Connectivity and Ecological Indicators Analysis of Tropical Forest Landscape in Batang Toru Watershed - Indonesia

Abstract

Connectivity is one of the important issues in the context of natural resources due to its potential in preventing the impact of habitat fragmentation. Landscape forest connectivity facilitates organism movement, genetic exchange, and other ecological material flows. Loss of connectivity may result declining of ecosystem production and cut the material flows within the forest ecosystems. Connectivity degree is needed to determine the management strategy of forest landscape as a wildlife habitat. This paper defines connectivity index of forest landscape in Batang Toru watershed, and describes correlation between connectivity with ecological indicators, biophysical and anthropogenic factors. Landsat satellite imageries acquired in 1989, 2001 and 2013 were used to detect land cover in several different years. Fragstat was used to generate landscape metrics. Landscape metrics were analyzed using a scoring method to determine the connectivity index of forest landscape. A Pearson correlation analysis was performed to obtain a correlation between connectivity index and the distance from roads, the distance from rivers, elevation and slope. The study found that the landscape connectivity tend to decline over the period from 1989 to 2013. The lowest connectivity index was found in the downstream area of Batang Toru watershed. Areas with low connectivity index were identified as having a relatively low diversity index of tree species. The connectivity index of forest landscape has a positive correlation with the distance from roads and the distance from rivers.