Evaluating suitability of land for forest landscape restoration: A case study of Three Gorges Reservoir, China

Abstract

Restoring degraded lands is now a global priority for conservation, and world leaders even made positive commitments to do so as part of the Bonn Challenge. Forest Landscape Restoration, which focuses on improving ecological functioning, biodiversity conservation and human livelihoods was introduced to meet these restoration goals. However, the restoration can be carried out only after a series of evaluations. One such evaluation is that of land for its suitability for forest landscape restoration and has become the basis for successful restoration of forest landscapes. A land suitability assessment method for forest landscape restoration is therefore fundamental. This study introduces a matter-element model-based methodology to assess land suitability for forest landscape restoration. The case study was evaluated in terms of altitude, slope, aspect, soil depth, soil type, and nutrient status of soil, all of which greatly influence the type of vegetation and plant growth. The results showed that the main factors influencing forest restoration in Zigui were altitude, slope, and soil depth. Roughly 100 km2 are suitable for restoration in Zigui County, accounting for about 60% of the theoretical recoverable area, a little more than one-third of which consists of slopes steeper than 25° and approximately 16% consists of slopes between 15° and 25°. The area under low quality forest land is a little over 40 km2, that under low quality garden land is roughly 15 km2, and that under sloping cultivated land is 40 km2. Evaluating the suitability of land for restoration can serve as a basis for forest-restoration projects and structural adjustments in shelter forests in this fragile area. Specifically, this method of evaluation can be replicated on different spatial and temporal scales and represents a new framework for evaluating the suitability of land for restoration of forests in other regions as well.