Ethno-ecological importance of plant biodiversity in mountain ecosystems with special emphasis on indicator species of a Himalayan Valley in the northern Pakistan

Mountain ecosystems support a high biological diversity and a large number of endangered plant species many of which are ecological indicators of those specific habitats. The Himalayas are the world's youngest, highest and largest mountain range and support a high plant biodiversity. People living in this region use their traditional ecological knowledge to utilize local natural resources and hence have valuable understanding about their surroundings. Many areas within this region still remain poorly known for their floristic diversity, plant species distribution and vegetation ecosystem services, yet the indigenous people depend heavily upon local plant resources and, through unsustainable use, can cause an irreversible loss of plant species. The valley used in this study is typical of such areas and occupies a distinctive geographical location on the edge of the western Himalayan range, close to the Hindu Kush range to the west and the Karakorum Mountains to the north. It is also located on geological and climatic divides, which further add to its ecological interest. This paper focuses on (i) identification of ecological indicators at various elevation zones across an altitudinal range of 2450–4100m and (ii) recognition of social perceptions of plant species populations based on the ecosystem services that they provide. We used robust approaches to identify the plant indicator species of various elevation zones. Using phytosociological techniques, Importance Values (IVs) for each plant species were calculated. The statistical package PCORDS was used to evaluate the species area curves and indicator species for each elevation zone. Data attribute plots derived from Canonical Correspondence Analysis (CCA) using CANOCO were deployed to illustrate the location of indicator species in each habitat type. Furthermore, the social perceptions of the local inhabitants as to whether the populations of the recorded species were increasing or decreasing over the recent past were recorded. We argue that the assessment of ecological indicators combined with the ecological knowledge of the indigenous population can assist in developing priorities for local and regional conservation strategies, especially for fragile mountain ecosystems.