The third and fourth stage of ecosystem thinking (Mace, 2014) requires a concept that takes into account the mutual connection between society and the natural environment. The concept of ecosystem services has been a major success in attempting to bridge the gap between the two elements. The idea of ecosystem services as a concept in today’s thinking has been developed over years of academic and applied work and gained recognition in management policies in the public and private sectors (Waage & Kester, 2013), as well as on the societal level (Beery et al., 2016). The understanding of the pressures and drivers in and on the environment has increased and the impacts of nature on humans, and vice versa, has led to a much better understanding of the goods and services required and provided by the environment.
The concept of ecosystem services has, as Gómez-Baggethun et al. (2010) point out, developed from a mainly pedagogical concept, which aimed to raise public interest for biodiversity conservation. The term, coined by Ehrlich & Ehrlich (2008) and further developed in Ehrlich & Mooney (1983) for the use in the context of species disappearance.
26 Despite this limited initial ambition, the concept has widened in its use, and is also used for economic purposes with an emphasis on the commodities associated with ecosystem services and their influence on markets (Gómez-Baggethun et al., 2010; Peterson, Hall, Feldpausch-Parker, & Peterson, 2010), and in the field of Natural Capital (Costanza et al., 2006; Natural Capital Committee, 2017b).
Ecosystem services can be understood as aspects of ecosystems, that through their active or passive use, produce direct or indirect contributions to human well- being (Fisher, Turner, & Morling, 2009; TEEB, 2010a). This supports the idea to combine the assessment of ecosystem services in recognition of human activity, because humans as beneficiaries of these services play a crucial role in the perception of the received services.
While the term ‘ecosystem service’ has been used in different contexts and by different assessment approaches (e.g. Millennium Ecosystem Assessment, UK National Ecosystem Assessment, The Economics of Ecosystems and Biodiversity), its use remained largely similar: organising and conceptualising science and knowledge of ecosystems into a social context (Danley & Widmark, 2016). With regard to the use of the ecosystem approach and the idea of ecosystem services in the light of socio-ecological systems, it is relevant to discuss the change in definitions of the term to be able to use a definition that is relevant to this research project and the intended methodology.
The term ‘ecosystem service’ has been defined multiple times. In the Millennium Ecosystem Assessment (2005b, p. 78) it is described as ‘the benefit humans obtain from ecosystems’. As described in the previous section, the term emerged around the millennium, when the connection between humans and the environment became a focus in environmental management. The ‘service’ that the environment provides is always linked to humans, through direct or indirect services to form a socio-ecological system (Costanza et al., 1997). Generally, four categories are recognised when classifying ecosystem services. Supporting services form the basis of all other ecosystem services by providing the essential elements of natural processes and the basic elements for all other ecosystem services. Provisioning, regulating, and cultural services are those services that form final ecosystem services, and which can finally be translated into benefits.
27 An example of the structure of ecosystem services derivation from structures and processes is shown in Figure 9 for an industrialised estuarine environment (Jacobs et al., 2015). The figure gives an impression of how processes in a particular habitat impact the reception of benefits for humans through interactions with other functions. Several structures and processes form intermediate service, which again translated into final services, or are directly related to benefits for humans. It becomes clear that every process is highly site-specific regarding its final ecosystem services and benefits rely highly on site-specific conditions.
28
Figure 9 From structures and processes to ecosystem benefits of ecosystem services in industrialised estuaries, based on Jacobs et al. (2015). The coloured arrows are used for improved readability to show the process from structures and processes to benefits.
29 In the last decades, the definition of ecosystem services has been evolving and changing. In the previous sections, the term ‘ecosystem services’ has been used regularly, without the need of commitment to one particular definition. This alone shows that the concept of ecosystem services is a versatile approach and tool that can be used in multiple conceptions (Lele, Springate-Baginski, Lakerveld, Deb, & Dash, 2013), that allows a general understanding, based on a basic definition. Danley & Widmark (2016) highlight that the debate regarding a definition of ecosystem services is based around three overlapping ideas: i) the physical component (structure), ii) the functioning and interaction of the physical components (process), and iii) the resulting contribution to human well-being from the ecosystem (benefit).
