Opposing effects of nitrogen versus phosphorus additions on mycorrhizal fungal abundance along an elevational gradient in tropical montane forests
Opposing effects of nitrogen versus phosphorus additions on mycorrhizal fungal abundance along an elevational gradient in tropical montane forests
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DOI：
10.1016/j.soilbio.2015.11.011
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发表时间：
2016-03-01
影响因子：
9.7
通讯作者：
Rillig, Matthias C.
中科院分区：
文献类型：
--
作者：
Camenzind, Tessa;Homeier, Juergen;Rillig, Matthias C.
在温带系统中的研究提供的证据表明，丰富的丛枝菌根真菌（AMF）取决于土壤养分的有效性，这主要是在资源化学计量和差异植物生物量分配的背景下解释。我们将这一概念应用于一个未充分研究的生态系统-热带山地森林-分析根和AMF丰度沿着海拔梯度与减少养分的可用性，结合响应氮（N）与磷（P）的添加。在海拔1000至3000米的三个地点，我们分析了细根长度，AMF根定殖以及根外AMF生物量（中性脂肪酸16：1 Ω 5，菌丝长度和孢子数）在营养操纵实验。我们发现一个显着增加根长以及根内和根外AMF丰度与海拔。总体而言，P的增加显着增加，而N的增加减少AMF丰度，差异，但非系统的变化沿着海拔梯度。在中间部位明显观察到最强的效应。这些研究结果表明，根和AMF的养分供应的一般依赖性，虽然反应的N和P添加不同，从以前的研究在温带系统。在未来的养分沉积的背景下，结果表明不同的AMF丰度的响应取决于网站的特点。(C)2015爱思唯尔有限公司版权所有。
Studies in temperate systems provide evidence that the abundance of arbuscular mycorrhizal fungal (AMF) depends on soil nutrient availability, which is mainly explained in the context of resource stoichiometry and differential plant biomass allocation. We applied this concept to an understudied ecosystem - tropical montane forest - analyzing root and AMF abundance along an elevational gradient with decreasing nutrient availability, combined with responses to nitrogen (N) versus phosphorus (P) additions. At three sites from 1000 to 3000 m above sea-level we analyzed fine root length, AMF root colonization as well as extraradical AMF biomass (neutral lipid fatty acid 16:1 omega 5, hyphal length and spore counts) in a nutrient manipulation experiment. We found a significant increase in root length as well as intra- and extraradical AMF abundance with elevation. Overall, P additions significantly increased, whereas N additions decreased AMF abundance, with differential though nonsystematic changes along the elevational gradient. Strongest effects were clearly observed at the intermediate site. These findings suggest a general dependency of roots and AMF on nutrient availability, though responses to N and P additions differed from previous studies in temperate systems. In the context of future nutrient depositions, results suggest diverging responses of AMF abundance depending on site characteristics. (C) 2015 Elsevier Ltd. All rights reserved.