Historical Change in the Flow Duration Curve for the Upper Nan River Watershed, Northern Thailand

Abstract

This study investigated the relationship of edaphic factors and tree composition were regenerated in 40-year old of restoration area and natural mixed deciduous forest at M 20 m x 20 m sampling plots were established in each sites; Pterocarpus macrocarpus (PMP), Tectona grandis (TGP), and Eucalyptus camaldulensis (ECP) plantation and composition of trees and soil were collected for analyze plant community and relationship with soil factores. The results showed 61 species 53 genera and 27 family all of 4 similarity index with MDF (63.64 %) higher than TGP and ECP. Suggestting that, P. macrocarpus had high ability for restoration, by induced native species establish in the The dominant species of MDF influenced by organic matter and clay, TGP affected by magnesium, but ECP persented at poor soil area. Suggesting that, soil properties af species for restoration, and changes environmental factors for native species establishment. Therefore, the forest restoration policy should begin with the selection of tree s each area, and potential to help adjust environmental factors and establishment ability of each species.