Ethnobotanical study of wild food plants used by rice farmers in Northeast Thailand

Wild food plants have been recognized as an essential component of the world’s food basket. Farmer’s gathering locations are increasingly from anthropogenic ecosystems given the decline of pristine environments. However, there are neither quantitative studies on the ecological characterization nor on the seasonal gathering of wild food plants in anthropogenic ecosystems; moreover, systematic studies on the seasonal implications of these food plants for households are rare. Therefore, this thesis aimed at contributing to the understanding of wild food plant gathering by rice farmers, by developing a theoretical and analytical framework supported by multi-facetted empirical evidence on the spatial and seasonal complementarity of anthropogenic ecosystems and sub-systems, as well as its implications for the food security and dietary diversity of households from an ethnobotanical perspective. A theoretical model was developed and field work was conducted inKalasin, Northeast Thailand. The empirical analysis comprised three principle analytically and methodologically coherent research components: (a) botanical (species level), (b) ecological (ecosystem and sub-system level) and (c) anthropological (household level). This was reflected in the use of research methodologies drawn from (ethno)botany, ecology and anthropology, respectively. Results showed a total of 87 elicited wild food plant species comprising trees, terrestrial and aquatic herbs, climbers, shrubs, bamboos and a rattan; growing in anthropogenic ecosystems including rice fields, home gardens, secondary woods, upland fields, swamps and roadsides. Most species can be found in different places and more than two thirds of the species have extra uses besides food. A total of 42 wild food plant species were reported in 102 sampling sites corresponding to seven sub-systems associated to lowland rice production, including shelters, hillocks, ponds and their margins, tree rows, dikes and field margins. Likewise, 20 wild food plant species were observed in 77 sampling sites corresponding to five home garden sub-systems, comprising yards, fenced gardens and their margins, hedgerows and fences constituting household boundaries, and pots. Species density, Shannon and Simpson diversity indexes were calculated per sub-system in the dry and rainy seasons. Whereas rice fields presented more species during the rainy season, their diversity in home gardens was higher in the dry season, because farmers encourage the availability of these plants though management. The findings also showed that communities of wild food plant species are different for each sub-system and season, and consequently all sub-systems, providing different habitats ranging from terrestrial to aquatic, are important for ensuring wild food plant diversity. The findings of the 12-month study conducted with a sample of 40 households visited every month to conduct 7-day recalls on wild food plant acquisition events, revealed a substantial number of gathered species (n=50), high monthly percentages of families gathering these plants (100% to 93%) and a great number of collection events (n=2196). It was evidenced that all households gathered wild food plants from both paddy fields and home gardens throughout the year, whereas most families gathered from roadsides. Wild food gathering was principally essential for local households during lean months, constituting a ‘rural safety net’, in particular for the most vulnerable families. This study highlighted the importance of diversity at species, sub-system and ecosystem level, and confirmed the theoretical model on seasonal and spatial complementarity of anthropogenic ecosystems and sub-systems for provisioning and gathering wild food plants. It was concluded that this complementarity is crucial for household food security and dietary diversity, and has major societal implications for agricultural programs, food policies, biodiversity conservation initiatives and poverty alleviation strategies in the region. Keywords: Wild food plant, ethnobotany, domestication, anthropogenic ecosystem, rice ecosystem, home garden, gathering, abundance, diversity, seasonality, ecosystem complementarity, multi-functionality, poverty, vulnerability, rice farmers, Thailand, Southeast Asia.