The Role of Managed Forest Ecosystem: An Inventory Approach - The Greenhouse Gas Balance of Italy - page 59

and soils), scaling up measurements taken on field sample plots of tree biomass
correlated variables, deadwood and soil carbon content.
The National Registry for carbon sinks incorporates the INFC set of the first
phase sample points within a wider land use inventory system to enable the esti-
mate of GHGs removals/emissions associated to LULUFC activities in Italy
and corresponding uncertanities. Inter alia, the Registry is composed of two key
components:
• the land use inventory ( Inventario dell'Uso delle Terre —IUTI) aimed at
estimating the area covered by different land use categories, as defined by GPG-
LULUCF good practices , at given points in time (1990, 2000, 2008, 2012);
• the carbon stock inventory ( Inventario degli Stock di Carbonio —ISCI) targeted
to assess carbon stock changes in forest carbon pools by repeated assessments
on the field plots from the INFC third sampling phase.
The following sections are aimed at presenting the methodological framework of
the Italian National Registry for Carbon Sinks, as an exemplificative application of
the inventory-based approach to forest carbon accounting.
4.2 Building Up a Consistent Time Series by Integration
of Land Use and Forest Inventory
The National Registry for Carbon Sinks is conceived to implement a spatial-
temporal sampling strategy so to estimate GPG-LULUCF land use categories and
the state of forest carbon stocks and their changes over time. The use of formal
statistical procedures is a key advantage in comparison to other methods, such
as land use mapping; the reliability of the estimates of the quantities of inter-
est can be quantitatively evaluated by the corresponding uncertainties estimates
(Corona 2010 ; Corona et al. 2012 ; Travaglini et al. 2013 ). Sampling methods and
approaches for the estimation GPG-LULUCF land use classes and changes in for-
est carbon stock are further discussed in the next sections.
4.2.1 IUTI Land Use Inventory
The amount of lands under FM, AF/R and D activities can fluctuate over time
because of various land use changes. Land use transitions are associated with the
highest annual changes in carbon stock. Thus, IUTI is targeted to estimate GPG-
LULUCF land use categories area at given points in time, from 1990 to the end of
the commitment period, while providing adequate levels of statistical accuracy for
the administrative units selected for reporting under UNFCC framework in Italy
(i.e. district level).