Why ecosystem services

Without supporting services, provisional, regulating, and cultural services wouldn't exist. Wetlands are one of the most threatened ecosystems in the United States. We have lost more than 50 percent of wetlands in the contiguous United States. Just a quick overview of some of the services provided by wetlands shows how important they are to people and why we should work to protect and restore them. Many of the fish we rely on for food spend at least part of their life cycle in wetland habitats.

Wetlands retain and control flood waters. Wetland plants absorb nutrients and chemicals from the water, and they act as a natural filtration system. Wetland plants and soils store large amounts of carbon that, if released, would contribute to climate change.

Wetlands are also a vital habitat for migratory birds , fish , and mammals , and their loss impacts recreation and biodiversity. Adams, J. Kutner and B. Stein, ed. New York: Oxford University Press, Sustaining Life. Chivian, E. However, such estimates are difficult to scale up to a whole field or farm. Pollination of potted plants, so called phytometers, is a promising technique to estimate pollination potential Woodcock et al. Sih and Baltus, Ecologists, in collaboration with agricultural and forest scientists, thus need to identify scientifically sound ecological measures that are reliable indicators of ecosystem service provision.

As a first and simple step to account for the characteristics of processes underlying service provision, it is suggested here to choose among a small set of measures that form joint, reliable indicators of an individual service.

The following example illustrates why the selection of a set of indicators may be superior to the use of a single indicator using the ecosystem service of biological control see also Kandziora et al.

Processes underlying the service of biological control are related to service-providing units predators and parasitoids , units that provide a disservice pests; Letourneau et al. The assessment of biological control may therefore be improved if a small set of selected measures is included that covers aspects of service and disservice-providing units e.

Consideration of abiotic variables such as climate Diehl et al. Ecosystem service research is particularly focused on predicting the consequences of future management options. Statistical models can be used to identify driving forces of changes in service provision and to predict system shifts and fluctuations in service provision as a consequence of environmental change and anthropogenic intervention Evans et al.

Simple statistical models e. In contrast, process-based models are based on the assumption that essential features of ecological processes can be extrapolated to conditions not currently observed. These models rely on knowledge about the dynamics of ecological processes, i. For example, models based on the food and nestling requirement of bees can be used to predict pollinator abundance across landscapes because fundamental assumptions about bee behavior hold under novel conditions Kennedy et al.

In this context, climatic conditions deserve particular attention, since climate change will have a strong impact on service-providing units, intermediate and final ecosystem services Montoya and Raffaelli, ; Birkhofer and Wolters, ; Diehl et al. Predictions of future changes will only be possible if studies address this aspect by using mechanistic models e.

However, mechanistic models are never better than the theories and empirical data underpinning them and the development of models with predictive power is a challenge for ecologists. The quantification of uncertainty in predictive modeling requires critical evaluation Cheaib et al.

Mapping of ecosystem services is fraught with multiple uncertainties stemming from uncertainty in the ability to capture relevant processes as well as translating and scaling mapped information Hou et al. The evaluation of uncertainty, the integration of knowledge about evolutionary aspects and human impacts into the development of process-based models and their coupling with socio-economic models are important fields of future research to which ecologists need to contribute e.

Ecosystem services may demonstrate joint variation, either synergistic or antagonistic, in space and time. The interpretation of such patterns between multiple ecosystem services more than two has become an intensively debated subject Cimon-Morin et al. Such joint variation may also concern relationships between beneficial ecosystem services and so called ecosystem disservices, for example environmental externalities such as water pollution Zhang et al.

Ecologists can contribute to the analyses of joint variation of services and disservices by identifying the underlying mechanisms that explain relationships between services and their response patterns to environmental change. For instance, the marginal contribution of enhancing pollination on crop yield may partly depend on the level of other ecosystem services, with highest yield under a simultaneous increase of pollination and biological control Bos et al.

Alterations of a single ecosystem service by agricultural management can, for example, have unintended effects on other services and a better understanding of such unexpected relationships will safeguard human societies against the consequences of sudden regime-shifts in ecosystems e. Improving the understanding of the relationships between ecosystem services poses two major challenges to ecological research: i drawing conclusions about relationships between ecosystem services by understanding if relationships are indirect through shared environmental drivers or direct because one ecosystem services causally affects another and ii solving issues of visualization and statistical testing when analyzing relationships between multiple more than two ecosystem services.

To be able to predict the consequences of environmental change as drivers of changes in ecosystem services, it is important to distinguish between indirect and direct relationships Bennett et al. Both direct relationships if services are related to each other and indirect relationships if services are related through a driver can lead to synergies and trade-offs between the services Bennett et al.

Ecosystem services may be directly and causally linked, because one ecosystem service directly interacts with another ecosystem services Figure 1A , direct relationships. For example, fertility of agricultural soils service 1 is directly and positively linked to crop yields service 2; Lal, Given this direct relationship and assuming the absence of other driving forces, a manipulation of one service e.

