Fine root decomposition in tropical dry evergreen and dry deciduous forests in Thailand
Fine root decomposition in tropical dry evergreen and dry deciduous forests in Thailand
复制标题
DOI：
10.1007/s10310-008-0087-3
复制
发表时间：
2008-12-01
影响因子：
1.5
通讯作者：
Wiwatiwitaya, Decha
中科院分区：
文献类型：
--
作者：
Fujimaki, Reiji;Takeda, Hiroshi;Wiwatiwitaya, Decha
干燥万年青林（DEF）和干燥落叶龙脑香林（DDF）是泰国东北部广泛分布的主要森林类型，具有不同的养分循环特性。本研究旨在提高对DEF中铁坡垒（Hopea ferrea）细根（< 2 mm）和小根（2-5 mm）以及DDF中混交林和矮生竹（Arundinaria pusilla）细根的质量损失和氮释放规律的认识。采用垃圾袋埋置技术进行了12个月以上的腐解试验。四种根系凋落物的初始化学组成存在显著差异，H.铁尿素具有低的C：N和酸不溶物：N比。矮秆竹细根具有总糖和灰分含量高的特点。细根和小根的分解速率常数（年）分别为1.27和0.55;铁，混交林细根和矮生竹细根的铁含量分别为0.73和0.66。试验结束时，细根和小根中的N浓度均高于对照。Ferrea增加到初始浓度的1.5倍。而矮秆竹的氮质量在试验过程中呈下降趋势。这表明在两个森林生态系统中的根分解和N释放的不同模式。一般而言，DEF中细根的分解比DDF中快。在我们的研究中，初始凋落物化学的作用比气候季节性对地下分解模式的作用更明显。
Dry evergreen forest (DEF) and dry deciduous dipterocarp forest (DDF) are major forest types extensively distributed in northeastern Thailand, exhibiting different nutrient cycling properties. This study aims to improve our understanding on the pattern of mass loss and nitrogen release from two categories of roots (fine, < 2 mm and small, 2-5 mm) of Hopea ferrea at DEF and fine roots of mixed trees and dwarf bamboo (Arundinaria pusilla) at DDF sites. Decomposition experiment was performed for more than 12 months using buried litter bag technique. Initial chemistry was significantly different among the four root litters; fine root of H. ferrea exhibited a low ratios of C:N and acid-insoluble:N. The fine root of dwarf bamboo was characterized by high contents of total carbohydrate and ash. Decomposition rate constants (year(-1)) of ash-free weight remaining were 1.27 and 0.55 for fine and small roots of H. ferrea, and 0.73 and 0.66 for fine root of mixed trees and dwarf bamboo, respectively. At the end of the experiment, the N concentration in fine and small roots of H. ferrea increased to 1.5 times the initial concentration. Whereas, N mass of dwarf bamboo decreased during the experiment. This suggests a different pattern of root decomposition and N release in two forest ecosystems. Generally, the fine root decomposition was faster in the DEF than in the DDF. The role of initial litter chemistry was more pronounced than the climatic seasonality on the belowground decomposition pattern in our study.