The impacts of soil and local humans on plant distribution and diversity in the fluvial floodplain, An Giang province

Abstract

Four types of alluvial soils in the fluvial floodplain of An Giang province were characterized by silt, porosity, slight acidity, and high nutrients. The results recorded 230 plant species of 80 wild plants and 150 cultivated plants, mainly medicinal and edible plants. Fabaceae, Poaceae, Asteraceae, and Cucurbitaceae were the most diverse families. Woody diversity was the highest in Orthofluvic fluvisols. The source of herbs was richest in Orthofluvic fluvisols but most diverse in Gleyic fluvisols. The RDA analysis showed that soil and humans played an equal role in plant diversity (relatively 7.0% explanatory variables by soil, 6.1% by human activities, and 12.6% by the combination of soil and humans). Porosity and silt affected the diversity in Anofluvic and Orthofluvic fluvisols while clay affected the diversity in Gleyic and Cambic fluvisols. Local people's planting habits and hobbies increased woody diversity while weed control and tillage decreased herbaceous diversity.