The Effect of Different Slope Aspects on Plant Diversity and Soil Characteristics in a Temperate Grassland of Kumaun Himalaya

A floristic and structural survey of a natural temperate grassland community was conducted in the Nainital district of Kumaun Himalaya, India, to examine the effect of slope aspect as one of the topographical factors on the vegetation composition and soil characteristics. Structural data was collected by sampling the vegetation from three slope aspects viz. North aspect (NA), East aspect (EA) and South aspect (SA). Three permanent plots of 20 m × 20 m were established at each aspect and within each of these plots 10 quadrats of 1 m × 1 m were placed randomly, and various ecological parameters were determined. Soil samples were collected from 2 depths i.e. 0–15 cm (surface layer) and 15–30 cm (subsurface layer) and soil characteristics were determined. A total of 22 species were recorded out of which NA had 16 species belonging to 8 families, EA had 14 species belonging to 9 families and SA had 7 species belonging to 5 families. Density, total basal area, diversity, evenness, and biomass showed significant effects of slope aspect. Significant positive relationships between ecological parameters (density, total basal area, diversity, species richness, and biomass) with soil characteristics (moisture, temperature and water holding capacity) suggested strong influence of edaphic variables on ecological parameters. NA contained more moisture, had a higher water holding capacity and lower soil temperature as compared to SA which encourages the herbaceous vegetation and facilitates the growth of species.