STUDIES ON THE DYNAMIC PROPERTIES OF TERRESTRIAL ECOSYSTEMS BASED ON A SIMULATION MODEL II. TROPICAL RAINFOREST DYNAMICS AND STABILITY AS INFLUENCED BY STEM MORTALITY
STUDIES ON THE DYNAMIC PROPERTIES OF TERRESTRIAL ECOSYSTEMS BASED ON A SIMULATION MODEL II. TROPICAL RAINFOREST DYNAMICS AND STABILITY AS INFLUENCED BY STEM MORTALITY
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DOI：
10.1007/bf02346947
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发表时间：
1989-01-01
影响因子：
2
通讯作者：
OIKAWA T
中科院分区：
文献类型：
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作者：
OIKAWA T
使用先前研究中开发的微型计算机模型对热带雨林动态和稳定性与茎死亡率的关系进行了进一步分析（Oikawa，1985）。通过长达100年的模拟实验，研究了茎死亡率(.delta.c)变化对热带雨林的影响。茎死亡率从标准值 (3% yr-1) 增加到 4 倍值 (12% yr-1) 会导致茎生物量减少，从而导致总生物量减少，而在森林生态系统稳定状态下，茎凋落物通量则相反增加。同时，稳定状态下茎生物量的减少预计会导致总产量（Pg）和净产量（Pn）的增加，以及模型雨林生产效率（以 Pn/Pg 比率表示）的提高。类似的模拟实验预测，森林中生产效率的提高和茎死亡率提高了 4 倍，能够增强对生产力较低的环境的耐受性，例如延长的旱季或降低的入射光通量密度。另一方面，标准茎死亡率（δ.c = 3% yr-1）是西马来西亚巴索森林的概算值，被认为近似于实现森林稳定所需的下限阈值。根据所获得的结果，讨论了δc对于热带雨林生态系统动态和稳定性的重要性以及树木的竞争和耐受性。此外，还强调了这里采用的模拟方法的有效性。
Further analysis of tropical rainforest dynamics and stability in relation to stem mortality has been conducted using a microcomputer model developed in a previous study (Oikawa, 1985). By simulation experiments covering a period of 100 years, the effects of changing stem mortality (.delta.c) upon a tropical rainforest were investigated. Increasing stem mortality ranging from a standard value (3% yr-1) to a 4-fold value (12% yr-1) brings about decreases in stem biomass and thus total living biomass, and a contrasting incresae of stem litterfall flux at the steady state of the forest ecosystem. At the same time, the decreased stem biomass at the steady state is predicted to result in increases of gross production (Pg) and net production (Pn), and an improvement in production efficiency of the model rainforest expresed as the Pn/Pg ratio. Similar simulation experiments predict that the improved production efficiency in the forst with a 4-fold stem mortality is able to enhance tolerance to less productive environments such as a prolonged dry season or a reduced incident light flux density. On the other hand, the standard stem mortality (.delta.c = 3% yr-1), which was estimated as a probable value for the Pasoh forest, West Malaysia, is considered to approximate the lower threshold necessary for attaining forest stability. Based on the results obtained, the significance of .delta.c for the dynamics and stability of a tropical rainforest ecosystem is discussed in relation to the competition and tolerance of trees. In addition, the effectiveness of the simulation approach adopted here is emphasized.