title: Nutrient co-limitation of primary producer communities.
abstract: Synergistic interactions between multiple limiting resources are common, highlighting the importance of co-limitation as a constraint on primary production. Our concept of resource limitation has shifted over the past two decades from an earlier paradigm of single-resource limitation towards concepts of co-limitation by multiple resources, which are predicted by various theories. Herein, we summarise multiple-resource limitation responses in plant communities using a dataset of 641 studies that applied factorial addition of nitrogen (N) and phosphorus (P) in freshwater, marine and terrestrial systems. We found that more than half of the studies displayed some type of synergistic response to N and P addition. We found support for strict definitions of co-limitation in 28% of the studies: i.e. community biomass responded to only combined N and P addition, or to both N and P when added separately. Our results highlight the importance of interactions between N and P in regulating primary producer community biomass and point to the need for future studies that address the multiple mechanisms that could lead to different types of co-limitation.
authors.affiliation: Department of Ecology, Evolution and Organismal Biology, Iowa State University, 133 Bessey Hall, Ames, IA 50010, USA. harpole@iastate.edu
authors.forename: W Stanley
authors.initials: WS
authors.lastname: Harpole
authors.forename: Jacqueline T
authors.initials: JT
authors.lastname: Ngai
authors.forename: Elsa E
authors.initials: EE
authors.lastname: Cleland
authors.forename: Eric W
authors.initials: EW
authors.lastname: Seabloom
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Borer
authors.forename: Matthew E S
authors.initials: ME
authors.lastname: Bracken
authors.forename: James J
authors.initials: JJ
authors.lastname: Elser
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Gruner
authors.forename: Helmut
authors.initials: H
authors.lastname: Hillebrand
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Shurin
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Smith
mesh_terms: D018533:Biomass; D017753:Ecosystem; D005618:Fresh Water / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry; D012987:Soil / Q000737:chemistry
chemical_list: D012987:Soil; D010758:Phosphorus; D009584:Nitrogen