4.2.2 Intensive monitoring sites
Intensive monitoring sites such as long term ecosystem research projects and national or even regional research observational and experimental plots can provide useful data sets for developing estimates of change in carbon density following land use changes. Unlike statistically based forest inventories, intensive monitoring sites generally use purposely selected sites and these networks of plots commonly consist of few (sometimes only one) large plots where the focus is on ecosystem functioning and processes. These typically have a long history of repeated measurements of a common and comprehensive suite of ecological variables relevant to producing estimates of emissions and removals, to a greater level of detail than may be available from extensive statistically based forest inventories alone.
Data from intensive monitoring sites can be used to develop emissions and removals factors or to parameterize models to scale-up estimates to regional and national levels when combined with remote sensed and national forest inventory data. Typically intensive field observations are used to assess effects of individual REDD+ activities and natural disturbances on above- and below-ground biomass, litter, deadwood and soil organic carbon pools. To be useful original data sets (not just means and distributions) should be available and data collection protocols documented and data quality checks undertaken. These characteristics are important for transparent reporting and assessment of generated estimates.
Intensive monitoring sites can be part of the ground data referred to in the decision tree on national choices in emission and removals estimation (Figure 13). To be useful, data collection at these sites should be harmonized as described in the notes for decision point 3 in the decision tree. They may facilitate inclusion of below-ground biomass using country-specific data rather than generic root-to-shoot ratios, and help with inclusion of non-biomass pools, and the inclusion of non-CO2 gases. This information may be used to supplement data and information necessary to transition to higher tiers in MRV systems. These sites can provide detailed information about physiological parameters to develop and test models of carbon exchange, and to relate carbon fluxes to remote-sensing data. Data collection and analysis are combined across multiple spatial and temporal scales, with intensive and detailed studies providing specific information to scale-up through the use of remote-sensing techniques, extensive forest inventories and empirical and process modelling (Birdsey et al., 2013).