PARENT SESSION
Poster Session 24: Agro-Ecology
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Field margins as reservoirs of biodiversity in agricultural landscapes in Chiang Dao, Thailand.

Paule, Audrey^*,1, Pai, Aswini¹, ¹ St. Lawrence University, Canton, New York, USA

ABSTRACT- Field margins in traditional tropical agroecosystems strive to preserve biodiversity in human-dominated landscapes. Visually distinct field margins separate small multicropped agricultural plots from adjacent forest areas in the dry deciduous ecosystems of Northern Thailand. We hypothesized that the angiosperm community in tropical field margins would be comparable to that of adjacent forest areas though the multicropped fields would be depauperate in plant species. Vegetation was sampled in forests, fields and field margins at three sites in Chiang Dao, Thailand using circular equidistant plots along transects of 160 m in length. Preliminary data analysis shows that margin and forest areas had the highest number of species (108 and 93 species, respectively) whereas field areas had 84 species. Measures of species richness and diversity for both tree and shrub species (H′ Forest = 3.37, H′ Field margin = 3.58) were comparable in forests (H′ Tree = 2.26, H′ Shrubs = 2.91) and field margins (H′ Tree = 2.48, H′ Shrubs = 3.06) though distinct from the multicropped fields (H′ Tree = 0.50, H′ Shrubs = 1.54). Principal component analysis based on species presence abscence data further indicated considerable overlap of species composition of forest and field margin communities. However there is a significant difference (F = , p < 0.0001 ) between field margins and forests in Importance Values derived for tree as well as shrub species indicating a difference in species population structures. Our results suggest that human selection plays an important role in maintaining and defining biodiversity in field margin areas.′

Key words: field margins, agrobiodiversity