Ecological Production Functions Research Articles

Paved with good intentions: From digitalization to carbon neutrality

Researchers and practitioners have promoted digitalization as a crucial tool for achieving carbon neutrality. In this paper, we argue that for digitalization to positively impact carbon neutrality, several essential supporting conditions are required. Using the Georgescu-Roegen/Daly ecological production function approach, we argue that digitalization alone a) will not necessarily lead to dematerialization, partly because it tends to economize on labor rather than other, less sustainable production factors, and partly because it requires a material- and energy-intensive infrastructure; b) will result in both quantitative and qualitative output expansion rather than substituting existing products and services with more sustainable alternatives; and c) will not promote carbon-conscious corporate governance practices. We suggest that a systemic perspective is necessary to analyze the complex relationships between digitalization and carbon neutrality.

Estimating the benefits of stream water quality improvements in urbanizing watersheds: An ecological production function approach

Streams in urbanizing watersheds are threatened by economic development that can lead to excessive sediment erosion and surface runoff. These anthropogenic stressors diminish valuable ecosystem services and result in pervasive degradation commonly referred to as "urban stream syndrome." Understanding how the public perceives and values improvements in stream conditions is necessary to support efforts to quantify the economic benefits of water quality improvements. We develop an ecological production framework that translates measurable indicators of stream water quality into ecological endpoints. Our interdisciplinary approach integrates a predictive hierarchical water quality model that is well suited for sparse data environments, an expert elicitation that translates measurable water quality indicators into ecological endpoints that focus group participants identified as most relevant, and a stated preference survey that elicits the public's willingness to pay for changes in these endpoints. To illustrate our methods, we develop an application to the Upper Neuse River Watershed located in the rapidly developing Triangle region of North Carolina (the United States). Our results suggest, for example, that residents are willing to pay roughly $127 per household and $54 million per year in aggregate (2021 US$) for water quality improvements resulting from a stylized intervention that increases stream bank canopy cover by 25% and decreases runoff from impervious surfaces, leading to improvements in water quality and ecological endpoints for local streams. Although the three components of our analysis are conducted with data from North Carolina, we discuss how our findings are generalizable to urban and urbanizing areas across the larger Piedmont ecoregion of the Eastern United States.

The use of ecological models to assess the effects of a plant protection product on ecosystem services provided by an orchard

The objective of this case study was to explore the feasibility of using ecological models for applying an ecosystem services-based approach to environmental risk assessment using currently available data and methodologies. For this we used a 5 step approach: 1) selection of environmental scenario, 2) ecosystem service selection, 3) development of logic chains, 4) selection and application of ecological models and 5) detailed ecosystem service assessment. The study system is a European apple orchard managed according to integrated pest management principles. An organophosphate insecticide was used as the case study chemical. Four ecosystem services are included in this case study: soil quality regulation, pest control, pollination and recreation. Logic chains were developed for each ecosystem service and describe the link between toxicant effects on service providing units and ecosystem services delivery. For the soil quality regulation ecosystem service, springtails and earthworms were the service providing units, for the pest control ecosystem service it was ladybirds, for the pollination ecosystem service it was honeybees and for the recreation ecosystem service it was the meadow brown butterfly. All the ecological models addressed the spatio-temporal magnitude of the direct effects of the insecticide on the service providing units and ecological production functions were used to extrapolate these outcomes to the delivery of ecosystem services. For all ecosystem services a decision on the acceptability of the modelled and extrapolated effects on the service providing units could be made using the protection goals as set by the European Food Safety Authority (EFSA). Developing quantitative ecological production functions for extrapolation of ecosystem services delivery from population endpoints remains one of the major challenges. We feel that the use of ecological models can greatly add to this development, although the further development of existing ecological models, and of new models, is needed for this.

