Consequences of Swidden Transitions for Crop and Fallow Biodiversity in Southeast Asia

Swidden agriculture, once the dominant form of land use throughout the uplands and much of the lowlands of Southeast Asia, is being replaced by other land uses. While change and adaptation are inherent to swiddening, the current rapid and widespread transitions are unprecedented. In this paper we review some recent findings on changes in biodiversity, especially plant diversity at various scales, as swidden farming is replaced by other land uses. We focus particularly on two areas of Southeast Asia: northern Thailand and West Kalimantan. We examine actual and potential changes in the diversity of crops that characterize regional swidden systems, as well as that of the spontaneously occurring plants that appear in swidden fields and fallows. Severe declines in plant diversity have been observed in most areas and at most spatial scales when swidden is replaced by permanent land use systems. However, shifts away from swidden agriculture do not invariably result in drastic declines or losses of biological diversity, but may maintain or even enhance it, particularly at finer spatial scales. We suggest that further research is necessary to understand the effects of swidden transitions on biodiversity.     

Assortative mating and offspring well-being: theory and empirical findings from a native Amazonian society in Bolivia

Mate choice matters for inclusive fitness, household economic efficiency, assimilation, stratification, and economic inequalities in society. In positive assortative mating, people pair with someone who resembles them along a trait, whereas in negative assortative mating, people pair with someone who differs from them along a trait. In industrial nations, people tend to follow positive assortative mating for fundamental demographic dimensions (e.g., age, schooling) and might practice negative assortative mating for economic outcomes (e.g., earnings). Research on assortative mating has focused on industrial nations, generally compared only one trait between couples, and paid scant attention to the effects of assortative mating for offspring well-being. If assortative mating enhances inclusive fitness, it might also enhance offspring well-being. Drawing on data from a farming–foraging society in the Bolivian Amazon (Tsimane') that practices preferential cross-cousin marriage, we (a) identify six parental traits (age, knowledge, wealth, schooling, height, and smiles) for which Tsimane' might practice assortative mating and (b) test the hypothesis that assortative mating enhances offspring well-being. Proxies for offspring well-being include height and school attainment. Tsimane' resemble people of industrial nations in practicing mostly positive assortative mating. Pairwise, mother–father and Pearson correlations of age, schooling, and earnings among Tsimane' resemble correlations of industrial nations. Correlation coefficients for the six parental traits were far higher than correlations that might happened just by chance. We found weak support for the hypothesis that assortative mating improves offspring well-being.     

Indigenous Knowledge and Management of Araucaria Araucana Forest in the Chilean Andes: Implications for Native Forest Conservation

Southern Chile experienced serious deforestation during the past century and it is projected that by the year 2025 Chile will be devoid of native forests. One of the most important endemic tree species of the country and at the same time one of the most endangered ones is Araucaria araucana (Mol.) C. Koch, the monkey-puzzle tree. It grows in the Andes Mountains, homeland of the indigenous Mapuche Pewenche people who depend on this tree. This paper is based on participatory field research with a Mapuche Pewenche community in the southern Chilean Andes on their ecological knowledge, values, use and management of the Araucaria araucana forest. It attempts to reveal how indigenous people and their knowledge contribute to the sustainable management of these forests. The paper (1) illustrates the complexity of indigenous ecological knowledge of Araucaria araucana and its efficacy in native forest management, (2) explores the link between the conservation and use of biodiversity by the indigenous people, and (3) provides answers relevant to native forest management and conservation strategies ex-situ and in-situ incorporating indigenous and scientific knowledge, thus providing a contribution towards integrated natural resource management.     

Patterns of use and knowledge of wild edible plants in distinct ecological environments: a case study of a Mapuche community from northwestern Patagonia

The multiple use of distinct ecological environments in the search for wild resources has been practiced since ancestral times in aboriginal communities inhabiting northwestern Patagonia. This paper examines the actual use and knowledge of wild edible plants in a Mapuche community presently settled in one of the most arid areas of Patagonia, far from the temperate forests where their ancestors used to live. The difference between knowledge of and use of wild plants is analyzed emphasizing that these differences could contribute to the understanding of eroding processes believed to be occurring in the community. These objectives are studied quantitatively by utilizing ethnobotanical indices, partially derived from ecological theory. Our results indicate that the Paineo dwellers still utilize multiple ecological gathering environments and have thorough plant knowledge of both native and exotic species. The Andean forest, more than 50km away from this community, is the environment from which the Paineo dwellers know the greatest total richness and the highest diversity of wild edible plants, followed by the Monte–Steppe species and lastly, those growing around their homes. The transmission of wild edible plant knowledge in the Paineo community diminishes with age, and the forest plants are the most vulnerable to loss. Our results have shown that the knowledge and consumption of wild edible plants follows a pattern according to ecological conditions of the gathering environments, as well as the cultural heritage of the Paineo people.     

Traditional Ecological Knowledge of a Riverine Forest in Turkana, Kenya: Implications for Research and Management

The present study explores traditional ecological knowledge (TEK) of Turkana pastoralists and cultivators in the context of a riverine forest in northern Kenya. The Turkwel River and its floodplain sustain a thick forest, which is used for grazing and extraction of non-timber forest products. However, sedentarisation and agricultural expansion have resulted in localised clear-felling of trees, while river damming has altered the natural flow regime. A series of structured, semi-structured, and group interviews were combined with a botanical inventory in order to assess the relevance of TEK to ecological research and forest conservation. Turkana informants gave 102 vernacular names for the 113 woody species. Of these, 85% had a domestic or pastoral use among the 105 specific uses that were described. Ethnobotanical knowledge was relatively homogenous and not related to age, gender, or source of livelihood. The informants had in-depth knowledge of some key ecological processes. The conceived threats to forest survival were primarily cultivation and permanent settlements, while the effects of river damming and livestock grazing were disputed. A claimed decline in rainfall was confirmed by official data. There is strong evidence that TEK could be used to generate hypotheses for research and to design sustainable conservation strategies. A revised version of the indigenous system of tree management should be incorporated into the official forestry policy in order to resolve future conflicts between pastoralists and cultivators.