Effect of Road Construction on Phytogeography of Herbaceous Flora in Areas Adjacent to Balakot-shogran Road, Mansehra District, N.W.F.P, Pakistan

Abstract

The distribution and abundance of major plant taxa along Balakot to Shogran road was examined. The sampling was carried out at places where rocky slopes were exposed due to road expansion and adjacent undisturbed plots. Frequency of most of the herbaceous species was lower in disturbed sites although the differences were not significant. Total plant cover however, was significantly lower in all sites disturbed due to road construction. The microtopography of rock substrate revealed a significant impact on amount of vegetation present and type of rock plus time of revegetation after being disturbed. Crustose lichens were particularly sensitive and their distribution was restricted to sites that were least altered or otherwise representing the early stages of succession. We found disturbance regime a major factor that decreased vegetation frequency and cover along road sites but a careful assessment of the geological and environmental factors must also be considered on vegetation dynamics.