Assessing chemical risk within an ecosystem services framework: Implementation and added value

An ecosystem services (ES) approach to chemical risk assessment has many potential advantages, but there are also substantial challenges regarding its implementation. We report the findings of a multi-stakeholder workshop that evaluated the feasibility of adopting an ES approach to chemical risk assessment using currently available tools and data. Also evaluated is the added value such an approach would bring to environmental decision making. The aim was to build consensus across disparate stakeholders and to co-produce a common understanding of the regulatory benefits and feasibility of implementing an ES approach in European chemicals regulation. Workshop discussions were informed by proof of concept studies and resulted in the development of a novel tiered framework for assessing chemical risk to ES delivery. There was consensus on the substantial added value of adopting an ES-based approach for regulatory decision making. Ecosystem services provide a common currency and a ‘unifying approach’ across environmental compartments, stressors and regulatory frameworks. The ES approach informs prioritisation of risk and remedial action and aids risk communication and risk management. It facilitates a more holistic assessment, enables ES trade-offs to be compared across alternative interventions, and supports comparative risk assessments and a socio-economic analysis of management options and decisions. Key to realising this added value is a shift away from using a single threshold value to categorise risk, towards a consideration of the exposure-effect distribution for individual ES of interest. Also required is the development of an integrated systems-level approach across regulatory frameworks and agreement on specific protection goals and scenarios for framing environmental risk assessments. The need to further develop tools for extrapolating toxicity data to service providers and ES delivery, including logic chains and ecological production functions, was highlighted. Also agreed was the need for methods and metrics for ES valuation to be used in assessing trade-offs.

Projecting effects of land use change on human well-being through changes in ecosystem services

Changing patterns of land use, temperature, and precipitation are expected to impact ecosystem services, including water quality and quantity, buffering of extreme events, soil quality, and biodiversity. Scenario analyses that link such impacts on ecosystem services to human well-being may be valuable in anticipating potential consequences of change that are meaningful to people living in a community. Ecosystem services provide numerous benefits to community well-being, including living standards, health, cultural fulfillment, education, and connection to nature. Yet assessments of impacts of ecosystem services on human well-being have largely focused on human health or monetary benefits (e.g. market values). This study applies a human well-being modeling framework to demonstrate the potential impacts of alternative land use scenarios on multi-faceted components of human well-being through changes in ecosystem services (i.e., ecological benefits functions). The modeling framework quantitatively defines these relationships in a way that can be used to project the influence of ecosystem service flows on indicators of human well-being, alongside social service flows and economic service flows. Land use changes are linked to changing indicators of ecosystem services through the application of ecological production functions. The approach is demonstrated for two future land use scenarios in a Florida watershed, representing different degrees of population growth and environmental resource protection. Increasing rates of land development were almost universally associated with declines in ecosystem services indicators and associated indicators of well-being, as natural ecosystems were replaced by impervious surfaces that depleted the ability of ecosystems to buffer air pollutants, provide habitat for biodiversity, and retain rainwater. Scenarios with increases in indicators of ecosystem services, however, did not necessarily translate into increases in indicators of well-being, due to covarying changes in social and economic services indicators. The approach is broadly transferable to other communities or decision scenarios and serves to illustrate the potential impacts of changing land use on ecosystem services and human well-being.

Hedonic Price Estimates of Lake Water Quality: Valued Attribute, Instrumental Variables, and Ecological-Economic Benefits

We estimate the effect of lake water quality on residential housing prices using cross-sectional data on water clarity from 113 lakes across the United States. An instrumental-variables approach is developed to address potential endogeneity bias in the water-clarity variable. Three lake-based physical variables serve as instrumental variables: total nitrogen concentration in lake water, total phosphorus concentration in lake water, and water temperature near the lake surface. The econometric results include three methodological findings: the instruments are valid and strong; the ordinary-least-squares estimate of the coefficient on the water-clarity variable is unbiased; and water clarity is the attribute of water quality valued in the housing market. The estimated water-clarity effect shows that a one-tenth of a meter change in water clarity leads to a one-percent change in housing price, or an elasticity of 0.20 at mean clarity. Coupling this effect with estimates of an ecological production function, a lake-specific benefit index is developed that shows the effect on housing values of bringing lakes into compliance with the US Environmental Protection Agency's regional recommendations for phosphorous concentration in lake waters.

