Ecosystem services and service cascades

ES is a concept aiming to link ecosystems and human well-being in order to incorporate the values human place on ecosystems and the effects of management changes on human well-being into decision making (see e.g. Chee, 2004; de Groot et al., 2002; Farber et al., 2002;

Turner & Daily, 2008). The scientific discourse about ES did not emerge before the late 1970s (Gomez-Baggethun et al., 2010). Still, awareness about services provided by ecosystems or rather negative impacts due to degradation of ecosystems dates back to the ancient world when, for example, Plato wrote about negative impacts of deforestation of the hills of Attica (Mooney

& Ehrlich, 1997). The concept gained popularity since the 1980s (Ehrlich & Ehrlich, 1981) and since the Millennium Ecosystem Assessment (2003) the scientific interest in ES and their valuation has risen substantially (Fisher et al., 2009; Kull et al., 2015).

A unique definition of ES does not exist (see Table 2-2 for an overview of definitions). In the context of economic environmental valuation, ES are usually defined in terms of ecosystems’

benefits to humans (Millennium Ecosystem Assessment, 2005) or ecosystems’ contribution to human well-being (TEEB, 2010).

Table 2-2 Different definitions of ecosystem services

Definition of ecosystem services Source

The conditions and processes through which natural ecosystems,

and the species that make them up, sustain and fulfil human life Daily (1997) Benefits human populations derive, directly or indirectly, from

ecosystem functions Costanza et al. (1997)

Benefits people obtain from ecosystems Millennium Ecosystem

Assessment (2005) Final ecosystem services are components of nature directly

enjoyed, consumed or used to yield human well-being

Boyd and Banzhaf (2007) The aspects of ecosystems utilized (actively or passively) to

produce human well-being Fisher et al. (2009)

Ecosystems contribution to human well-being TEEB (2012)

Contributions of ecosystem structure and function – in

combination with other inputs – to human well-being Burkhard et al. (2012)

Source: Own illustration adapted from Häyhä and Franzese (2014, p. 125)

As for definitions of ES also not a single classification of ES exists (see Table 2-3 for an overview of competing classifications).

Table 2-3 Different classifications of ecosystem services

Commonly used classifications of ecosystem services Reference Provisioning (e.g. food, timber) Habitat (e.g. nursery habitat, gene pool protection) Provisioning (e.g. biomass, water)

Haines-Young and Potschin (2013) Regulation and maintenance (e.g. mediation by ecosystems, pest and disease

control)

Cultural (e.g. physical, intellectual and spiritual interaction with ecosystems) Alternative classifications of ecosystem services

Adequate resources (e.g. food, water, energy)

Wallace (2007) Protection from predators, disease, parasites

Benign physical and chemical environment (e.g. temperature, moisture, light) Socio-cultural fulfilment (spiritual contentment, benign social group)

Rival and excludable (marketed ecosystem goods; e.g. timber)

Costanza (2008);

Fisher et al. (2009) Rival and non-excludable (open access sources; e.g. berries)

Non-rival and excludable (club goods; e.g. some recreational services)

Non-rival and non-excludable (public services, climate regulation, aesthetic experience)

Global non-proximal (does not depend on proximity; e.g. carbon sequestration)

Costanza (2008) Local proximal (depends on proximity; e.g. disturbance regulation, pollination)

Directional flow related: flow from point of production to point of use (e.g. water supply)

In situ (point of use; e.g. soil formation, food, raw materials)

User movement related: flow of people to unique natural features (e.g. genetic resources, cultural services)

Source: Own illustration adapted from Häyhä and Franzese (2014, p. 126)

The Millennium Ecosystem Assessment (2005) differentiates ES into four major categories:

provisioning services (e.g. food, timber), regulating services (e.g. climate regulation, flow regulation), cultural services (e.g. recreation, aesthetic experiences) and supporting services (e.g. photosynthesis, soil formation). This classification was used as a starting point for the Common International Classification of Ecosystem Services (CICES) which is commonly applied. The distinguishing feature is that supporting services were integrated into the category of regulating services as the former do not directly influence human well-being but other services may build upon them. This integrated category is referred to as regulation and maintenance services (Haines-Young & Potschin, 2013).

