<Articles>Homegardens of the Cao Lan, a Tai-Speaking Ethnic Minority in Vietnam's Northern Mountains

The Cao Lan are a Tai-speaking ethnic group living in the Midlands of Northern Vietnam. Homegardens are an important component of their agroecosystem. The ecological structures of each homegarden of 17 households of the Cao Ngoi village in Tuyen Quang province were described and modal patterns identified. Most homegardens have organically shaped planting areas with indeterminate boundaries, polycentric planting patterns, and contain multiple species within the same bed or planting area. All of the gardens have multiple vegetation levels, with the largest share having 5 levels and a majority having more than 50% of their planting area covered by overlapping vegetation layers. Biodiversity is high with a total of 113 species recorded. Most plant species are used for food, but smaller numbers have ornamental, medicinal, and construction uses or are used for animal fodder, as stimulants, or for other purposes. Comparison of the modal structure of the Cao Lan homegardens with several Tai minority groups in Northeast Thailand, shows that, although the Cao Lan have been geographically isolated from other Tai groups for many centuries, their homegardens share a similar structural pattern, one commonly referred to as the tropical forest type. This structure is very different from the temperate type gardens of the Kinh in Vietnam with whom the Cao Lan share a common environment and are in frequent contact. The persistence of a common structural pattern among these related Tai ethnic groups, despite their inhabiting different environments, and having had no direct contact with each other for a very long time, suggests that culture exerts a strong influence over agroecosystem structure

The Influence of Culture on Agroecosystem Structure: A Comparison of the Spatial Patterns of Homegardens of Different Ethnic Groups in Thailand and Vietnam.

Different ethnic groups have evolved distinctive cultural models which guide their interactions with the environment, including their agroecosystems. Although it is probable that variations in the structures of homegardens among separate ethnic groups reflect differences in the cultural models of the farmers, empirical support for this assumption is limited. In this paper the modal horizontal structural patterns of the homegardens of 8 ethnic groups in Northeast Thailand and Vietnam are described. Six of these groups (5 speaking Tai languages and 1 speaking Vietnamese) live in close proximity to each other in separate villages in Northeast Thailand, and 2 of the groups (one Tai-speaking and one Vietnamese-speaking) live in different parts of Vietnam. Detailed information on the horizontal structure of homegardens was collected from samples of households belonging to each group. Although each ethnic group has a somewhat distinctive modal structure, the groups cluster into 2 different types. The Tai speaking Cao Lan, Kalaeng, Lao, Nyaw, and Yoy make up Type I while both of the Vietnamese groups, along with the Tai speaking Phu Thai, belong to Type II. Type I gardens have predominantly organic shapes, indeterminate boundaries, polycentric planting patterns, and multi-species composition within planting areas. Type II homegardens have geometric shapes, sharp boundaries, lineal planting patterns, and mono-species composition of planting areas. That the homegardens of most of the Tai ethnic groups share a relatively similar horizontal structural pattern that is quite different from the pattern shared by both of the Vietnamese groups suggests that the spatial layout of homegardens is strongly influenced by their different cultural models

Comparison of modal structural patterns of homegardens of different ethnic groups in Northeast Thailand and Vietnam (% of gardens having characteristic).

<p>Comparison of modal structural patterns of homegardens of different ethnic groups in Northeast Thailand and Vietnam (% of gardens having characteristic).</p

Classification system of horizontal structural characteristics of homegardens.

<p>Classification system of horizontal structural characteristics of homegardens.</p

Ethnolinguistic taxonomy of groups in Northeast Thailand and Vietnam [44].

<p>Ethnolinguistic taxonomy of groups in Northeast Thailand and Vietnam [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0146118#pone.0146118.ref044" target="_blank">44</a>].</p

Hierarchical cluster analysis based on percentages of modal characteristics of structural dimensions of homegardens of ethnic groups in Northeast Thailand and Vietnam.

<p>Hierarchical cluster analysis based on percentages of modal characteristics of structural dimensions of homegardens of ethnic groups in Northeast Thailand and Vietnam.</p

Map showing location of study villages in Northeast Thailand and Vietnam.

<p>Map showing location of study villages in Northeast Thailand and Vietnam.</p