Impacts of the EU's Common Agricultural Policy “Greening” Reform on Agricultural Development, Biodiversity, and Ecosystem Services

AbstractThe EU's Common Agricultural Policy (CAP) has had limited success in mitigating agriculture's environmental degradation. In this paper we simulate the impacts of the 2013 “greening” reform on biodiversity and ecosystem services in environmentally contrasting landscapes. We do this by integrating an agent‐based model of structural change with spatial ecological production functions, and show that the reform will likely fail to deliver substantial environmental benefits. Our study implies that greening measures need to be tailored to local conditions and priorities, to generate environmental improvements. Such spatial targeting of measures is though incompatible with the design of a common direct payments scheme.

The Ecological Limits of Poverty Alleviation in an African Forest-Agriculture Landscape

Cocoa yields in Ghana remain low. This has variously been attributed to low rates of fertilizer application, pollinator limitation, and particularly dry growing conditions. In this paper we use an African forest-agriculture landscape dominated by cocoa (Theobroma cacao) to develop an ecological production function, allowing us to identify key ecological and management limits acting on cocoa yields simultaneously. These included more consistent application of fertilizers inter-annually, distributing rotting biomass throughout the farm and reducing the incidence of capsid attacks. By relaxing these limits, we estimate plausible increases in yields and, by extension, farm incomes. Our analysis reveals that resulting increases in cocoa yields requiring both ecological and intensive management interventions could be significant (113 ± 60%); however, benefits are disproportionately realized by the wealthiest households. We found that wealthier households benefited proportionally more from ecological intensification methods (e.g., leaving more rotting biomass in their farms) and the poorest households benefited proportionally more from capital-intensive intensification methods (e.g., pesticide and fertilizer applications). We treated poverty as multi-dimensional, and show that only certain dimensions of poverty (school attendance, assets, and food security) are significantly related to cocoa incomes, while several other dimensions (access to clean water, sanitation and electricity, and infant mortality) are not. We explore how increased household cocoa incomes could impact different dimensions of poverty. Our findings suggest, that if all households adopted the optimal level of each of these management options, and in so doing had similar poverty profiles to those households already managing optimally, we would see the community-averaged probability: a child of a household misses school decrease from 47 to 31%, a household would be able to acquire assets increase from 40 to 59% and a household would have access to an adequate amount of food increase from 62 to 79%.

Application of duality theory to solve two-criteria problem of linear programming for ecological-economic system

In the paper, we investigate two-criterion optimization problem: maximization of one target function and minimization of another target function. To solve the offered two-criterion problem, the method of the main criterion is applied. We consider the problem of production activity of the ecological-economic system with the maximization of the value of the final product as the first target function and the minimization of emissions of polluters into the environment as the second target function. We constructed of two production functions (economic and ecological). To construct the economic production function, we select maximal producing of the final products in a costing form as the most essential (main) criterion. Also, there is introduced the appropriate data of the criterion level total volume of emissions of polluters into the environment. After this two-criteria problem is reduced to one-criteria problem. For the construction of ecological production function, the main criterion in the problem of the minimal general volume of emissions of polluters into the environment is defined. We use a parameter of the criterion level of the second criterion and obtained one-criterion problem. Therefore, investigation of the appropriate dual problems explicitly provides economic and ecological production functions to the deduced one-criterion problems. These functions in input two-criterion problem give way to optimal manage of ecological-economic system.

Trade-offs and synergies between livestock production and other ecosystem services

