Plant and soil diversities in a sub tropical forest of the Garhwal Himalaya
The forest plays a significant role in influencing the structure of the soil by adding organic matter and also affects its basic status and nutrient level. The ability of the soil to retain and the percolation of water depend upon the percent amount of sand, silt and clay. Biotic disturbances generally have caused substantial reduction in forest cover. It has been observed that among the aspects the regeneration status of species was poor. A number of studies relating to regeneration of either specific species or the forest stand as a whole have focused on the impact of anthropogenic factors and natural disturbances. In general, human interference and other causative factors such as grazing, browsing, trampling are severely affecting the regeneration of this region. The study sites were dominated by Anogeissus latifolia, which is the most important fodder, fuel wood and timber tree for local people. Therefore, the heavy pressure of villagers by lopping of leaves, cutting new saplings and tree branches especially for firewood, are leading to poor regeneration. Among the aspects the average range of values of soil pH (6.33 to 6.47), soil organic carbon (0.47 to 0.68 %), phosphorus (9.67 to 10.67 Kg ha-1) and potassium (141.87 to 172.48 Kg ha-1) were recorded. The total highest density of tree layer (380 trees ha-1) was observed on south aspect, whereas the lowest (260 trees ha-1) was recorded on west aspect. In shrub layer, the total highest density (1790 shrubs ha-1) was recorded on east aspect and the lowest (970 shrubs ha-1) on west aspect. The range of values of total density and total basal cover of saplings were 200 to 550 saplings ha-1 and 0.78 to 1.43 m2 ha-1 respectively. Similarly for seedlings layer, these values ranged from 80 to 430 seedlings ha-1 and 0.01 to 0.034 m2 ha-1 respectively. The values of similarity among the aspects and different layers ranged from 25.0 to 66.67%, 22.22 to 57.14%, 28.57 to 57.14% and 57.14 % to 72.72% for trees, saplings, seedlings and shrubs respectively. The range of diversity was 0.846 to 1.710 (trees), 1.943 to 2.847 (shrubs), 1.10 to 1.520 (saplings) and 0.496 to 1.435 (seedlings).
Keywords: Diversity, disturbance, layer, Anogeissus latifolia, Garhwal Himalaya
Ghana Journal of Forestry Vol. 19 & 20 2006: pp. 1-19