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Forest ecosystems provide human society with a number of ecosystem services (ES) essential for our wellbeing. In order to sustain the supply of ES humans have altered the natural ecosystems to various degrees and maintained them in modified states. However, forest ecosystems are inherently dynamic and adaptive and possess the capacity to respond to anthropogenic pressure, through changes in structure and composition. This implies that one forest type is not a static system and but rather a stage in a successional sequence of vegetation formations. Each stage of succession delivers a certain set of ES that may differ from the previous or forthcoming stages. The relationship between dynamism of forest structure and composition and ES essential for human well-â€Âbeing becomes even more important in areas where a large proportion of the population is dependent on forest resources, like the Himalayan region. This study intends to understand the interplay between human well-â€Âbeing and forest dynamics through three objectives each analysing vegetation dynamics, ES supply, and changes in flow of ES with disturbances, respectively. The dynamics and flow of ES from five vegetation types of central Himalaya (Grassland, Pine, Pine Oak, Open Oak, and Dense Oak), representing a theoretical successional sequence, was evaluated in this study.
A comprehensive vegetation survey, conducted as a part of the study, highlights that site condition across the study area do not inhibit the successional process instead anthropogenic disturbances including grazing, fire, and lopping act as primary drivers of change. The regeneration of late successional Oak, in particular, was severely hampered by chronic disturbances that arrest the progressive successional dynamics across the landscape. In terms of ES essential for local livelihoods, an intensive social survey covering 19 villages and 702 households revealed that oak forests were the most valued for their contribution to the supply of provisioning services. The mean quantity of products extracted per household per year was staggeringly high from dense oak forests as compared to any other vegetation type, with a steady decline in quantity extracted from late successional oak to pioneering pine forests and grasslands. Such trends in resource use along natural ecological succession clearly indicate that the late successional community is preferred in the region for ES supply. The net carbon stock also showed an increasing trend from early successional Pine (89.6 Mgha-â€Â1) to late successional dense Oak forests (378.3 Mgha-â€Â1). However, resource extraction practices (e.g. grazing, lopping, collection, and fire) used by the people to procure provisioning ES act as anthropogenic disturbances for the vegetation community, restricting the successional regime, creating a counter-â€Âproductive feedback mechanism between ES supply and vegetation dynamics.
The potential land cover changes in the absence of disturbance, and subsequent flow of ES from the study area, depend on the bioclimatic potential of the site to support Oak. Ecological niche modelling tool MaxEnt, used to identify the fundamental niche of Oak and Pine in the study area, reveals that potential distribution of both species in the absence of competition and disturbance can be much larger than their present distribution. In a no-â€Âdisturbance scenario the study estimates a 63% increase in the area under Oak forests which translates into a 51% increase in carbon stock, 88% increase in non-â€Âwood forest products, 56% increase in fuelwood, and 44% increase in fodder availability. However the slated increase in provisioning services would come at the cost of curbing present extraction by the local population. This trade-â€Âoff between maintaining present demand for provisioning services and ensuring sustainable supply of regulating and supporting ES for the future is the biggest challenge for landscape managers today. An understanding of trade-â€Âoffs between ES would enable forest managers to choose the best-â€Âsuited management regime depending on their aim and stakeholder demands.
The study concludes that present management approach grossly underutilizes the potential of the landscape for ES supply and the services coming from Oak forests can potentially be obtained from a much larger area. Potential trade-â€Âoffs and alternations in ES supply with changes in land-â€Âuse practices, presented in the study, can serve as baseline data for developing ecosystem services based landscape management plans.
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