The methods and procedures described below are directed to those concerned with the assessment of the current status of carbon stocks, biodiversity and land degradation in a given geographical area, typically a watershed, and with the development of scenarios of carbon sequestration, biodiversity and land degradation or restoration resulting from potential land use and management changes.
The methods focus on taking stock of the current situation and then projecting the scenarios of changes that would occur if LUCs were implemented. In doing so, they do not attempt to concentrate on any particular type of ecosystem, i.e. forest, agriculture, pastureland, etc. Rather, they tackle the present land use in the geographic area of concern, i.e. the watershed. Thus, the focus is on assessing what is present in the area of concern, i.e. forests, agroforestry, agricultural crops or grasslands, or mixtures of the above, depending on the present land use in the ecological zone being assessed.
The methodology attempts to address the four main interlinked areas of concern, namely:
enhancement of carbon sequestration,
conservation of biodiversity,
prevention of land degradation,
promotion of sustainable land productivity.
The last area of concern is dealt with only indirectly, through formulating LUCs that meet the first three areas of concern but also provide for staple foods and income.
The meeting point of these concerns, crucial to addressing the interlinkages between them, is LUC.
These four areas of concern may be thought of as objectives that need to be optimized simultaneously. Interventions in any ecosystem in order to optimize the above objectives can be made through LUC and the improvement of ecosystem and land management practices. Thus, for any given area of the world, the methodology sets out to:
assess quantitatively the current situation regarding the objectives in turn (i.e. determine the status quo), except in the case of related issues that are not directly in line with the project objectives, such as food security assessment and poverty alleviation, which are assessed only qualitatively and indirectly;
assess quantitatively the improvements that can be made in the objectives by a given potential land utilization type (PLUT), including management practices, and generate scenarios consisting of land-use patterns that include the PLUTs that optimize the objectives;
outline participatory mechanisms that ensure stakeholder (farmer) participation in the selection of land-use patterns for a given geographical area (i.e. a watershed or subwatershed) and by and large serving as a forum for farmer information and participation in stating preferences values and aspirations;
optimize quantitatively the objectives through Pareto optimality criteria incorporating stakeholder preferences and aspirations that allow for reaching compromise solutions, generating optimal LUC scenarios at the watershed level;
provide a mechanism for upscaling and generalization of computed estimates.
The methodology consists of four main sections or modules (one for each main area of concern). Within each module, it assesses the current situation and evaluates promising alternatives by creating scenarios. The sections are:
the assessment of carbon stock and carbon sequestration potentials.
the assessment of the status of biodiversity and its potential changes implicit in an LUC.
the assessment of the current status of land degradation via its indicators, and the formulation of required land management practices for every suggested land utilization type (LUT) that would enhance the prevention of land degradation.
the simultaneous optimization of the objectives above, including constraints for food security and minimum income by means of multicriteria programming models.
Details of procedures and activities in each of the modules are provided below. The methods described are part of a proposal advanced as a methodological framework. The procedures may require adaptation to the particular circumstances of the environment where the framework is being applied. It is not claimed that the framework is perfect or complete. In some instances, it may require further elaboration for its implementation in practice. This report provides the technical details of the three main modular components of the methodology, namely:
assessment of carbon stock and carbon sequestration in present and potential LUT. This component module, in turn, can be divided into: (i) assessment of present land use; and (ii) assessment of potential land use. In both, present and potential land use, two main submodules need to be considered: (i) estimation of biomass (aboveground and belowground) and its conversion to C; and (ii) estimation of carbon sequestration in soils through computer simulation modelling of soil organic matter (SOM) and carbon turnover dynamics.
assessment of biodiversity status through the estimation of biodiversity indices from field data and geographical information systems (GISs).
assessment of the status of chemical, physical and biological land degradation through a parametric semi-quantitative approach based on indicator variables.
For reasons of length and detail, issues pertaining to multicriteria optimization are only dealt with conceptually. Thus, the following is a detailed description of procedures and methods by modules in that order.
