Department of Forest Science, Tokyo University of Agriculture, Setagaya, Tokyo, Japan.
Center for Biodiversity, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki, Japan.
PLoS One. 2018 May 15;13(5):e0197391. doi: 10.1371/journal.pone.0197391. eCollection 2018.
While many tropical countries are experiencing rapid deforestation, some have experienced forest transition (FT) from net deforestation to net reforestation. Numerous studies have identified causative factors of FT, among which forest scarcity has been considered as a prerequisite for FT. In fact, in SE Asia, the Philippines, Thailand and Viet Nam, which experienced FT since 1990, exhibited a lower remaining forest area (30±8%) than the other five countries (68±6%, Cambodia, Indonesia, Laos, Malaysia, and Myanmar) where forest loss continues. In this study, we examined 1) the factors associated with forest scarcity, 2) the proximate and/or underlying factors that have driven forest area change, and 3) whether causative factors changed across FT phases (from deforestation to net forest gain) during 1980-2010 in the eight SE Asian countries. We used production of wood, food, and export-oriented food commodities as proximate causes and demographic, social, economic and environmental factors, as well as land-use efficiency, and wood and food trade as underlying causes that affect forest area change. Remaining forest area in 1990 was negatively correlated with population density and potential land area of lowland forests, while positively correlated with per capita wood production. This implies that countries rich in accessible and productive forests, and higher population pressures are the ones that have experienced forest scarcity, and eventually FT. Food production and agricultural input were negatively and positively correlated, respectively, with forest area change during 1980-2009. This indicates that more food production drives deforestation, but higher efficiency of agriculture is correlated with forest gain. We also found a U-shaped response of forest area change to social openness, suggesting that forest gain can be achieved in both open and closed countries, but deforestation might be accelerated in countries undergoing societal transition. These results indicate the importance of environmental, agricultural and social variables on forest area dynamics, and have important implications for predicting future tropical forest change.
虽然许多热带国家正经历着快速的森林砍伐，但也有一些国家经历了从森林净减少到净增加的森林转型（FT）。许多研究已经确定了 FT 的成因因素，其中森林稀缺被认为是 FT 的前提条件。事实上，在 1990 年以来经历了 FT 的东南亚国家中，菲律宾、泰国和越南的剩余森林面积（30±8%）低于其他五个国家（68±6%，柬埔寨、印度尼西亚、老挝、马来西亚和缅甸），这些国家的森林仍在减少。在本研究中，我们检验了：1）与森林稀缺相关的因素，2）驱动森林面积变化的直接和/或根本因素，以及 3）在 1980-2010 年期间，导致因素是否在 FT 阶段（从森林砍伐到净森林增益）发生变化，在这八个东南亚国家。我们使用木材、粮食和出口导向型粮食商品的产量作为直接原因，以及人口、社会、经济和环境因素，以及土地利用效率、木材和粮食贸易作为影响森林面积变化的根本原因。1990 年的剩余森林面积与人口密度和低地森林潜在土地面积呈负相关，与人均木材产量呈正相关。这意味着那些拥有丰富的、可获取的、生产力高的森林资源和更高人口压力的国家，经历了森林稀缺，最终实现了 FT。1980-2009 年期间，粮食生产和农业投入分别与森林面积变化呈负相关和正相关。这表明，粮食产量的增加会导致森林砍伐，但农业效率的提高与森林增益相关。我们还发现森林面积变化对社会开放度呈 U 型响应，这表明森林增益可以在开放和封闭的国家实现，但社会转型中的国家可能会加速森林砍伐。这些结果表明，环境、农业和社会变量对森林面积动态具有重要影响，对预测未来热带森林变化具有重要意义。
