Letters to Nature

Nature 415, 68-71 (3 January 2002) | doi:10.1038/415068a; Received 20 September 2001; Accepted 8 November 2001

Resource-based niches provide a basis for plant species diversity and dominance in arctic tundra

Robert B. McKane1, Loretta C. Johnson2, Gaius R. Shaver3, Knute J. Nadelhoffer3, Edward B. Rastetter3, Brian Fry4, Anne E. Giblin3, Knut Kielland5, Bonnie L. Kwiatkowski3, James A. Laundre3 & Georgia Murray6

  1. US Environmental Protection Agency, Corvallis, Oregon 97333, USA
  2. Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
  3. The Ecosystems Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA
  4. Institute of Pacific Islands Forestry, USDA Forest Service, Honolulu, Hawaii 96813, USA
  5. Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska 99775, USA
  6. Appalachian Mountain Club, Gorham, New Hampshire 03581, USA

Correspondence to: Robert B. McKane1 Correspondence and requests for materials should be addressed to R.B.M. (e-mail: Email: mckane.bob@epa.gov).

Ecologists have long been intrigued by the ways co-occurring species divide limiting resources. Such resource partitioning, or niche differentiation, may promote species diversity by reducing competition1, 2. Although resource partitioning is an important determinant of species diversity and composition in animal communities3, its importance in structuring plant communities has been difficult to resolve4. This is due mainly to difficulties in studying how plants compete for belowground resources5. Here we provide evidence from a 15N-tracer field experiment showing that plant species in a nitrogen-limited, arctic tundra community were differentiated in timing, depth and chemical form of nitrogen uptake, and that species dominance was strongly correlated with uptake of the most available soil nitrogen forms. That is, the most productive species used the most abundant nitrogen forms, and less productive species used less abundant forms. To our knowledge, this is the first documentation that the composition of a plant community is related to partitioning of differentially available forms of a single limiting resource.