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Graefe, S.; Hertel, D. &amp; Leuschner, C. (2010): <b>N, P and K limitation of fine root growth along an elevation transect in tropical mountain forests</b>. <i>Acta Oecologica</i> <b>36</b>, 537-542.

Resource Description

Title: N, P and K limitation of fine root growth along an elevation transect in tropical mountain forests
FOR816dw ID: 1271
Publication Date: 2010-09-01
License and Usage Rights: PAK 823-825 data user agreement. (www.tropicalmountainforest.org/dataagreementp3.do)
Resource Owner(s):
Individual: Sophie Graefe
Contact:
Individual: Dietrich Hertel
Contact:
Individual: Christoph Leuschner
Contact:
Abstract:
It is generally assumed that tree growth in tropical low-elevation forests is primarily limited by phosphorus<br/> while nitrogen limitation is more prominent in tropical montane forests where temperature is<br/> lower and the soils are poorly developed. We tested this hypothesis in mountain rainforests of South<br/> Ecuador by investigating the growth response of tree fine roots to N, P and K fertilization in ingrowth cores<br/> exposed at 1050 m (pre-montane) and 3060 m (upper montane) elevation. Root growth into unfertilized<br/> ingrowth cores (control treatment) was about 10 times slower at 3060 m than at 1050 m. At 1050 m, root<br/> growth was stimulated not only by P, but also by N and K. In contrast, N was the only element to promote<br/> root growth at 3060 m. The N concentration in fine root biomass dropped to nearly a third between 1050<br/> and 3060 m, those of P, K, Ca and Mg decreased as well, but to a lesser degree. According to a 15NO3<br/> 15NH4<br/> tracer study along the slope, tree fine roots accumulated nitrate and ammonium in root biomass at similar<br/> rates between 1050 and 3060 m, despite lower temperatures higher upslope.We conclude that the nature<br/> of nutrient limitation of tree fine root growth changes with elevation from an apparent co-limitation by<br/> P together with N and K at 1050 m to predominant N limitation at 3060 m, which is also reflected by low<br/> foliar N concentrations. Increasing N limitation may have caused the high fine root biomass and root/shoot<br/> ratio in the high elevation forest, while the capability of the roots to acquire mineral N apparently was not<br/> affected by lower temperatures at high elevations.
Keywords:
| nitrogen | phosphorus | potassium | nutrient limitation | ecuador | fine roots | 15N tracer study |
Literature type specific fields:
ARTICLE
Journal: Acta Oecologica
Volume: 36
Page Range: 537-542
Metadata Provider:
Individual: Sophie Graefe
Contact:
Online Distribution:
Download File: http://www.lcrs.de/publications.do?citid=1271


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