Haines-Young and Potschin (2010) developed the so-called cascade model (Figure 2-1) to illustrate the connection between the biophysical context incorporating the underlying functions and processes, ES (which represent the final services) and associated benefits and values. The cascade model depicts a linear relationship between the biophysical context, so all processes and structures created by living organisms and their capacities to provide ES, and the socio-cultural and economic context associated with all benefits to humans, and accordingly value to humans.

Figure 2-1 The ecosystem service cascade model

Source: Own illustration adopted from Potschin-Young et al. (2018); see also Haines-Young and Potschin (2010, p. 116) Biophysical

intermediate services Final services Goods and Benefits

Ʃ Pressures

This simplified depiction does not account for the general complexity of ecological structures but aims at illustrating the ‘production chain’ in context of ES (Haines-Young & Potschin, 2010, p. 115). ES build the bridge between ecosystem functions and benefits and values. This is important to note as it emphasises the difference between an ecosystem’s capability to provide services and the actual services which cannot exist isolated of human needs (Haines-Young & Potschin, 2010, p. 115). Furthermore, the production chain suggests a unidirectional flow. However, decision-making based on value may influence the biophysical structure through pressures, e.g. overexploitation of natural resources. Hence, the concept suggests a feedback from the socio-cultural and economic context to the biophysical context as indicated by bold arrows leading from value over pressures back to the biophysical structure.

Daily et al. (2009) illustrated how ES can be incorporated into decision-making (see Figure 2-2). The framework reflects a continuous loop. Starting at the “decisions” oval the natural sciences and biophysical models are essential to understand how decisions affect ecosystems through actions and scenarios, and how ecosystems functions and processes translate into services. Combining these insights with economic and cultural models is central to assess the multidimensional value of ES. Information about the value of ES can then be used to design institutions which are guiding decisions (Daily et al., 2009).

Source: Own illustration adopted from Daily et al. (2009, p. 23)

Recently the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) introduced the concept of nature’s contribution to people (NCP) out of criticism against the ES concept and with the aim to substitute it (Díaz et al., 2018). There is an

Decisions

Ecosystems Institutions

Values Services

Actions and scenarios

Biophysical models Information

Economic and cultural models Incentives

Figure 2-2 Framework integrating ecosystem services into decision-making

ongoing debate if or to what extent this new conceptual framework reflects the paradigm shift suggested by Díaz et al. (2018) (see e.g. Braat, 2018; Kenter, 2018; Peterson et al., 2018).

NCP has contributed to the discussion about links between nature and human well-being or rather quality of life by highlighting the importance of cultural context and recognising culture as mediator between NCP and peoples’ good quality of life. Further, NCP calls for a broader acknowledgement of indigenous and local knowledge in the assessments (Díaz et al., 2018;

Peterson et al., 2018). However, it has been questioned if replacing the term service with contributions is sufficient to overcome the criticised instrumental view of human-nature relationship and it has been argued that NCP do not succeed ES but that the latter are complementary to the former (Kenter, 2018). Furthermore, it has to be emphasized that attempts to integrate value pluralism are also increasing in the ES literature (see e.g. Arias-Arévalo et al., 2018; Bartkowski & Lienhoop, 2018; Chan et al., 2012b; Hansjürgens et al., 2017; Kenter, 2016a; Kenter et al., 2019; Spangenberg & Settele, 2016). Therefore, in the following the term ecosystem services will be used in an attempt to integrate value pluralism under this umbrella framework.²

This section has illustrated the supply or flow of direct and indirect benefits ecosystems provide to humans which is the underlying incentive to conduct economic environmental valuation. In the following, it shall be shortly discussed how the resulting value is conventionally conceptualised in economics and which conventional economic valuation methods are available to estimate these values empirically.