Land Quality Assessment and Monitoring:The Next Challenge for Soil Science

Sustainable land management (SLM) is the key to harmonizing environmental and ecological concernsof society with the economic realities of producing adequate food and fiber of high quality and ensuring abasic minimal quality of life. The aim of SLM is to maintain the integrity of the biophysical land resourcebase, but it can only be realized if land users understand the impacts of land management options on theirlands but also on other off-site areas and can optimize the socioeconomic and environmental benefits of theirchoice. To facilitate this, the contribution of soil survey organizations would be through the assessment andmonitoring of land quality. Land quality is a measure of the ability of land to perform specific functions and isderived by an integration of soil survey information with other environmental, and if necessary, socioeconomicinformation. The desired reliability influences the operational scale of the assessment. Such an assessmentwould assist in: 1) locating homologous areas for research sites or for transferring technologies; 2) providingthe geographic basis for systems analysis (e.g. by modeling); 3) serving as a basis for local, national andglobal resource assessment and monitoring; 4) providing an ecosystem context for land use, assessments oftemporal and spatial variability, and impact of human interventions; 5) serving as a framework for moredetailed assessment for all levels of interest; and 6) evaluating global issues such as food security, impacts ofclimate change, biodiversity monitoring, and addressing desertification.Based on an evaluation of the progress made in soil resource inventories and considering the demandsof the environment focused world, the paper considers the need for countries to mount such a program. Theauthors believe that this is the next demand of soil science and that we can fulfill our social contract byperiodically providing such information on the state of a nation's land resource.

Evaluating the Spatial Uncertainty of Future Land Abandonment in a Mountain Valley(Vicdessos, Pyrenees-France): Insights from Model Parameterization and Experiments

European mountains are particularly sensitive to climatic disruptions and land use changes.The latter leads to high rates of natural reforestation over the last 50 years. Faced with the challenge of predicting possible impacts on ecosystem services,LUCC models offer new opportunities for land managers to adapt or mitigate their strategies.Assessing the spatial uncertainty of future LUCC is crucial for the definition of sustainable land use strategies. However, the sources of uncertainty may differ, including the input parameters, the model itself, and the wide range of possible futures. The aim of this paper is to propose a method to assess the probability of occurrence of future LUCC that combines the inherent uncertainty of model parameterization and the ensemble uncertainty of the future based scenarios. For this purpose, we used the Land Change Modeler tool to simulate future LUCC on a study site located in the Pyrenees Mountains(France) and two scenarios illustrating two land use strategies. The model was parameterized with the same driving factors used for its calibration. The definition of ‘static vs. dynamic' and ‘quantitative vs.qualitative(discretized)' driving factors, and their combination resulted in four parameterizations. The combination of model outcomes produced maps of the spatial uncertainty of future LUCC. This work involves adapting the definition of spatial uncertainty in the literature to future-based LUCC studies. It goes beyond the uncertainty of simulation models by integrating the uncertainty of the future to provide maps to help decision makers and land managers.