However, ecosystem services may be statistically associated, negatively or positively, because their underlying drivers are related Figure 1B ; indirect relationship. Water retention service 1 and landscape beauty service 2 , for example, may be statistically associated, because the proportion of urban area that reduces water retention driver 1 may be negatively related to the proportion of semi-natural land driver 2; Raudsepp-Hearne et al.

In this case, manipulation of one service e. In contrast, manipulation of one driver e. Finally, services may also be correlated because of independent responses to a common driver Figure 1C , indirect relationship. Pollination of crop plants service 1 and pest control in crop fields service 2 , for example, are both increased by the proportion of semi-natural habitats surrounding crop fields driver 1; Bianchi et al.

In addition, pollination is affected by the proportion of nesting habitats driver 2; Ricketts et al. Given this indirect relationship, increasing one service e. Manipulating the shared driver e. Figure 1. Potential relationships between two ecosystem services service 1 and service 2. A Direct relationships between ecosystem services and indirect relationships via B two associated drivers or C a shared driver.

It is without doubt important to describe relationships between multiple services independent of what causes statistical associations Tallis et al. However, the ability to manage situations in which multiple drivers act on multiple services would benefit from an improved understanding of the relationships between individual services indirect or direct , their relationships to drivers and the processes that affect both relationships Lautenbach et al.

To manage ecosystem service provisioning, planners and decision-makers need to know if ecosystem services respond to a shared driver or if services are directly linked to each other. If services respond independently, but contrastingly to a single shared driver, better ecological understanding of the individual relationships between the driver and the services will help to identify management strategies that mitigate trade-offs between services.

If services are directly linked to each other, improving management becomes more complicated as in addition to the relationship between services and the driver, interactions between services need to be considered. We therefore encourage ecologists to not only investigate the relationship between services and various drivers, but to also test for direct relationships between multiple ecosystem services.

Conclusions about direct links between ecosystem services can be derived from studies using large, replicated datasets in approaches that implicitly model direct and indirect effects of anthropogenic interventions on service provision e. Together, these approaches, coupled with the development of mechanistic models e. To study relationships between two or three ecosystem services techniques such as correlation analysis Figure 2A ; e.

Efficiency frontier analyses Nelson et al. It may be important to consider multiple services in the same analytical framework, as it is likely that most services observed in a study are related to each other. Simple spider web or flower diagrams can be used to illustrate relationships between several services Figure 2C ; e. For the purpose of relating multiple services to drivers in a single analytical framework, the frequent use of principal component analysis is notable Figure 2D ; e.

However, since relationships between ecosystem services in response to a driver can be non-linear, asymptotic, unimodal or characterized by tipping points e. The use of this method should therefore be constraint to datasets in which relationships between multiple services are approximately linear see also Quinn and Keough, Among the alternative methods to visualize trade-offs between multiple services in one analytical framework, principal coordinates analysis holds potential as it allows for the analysis of non-linear relationships Legendre and Legendre, Partial least squares regression is another promising technique to analyze relationships between intermediate ecosystem services based on empirical data e.

Figure 2. Scale is a contentious issue in ecosystem service research, because ecological processes are fundamentally scale dependent Levin, and a large number of diverging approaches to study spatial scales in ecological research adds to this complexity e. This potentially impedes the integration of different research fields e. Compared to spatial scales, temporal aspects have received remarkably little attention in ecosystem service research Kremen, Most of the existing ecological knowledge on ecosystem processes is based on investigations covering short periods of time e.

A better understanding of the i spatial and ii temporal scales at which the provision of ecosystem services is affected by environmental change or anthropogenic interventions is needed to satisfy the growing public and political demand for sustainable land use Tilman et al.

It is a major challenge for ecologists to scale up from experimental plots to scales that are relevant for the management of most ecosystem services Cardinale et al. These plot-level studies can often not account for the heterogeneity of complex landscapes and therefore may not provide adequate empirical data about ecosystem service provision from major land-use types in a landscape.

Studies relating biodiversity to ecosystem services often focus on ecological processes and intermediate ecosystem services at small spatial scales Cardinale et al. In contrast, research on spatial prioritizations for the protection of ecosystem services Luck et al. This suggests that there is a mismatch between species-oriented ecological research dealing with mechanisms underlying the provision of services, and conservation-oriented research identifying hotspots in space for particular services Figure 3.

Coupling these two research approaches is critically important to improve the understanding of ecosystem service provision across real landscapes. Figure 3. Number of published cases analyzing A regulating and supporting ecosystem services with respect to biodiversity-ecosystem service relationships, and B spatial prioritization of ecosystem services. Number of cases based on number of syntheses presented in Cardinale et al.