One of the biggest challenges today is to satisfy an increasing food demand while preserving ecosystem services. Farming systems have a huge impact on land cover and land use, it is therefore vital to understand how land cover and land use allocation can promote synergies between food production and other ecosystem services. Livestock production has multiple interactions with other ecosystem services and can promote synergies especially in grasslands. We investigated the interactions between livestock production and other ecosystem services and explored strategies to soften trade-offs and enhance synergies. We considered four ecosystem services (livestock production, crop production, carbon sequestration, and timber growth) in France. We considered 709 land units covering a wide range of farming systems where both food production and other ecosystem services are provided. For each land unit, we built ecological production functions that are models measuring the statistical influence of driving variables (i.e. land cover, land use, pesticide expense, and climate) on the provision of ecosystem services. Using an optimization procedure, we studied the extent to which livestock production could be increased without reducing other ecosystem services and without increasing total pesticide expense. We found that a 20% increase in livestock production could be achieved by all farming systems in France under those general constraints. The 709 land units could be grouped based on similar combinations of increases or decreases in specific ecosystem services during the optimization. 48% of land units were specialised on food production, 24% were specialised on other ecosystem services, 16% were specialised on the mixed provision of food production and other ecosystem services, whereas the remaining 12% showed decrease or no change in all ecosystem services. Livestock production was either in trade-off or in synergy with the other ecosystem services. The trade-offs could be softened through intensified use of cultivated land and spatial segregation of livestock production. The synergies could be enhanced only through major grassland expansion.

Quantifying multiple ecosystem services for adaptive management of green infrastructure

AbstractDemands for ecosystem service assessments are growing around the world. However, management applications remain limited in part because we lack measurements linking ecosystem characteristics (ecosystem structure and processes) to final ecosystem services. Policymakers need marginal values, changes in final ecosystem services (direct link to human welfare) relative to additional units of ecosystem characteristics (∆final ecosystem services/∆ecosystem characteristics) to assess tradeoffs. Progress, however, has been slow due to confusion on ecological production functions (EPFs) in ecology. Here, we apply a new interdisciplinary approach to craft EPFs to evaluate four ecosystem services using the Yongding River Green Ecological Corridor as our case study. The Yongding Corridor is Beijing's largest, most expensive green infrastructure project (~ $2.5 billion USD), constructed as a network of seven artificial lakes and wetlands. The Beijing Government wants the Yongding Corridor to improve four ecosystem services: (1) water storage, (2) local climate regulation, (3) water purification, and (4) aesthetics. We first worked with stakeholders to determine final ecosystem service levels and then used the Variable Infiltration Capacity model to estimate key ecosystem processes from the designed lakes and wetlands. We coupled the modeling with ecological field data and social surveys to create EPFs. We evaluated the ecosystem services by calculating shortfalls and then determined synergies and tradeoffs to identify actions for reducing shortfalls. We found the Yongding Corridor is meeting desired levels for aesthetics, but incurred shortfalls on the remaining services. To obtain the desired services, we recommend managers: (1) maintain inflow rates and/or make the lakes deeper to reduce water loss rates; (2) improve water quality—wetlands have high nutrient retention, but nutrient loads must be reduced; and (3) plant shade trees since evaporative cooling from the lakes and wetlands is having no measurable impact on human comfort. Results indicate the absence of ecosystem functions in landscape design led to shortfalls, but solutions require coupling green and built infrastructure to obtain multi‐functionality. Managers found marginal values useful for clarifying connections, which led to adaptive policy changes for improving green infrastructure.

Priorities and opportunities in the application of the ecosystem services concept in risk assessment for chemicals in the environment

The ecosystem services approach has gained broad interest in regulatory and policy circles for use in ecological risk assessment. Whilst identifying several challenges, scientific experts from European regulatory authorities, the chemical industry and academia considered the approach applicable to all chemical sectors and potentially contributing to greater ecological relevance for setting and assessing environmental protection goals compared to current European regulatory frameworks for chemicals. These challenges were addressed in workshops to develop a common understanding across stakeholders on how the ecosystem services concept might be used in chemical risk assessment and what would need to be done to implement it. This paper describes the consensus outcome of those discussions. Knowledge gaps and research needs were identified and prioritised, exploring the use of novel approaches from ecology, ecotoxicology and ecological modelling. Where applicable, distinction is made between prospective and retrospective ecological risk assessment. For prospective risk assessment the development of environmental scenarios accounting for chemical exposure and ecological conditions was designated as a top priority. For retrospective risk assessment the top priority research need was development of reference conditions for key ecosystem services and guidance for their derivation. Both prospective and retrospective risk assessment would benefit from guidance on the taxa and measurement endpoints relevant to specific ecosystem services and from improved understanding of the relationships between measurement endpoints from standard toxicity tests and the ecosystem services of interest (i.e. assessment endpoints). The development of mechanistic models, which could serve as ecological production functions, was identified as a priority. A conceptual framework for future chemical risk assessment based on an ecosystem services approach is presented.

