Swidden agriculture is an age-old, widespread but controversial farming practice in Montane Mainland Southeast Asia （MMSEA）. In the uplands of northern Laos, swidden ag- riculture has remained a predominant human-do...Swidden agriculture is an age-old, widespread but controversial farming practice in Montane Mainland Southeast Asia （MMSEA）. In the uplands of northern Laos, swidden ag- riculture has remained a predominant human-dominated land-use type for centuries. However swidden system has undergone dramatic transformations since the mid-1990s. Debates on changes in swidden cultivation are linked to globally critical issues, such as land use/cover changes （LUCC）, biodiversity loss and environmental degradation. Since the implementation of Reducing Emissions from Deforestation and Forest Degradation （REDD）, much attention has been paid nationally and internationally to swidden agriculture in the tropics. However, knowledge of the explicitly spatial characteristics of swidden agriculture and the conse- quences of these transitions at macroscopic scale is surprisingly scarce. In this study, the intensity of swidden use and fallow forest recovery in northern Laos in 1990, 2002, and 2011 were delineated by means of Landsat Thematic Mapper （TM） and Enhanced Thematic Mapper plus （ETM＋） imagery （30 m） using a decision tree classification approach, followed by an analysis of the spatio-temporal changes in swidden agriculture. Next, annual successive TM/ETM＋ images during 2000-2010 were used to delineate the dynamics of the burning and cropping phase. Subsequently, the burned pixels identified in 2000 were compared respectively with their counterparts in the following years （2001-2011） to investigate temporal trends, land-use frequency, and the swidden cycle using time-series Landsat-based Normalized Difference Vegetation Index （NDVI） data. Finally, as the swidden cycle changed from 1 to 11 years, the fallow vegetation recovery process was studied. The results showed that： （1） from 1990 to 2011, the area of swidden agriculture increased by 54.98%, from 1.54× 10^5 ha to 2.38×10^5 ha in northern Laos. The increased swidden cultivation area was mainly distributed in Luang Prabang and southern Bokeo, whereas the decreased parts were mainly found in Phongsali; （2） swidden agriculture increased mainly at elevations of 500-800 m, 300-500 m, and 800-1000 m and on slopes of 10°-20° and 200-30°. Over 80% of swidden fields were transformed from forests; （3） during 2000-2011, the frequency of swidden use in northern Laos was about two or three times. The interval between two successive utilization of a swidden ranged from one to seven years. Comparison of swidden cycles and the related proportions of swidden farming in 2000, 2003, and 2007 revealed that swidden cycles in most areas were shortened; and （4） there was a significant correlation （0.97） between fallow vegetation recovery and the swidden cycle. The NDVI of regenerated vegetation could approach the average level of forest when the swidden cycle reached 10 years.展开更多
This paper discussed effects of lowland-associated influences on upland ecology, food security and biocultural diversity in the Sarangani farming communities of the Philippines. In the uplands of Sarangani Province, t...This paper discussed effects of lowland-associated influences on upland ecology, food security and biocultural diversity in the Sarangani farming communities of the Philippines. In the uplands of Sarangani Province, the conservation of traditional rice varieties, the centrality of rice in tribal life, and the continued observance of planting rituals attest to its cultural significance and convey a common desire for cultural preservation and community solidarity. Economic and socio-political pressures had transformed tribal communities, although vestiges of traditional farming systems are still being practiced in remote sitios（villages）. Changing land use patterns had also resulted in shrinking farm sizes and consequently in food insecurity in the Sarangani uplands. Extractive industries（i.e. logging, mining and charcoal making） and swidden farming were observed to cause widespread environmental degradation, while modern agriculture had undermined the capacity of indigenous peoples to survive because of their complete dependence on lands and resources. With the reality that cultural and biological diversities are inextricably linked, trans-disciplinary strategies coupling indigenous knowledge systems with scientific knowledge should, therefore, be instituted to save the Sarangani upland ecosystem, the indigenous peoples and their tribal resources.展开更多
