Mapping water-related ecosystem service for forest management
This research focused on developing a spatially-explicit method to map and assess a specific water-related ecosystem service (ES), the clean water provision service, under different scenarios of forest management. To meet forest certification and environmental impact assessment requirements is essential to prove that sustainable development is being applied with due diligence by forest managers. Mapping ES is a relevant support tool that can facilitate communicating the importance of ES to policy makers. Indeed, ES maps are key elements in understanding their spatial distribution over space and time, and integrating ES assessment into decision-making process. The developed mapping framework is based on a “proxy variables causal relationship approach” which is less complex to implement than hydrologic physical models and less subjective and more quantifiable/reproducible than expert opinions.
The proxy variables are calculated from available spatial data and then aggregated into an index or composite indicator. These proxy variables represent ecological function indicators (FI) necessary to describe the causal relationship to the water related service. The use of an index to map ES offers an interesting perspective for dealing with the multi-dimensional and complex nature of ES. It also facilitates results visualization into a single value. A robust index requires the independence of the selected FIs to avoid double account between ecological functions. The index is computed as a simple linear additive aggregation of a set of normalized (-1 to 1) and weighted indicators used to summarize the characteristics of the potential landscape capacities to provide the service. The Potential Capacity Index (PCI) has therefore been used to rank drainage catchments on a relative scale. The ranking highlights the most and the less sensitive catchments. It also identifies suitable management strategies and it supports prediction from future probable scenarios. Additionally, the index approach allows a stage-wise approach with feedback, revision, and reiteration at the selection of Function Indicator stage after computing the index. However, the construction of each index should be carefully conducted, in order to avoid misrepresentations of ES which can lead to unsuited management recommendations. Weight allocation of FI and the visualization scale of the potential capacity index can both lead to potential biais. The main challenge in the literature for the ES mapping is the lack of validation method of the results.
In our study, we proposed two alternatives for validation. The first evaluation alternative involves a questionnaire given to a reduced set of experts (forest managers, land management experts, research scientists). The questions deal with the relevance of all FIs found in the literature prior to selecting the independent set of FIs for mapping the ES. The second evaluation alternative involves comparing the Potential Capacity Index value with sediment runoff (tons/ha) simulated using the hydrological SWAT model. Comparisons are realized with Spearman’s ranks statistical analysis. Additionally, collecting water samples to be analysed for sediment content is another alternative not yet tested to improve the robustness of SWAT model simulations.
Schmidt, A., Fournier, R. A., Luther, J. E., Elkins, B., Van Lier, O., Pittman, B., Hearn, D., Knott, F., Harris, D., Hearn B., (2017) A multi-indicator framework for mapping the potential impacts of forest management activities on aquatic ecosystem services. Oral presentation. Colloque annuel du Centre d’étude de la forêt, Montréal, QC, 1-2 mai 2017.
Schmidt, A., Fournier, R. A., Luther, J. E., Elkins, B., Van Lier, O., Pittman, B., Hearn, D., Knott, F., Harris, D., Hearn B., (2017) Cartographie et évaluation des impacts potentiels des activités forestières sur les services écosystémiques aquatiques. Présentation orale. Conférence Vision Géomatique, Sherbrooke, QC, 17-19 octobre 2017.
Schmidt, A., Fournier, R. A., Luther, J. E., Elkins, B., Pittman, B., Hearn B., (2016). Cartographie des impacts des pratiques forestières sur les services écosystémiques de la forêt. Affiche. Colloque annuel du Centre d’étude de la forêt. Montréal, QC, 2-3 mai 2016.
Schmidt, A., (2015). Spatially-explicit quantification and map of forest ecosystem services. Oral presentation at Corner Brook Pulp Paper Limited. Meeting to define Study on Ecosystem Services, Corner Brook, NL, 17 June 2015.
Schmidt, A., (2016). A multi-indicator framework for mapping the potential impacts of forest management activities on aquatic ecosystem services. Oral presentation – Corner Brook Pulp Paper Limited – Update meeting, Corner Brook, NL, 19 July 2016.
Schmidt, A., Fournier, R.A. and Luther, J.E., (2016). Mapping the impacts of forest management activities on aquatic ecosystem services provided by forest. Methodological framework. Oral presentation at AWARE First Annual General Meeting, Corner Brook, NL, 25-26 May 2016.
Schmidt, A., Fournier, R.A. and Luther, J.E., (2017). A multi-indicator framework for mapping the potential impacts of forest management activities on aquatic ecosystem services. Preliminary results. Oral presentation at AWARE Second Annual General Meeting, Edmundston, NB, 17-18 May 2017.
Schmidt, A., (2017). A multi-indicator framework for mapping the potential impacts of forest management activities on aquatic ecosystem services. Preliminary results. Oral presentation at Corner Brook Pulp and Paper – CBPP Update, Corner Brook, NL, 15 June 2017.