The scale of ecological processes is relevant to ecosystem service research, because of the need to account for the spatial relationship between generation and consumption of ecosystem services Fisher et al.

One approach to account for this goal is based on spatially explicit modeling of ecological production functions e. In addition, ecological functions underlying final ecosystem services may depend on the spatial scale at which management is applied cf. Leibold et al. This generates context dependent responses of management interventions Tscharntke et al.

For example, populations of service-providing units may only maintain viable sizes given that enough habitats are preserved across multiple land-owners Drechsler et al. Hence, to optimize ecosystem service provision at larger spatial scales, the identification of conditions under which land-owners benefit from co-operation will be an important future topic in ecosystem services research e.

In addition, ecological research needs to cover the relevant spatial scales at which multiple ecosystem services are efficiently managed see also Mastrangelo et al.

Scaling up models for individual ecosystem services in space is certainly one of the major challenges Stuart and Gillon, , but it is also crucial to account for relationships between services that are caused by interactions between services or anthropogenic interventions at different spatial scales e. It is essential to understand the temporal dynamics of service provision for the development of sustainable management and conservation strategies.

For example, the quality of provision of an ecosystem service may not only depend on its average provision over time, but also on its variation over time Mori et al. It is therefore important to assess the stability of ecosystem service provision in simplified ecosystems, where losses of ecosystem resilience to disturbances can be expected to be strongest Bengtsson et al.

In addition, lag-effects of management decisions may make ecosystem service losses only apparent a long time after the anthropogenic intervention Millennium Ecosystem Assessment, Such lag-effects may be further accentuated by climate change, where loss of biodiversity may reduce resilience of critical functions cf.

Elmqvist et al. We therefore need long-term estimates of ecosystem service provision to better understand how inter-annual variation in environmental conditions, such as climate change, affects the magnitude and stability of service provision.

However, the time-span of ecological research is often constrained to a few years due to generally short funding periods. Such short research periods will fail to provide reliable estimates of altered behavior of service-providing units in response to climate change e.

We call for more such approaches to get a better understanding of both long-term changes and temporal variability of ecosystem service provision. Although the ecosystem service concept is based on an ecological understanding of ecosystems, ecologists are confronted with a range of challenges when researching ecosystem services.

This is partly explained by the wide variety of terms and definitions from different scientific disciplines as well as a lack of generally accepted assessment methods, difficulties with analytical and modeling methods and mismatches of spatial and temporal scales between service provision and anthropogenic interventions.

Ecologists need to adapt their perspective and methods to a larger societal context for the improvement of ecosystem service research. Particular emphasis needs to be directed toward supporting decision makers with relevant information about service-providing units and mechanisms underlying the provision of services at appropriate temporal and spatial scales. To conclude, ecosystem service research is challenging for ecologists, but developing a multifaceted understanding of how nature promotes human well-being is crucial for the sustainable use of the earth's resources.

Ecosystem service research offers ecologists the unique opportunity to act as promoters for the understanding of how to conserve and sustain benefits gained from nature. All authors contributed to the manuscript by reviewing literature, discussing and developing ideas during two workshops, writing text sections and revising sections written by other authors.

Eva Diehl and Klaus Birkhofer had the initial idea for the manuscript and wrote general parts of the manuscript abstract, introduction and conclusion together with Henrik G. Henrik G. Smith and Volkmar Wolters contributed to all sections in the manuscript. Eva Diehl contributed to challenges Franziska Machnikowski contributed to the introduction and challenge 4.

Jesper Andersson contributed to the introduction. Johan Ekroos contributed to challenge 4. Klaus Birkhofer contributed to challenges Keiko Sasaki contributed to the introduction and challenges Lovisa Nilsson contributed to challenges 1 and 4. Viktoria L. Mader contributed to challenges The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

We thank Johan G. Zaller, Quang Bao Le and Visa Nuutinen for very helpful comments that helped improving earlier versions of the manuscript. Barry, S. Error and uncertainty in habitat models. Changes in the global value of ecosystem services. Global Environmental Change — De Bello, F. Functional traits underlie the delivery of ecosystem services across different trophic levels. Deliverable of the Rubicode Project download: www.

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Island Press. Valuing nature in a way that can speak to decision makers, may help promote conservation efforts in the future. It brings nature back into the cost-benefit discussion in a way that can be easily understood. Ecosystem Services help measure the true cost of industrial development. Often, the impact industrial development has on the economy and job creation overshadows the cost it will have on surrounding lakes, forests, keystone species, and so on.

Assigning a dollar value to these lakes and forests, and the Ecosystem Services they provide, helps adjust the cost benefit analysis by evaluating the negative effects development will have on the natural environment. Companies have also started to use Ecosystem Services in conservation offset planning, where they can buy and sell credits to offset a development or set aside land to meet a specific offset.