Collapsing Mechanisms and Restructuring Ways of Sustainable Agro-Ecosystem in the upper Part of Watershed in Humid Tropics

利用高分辨率遥感影像QuickBird对印度尼西亚西爪哇上Citarum流域的景观变化进行了监测。因此，它的变化与限制农业活动的水文地貌条件密切相关。林地仍然留在火山的顶端。在该地区，当地农民的农业活动和日常生活依赖于从林地获得的生物资源。然而，他们中的一些人非法侵占林地，种植一年生经济作物。森林砍伐造成了生物资源与其他森林资源使用者的冲突。因此，该地区的社会生态系统恶化。在没有林地的火山山坡上的村庄，当地农民利用生物资源，如来自包括竹子农林在内的林地的燃料材料。尽管如此，由于市场经济的影响，农用林的物种组成也在发生变化，甚至正在消失。从传统农林到商品林，在对各种类型农林的生态系统服务功能进行评价时，一些商品化类型降低了其服务功能。其中，以几种果树和用材树种为主的类型在保持多功能方面评价较好，具有较高的经济价值，被认为是重建湿润热带农业生态系统的最佳土地利用系统。当向当地农民询问他们是否愿意采用农林类型时，他们中的大多数人都表现出了积极的看法。

Landscape change in the studied site of Upper Citarum watershed, West Java, Indonesia was monitored using very high resolution remote sensing image QuickBird. In result, its change was significantly associated with hydrogeomophic condition, which limits agricultural activity. Forestlands still remained on volcanic summit. In the area, local farmers depended on bioresources acquired from forestlands for their agricultural activities and daily life. However, some of them encroached the forestlands illegally to cultivate annual cash crops. The deforestation caused the bioresource conflict with other forest resource users. Thus, socio-ecological system in the area was deteriorated. In villages on volcanic footslopes where there was no forestlands, local farmers utilized bioresources such as fuel materials from woodlands including bamboo-tree agroforest. Even though, the agroforests also have been changing in species composition or disappearing due to market economy. When evaluated ecosystem services of various types of agroforests from traditional to commercialized ones, some commercialized types reduced its services. Among them, a type dominated by several fruit trees and timber species was evaluated better in terms of maintaining multifunctionality with relatively high economic values, then considered as an optimal land-use system to reconstruct agroecosystem in humid tropics. When interviewed to local farmers about their willingness to adopt the agroforest type, most of them showed positive perception.