Pedogenesis, permafrost, and soil moisture as controlling factors for soil nitrogen and carbon contents across the Tibetan Plateau
Pedogenesis, permafrost, and soil moisture as controlling factors for soil nitrogen and carbon contents across the Tibetan Plateau
复制标题
成土作用、多年冻土和土壤湿度是青藏高原土壤氮和碳含量的控制因素
DOI：
10.1111/j.1365-2486.2009.01953.x
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发表时间：
2009-12-01
影响因子：
11.6
通讯作者：
Scholten, Thomas
中科院分区：
文献类型：
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作者：
Baumann, Frank;He, Jin-Sheng;Scholten, Thomas
在青藏高原中东部高海拔低纬度多年冻土区沿着1200 km样带的47个样点上，研究了影响土壤有机碳（Corg）、土壤全氮（Nt）和植物有效氮（Nmin）的主要参数（年平均气温、年平均土壤温度、年平均降水量、土壤水分（SM）、土壤化学和物理）。这一大规模的调查允许测试的假设，除了常用的生态变量，成土作用的多样性是另一个主要组成部分，用于评估碳（C）和氮（N）循环。所提出的研究的目的是评估C和N股票的永久冻土退化的后果，因此植物的养分供应，因为样带涵盖了所有类型的永久冻土，包括严重退化的地区和地区没有永久冻土。我们的研究结果表明，SM是占主导地位的参数解释64%的Corg和60%的N变异。SM的影响程度是由冻土，目前的风沙沉积主要发生在退化的网站，和成土作用。因此，C和N浓度的解释能力显着提高，通过添加CaCO 3含量（P=0.012 Corg; P=0.006 Nt）和土壤质地（P=0.077 Corg; P=0.015 Nt）的模型。对于土壤温度，没有检测到相关性，表明在受冻土影响的高海拔草地生态系统中，SM取代土壤温度作为景观尺度的主要驱动参数。多年冻土的退化和相应的土壤水文变化以及成土作用从成熟阶段向初始阶段的转变对土壤C和植物有效N产生了严重影响。这可能会改变生物多样性模式以及青藏高原生态系统的发展和功能。
We investigated the main parameters [e.g. mean annual air temperature , mean annual soil temperature, mean annual precipitation, soil moisture (SM), soil chemistry, and physics] influencing soil organic carbon (Corg), soil total nitrogen (Nt) as well as plant available nitrogen (Nmin) at 47 sites along a 1200 km transect across the high‐altitude and low‐latitude permafrost region of the central‐eastern Tibetan Plateau. This large‐scale survey allows testing the hypothesis that beside commonly used ecological variables, diversity of pedogenesis is another major component for assessing carbon (C) and nitrogen (N) cycling. The aim of the presented research was to evaluate consequences of permafrost degradation for C and N stocks and hence nutrient supply for plants, as the transect covers all types of permafrost including heavily degraded areas and regions without permafrost. Our results show that SM is the dominant parameter explaining 64% of Corg and 60% of N variation. The extent of the effect of SM is determined by permafrost, current aeolian sedimentation occurring mostly on degraded sites, and pedogenesis. Thus, the explanatory power for C and N concentrations is significantly improved by adding CaCO3 content (P=0.012 for Corg; P=0.006 for Nt) and soil texture (P=0.077 for Corg; P=0.015 for Nt) to the model. For soil temperature, no correlations were detected indicating that in high‐altitude grassland ecosystems influenced by permafrost, SM overrides soil temperature as the main driving parameter at landscape scale. It was concluded from the current study that degradation of permafrost and corresponding changes in soil hydrology combined with a shift from mature stages of pedogenesis to initial stages, have severe impact on soil C and plant available N. This may alter biodiversity patterns as well as the development and functioning of the ecosystems on the Tibetan Plateau.