Distribution patterns of trees in paddy field landscapes in relation to agro-ecological settings in northeast Thailand.
Distribution patterns of trees in paddy field landscapes in relation to agro-ecological settings in northeast Thailand.
复制标题
泰国东北部稻田景观中树木的分布模式与农业生态环境的关系。
DOI：
10.1016/j.agee.2014.12.011
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
S. Miyagawa and Y. Kosaka
中科院分区：
文献类型：
--
作者：
Pham T. H.;S. Miyagawa and Y. Kosaka
森林砍伐伴随着农业用地的扩张，使得热带许多地区的树木资源减少，小规模农民往往将树木与农业用地结合起来，以满足他们对粮食、木材、薪材或饲料的需求。本研究分析了在泰国东北部森林枯竭地区的稻田中生长的多个树种的分布格局和管理-该地区的林地仅占总土地面积的16.32%。从11个省的20个村庄中选择了树木密度和微生境的遥感分析。对村民进行了树木利用和管理的访谈调查，并进行了实地观察，以确定树种组成。平均单位树密度（根据卫星图像中出现的单棵树或粘性树的树冠数）为6.27个单位/公顷，与堤坝上的密度（平均5.30个单位/公顷）和单位稻田面积的堤坝长度（平均475.25米/公顷）相关。防洪堤作为洪泛平原上那些村庄的树木栖息地更为重要，因为早期引进农业机械和直接播种减少了种植水稻作物的田地内的树木数量。结果表明，稻田中共有乔木33科66属79种。原始森林的残存树木，主要是龙脑香科和豆科，由于砍伐用作木材和燃料而减少。最近，在堤坝上种植了桉树和柚木作为木材，芒果和罗望子作为食用水果，作为收入来源。农民们已经认识到，虽然落叶使土壤肥沃，但过度的遮荫会降低水稻产量。进行了灌木的抚育和Mitragyna diversifolia的截顶，以实现木材和薪材的可持续收获，并避免产生过多的阴影。稻田是单一的主要作物，但它们可以在堤坝上种植多种树木，这对林地的减少起到了反作用。
Deforestation accompanied by the expansion of agricultural land makes tree resources less available in many regions in the tropics, and small-scale farmers often incorporate trees with agricultural lands to meet their demands for food, timber, fuelwood, or fodder. This study analyzed the distribution patterns and management of multiple tree species grown in the rice paddy fields of a forest-depleted region in northeast Thailand – a region whose forestland represents only 16.32% of the total land area. Twenty villages from 11 provinces were selected for the remote sensing analysis of tree density and microhabitat. Interview surveys were conducted among villagers on their tree use and management, and field observations were performed to determine tree species’ composition. The average tree-unit density (based on the number of tree crowns, either of a single tree or of cohesive trees, appearing in satellite images) was 6.27 units/ha, and was correlated with both density on the levee (5.30 units/ha on average) and levee length per unit paddy area (475.25 m/ha on average). The levees were more significant as tree habitats in the villages on the floodplain where the early introduction of agricultural machinery and direct seeding reduced the number of trees inside the fields where rice crops are grown. In total, 79 tree species representing 66 genera and 33 families were observed in the paddy fields. Remnant trees from the original forest, mostlyDipterocarpaceaeandFabaceae, have decreased due to cutting for use as timber and fuel. More recently, eucalypt and teak for timber, and mango and tamarind for edible fruits, have been planted on the levees as income sources. Farmers have recognized that while leaf litter fertilizes the soil, excess shading reduces the rice yield. The coppicing of eucalypt and pollarding ofMitragyna diversifoliawere conducted for the sustainable harvest of timber and fuelwood, and also to avoid creating excess shade. Paddy rice fields are the monoculture of a staple crop, but they can harbor multiple trees on their levees, which play a counteractive role in forestland decline.