A Resilience Framework for Chronic Exposures: Water Quality and Ecosystem Services in Coastal Social-Ecological Systems

Water quality degradation is a chronic problem which influences the resilience of a social-ecological system differently than acute disturbances, such as disease or storms. Recognizing this, we developed a tailored resilience framework that applies ecosystem service concepts to coastal social-ecological systems affected by degraded water quality. We present the framework as a mechanism for coordinating interdisciplinary research to inform long-term community planning decisions pertaining to chronic challenges in coastal systems. The resulting framework connects the ecological system to the social system via ecological production functions and ecosystem services. The social system then feeds back to the ecological system via policies and interventions to address declining water quality. We apply our resilience framework to the coastal waters and communities of Cape Cod (Barnstable County, Massachusetts, USA) which are affected by nitrogen over-enrichment. This approach allowed us to design research to improve the understanding of the effectiveness and acceptance of water quality improvement efforts and their effect on the delivery of ecosystem services. This framework is intended to be transferable to other geographical settings and more generally applied to systems exposed to chronic disturbances in order to coordinate interdisciplinary research planning and inform coastal management.

Zoning does not improve the availability of ecosystem services in urban watersheds. A case study from Upstate South Carolina, USA

When making governance decisions, such as land-use plans, policymakers must decide if and how to balance economic growth with environmental conservation. Often, and frequently not by choice, these decisions are made with limited or poor-quality data, which is often either too theoretical or too fine-scale, leading to poor land use planning within urban watersheds. As a case study of a governance technique, we analyzed the function of zoning on the relationship between development and ecosystem services across 65 watersheds in South Carolina, USA. Our research question was whether zoning regulations have helped preserve natural capital. Habitat, carbon storage, nutrient and sediment export were measured using Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), which maps distributions of services based on ecological production functions. Over a ten-year window, increased development resulted in the loss of services. Zoning reduced the impact of development on phosphorus export, but not on other services, revealing the need for more explicit consideration of services in creation of zoning ordinances. If residents of urban watersheds want to benefit from development, improved and more accessible data and rigorous evaluation are important first steps towards improved governance decisions about zoning and regional planning in both public and private sectors.

Effect of Forest Cover on Water Treatment Costs

This paper studies the relationship between forest cover and drinking water chemical treatment costs using land use data and a survey by the American Water Works Association (AWWA). The survey gathers cost and water quality data from 37 treatment plants in forested ecoregions of the United States. We model the effect of forest conversion on the cost of water treatment using a two-step process. First, we examine the effect of changes in land use on water quality through an ecological production function. Second, we examine the effect of changes in water quality on cost of treatment through an economic benefits function. We find a negative relationship between forest cover and turbidity, but no relationship between forest cover and total organic carbon (TOC). Increasing forest cover in a watershed by 1% reduces turbidity by 3%, and increasing development by 1% in a watershed increases turbidity by 3%. The impact of development is more consistent across models than the impact of forest cover. We also find a large impact on turbidity from grazing in the watershed. Our economic benefits function shows a 1% increase in turbidity increases water treatment costs by 0.19%, and 1% increase in TOC increases water treatment costs by 0.46%. TOC has a clearer impact on costs than turbidity, which becomes insignificant when we omit one of our observations with high turbidity.

