The Effect of Fallow Period Length on the Abundance and Diversity of Usable Plant Assemblages in Shifting Cultivation System (Swidden Agriculture) in Northern Laos
The Effect of Fallow Period Length on the Abundance and Diversity of Usable Plant Assemblages in Shifting Cultivation System (Swidden Agriculture) in Northern Laos
复制标题
老挝北部轮耕制度（轮耕农业）休耕期长度对可用植物群落丰度和多样性的影响
DOI：
10.3161/15052249pje2016.64.3.005
复制
发表时间：
2016
影响因子：
0.5
通讯作者：
K. Chun
中科院分区：
文献类型：
--
作者：
C. O. Delang;Xu Weiyi;B. Brooke;K. Chun
轮作耕作，或称扫荡耕作，涉及种植期和休耕期的交替循环。这些休耕的湿地不但没有被遗弃，反而为偏远的森林居民社区提供了重要的植物产品来源。在老挝北部，传统的休耕时间通常在5年到11年之间，这取决于土地的可用性和土壤质量。由于人口压力和政府政策，休耕期目前正在缩短。为了确定休耕期缩短的潜在影响，在老挝北部海拔400至800米的128个不同年龄（最高达20年）的休耕区取样，寻找可用植物。分析了休耕长度对植物丰度和物种多样性的影响。可用植物种类数量随休耕年龄的增加而增加，休耕至11 ~ 12岁后逐渐减少，休耕后可用植物丰度增加。我们的结论是，休耕时间的缩短将导致村民可利用的植物丰度和物种多样性明显减少。我们建议考虑11 - 12年的休耕，以充分利用老休耕中较大的植物体积以及休耕中物种组成随时间的变化。
ABSTRACT Shifting cultivation, or swiddening, involves alternating cycles of cropping and fallow periods. Rather than being abandoned, the fallow swidden fields provide a source of important plant products for remote, forest-dwelling human communities. In northern Laos, the traditional length of fallow periods used to range between five and 11 years, depending on the availability of land and quality of the soil. Fallow periods are currently being shortened because of population pressures and government policies. To determine the potential impacts of shorter fallow periods, 128 swidden fallows of various ages (up to 20 years), located at altitudes between 400 and 800 m a.s.l. in northern Laos were sampled for usable plants. The impact of fallow length on plant abundance and species diversity was analysed. The number of usable plant species was found to increase with the fallow age until it was 11–12 years old, and then decline, while the abundance of usable plants increased beyond that period. We conclude that shorter fallows will result in a significantly smaller usable plant abundance and species diversity for the villagers. We propose that 11–12-year-long fallows should be considered in order to fully exploit the greater plant volume of older fallows as well as the compositional shift of species in fallows over time.