Interactions among nitrogen fixation and soil phosphorus acquisition strategies in lowland tropical rain forests. (28th July 2014)

• Record Type: Journal Article
• Authors: Nasto, Megan K.; Alvarez‐Clare, Silvia; Lekberg, Ylva; Sullivan, Benjamin W.; Townsend, Alan R.; Cleveland, Cory C.; Johnson, Nancy
• Is Part Of: Ecology letters. Volume 17:Number 10(2014:Oct.)
• Page Start: 1282
• Page End: 1289
• Publication Date: 2014-07-28
• Subjects: Ecology -- Periodicals; 577
• DOI: 10.1111/ele.12335
• Languages: English
• ISSNs: 1461-023X

Abstract

<abstract abstract-type="main" id="ele12335-abs-0001"> <title>Abstract</title> <p>Paradoxically, symbiotic dinitrogen (N₂) fixers are abundant in nitrogen (N)‐rich, phosphorus (P)‐poor lowland tropical rain forests. One hypothesis to explain this pattern states that N₂ fixers have an advantage in acquiring soil P by producing more N‐rich enzymes (phosphatases) that mineralise organic P than non‐N₂ fixers. We assessed soil and root phosphatase activity between fixers and non‐fixers in two lowland tropical rain forest sites, but also addressed the hypothesis that arbuscular mycorrhizal (AM) colonisation (another P acquisition strategy) is greater on fixers than non‐fixers. Root phosphatase activity and AM colonisation were higher for fixers than non‐fixers, and strong correlations between AM colonisation and N₂ fixation at both sites suggest that the N–P interactions mediated by fixers may generally apply across tropical forests. We suggest that phosphatase enzymes and AM fungi enhance the capacity of N₂ fixers to acquire soil P, thus contributing to their high abundance in tropical forests.</p> </abstract>