Different definitions are listed in Table 2. Originating from a natural science background, the initial definitions of ecosystem services were based on the functions and processes that were observed to influence and sustain human life (e.g. Daily (1997)). Around the same time, the approach of economic valuation created new ideas of how ecosystem services were perceived by the scientific community. Costanza et al. (1997) described goods and services which could be used as a means to represent and calculate the benefits humans receive from functions. This takes the definition of ecosystem services a step further than Daily (1997), but relates it to functions and processes in an ecosystem.
Possibly the most commonly used definitions are those originating from the Millennium Ecosystem Assessment (2005) and TEEB (2010b). Even though not mentioned in the Millennium Ecosystem Assessment definition of ecosystem services directly, both definitions incorporate direct as well as indirect services, therefore, including underlying supporting services. Those, in turn, can be defined as the functions and processes, and structures behind the final benefit of the nature’s provision of services. The consideration and use of underlying structures and processes is important when these aspects are the focus point of a research project. As discussed previously, the focus on the explicit functions and processes in a system relates to the idea of understanding the system to either improve it, or maximise its value for resource abstraction. In research which focused on the final ecosystem services and well-being, supporting services are not necessarily always directly considered in the assessment, but recognised as underlying
30 functions (Atkinson, Bateman, & Mourato, 2012; Downing et al., 2014). The idea of socio-ecological systems and the incorporated human well-being aspect is not yet included in those definitions.
Table 2 Definitions of ‘Ecosystem Services’ ordered chronologically.
Author Definition Source
Daily ‘Ecosystem services are the conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfil human life.’
Daily (1997, p. 3)
Costanza et al. ‘Ecosystem goods (such as food) and services (such as waste assimilation) represent the benefits human populations derive, directly or indirectly, from ecosystem functions.’ Costanza et al. (1997, p. 253) Millennium Ecosystem Assessment
‘Ecosystem services are the benefits people obtain from ecosystems.’
Millennium Ecosystem Assessment, (2005d, p.53) Boyd and Banzhaf
‘Final ecosystem services are components of nature, directly enjoyed, consumed, or used to yield human well- being.’
Boyd & Banzhaf, (2007, p. 619)
TEEB ‘The direct and indirect contributions of ecosystems to human well-being.’
TEEB (2010b, p. 19)
UK National Ecosystem Assessment
‘The benefits people obtain from ecosystems.’
UK National Ecosystem Assessment, (2011, p. 84) CICES ‘[Final ecosystem services are] the
contributions that ecosystems make to human well-being.’
Haines-Young & Potschin, (2013, p. 8)
The most recent definition (Haines-Young & Potschin, 2013) concentrates on the final ecosystem services, not taking into account the intermediate services that
31 may or may not occur in a system as they are dependent upon specific site conditions. As Danley & Widmark (2016) point out, this makes it possible to include a range of non-tangible ecosystem services, instead of concentrating on the physical environment. However, after years of research and debate surrounding the definition of ecosystem services, even the most recent research is not able to create consistent answers or definitions, as Saarikoski et al. (2015) describe with the example of cultural ecosystem services within the CICES approach or Costanza et al. (2017), reviewing the ecosystem service definitions of the past twenty years.
It is apparent that it is ultimately the decision of the respective researcher which ecosystem services are included in the research, depending on the socio- ecological composition of the system in question. Therefore, in this context, it is ‘more useful to express that nature is important to human welfare than it is useful to carefully and deliberately specify how one identifies ecosystem services among nature’s structures, processes, and benefits’ (Danley & Widmark, 2016, p. 136). It emerges that it is important not to get carried away defining all elements in the ecosystem, if the ecosystem service assessment is aimed at making ecosystems more manageable, as otherwise the system’s complexity is overwhelming and manageable portions not possible to be identified.
2.6. Ecosystem Approach and Ecosystem Assessment – International