Ethnobotanical significance, species richness and ecosystem services of vegetation along an altitudinal gradient in Tehri Garhwal region, India

Abstract

The study examines variations in plant diversity across an altitudinal gradient of up to 2600 m above mean sea level (amsl) in Tehri Garhwal district of Uttarakhand, India. Using a survey questionnaire method, we analysed changes in tree diversity, habitat similarity, and the ecosystem services provided by documented vegetation. Local residents were interviewed to gather their perceptions of ecosystem services and the traditional uses of available plant species in their surroundings. This study documented a total of 235 plant species, identifying each by its altitude range and ethnobotanical significance. Among these species, 211 were found at an altitude range of below 1200 m amsl, while 199 and 95 species were recorded at 1200–1900 m amsl and 1900–2600 m amsl, respectively. The species were grouped under nine major ethnobotanical uses. More than one-third (38.3%) of species were classified as medicinally important and traditionally used by local inhabitants in hilly areas. Asteraceae and Fabaceae were the most prominent families, with 24 and 23 species, respectively. The most dominant genus was Ficus, represented by seven species. The Sorensen similarity index showed the highest similarity between lower and middle elevation communities, while the lowest similarity was between high and low elevations. Beyond their ethnobotanical uses, all documented tree species provided ecosystem services, such as 77 species offered provisioning services, 46 provided regulatory services, 20 contributed to cultural services, and 24 supported ecosystem processes. These findings highlight the critical role of vegetation in sustaining ecosystem services and the need for conservation strategies that integrate traditional knowledge.