Beschreibung:
Measuring and monitoring emissions from deforestation and forest degradation are central elements in a REDD scheme. Emissions from deforestation and degradation can be estimated from two important variables: (i) areal extent of deforestation and degradation, and (ii) carbon stock densities per area. Current remote sensing technology can adequately measure tropical deforestation; currently it is less useful for assessing forest degradation and forest carbon densities which thus rely mainly on ground measurements. To increase cost-effectiveness, sampling and stratification techniques have been developed for both remote sensing and ground-based monitoring. The two most common approaches in remote sensing are wall-to-wall mapping, and sampling. Data resolution is a decisive factor, and a trade-off exists between data resolution (and thus accuracy) and costs. Monitoring forest degradation is more challenging than mapping deforestation, requiring ground-based measurements in addition to remote sensing. Current approaches to estimating forest carbon stocks in tropical countries include biome averages, forest inventories, and remote sensing measurements. There are two fundamentally different, but equally valid, approaches to estimating emissions from deforestation or forest degradation: the stock-difference approach and the gain-loss approach. The second is likely to become the long-term objective, but the first is more applicable in the short-term.