Diatoms to human uses: linking nitrogen deposition, aquatic eutrophication, and ecosystem services

AbstractNitrogen (N) loading to aquatic ecosystems can lead to eutrophication, changing the ecosystem within a waterbody, including primary productivity, water clarity, and food web dynamics. Nutrient loading often first affects the primary productivity of aquatic systems through shifts in phytoplankton communities. However, ecologically important changes in phytoplankton are often not relatable to the general public—whose behavior would need to change to alter patterns of nutrient loading. Therefore, we use the STressor–Ecological Production function–final ecosystem Services Framework to develop 154 chains that link changes in biological indicators of aquatic eutrophication (a shift in phytoplankton community) to final ecosystem services that people use or appreciate. We identify 13 ecological production functions (EPF) within three different ecosystems (alpine lakes, lakes, and estuaries) that connect changes in phytoplankton and algae to ecological endpoints that the general public and policy makers can appreciate. Using the Final Ecosystem Goods and Services Classification System, we identify 18 classes of human beneficiaries that potentially will be impacted by a change in one of these endpoints. We further assign strength‐of‐science scores to each link within the EPFs for the 154 chains according to how well each link is supported by current peer‐reviewed literature. By identifying many pathways through which excess N loading in U.S. surface waters can affect ecosystems and ultimately the beneficiaries of ecosystem services, this work intends to draw attention to gaps in empirical ecological literature that constrain understanding of the magnitude of effects that excess N loading can have on human well‐being. Results highlight the importance of intersections between the natural and social sciences when managers and policy makers evaluate impacts from ecological stressors. A balance between knowledgeable specialists proved key to applying this approach and will continue to remain important.

Nitrogen‐induced terrestrial eutrophication: cascading effects and impacts on ecosystem services

AbstractHuman activity has significantly increased the deposition of nitrogen (N) on terrestrial ecosystems over pre‐industrial levels leading to a multitude of effects including losses of biodiversity, changes in ecosystem functioning, and impacts on human well‐being. It is challenging to explicitly link the level of deposition on an ecosystem to the cascade of ecological effects triggered and ecosystem services affected, because of the multitude of possible pathways in the N cascade. To address this challenge, we report on the activities of an expert workshop to synthesize information on N‐induced terrestrial eutrophication from the published literature and to link critical load exceedances with human beneficiaries by using the STressor–Ecological Production function–final ecosystem Services Framework and the Final Ecosystem Goods and Services Classification System (FEGS‐CS). We found 21 N critical loads were triggered by N deposition (ranging from 2 to 39 kg N·ha−1·yr−1), which cascaded to distinct beneficiary types through 582 individual pathways in the five ecoregions examined (Eastern Temperate Forests, Marine West Coast Forests, Northwestern Forested Mountains, North American Deserts, Mediterranean California). These exceedances ultimately affected 66 FEGS across a range of final ecosystem service categories (21 categories, e.g., changes in timber production, fire regimes, and native plant and animal communities) and 198 regional human beneficiaries of different types. Several different biological indicators were triggered in different ecosystems, including grasses and/or forbs (33% of all pathways), mycorrhizal communities (22%), tree species (21%), and lichen biodiversity (11%). Ecoregions with higher deposition rates for longer periods tended to have more numerous and varied ecological impacts (e.g., Eastern Temperate Forests, eight biological indicators) as opposed to other ecoregions (e.g., North American Deserts and Marine West Coast Forests each with one biological indicator). Nonetheless, although ecoregions differed by ecological effects from terrestrial eutrophication, the number of FEGS and beneficiaries impacted was similar across ecoregions. We found that terrestrial eutrophication affected all ecosystems examined, demonstrating the widespread nature of terrestrial eutrophication nationally. These results highlight which people and ecosystems are most affected according to present knowledge, and identify key uncertainties and knowledge gaps to be filled by future research.

Terrestrial acidification and ecosystem services: effects of acid rain on bunnies, baseball, and Christmas trees.

