title: Relationships among net primary productivity, nutrients and climate in tropical rain forest: a pan-tropical analysis.
abstract: Tropical rain forests play a dominant role in global biosphere-atmosphere CO(2) exchange. Although climate and nutrient availability regulate net primary production (NPP) and decomposition in all terrestrial ecosystems, the nature and extent of such controls in tropical forests remain poorly resolved. We conducted a meta-analysis of carbon-nutrient-climate relationships in 113 sites across the tropical forest biome. Our analyses showed that mean annual temperature was the strongest predictor of aboveground NPP (ANPP) across all tropical forests, but this relationship was driven by distinct temperature differences between upland and lowland forests. Within lowland forests (< 1000 m), a regression tree analysis revealed that foliar and soil-based measurements of phosphorus (P) were the only variables that explained a significant proportion of the variation in ANPP, although the relationships were weak. However, foliar P, foliar nitrogen (N), litter decomposition rate (k), soil N and soil respiration were all directly related with total surface (0-10 cm) soil P concentrations. Our analysis provides some evidence that P availability regulates NPP and other ecosystem processes in lowland tropical forests, but more importantly, underscores the need for a series of large-scale nutrient manipulations - especially in lowland forests - to elucidate the most important nutrient interactions and controls.
authors.affiliation: Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT 59812, USA. cory.cleveland@umontana.edu
authors.forename: Cory C
authors.initials: CC
authors.lastname: Cleveland
authors.forename: Alan R
authors.initials: AR
authors.lastname: Townsend
authors.forename: Philip
authors.initials: P
authors.lastname: Taylor
authors.forename: Silvia
authors.initials: S
authors.lastname: Alvarez-Clare
authors.forename: Mercedes M C
authors.initials: MM
authors.lastname: Bustamante
authors.forename: George
authors.initials: G
authors.lastname: Chuyong
authors.forename: Solomon Z
authors.initials: SZ
authors.lastname: Dobrowski
authors.forename: Pauline
authors.initials: P
authors.lastname: Grierson
authors.forename: Kyle E
authors.initials: KE
authors.lastname: Harms
authors.forename: Benjamin Z
authors.initials: BZ
authors.lastname: Houlton
authors.forename: Alison
authors.initials: A
authors.lastname: Marklein
authors.forename: William
authors.initials: W
authors.lastname: Parton
authors.forename: Stephen
authors.initials: S
authors.lastname: Porder
authors.forename: Sasha C
authors.initials: SC
authors.lastname: Reed
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Sierra
authors.forename: Whendee L
authors.initials: WL
authors.lastname: Silver
authors.forename: Edmund V J
authors.initials: EV
authors.lastname: Tanner
authors.forename: William R
authors.initials: WR
authors.lastname: Wieder
mesh_terms: D002244:Carbon / Q000378:metabolism; D057486:Carbon Cycle; D017753:Ecosystem; D009584:Nitrogen / Q000378:metabolism*; D009747:Nutritional Physiological Phenomena; D010758:Phosphorus / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D018521:Plant Physiological Phenomena; D012044:Regression Analysis; D012987:Soil / Q000737:chemistry; D014197:Trees / Q000378:metabolism / Q000502:physiology; D014329:Tropical Climate
chemical_list: D012987:Soil; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen