FOREST METHODS

Forest estimations constitute a valuable tool to help decision making in forest management. It helps to assess the wood resources, biomass, mineralomass and carbon stock available in forest ecosystems. Hence, it provides essential information for policy planning and forest resources management. Due to their large surface area, time and means to achieve reliable results, the assessment of forest resources is often based on estimation. Therefore, minimizing estimation errors becomes an important issue for reliable decision. The Forest Estimations research unit falls thus into the overall perspective of the development of accurate and robust methods for estimating forest resources.

How to estimate the nutritional risk due to the increased harvesting forest biomass? Development of a methodology and application to native oaks (Quercus petraea, Quercus robur)

Forest bioenergy is gaining more and more interest because of the volatility of energy prices, some dependence towards the imports of energy, and net emission reduction targets of greenhouse gases. However, this increase in demand for biomass in the form of wood energy may negatively affect the preservation of forest ecosystems under certain conditions. Unsuitable or badly practiced harvests can cause significant export mineral nutrients harmful to the chemical fertility of forest ecosystems in the short-, medium- or long-term. It is therefore important to specify the allowable harvest rates according to the stations potentialities and susceptibilities. It is in this context that the present project is designed to determine the woody biomass harvesting level compatible with the long-term maintenance of the chemical fertility of forest ecosystems. This study aims to develop a decision-making tool for estimating mineral exports related to the management of broadleaves forests dominated by beech (Fagus sylvatica) and native oaks (Quercus petraea and Quercus robur) and to assess the risk to the maintenance of long-term fertility by type of stands, silvicultural scenarios and soil characteristics. On this basis, dedicated management guidelines will be established. For more details, contact Paul-Igor Ablo HOUNZANDJIA quantitative framework to assess ecosystem services provided by forests and trees in a landscape context

Many people depend on both natural and planted forest ecosystems as sources of varied goods and services. With the ongoing rapid growth of the world population, which increases resource demand, approaches for landscape management to optimize delivery of services are required. As tree species growing on different land uses perform differently, it is important to understand the relative contribution of tree species and forests to the provision of services and to the livelihoods of people. Moreover, the mere provision of an ecosystem service in a landscape is not guaranteed to contribute to human well-being, because people gain benefits from these services differently, according to their accessibility to these resources. The social perceptions towards ecosystem services from different land uses may help to identify the trade-off and the most important/relevant services to people. Through this research project, we are studying how land uses affect key ecosystem services such as timber, carbon sequestration, diversity maintenance and pollination; we are also modelling the effects of these land uses on the utilization of forest provisioning goods such as timber and firewood, edible plants, honey, edible fruits, edible insects, medicinal plants and mushrooms by local people. The project is implemented in a landscape of natural forests and plantations in South Africa. The results will contribute to minimize the conflicts between land uses and support the decision for sustainable and holistic landscape management. For more details, contact Sylvanus MENSAH