyarov V, Murdoch P, Zhu ZL. 1996. Regional nitrogen budget and riverine N & P fluxes for the drainages to the North Atlantic Ocean: Natural and human influences. Biogeochemistry 35:75–139CrossRefGoogle Scholar
  17. Lovett GM, Traynor MM, Pouyat RV, Carreiro MM, Zhu WX, Baxter JW. 2000. Atmospheric deposition to oak forests along an urban–rural gradient. Environ Sci Technol 34:4294–300CrossRefGoogle Scholar
  18. Luck M, Wu JG. 2002. A gradient analysis of urban landscape pattern: a case study from the Phoenix metropolitan region, Arizona, USA. Lands Ecol 17:327–39CrossRefGoogle Scholar
  19. Luck MA, Jenerette GD, Wu J, Grimm NB. 2001. The urban funnel model and the spatially heterogeneous ecological footprint. Ecosystems 4:782–96CrossRefGoogle Scholar
  20. McDonnell MJ, Pickett STA. 1990. Ecosystem structure and function along urban–rural gradients: an unexploited opportunity for ecology. Ecology 71:1232–37CrossRefGoogle Scholar
  21. McDonnell MJ, Pickett STA. 1993. Humans as components of ecosystems: the ecology of subtle human effects and populated areas. Berlin Heidelberg, New York: SpringerGoogle Scholar
  22. McDonnell MJ, Pickett STA, Groffman P, Bohlen P, Pouyat RV, Zipperer WC, Parmelee RE, Carreiro MM, Medley K. 1997. Ecosystem processes along an urban-to-rural gradient. Urban Ecosyst 1:21–36CrossRefGoogle Scholar
  23. Mun HT, Whitford WG. 1989. Effects of nitrogen amendment on annual plants in the Chihuahuan Desert. Plant Soil 120:225–31CrossRefGoogle Scholar
  24. Padgett PE, Allen EB, Bytnerowicz A, Minich RA. 1999. Changes in soil inorganic nitrogen as related to atmospheric nitrogenous pollutants in southern California. Atmas Environ 33:769–81CrossRefGoogle Scholar
  25. Paul EA, Clark FE. 1996. Soil microbiology and biochemistry, 2nd ed. New York: AcademicGoogle Scholar
  26. Peterjohn WT, Schlesinger WH. 1990. Nitrogen loss from deserts in the southwestern United States. Biogeochemistry 10:67–79CrossRefGoogle Scholar
  27. Peterjohn WT, Schlesinger WH. 1991. Factors controlling denitrification in a Chihuahuan desert ecosystem. Soil Sci Soc Am J 55:1694–701CrossRefGoogle Scholar
  28. Peterson SA, Urquhart NS, Welch EB. 1999. Sample representativeness: a must for reliable regional lake condition estimates. Envrion Sci Technol 33:1559–65CrossRefGoogle Scholar
  29. Pickett STA, Cadenasso ML, Grove JM, Nilon CH, Pouyat RV, Zipperer WC, Costanza R. 2001. Urban ecological systems: linking terrestrial ecological, physical, and socioeconomic components of Metropolitan areas. Annu Rev Ecol Syst 32:127–57CrossRefGoogle Scholar
  30. Pouyat RV, Carreiro MM, McDonnell MJ, Pickett STA, Groffman PM, Parmelee RW, Medley KE, Zipperer WC. 1995. Carbon and nitrogen dynamics in oak stands along an urban–rural gradient. In: McFee WW, Kelly JM, Eds. Carbon forms and function in forest soils. Madison (Wisconsin, USA): Soil Science Society America, p 569–87Google Scholar
  31. Rebele F. 1994. Urban ecology and special features of urban ecosystems. Glob Ecol Biogeogr Lett 4:173–87CrossRefGoogle Scholar
  32. Reynolds JF, Viginia RA, Kemp PR, de Soyza AG, Tremmel DC. 1999. Impact of drought on desert shrubs: effects of seasonality and degree of resource island development. Ecol Monogr 69:60–106CrossRefGoogle Scholar
  33. Robertson GP, Wedin D, Groffman PM, Blair JM, Holland EA, Nadelhoffer KJ, Harris D. 1999. Soil carbon and nitrogen availability: nitrogen mineralization, nitrification, and soil respiration potentials. In: Robertson GP, Coleman DC, Bledsoe CS, Sollins P, Eds. Standard soil methods for long-term ecological research. New York: Oxford University PressGoogle Scholar
  34. Schlesinger WH, Gray JT, Gilliam FS. 1982. Atmospheric deposition processes and their importance as sources of nutrients in a chaparral ecosystem of southern California. Wat Res Res 18:623–29Google Scholar
  35. Schlesinger WH, Raikes JA, Hartley AE, Cross AF. 1996. On the spatial pattern of soil nutrients in desert ecosystems. Ecology 77:364–74CrossRefGoogle Scholar
  36. Stevens DL Jr. 1997. Variable density grid-based sampling designs for continuous spatial populations. Environmetrics 8:167–95CrossRefGoogle Scholar
  37. Townsend AR, Howarth RW, Bazzaz FA, Booth MS, Cleveland CC, Collinge SK, Dobson AP, Epstein PR, Keeney DR, Mallin MA, Rogers CA, Wayne P, Wolfe AH. 2003. Human health effects of a changing global nitrogen cycle. Front Ecol Environ 1:240–46Google Scholar
  38. Virginia RA, Jarrell WM, Franco-Vizcaino E. 1982. Direct measurement of denitrification in a Prosopis (Mesquite) dominated Sonoran desert ecosystem. Oecologia 53:120–22CrossRefGoogle Scholar
  39. Vitousek PM, Mooney HA, Lubchenco J, Melillo JM. 1997. Human domination of earth’s ecosystems. Science 277:494–9CrossRefGoogle Scholar
  40. Walvoord MA, Phillips FM, Stonestrom DA, Evans RD, Hartsough PC, Newman BD, Striegl RG. 2003. A reservoir of nitrate beneath desert soils. Science 302:1021–24PubMedCrossRefGoogle Scholar
  41. West NE, Klemmedson JO. 1978. Structural distribution of nitrogen in desert ecosystems. In: West NE, Skujins J, Eds. Nitrogen in desert ecosystems. Stroundsburg: Dowden, Hutchinson & Ross, pp 1–16Google Scholar
  42. Whitford WG. 2002. Ecology of desert systems. San Diego: AcademicGoogle Scholar
  43. Zar JH. 1999. Biostatistical analysis. Upper Saddle River (New Jersey): Prentice HallGoogle Scholar
  44. Zhu WX, Carriero MM. 2004. Temporal and spatial variations in nitrogen cycling in deciduous forest ecosystems along an urban-rural gradient. Soil Biol Biochem 36:267–78CrossRefGoogle Scholar
  45. Zhu WX, Dillard ND, Grimm NB. 2004. Urban nitrogen biogeochemistry: status and processes in green retention basins. Biogeochemistry 71:177–96CrossRefGoogle Scholar
  46. Zipperer WC, Wu J, Pouyat RV, Pickett STA. 2000. The application of ecological principles to urban and urbanization landscapes. Ecol Appl 10:685–88Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Wei-Xing Zhu
    • 1
    Email author
  • Diane Hope
    • 2
  • Corinna Gries
    • 2
  • Nancy B. Grimm
    • 3
  1. 1.Department of Biological SciencesState University of New York–BinghamtonBinghamtonUSA
  2. 2.Center for Environmental StudiesArizona State UniversityTempeUSA
  3. 3.School of Life SciencesArizona State UniversityTempeUSA

Personalised recommendations