Impact of Banana Based Agroforestry on Degraded Sal Forest (Shorea robusta C.F. Gaertn) of Bangladesh: a Study from Madhupur National Park

Over three decades various agroforestry systems have been introduced in Madhupur Sal forest in an attempt to check for over-exploitation, encroachment and agricultural expansion. An explanatory survey has been conducted to assess the impacts of banana based agroforestry system through respondents’ survey using a semi structured questionnaire, soil properties analysis and quantitative analysis of species diversity. A total of sixty farmers engaged in banana based agroforestry have been interviewed randomly from the two ranges of Madhupur National Park. A total of 50 plots (10m x 10m) were established randomly for quantitative analysis of species and twenty soil samples were collected for soil analysis from two land uses (25 in each) i.e. banana based agroforestry land use and in the Sal forest of Madhupur NP. Results obtained from soil analysis revealed that soil pH condition (4.62) and average organic matter (OM) content (2.57%) were higher in banana based agroforestry soil than that of Sal forest (pH 5.03 and OM 2.02%). Conversely, the amount of moisture content (11.62%) and Sulphur (S) were higher in Sal forest (66.06 μg/g soil). Biological diversity indices were calculated in order to check the status of species diversity for both land use systems. Indiscriminate use of fertilizers, chemicals in soil together with clearing forest for banana cultivation have been reducing the coppicing power Sal trees and destroying the biodiversity of the forest. A sustainable forest management plan giving priority on Sal trees on all degraded areas and creating alternative income generation activities for banana cultivators has been recommended highly in order to maintain the uniqueness of the forest.