Plant Communities and Vegetation Ecosystem Services in the Naran Valley, Western Himalaya
thesisposted on 12.06.2012, 13:42 by Shujaul Mulk Khan
The Naran Valley, western Himalayas, is of high floristic interest owing to its geographic location and altitudinal range. It represents other remote Himalayan valleys where rugged terrain and geopolitics restrict plant biodiversity and conservation assessment, but has experienced no previous quantitative ecological or ethnobotanical research. This study had three objectives: (i) assess species distributions and plant communities using phytosociological techniques; (ii) identify environmental gradients responsible for vegetation variation; (iii) quantify vegetation ecosystem services for indigenous people. Species attributes were measured along altitudinal gradients using transect and quadrat methods on slopes with different aspects (elevation range 2400-4100 m). One hundred and ninety-eight plant species from 68 families were quantified along 24 transects. Classification and ordination techniques (PCORD & CANOCO) identified 5 major plant communities. Indicator Species Analysis (ISA) and assortment of fidelity classes identified indicator/characteristic species. Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) showed altitude and aspect to be the strongest drivers of community classification. The vegetation changed from a moist-cool temperate community characterised by woody species, to dry-cold subalpine and alpine herbaceous communities both along valley sides and at higher elevations. Plant species diversity reached an optimum at mid-altitude (2800-3400 m) as compared to lower (2400-2800 m) and higher elevations (3400-4100 m). Questionnaire methods were used to record and quantify plant uses and indigenous ethnobotanical knowledge. Plant Use Values (UV) were calculated using quantitative ethnobotanical techniques while the phytosociological data yielded Importance Values (IV). UV and IV data were combined to illustrate anthropogenic influences, with a focus on rare, endangered and endemic species. This study contributes to an enhanced understanding of (i) plant diversity in the Western Himalayas; (ii) ethnobotanical and ecosystem service values of mountain vegetation within the context of anthropogenic impacts; (iii) local and regional plant conservation strategies and priorities.