Comparison of remote sensing and plant trait‐based modelling to predict ecosystem services in subalpine grasslands

L Homolová,F De Bello,J G P W Clevers,W Thuiller,P Lamarque,S Lavorel,M E Schaepman

doi:10.1890/es13-00393.1

Abstract

There is a growing demand for spatially explicit assessment of multiple ecosystem services (ES) and remote sensing (RS) can provide valuable data to meet this challenge. In this study, located in the Central French Alps, we used high spatial and spectral resolution RS images to assess multiple ES based on underpinning ecosystem properties (EP) of subalpine grasslands. We estimated five EP (green biomass, litter mass, crude protein content, species diversity and soil carbon content) from RS data using empirical RS methods and maps of ES were calculated as simple linear combinations of EP. Additionally, the RS‐based results were compared with results of a plant trait‐based statistical modelling approach that predicted EP and ES from land use, abiotic and plant trait data (modelling approach). The comparison between the RS and the modelling approaches showed that RS‐based results provided better insight into the fine‐grained spatial distribution of EP and thereby ES, whereas the modelling approach reflected the land use signal that underpinned trait‐based models of EP. The spatial agreement between the two approaches at a 20‐m resolution varied between 16 and 22% for individual EP, but for the total ecosystem service supply it was only 7%. Furthermore, the modelling approach identified the alpine grazed meadows land use class as areas with high values of multiple ES (hot spots) and mown‐grazed permanent meadows as areas with low values and only few ES (cold spots). Whereas the RS‐based hot spots were a small subset of those predicted by the modelling approach, cold spots were rather scattered, small patches with limited overlap with the modelling results. Despite limitations associated with timing of assessment campaigns and field data requirements, RS offers valuable data for spatially continuous mapping of EP and can thus supply RS‐based proxies of ES. Although the RS approach was applied to a limited area and for one type of ecosystem, we believe that the broader availability of high fidelity airborne and satellite RS data will promote RS‐based assessment of ES to larger areas and other ecosystems.

Highlights

Human societies benefit from a multitude of resources and processes that are supplied by ecosystems
The best model for green biomass estimation was based on a narrow-band normalized difference (ND) index, whereas stepwise multiple linear regression (SML) provided the most accurate solution for other ecosystem properties (EP)
Green biomass was estimated with the lowest accuracy among all EP (R2 1⁄4 0.54), which was lower than the modelling approach (R2 1⁄4 0.70)

Summary

Introduction

Human societies benefit from a multitude of resources and processes that are supplied by ecosystems. They provide a vast range of services such as food, timber or clean water production, they regulate climate and diminish natural hazards, and they offer nonmaterial cultural assets (Costanza et al 1997, de Groot et al 2002, MEA 2005, Burkhard et al 2009). Explicit mapping of ES at different scales is required for sustainable land use planning and environmental decision making (Burkhard et al 2012). There is a growing interest in mapping of multiple ES and identification of areas with concentrated ES supply (Naidoo et al 2008, O’Farrell et al 2010, Lavorel et al 2011)

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Discussion

Conclusion