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Dietrich, K.; Sp&ouml;ri, E. &amp; Oelmann, Y. (2016): <b>Nutrient addition modifies phosphatase activities along an altitudinal gradient in a tropical montane forest in Southern Ecuador</b>. <i>Frontiers in Earth Science</i> <b>4</b>, 1-9.

Resource Description

Title: Nutrient addition modifies phosphatase activities along an altitudinal gradient in a tropical montane forest in Southern Ecuador
FOR816dw ID: 1468
Publication Date: 2016-02-15
License and Usage Rights: PAK 823-825 data user agreement. (www.tropicalmountainforest.org/dataagreementp3.do)
Resource Owner(s):
Individual: Karla Dietrich
Contact:
Individual: Elena Spöri
Contact:
Individual: Yvonne Oelmann
Contact:
Abstract:
Atmospheric nutrient deposition and climate change are expected to endanger the diversity of tropical forest ecosystems. Nitrogen (N) deposition might influence nutrient fluxes beyond the N cycle by a concomitant increased demand for other nutritional elements such as phosphorus (P). Organisms might respond to the increased P demand by enhanced activity of enzymes involved in releasing inorganic P from organic matter (OM). Our aims were to assess the effect of i) climate shifts (approximated by an altitudinal gradient), and ii) nutrient addition (N, P, N+P) on phosphatase activity (PA) in organic layer and mineral soil of a tropical montane rainforest in Southern Ecuador. A nutrient manipulation experiment (NUMEX) was set up along an altitudinal gradient (1000, 2000, and 3000 m a.s.l.). We determined PA and inorganic and total P concentrations. PA at 1000 m was significantly lower (mean ± standard error: 48 ± 20 µmol p-NP g-1 dm h-1) as compared to 2000 m and 3000 m (119 ± 11 and 137 ± 19, respectively). One explanation might be that very rapid decomposition of OM at 1000 m results in very thin organic layers reducing the stabilization of enzymes and thus, resulting in leaching loss of enzymes under the humid tropical climate. We found no effect of N addition on PA neither in the organic layer nor in mineral soil, probably because of the low nutrient addition rates that showed ambiguous results so far on productivity measures as a proxy for P demand. In the organic layers of P and N+P treatments, we found decreased PA and increased concentrations of inorganic P. This indicates that the surplus of inorganic P reduced the biosynthesis of phosphatase enzymes. PA in megadiverse montane rainforests is likely to be unaffected by increased atmospheric N deposition but reduced upon atmospheric P deposition.
Keywords:
| Ecuador | NUMEX | phosphorus | fertilization | tropical montane forest | phosphatase activity |
Literature type specific fields:
ARTICLE
Journal: Frontiers in Earth Science
Volume: 4
Page Range: 1-9
Metadata Provider:
Individual: Karla Dietrich
Contact:
Online Distribution:
Download File: http://www.tropicalmountainforest.org/publications.do?citid=1468


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