For decades, land use practices of ethnic minority people in the uplands of northern Thailand have been blamed by many scientists and policy-makers as being unsustainable and causing degradation of natural forests and watershed functions. Recent flashfloods, landslides and droughts affecting the lowland areas have also been associated with upland agriculture. The objectives of this case study, carried out in Ban Nor Lae and Ban Khob Dong, Fang District, Chiang Mai Province, were to scrutinize these claims by exploring the knowledge of Palong and Black Lahu on sustainable forest watershed management and by contrasting their local ecological knowledge (LEK) systems with scientific findings.
Key informants and randomly selected villagers were interviewed by means of semi-structured questionnaires. Selected Participatory Rural Appraisal (PRA) tools, such as mapping and transects, were also employed to collect information. The elicited information was recorded in a durable and accessible way by the Agroecological Knowledge Toolkit (AKT5). This toolkit helped us to create text statements and to determine causal relationships through diagrams and hierarchies.
Based on the information collected, traditional agricultural systems of Palong and Black Lahu could be divided into three categories: swidden cultivation, paddy field and sylvopastoral system. Mixed orchards were only recently introduced as a major innovation into the farming system, partly on the initiative of the Royal Project Station in Angkhang. Lahu farmers in Ban Khob Dong – commonly labeled as ‘pioneer shifting cultivators’ in Thailand – have developed a sustainable system of paddy rice terraces. They supplement their diet through crops grown in home gardens, thus enabling them to base their livelihoods on a low-external input system. Recently, however, these traditional systems are increasingly replaced by very intensive cash crop production in greenhouses. The Palong of Ban Nor Lae – who have a very recent history of settling in this Thai-Myanmar border region and face a shortage of water – are not able to grow paddy rice, but instead have developed a sylvopastoral system, raising mainly cattle, horses and mules. Apart from providing a major source of the family income, raising animals in the sylvopastoral and mixed orchard systems indirectly helps them in distributing seeds of valuable multi-purpose trees and in increasing soil fertility through animal manure. On the other hand, scientists have found that the tramping of animals decreases soil infiltration and water uptake of roots, thus reducing the growth rate of crops. These tradeoffs related to animal husbandry can be countered by limiting livestock numbers and by regulating grazing activities in mixed orchard systems according to seasons. As regards forest watershed management, Palong villagers conserve tree species with a high capacity of storing water and of gradually releasing it to the creeks. In areas where some villagers have cut these trees with high water absorption capacity, the Palong observed a decrease of the groundwater table. As a result they have stepped up their conservation efforts to ensure a continuous water supply for their village.
This study demonstrated that the Local Ecological Knowledge (LEK) collected from key informants and ordinary villagers was explanatory and of technical relevance. The knowledge and practices of ethnic minority groups contrast with the simplified and negative image that mainstream society tends to construct of highland agricultural systems. We conclude that if this knowledge is integrated into scientific analysis and policy-making it can provide a useful resource for improving the sustainability of the highland watershed agro-ecosystems.
