Influence of environmental variables on the distribution of woody species in Muslim graveyards of Malakand Division, Hindukush range mountains of Pakistan

摘要

Muslim graveyards are believed to be the most protected microecosystems and were regarded the most ideal habitats for natural vegetation due to special cultural roles and religious privileges. In the foothills of Malakand division, located in the Hindukush range mountains, these microecosystems have been substantially disturbed by the recent army incursion but still offer an opportunity for studying comparatively less disturbed vegetation where vegetation-environment relationships have hardly been explored. Therefore, we investigated the effect of environmental variables on the composition and structure of woody vegetation, crucial to understand for the conservation of these graveyards. An investigation of the vegetation and its associated environmental variables in thirty different graveyards was performed by using 10 × 10 m 2 plots resulted to encounter 2592 trees (DBH ≤ 5 cm) of twenty different woody species belonging to 16 families in the entire landscape. The cluster analysis identified five major community types with density and basal area ranging from 150 to 1620 trees ha -1 and 20 to 2523 m 2 ha -1 respectively. The analysis revealed that family Moraceae contributed maximum number of species followed by Rosaceae, Meliaceae and Fabaceae to the overall floristic composition. Canonical correspondence analysis (CCA) was used to assess the relative explanatory power of different physiographic and soil’s physical and chemical properties for the vegetation structure and composition. Significant interactions with elevation, soil clay, silt, sand, phosphorus and potassium suggest that several factors explained the spatial pattern but effect of physiographic factors were comparatively higher than soil factors on the vegetation composition. Thus, we predict that elevation coupled with soil physical and chemical properties are more influential and could be considered in vegetation restoration and conservation in these graveyards. Our results suggest that both local and regional scale analyses are warranted to disentangle the vegetation-environment relationships, if the ultimate goal is to conserve these less disturbed, self-sustainable ecosystems.