Browsing by Subject "Elevational gradient"
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Item Pattern of Tree Species Richness along the Elevation Gradient of Modi River Basin in Annapurna Conservation Area, Central Nepal(Faculty of Botany, 2020) Khanal, Ram PrasadElevational diversity gradient is an ecological pattern where biodiversity changes with elevation. Main aim of this study was to find the relationship between species richness along the elevational gradients in southern aspect of Modi River basin Annapurna Conservation Area, Central Nepal. The study was carried out in three elevational zones namely lower (1000-1800m), middle (2000-2800m) and upper elevation (30003800m). Starting from 1000m at Birethanti and ending to 3800m at Machhapuchhare Base camp at an interval of 200 m. Two transects having 25m × 2.5m sizes were laid at each elevation band. R- Software, SPSS- Software and Microsoft Excel were used to perform the statistical analysis. All together 30 tree species belonging to 27 genera and 21 families have been documented. Among the 21 families Fabaceae was found to be the largest family having highest number of genera and species followed by Betulaceae and Anacardiaceae. Species richness of tree species showed bimodal pattern of distribution with elevational gradients. The tree species richness significantly differs along the elevational gradients within different sites. Tree species like Alnus nepalensis, Bombax ceiba were dominant in lower elevational zone; Rhododendron arboreum, Alnus nepalensis were dominant in middle and Betula utilis, Rhododendron arboreum were observed dominant in upper elevational sites. The size class distribution diagram of overall tree species showed reverse J shaped pattern indicating a good regenerating capability of the forest. The regeneration of Alnus nepalensis, Rhododendron arboreum and Betula utilis were higher in comparison to other tree species which was indicated by the higher density of 0-20 size classes of them. The Canonical Correspondence Analysis (CCA) diagram shows elevational gradient strongly affected the study area sites vegetation.Item Plant Diversity of Phulchoki Area, Central Nepal(Department of Botany, 2015) Gaire, BijayThe present study aims to find out the relationship between species richness along elevational gradient and forest types. The study was carried out in Phulchoki hill of Lalitpur district. In the study three types of forest have been categorized viz. Castanopsis Broadleaved forest,Mixed Broadleaved forest and Quercus semecarpifolia forest. The sampling plots wereconductedfrom lower altitude at 1600 m to the upper elevation at 2650 m. Fourquadrats of the size 10m×10 m was laid horizontally at interval of 100 meachon elevational band of 100m. Plant species were collected from July to August 2013. From the study a total of 230 plant species belonging to 185 genera and 84 families were recorded. Among 84 families Asteraceae was found to be the largest having 14 genera and 16 species each.From the total life forms of plants the angiospermic species richness isnearly equals in Mixed Broadleaved forest and Quercus semecarpifolia forest. From the overall IVI of tree species Quercussemecarpifolia was the dominant tree species with the highest importance value index(51.53), followed by Castanopsis tribuloides (34.38).The cause of the changes of species richness in different forest types may be due to changes in environmental factors. But there isincreasing trend of species richness along elevation. The Detrended correspondence analysis(DCA) diagram showed complete turnover of the species i.e., the axis length 4.05 SD units along environmental variables which showed that species is highly heterogenous and rich in beta diversity.On the basis of recorded species,it can be concluded that the study a rearich in plant diversity. Keywords: Species richness, forest types, elevational gradient, importance value index,detrended correspondence analysisItem Woody plant Species Diversity in a Subtropical-Temperate Ecotone Forest of Central Nepal(Department of Botany, 2015) Paudyal, Bhishma PrasadMain aim of this study was to find the relationship between woody species richness along the elevational gradients in a Subtropical-Temperate Ecotone Forest of Central Nepal. Forest stand was sampled on northern slope of Resunga Region, Gulmi district. Standard quadrats each of 10 m × 10 m size were laid after dividing the forest stand into seven horizontal bands of 100 m elevation. Five quadrats located randomly at least 100 m apart from each other were laid on each elevation bands using systematic sampling method. All the woody species present within the quadrat were recorded whereas herbs were recorded from both inside and outside of the quadrats in the study area. Plants having diameter more than 10 cm at breast height (137 cm) were considered as trees and other woody plants were considered as understory shrubs. Diameter at breast height (DBH) was measured for all individuals of trees. IVI and diversity indices were calculated for trees and understory shrubs. Altogether 236 plant species under 79 families and 191 genera were identified. Among them, 196 species of Dicots belong to 155 genera and 68 families; 39 species of Monocots belong to 34 genera and 10 families. Gymnosperm was represented by single species (Pinus roxburghii Sarg.). Woody species richness along the elevational gradient showed the hump shaped pattern with elevation. The Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) were used to show species composition of woody species.