Effects of climatic and soil properties on cellulose decomposition rates in temperate and tropical forests
Effects of climatic and soil properties on cellulose decomposition rates in temperate and tropical forests
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DOI：
10.1007/s00374-013-0885-4
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发表时间：
2014-05-01
影响因子：
6.5
通讯作者：
Kosaki, Takashi
中科院分区：
文献类型：
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作者：
Hayakawa, Chie;Funakawa, Shinya;Kosaki, Takashi
在野外条件下进行了纤维素分解试验，以分析气候和土壤性质对温带和热带森林有机质分解速率的影响。通过测定土壤表层纤维素滤纸的质量损失率，估算了纤维素分解引起的呼吸碳通量和纤维素的平均停留时间。纤维素分解率随土壤温度的升高而增加，但在旱季，而分解速率常数（归一化温度）降低，因为较低的纤维素酶活性的pH值降低。温带森林土壤纤维素碳水化合物的估计MRT从81到495天不等，热带森林从31到61天不等。作为一种主要的有机基质，来自纤维素分解的碳通量可以占异养（基础）土壤呼吸的很大一部分。然而，呼吸碳通量可以限制在热带土壤中的低基质可用性和低pH值，尽管高微生物活性。纤维素分解的速率调节因素，即，温度、土壤pH值和基质有效性会相应地影响异养土壤呼吸速率。
Cellulose decomposition experiments were conducted under field conditions to analyze the effects of climatic and soil properties on rates of organic matter decomposition in temperate and tropical forests. The mass loss rates of cellulose filter papers buried in the soil surface were measured to estimate the respiratory C fluxes caused by cellulose decomposition and mean residence time (MRT) of cellulose. The rates of cellulose decomposition increased with soil temperature, except for during the dry season, while rate constants of decomposition (normalized for temperature) decreased with decreasing pH because of lower cellulase activity. The estimated MRTs of soil cellulosic carbohydrates varied from 81 to 495 days for the temperate forests and from 31 to 61 days for the tropical forests. As a major organic substrate, the C fluxes from cellulose decomposition can account for a substantial fraction of heterotrophic (basal) soil respiration. However, the respiratory C fluxes can be limited by the low substrate availability and low pH in tropical soils, despite high microbial activity. The rate-regulating factors of cellulose decomposition, i.e., temperature, soil pH, and substrate availability, can accordingly influence the rates of heterotrophic soil respiration.