Ecological Value and Change Sensitivity-Based Approach for Defining Integrity of Forests in West Himalaya, India

Abstract

The extent and diversity of Himalayan forests are well known, and evidence suggests these forests differ significantly from both tropical and temperate forests of the world. These forests are vulnerable to various perturbations (anthropogenic and natural). However, the extent of sensitivity for diverse forests is not known. Therefore, all forests are being treated equally for their conservation and management needs. Considering this, a repeat survey (conducted during 2010–2014) of some earlier studied (1988–1990) representative forest communities in part of Nanda Devi Biosphere Reserve (west Himalaya) provides evidence of importance level and change sensitivity of diverse forest communities. Various composition-based community indices, i.e., Community Importance Index (CII), Community Change Sensitivity (CSS), Community Threat Index (CTI), and Community Integrity (CI) score, were developed to signify importance of each forest community for conservation and management. Two most important communities that maintain compositional integrity in the region include Mixed Silver fir-Rhododendron-Maple (CII-90) and Quercus floribunda (CII-83) community. The Community Change Sensitivity (CCS) highlighted Q. floribunda (46) and A. pindrow (41) communities as most change sensitive, whereas Mixed Oak deciduous (CTI-93) and Q. floribunda (CTI-84) communities exhibited maximum threats of change. The overall scenarios of communities considering various priorities have been defined. Analysis of priorities, thus defined, suggests that different scenarios can be used for building strategies and management prescriptions depending upon the management objectives. The scenarios discussed herein are meant for (i) ensuring conservation of maximum plant diversity of the reserve by way of using CII, (ii) planning to accommodate the potential changes in community structure (i.e., shift in vegetation/species boundaries and/or change in dominance of forests, etc.) by building on CCS ranking, (iii) addressing the threats of non-native species proliferation through use of CTI, and (iv) defining community stability and resilience in a more holistic way using Community Integrity (CI) scores. The study for the first time provides diverse scenarios of management in regional forests.