Assessing Ecosystem Services across Scales: From methodological linkages to implementation

Abstract

Human activities and technical innovation have led to an unprecedented level of economic prosperity in society. However, they are also increasingly affecting the functioning of ecosystems: biodiversity is declining, and natural resources, such as soil and groundwater, are overused. These activities impact areas beyond those directly used by the benefiting society. The global degradation of ecosystems means that they are no longer or are only partially able to provide the services that society depends on. Moreover, restoring damaged ecosystems is costly and often impossible, partly because of their complexity. Ecosystems and the goods and services they provide—ecosystem services (ES)—are essential for human well-being as well as economic and social development. However, their importance is not sufficiently considered in planning. These services and goods are regarded as public goods that are freely available and do not require careful management or protection. The concept of ES aims to show the links between ecosystems and society and the contribution of ecosystems to human well-being. The value of these services (and thus the importance of functioning ecosystems) is insufficiently integrated into political decision-making processes, spatial planning considerations, and (local) management of natural resources. The characteristics and spatial distribution of ES need to be assessed to enable such an integration in the future. The same is true for the use of services and the intensity of demand. To this end, the existing assessment approaches must be further developed and expanded into a comprehensive, systematic assessment. By adequately assessing ES, they can also be integrated into regulatory impact assessments, environmental assessments, and planning to be considered in trade-off procedures. The concept of ES offers the opportunity to enrich such instruments with an array of arguments for the sustainable management of ecosystems. Thus, considering various ES and other aspects relevant to planning, synergies and conflicting objectives can be identified, and interests can be comprehensively balanced. The mapping and assessment of ES with the aim of integrating them into decision-making processes demand adequate methods to provide the required information in an appropriate manner. Many of the existing approaches meet these requirements to a limited extent only: they are not suitable for specific purposes, or their results are not directly usable for decision makers due to several reasons, including their complexity. The available methods and approaches are often tailored to defined objectives and thus cannot be transferred to other issues. The overall objective of this thesis is to improve the basis for the integration of the ES concept into spatial planning and decision-making. To this end, it is first of all necessary to gain knowledge about the suitability of methods for the respective purpose of use. In addition, methodological improvements must be achieved, particularly the linking of methods. Finally, it is necessary to develop concepts for the cross-scale application of methods for mapping and assessing ES. This leads to the following research questions. 1. Are the approaches and methods used in current ES assessments appropriate for their respective objectives? 2. How can qualitative and quantitative ES assessment methods be linked to improve ES assessments? 3. How can an ES assessment be designed and operationalized to be applicable across scales? These research questions were addressed through three articles that were submitted to and/or published in widely recognized scientific journals. The first publication shows how ES assessments are methodologically implemented and the extent to which the different approaches are appropriate for their respective purposes. In particular, it examines at what level of complexity, at what spatial scale, and for which objective assessments are applied and which ES are assessed. The results show that, in most assessments, the approaches used are consistent with the objectives pursued. This leads to the conclusion that there is an awareness that each objective imposes specific requirements on the respective application of the methods. It also shows that skills and resources are generally available for the respective implementations. There are therefore good preconditions for further embedding the ES concept and for encouraging the hitherto weak integration of this concept into policies and planning practice. Furthermore, this publication shows that different methods can be used within an assessment, but that these methods are not linked to each other to cover different aspects of an ES. The second publication demonstrates the linking of a model-based assessment approach with the user preferences of the public. The recreational suitability of the riverine zone in the canton of Zurich is assessed as an example. A comparison of the results of an expert model with the preferences of the potential users shows a clear correlation of the findings from both approaches, which are methodologically different. This opens up the possibility of developing expert-based models with a proportionate use of resources and refining them with social empirical methods. Finally, the third publication presents an approach to the development of a national ES assessment using indicators that can be applied at different scales and transferred to other countries. It is based on existing indicators and datasets and is compatible with international typologies of ES and their respective indicators. Suitable indicators for ES mapping are defined on the basis of an examination of the importance of various ES for Germany and an analysis of existing monitoring systems. The publication further shows how both the supply and demand for ES can be mapped with different indicators and datasets and how these indicators can be adapted for use at different scales. The following aspects are identified as key prerequisites for the implementation of such an assessment approach in spatial and landscape planning decision-making processes: (I) explicit consideration of synergies and trade-offs between ES in combination with consistent scalability for comparison at different planning levels, (II) spatially explicit information at the implementation level, and (III) consideration of supply, demand, and potential. In summary, this thesis makes important methodological contributions to the further development, combination, and application of different approaches to mapping and assessing ES. This thesis shows that, in many cases, especially for clearly defined issues, methodological approaches are already being used in a goal-oriented and appropriate manner, even though this is usually not done to develop comprehensive assessments of ES. Furthermore, it shows that approaches to assess ES can be combined with added value, as is particularly apparent in the case of cultural ES (CES). This thesis also shows that a comprehensive, cross-scale, cross-sectoral assessment is required to integrate ES appropriately into decision-making processes and that such an approach—built on existing datasets—is feasible and appropriate. However, the analyses also clarify that further efforts are needed to successfully integrate ES into planning and management decisions and thus ensure the long-term well-being of society. In this context, holistic approaches such as landscape approaches, can benefit from the concept of ES. These approaches aim to provide conceptual support in addressing challenges arising from competing land use interests and different objectives of various actors. The integration of the ES concept can support these approaches in the development of landscapes and socio-ecological systems.