The present study deals with impacts of fragmentation in vulnerable sub-tropical forest ecosystems of Jammu Siwaliks. The landscape analysis was performed with the objective to estimate and analyze the areas subjected to landscape dynamics by computing landscape indices using remote sensing and GIS techniques. The remotely sensed data derived vegetation map was used as input to fragmentation analysis. The classified map was evaluated for classification accuracy based on 750 field derived points laid separately for northern dry mixed deciduous (370), Himalayan sub-tropical scrub (280) and Himalayan sub-tropical pine forest (100) for quantitative sampling. The landscape parameters viz., fragmentation, porosity, patchiness, interspersion and juxtaposition have been evaluated for disturbance regime viz-a-viz biodiversity assessment and to evolve the conservation strategies thereof. The forest cover accounted for about 36% of the total area, whereas 33% of landmass was recorded fallow barren. It was observed that biodiversity levels are different in various fragments and with the changing fragments and patch size there is change in species richness and diversity. The spatial information generated thereof serves a vital input for effective forest management and in developing viable conservation strategies.