基金National Natural Science Foundation of China, No.41301090, No.41271117 Key Program for Strategic Science and Technology, Chinese Academy of Sciences, No.2014SJCB006
文摘Swidden agriculture is an age-old, widespread but controversial farming practice in Montane Mainland Southeast Asia （MMSEA）. In the uplands of northern Laos, swidden ag- riculture has remained a predominant human-dominated land-use type for centuries. However swidden system has undergone dramatic transformations since the mid-1990s. Debates on changes in swidden cultivation are linked to globally critical issues, such as land use/cover changes （LUCC）, biodiversity loss and environmental degradation. Since the implementation of Reducing Emissions from Deforestation and Forest Degradation （REDD）, much attention has been paid nationally and internationally to swidden agriculture in the tropics. However, knowledge of the explicitly spatial characteristics of swidden agriculture and the conse- quences of these transitions at macroscopic scale is surprisingly scarce. In this study, the intensity of swidden use and fallow forest recovery in northern Laos in 1990, 2002, and 2011 were delineated by means of Landsat Thematic Mapper （TM） and Enhanced Thematic Mapper plus （ETM＋） imagery （30 m） using a decision tree classification approach, followed by an analysis of the spatio-temporal changes in swidden agriculture. Next, annual successive TM/ETM＋ images during 2000-2010 were used to delineate the dynamics of the burning and cropping phase. Subsequently, the burned pixels identified in 2000 were compared respectively with their counterparts in the following years （2001-2011） to investigate temporal trends, land-use frequency, and the swidden cycle using time-series Landsat-based Normalized Difference Vegetation Index （NDVI） data. Finally, as the swidden cycle changed from 1 to 11 years, the fallow vegetation recovery process was studied. The results showed that： （1） from 1990 to 2011, the area of swidden agriculture increased by 54.98%, from 1.54× 10^5 ha to 2.38×10^5 ha in northern Laos. The increased swidden cultivation area was mainly distributed in Luang Prabang and southern Bokeo, whereas the decreased parts were mainly found in Phongsali; （2） swidden agriculture increased mainly at elevations of 500-800 m, 300-500 m, and 800-1000 m and on slopes of 10°-20° and 200-30°. Over 80% of swidden fields were transformed from forests; （3） during 2000-2011, the frequency of swidden use in northern Laos was about two or three times. The interval between two successive utilization of a swidden ranged from one to seven years. Comparison of swidden cycles and the related proportions of swidden farming in 2000, 2003, and 2007 revealed that swidden cycles in most areas were shortened; and （4） there was a significant correlation （0.97） between fallow vegetation recovery and the swidden cycle. The NDVI of regenerated vegetation could approach the average level of forest when the swidden cycle reached 10 years.
基金funded by the Department of Agriculture-XII was conducted jointly with the Office of the Provincial Agriculturist-Sarangani Province
文摘This paper discussed effects of lowland-associated influences on upland ecology, food security and biocultural diversity in the Sarangani farming communities of the Philippines. In the uplands of Sarangani Province, the conservation of traditional rice varieties, the centrality of rice in tribal life, and the continued observance of planting rituals attest to its cultural significance and convey a common desire for cultural preservation and community solidarity. Economic and socio-political pressures had transformed tribal communities, although vestiges of traditional farming systems are still being practiced in remote sitios（villages）. Changing land use patterns had also resulted in shrinking farm sizes and consequently in food insecurity in the Sarangani uplands. Extractive industries（i.e. logging, mining and charcoal making） and swidden farming were observed to cause widespread environmental degradation, while modern agriculture had undermined the capacity of indigenous peoples to survive because of their complete dependence on lands and resources. With the reality that cultural and biological diversities are inextricably linked, trans-disciplinary strategies coupling indigenous knowledge systems with scientific knowledge should, therefore, be instituted to save the Sarangani upland ecosystem, the indigenous peoples and their tribal resources.
