Regeneration Ecology of Quercus species in Gaurishankar Conservation Area, Nepal
Subsistence hill agriculture is widely practise in the mid hill areas of Nepal, which creates a big dependence and pressure on the forests, and on Quercus semecarpifolia and Q. lanata species in particular. These species have an important provisioning service value due to their capacity of supplying fodder, leaf litter, firewood and timber. They are however being overexploited and moreover, Q. semecarpifolia forests are facing an imminent threat due their failure to regenerate. This study aims to provide insight into the ecology of their regeneration, and to assess the condition of selected forests. 42 cluster of plots were established in Gaurishankar Conservation Area (Central Development Region), distributed in different land uses and along different environmental conditions. Each cluster of plots contained 4 subplots (1m²) in which regeneration densities of the studied species, microsite covers, soil characteristics, light availability and distance to the closest potential mother tree were recorded. Furthermore, vegetation surveys were conducted in 20 plots. The least degraded forests of both species had a continuous regeneration, as well as the degraded Q. lanata forest. However, regeneration was almost absent in the degraded Q. semecarpifolia forest, which had a very dense layer of competing vegetation. Distance to the potential mother tree had a strong negative effect on both species, highlighting a seeds dispersity failure in the study area. Both species favoured thick organic soil horizons. Q. semecarpifolia seedlings showed a preference for shadier environments in opposition to Q. lanata. Overall, the results corroborate the failure of Q. semecarpifolia forests to regenerate under heavy anthropogenic pressure. Furthermore, the high ability of Q. lanata to cope with these human-induced disturbances has been confirmed. The results of the microsites variables study were used to develop guidelines for current and future restoration and afforestation projects in the area.