Since the 2000s, an increasing number of initiatives have been undertaken in the attempt to measure the physical quantities or the monetary values of ecosystem services. However, concrete methodologies for the quantification of ecosystem services are still to be developed; even the governmental, corporate and academic initiatives for the development of assessment frameworks on ecosystem services have their limitations.
Following this trend, and in recognition of the need for Japan to actively participate in the assessment of ecosystem services and to contribute useful information to the international discussions on these assessment frameworks, this study has been conducted to implement a trial on the quantification of ecosystem services in Japan. Its aim was to serve as a pilot study to deepen understanding on the pros and cons, as well as the challenges in quantifying ecosystem services.
In developing a framework for the quantitative assessment of ecosystem services under the current study, the various services have been organised into broad categories based on existing research and international discussions. A wide range of ecosystem services has been targeted under provisioning, regulating and supporting services, within diverse ecosystem types including forest, agricultural land, urban area, freshwater and coastal ecosystems.
We compiled in the report the evaluated ecosystem services by each ecosystem type, respective indicators to be quantified, and the quantification results in Chiba prefecture, which provide the overview of this study and a sense of the scale of each ecosystem service. As this quantification exercise was at the trial stage, a review of the results through verification of the parameters or comparison with other studies will be an essential next step to improve the credibility of the quantification results.
For more comprehensive, reliable and meaningful measurement of ecosystem services, further technological improvement, especially refine of methodologies, expansion of the scope and development of scenarios, will be required. These can be exemplified with the consideration of trade-offs (e.g. provisioning versus regulating) and synergies (e.g. water regulation and flood control) between ecosystem services, the evaluation of biological resources and biological control as well as cultural services, and the development of future land scenarios affecting the level of ecosystem services provision.
This research report is based on our trial study on quantification of ecosystem services, which was commissioned by the Ministry of Environment Japan (MOEJ) under the title of “Research on the Quantification of Ecosystem Services.”