A review of methods, data, and models to assess changes in the value of ecosystem services from land degradation and restoration

This review assesses existing data, models, and other knowledge-based methods for valuing the effects of sustainable land management including the cost of land degradation on a global scale. The overall development goal of sustainable human well-being should be to obtain social, ecologic, and economic viability, not merely growth of the market economy. Therefore new and more integrated methods to value sustainable development are needed. There is a huge amount of data and methods currently available to model and analyze land management practices. However, it is scattered and requires consolidation and reformatting to be useful. In this review we collected and evaluated databases and computer models that could be useful for analyzing and valuing land management options for sustaining natural capital and maximizing ecosystem services. The current methods and models are not well equipped to handle large scale transdisciplinary analyses and a major conclusion of this synthesis paper is that there is a need for further development of the integrated approaches, which considers all four types of capital (human, built, natural, and social), and their interaction at spatially explicit, multiple scales. This should be facilitated by adapting existing models and make them and their outcomes more accessible to stakeholders. Other shortcomings and caveats of models should be addressed by adding the 'human factor', for instance, in participatory decision-making and scenario testing. For integration of the models themselves, a more participatory approach to model development is also recommended, along with the possibility of adding advanced gaming interfaces to the models to allow them to be "played" by a large number of interested parties and their trade-off decisions to be accumulated and compared.