Managed Land

Carbon Plantations Model, description

General 

Carbon plantations form a separate land-cover class in IMAGE for assessing land-use-related activities as options for achieving stabilization of the atmospheric CO2 concentration, the ultimate objective of Article 2 of the United Framework Convention on Climate Change (UNFCC). The net C sequestration potential is used to quantify the additional C sequestration by C plantations in comparision with the natural land cover that would otherwise grow at the same location. Also quantified are the C losses associated with the conversion from natural land cover into a plantation. this potential is calculated as follows according to:

where C_seq is the net C sequestration in a grid cell in the period t₀ to 2100 (Mg C km^-2), t the year (2000-2100), t₀ the starting year of C plantations in a grid cell, NEP_{CP, t} the NEP for the tree species with fastest growth in a grid cell (Mg C km^-2 yr^-1), NEP_t the NEP of the original vegetation according the baseline scenario (Mg C km^-2 yr^-1), E the above ground C of the original vegetation (Mg C km^-2), and b the burning of the original vegetation (b is either 0 or 1). When a natural forest or woodland is converted to a C plantation, it is assumed that the original vegetation is burnt entirely (b = 1), resulting in instantaneous CO₂ emission (E). Hence, all C fluxes and pools in vegetation and soil are considered, including the C losses due to the establishment of the plantations. Alternative land-use options are considered in the allocation of plantations in order to avoid conflicts with, for example, food production.

Carbon plantation types

Six plantation types have been selected on the basis of the ‘Top 14 Most Planted World’s Trees’ (FAO, 2001; Del Lungo, 2003)to represent the most suitable species in different geo-climatic regions around the world. NPP and NEP for each plantation type are determined by multiplying the NPP of the natural land-cover type that best matches the tree species considered with an additional growth factor (AGF).

Plantation management

Two types of management practices can be considered: 

1. harvesting, whereby a plantation is harvested at the moment of maximum C sequestration, followed by regrowth; 
2. a plantation is not harvested but grows to a stable level of C storage after which additional C sequestration is limited.   

Costs

In addition to the biophysical model for C plantations, costs are included, enabling a comparison with other options to mitigate the build-up of CO₂ in the atmosphere. Costs in this respect refer only to land and establishment costs. Other types of costs are excluded for different reasons (e.g. compensation by revenues from timber). We refer to Strengers et al. (2006) and Van Vuuren et al. (2006) for details on the cost aspects of C plantations. More details on the Carbon Plantations modeling is in Van Minnen et al. (2006).

• to  external references
• to  MNP references