Effects of nutrient manipulation (NUMEX) on nutrient use and carbon allocation of Andean forests: Stand level response and the performance of single tree species

养分操纵（NUMEX）对安第斯森林养分利用和碳分配的影响：林分水平响应和单一树种的表现

• 批准号: 36004341
• 负责人: Dr. Jürgen Homeier
• 金额: --
• 依托单位: Fakultät Ressourcenmanagement
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/36004341?language=en
• 关键词: Effects; nutrient; manipulation; NUMEX; use

Human activities will globally affect the cycles of N and P during the coming decades, both elements are of major importance for the productivity of plant communities. But it is not sufficiently understood how tropical forests will respond, particularly with regard to the expected increase of atmospheric N deposition. Although these forests store large amounts of carbon their quantitative role in the global carbon cycle remains uncertain, especially the contribution of montane tropical forests is unclear. This project combines experimental and descriptive studies along an elevational transect (1000 to 3000 m asl) of Andean forests to investigate (A) the natural variation of aboveground biomass and productivity related to nutrient availability and elevation, (B) the influence of tree functional traits on stand productivity, and, in the experimental part, the effects of continued nutrient addition (C) on the aboveground forest productivity and carbon allocation at the stand level, (D) on the tree seedling assemblage (establishment and species composition) and thereby the future species composition, and (E) on the growth performance and nutrient allocation of key species (mature trees and seedlings). The approaches (A) and (B) will be studied in the existing environmental matrix of 54 permanent forest plots, covering a wide range of site conditions. The effects of continued nutrient addition (C-E) will be investigated within the ongoing N and P addition experiment (Numex), that started in January 2008 (adding moderate amounts of N (50 kg ha-1 yr-1), P (10 kg ha-1 yr-1), and N and P to representative forest stands).

在未来的几十年里，人类活动将在全球范围内影响N和P的循环，这两个元素对植物群落的生产力至关重要。但是，人们还没有充分了解热带森林将如何作出反应，特别是在大气氮沉降的预期增加方面。虽然这些森林储存了大量的碳，但它们在全球碳循环中的数量作用仍然不确定，特别是山地热带森林的贡献尚不清楚。这个项目结合了沿沿着一条高程样带的实验性和描述性研究（海拔1000至3000米）的安第斯森林，以调查（A）与养分有效性和海拔有关的地上生物量和生产力的自然变化，（B）树木功能性状对林分生产力的影响，在实验部分，养分持续添加（C）对林分地上生产力和碳分配的影响，（D）对苗木组合的影响（E）关于关键物种（成熟树木和幼苗）的生长表现和养分分配。将在现有的54块永久性林地的环境矩阵中研究方法（A）和（B），这些森林包括各种各样的立地条件。将在2008年1月开始的氮和磷添加试验（Numex）中研究持续添加养分（C-E）的影响（向代表性林分添加适量的氮（50千克公顷/年）、磷（10千克公顷/年）以及氮和磷）。