Relationships between ecosystem condition and ecosystem services at different spatial scales

Abstract

Land degradation is one of the main drivers of decline in biodiversity, ecosystem condition and services. Agricultural expansion is the main form of land-use change and causes adverse effects on forests, wetlands, grasslands and their capacity to provide ecosystem services. Some of the most significant impacts of land degradation related to agricultural expansion occur in the soil. It causes the deterioration of soils' physical, chemical and biological characteristics and reduces the vegetation cover in the long term. Soil erosion is a direct consequence of land degradation, and it reduces nutrients and agricultural productivity and causes sedimentation and flooding in areas where the washed-out soil accumulates. Therefore, monitoring and measuring ecosystem condition are relevant to recognise early signs of land degradation. At the same time, the analysis of the relationship between ecosystem condition and the provision of ecosystem services helps identify priority areas where specific parameters need improvement to guarantee the sustainable provision of ecosystem services. Thus, the objective of this thesis is to improve the knowledge about ecosystem condition assessment and the relationship with ecosystem services. The aims are: (1) to identify the indicators used in Europe to assess ecosystem condition; (2) to test the indicators proposed by MAES to assess ecosystem condition; and (3) to analyse the relationships between ecosystem condition and services at a regional and continental scale using as an example the ecosystem service control of erosion rates.

First, the thesis provides some background information about ecosystem condition and services, emphasising on agroecosystems and control of erosion rates. Afterwards, a description of the methods used for the assessment is presented, followed by the research questions that guided the subsequent chapters.

Second, chapter 2 presents the literature review results on ecosystem condition mapping and assessment in Europe. The aim is to provide an overview of the state of research and highlight some limitations when evaluating ecosystem condition and services. The results show some gaps in ecosystem condition mapping, principally related to the methods used and the coverage of ecosystems. The outcomes indicate the need to explore the relationships between ecosystem condition and the capacity of ecosystems to provide services. The findings also highlight the need to improve the applicability of condition indicators in policy and decision making.

Third, based on the research gaps identified in the literature review, chapters 3 and 4 test the MAES indicators and analyse the relationship between agroecosystem condition and the ecosystem service control of erosion rates in Northern Germany and Europe, respectively. The studies follow an operational framework for the integrated mapping and assessment of ecosystems and their services. The results show an uneven distribution of the condition indicators across the study and positive, negative, and no significant correlations between the different pressures and conditions and the control of erosion rates with considerable regional differences.

This thesis concludes with a discussion of the main findings and the conclusions based on the most relevant results. Finally, the report ends with some practical recommendations and an outlook on future research.