Often termed “acid rain,” combined nitrogen and sulfur deposition can directly and indirectly impact the condition and health of forest ecosystems. Researchers use critical loads (CLs) to describe response thresholds, and recent studies on acid-sensitive biological indicators show that forests continue to be at risk from terrestrial acidification. However, rarely are impacts translated into changes in “ecosystem services” that impact human well-being. Further, the relevance of this research to the general public is seldom communicated in terms that can motivate action to protect valuable resources. To understand how changes in biological indicators affect human well-being, we used the STEPS (Stressor–Ecological Production function–final ecosystem Services) Framework to quantitatively and qualitatively link CL exceedances to ecosystem service impacts. We specified the cause-and-effect ecological processes linking changes in biological indicators to final ecosystem services. The Final Ecosystem Goods and Services Classification System (FEGS-CS) was used within the STEPS Framework to classify the ecosystem component and the beneficiary class that uses or values the component. We analyzed two acid-sensitive tree species, balsam fir (Abies balsamea) and white ash (Fraxinus americana), that are common in northeastern USA. These well-known species provide habitat for animals and popular forest products that are relatable to a broad audience. We identified 160 chains with 10 classes of human beneficiaries for balsam fir and white ash combined, concluding that there are resources at risk that the public may value. Two stories resulting from these explorations into the cascading effects of acid rain on terrestrial resources are ideal for effective science communication: the relationship between (1) balsam fir as a popular Christmas tree and habitat for the snowshoe hare, a favorite of wildlife viewers, and (2) white ash because it is used for half of all baseball bats, fine wood products, and musical instruments. Thus, rather than focusing on biological indicators that may only be understood or appreciated by specific stakeholders or experts, this approach extends the analysis to include impacts on FEGS and humans. It also lays the foundation for developing stakeholder-specific narratives, quantitative measures of endpoints, and for conducting demand-based valuations of affected ecosystem services.

A framework to quantify the strength of ecological links between an environmental stressor and final ecosystem services.

Anthropogenic stressors such as climate change, increased fire frequency, and pollution drive shifts in ecosystem function and resilience. Scientists generally rely on biological indicators of these stressors to signal that ecosystem conditions have been altered. However, these biological indicators are not always capable of being directly related to ecosystem components that provide benefits to humans and/or can be used to evaluate the cost-benefit of a change in health of the component (ecosystem services). Therefore, we developed the STEPS (STressor - Ecological Production function - final ecosystem Services) Framework to link changes in a biological indicator of a stressor to final ecosystem services. The STEPS framework produces "chains" of ecological components that explore the breadth of impacts resulting from the change of a stressor. Chains are comprised of the biological indicator, the ecological production function (EPF; which uses ecological components to link the biological indicator to a final ecosystem service), and the user group who directly uses, appreciates, or values the component. The framework uses a qualitative score (High, Medium, Low) to describe the Strength of Science (SOS) for the relationship between each component in the EPF. We tested the STEPS Framework within a workshop setting using the exceedance of critical loads of air pollution as a model stressor and the Final Ecosystem Goods and Services Classification System (FEGS-CS) to describe final ecosystem services. We identified chains for four modes of ecological response to deposition: aquatic acidification, aquatic eutrophication, terrestrial acidification, and terrestrial eutrophication. The workshop participants identified 183 unique EPFs linking a change in a biological indicator to a FEGS; and when accounting for the multiple beneficiaries, we ended with 1104 chains. The SOS scores were effective in identifying chains with the highest confidence ranking as well as those where more research is needed. The STEPS framework could be adapted to any system in which a stressor is modifying a biological component. The results of the analysis can be used by the social science community to apply valuation measures to multiple or selected chains, providing a comprehensive analysis of the effects of anthropogenic stressors on measures of human well-being.

Impacts to ecosystem services from aquatic acidification: using FEGS‐CS to understand the impacts of air pollution

AbstractIncreases in anthropogenic emissions of sulfur (S) and nitrogen (N) have resulted in increases in the associated atmospheric deposition of acidic compounds. In sensitive watersheds, this deposition has initiated a cascade of negative environmental effects on aquatic ecosystems, resulting in a degradation or loss of valuable ecosystem goods and services. Here, we report the activities of an expert workgroup to synthesize information on acidic deposition‐induced aquatic acidification from the published literature and to link critical load exceedances with ecosystem services and beneficiaries, using the Stressor–Ecological Production function–Final Ecosystem Services (STEPS) Framework and the Final Ecosystem Goods and Services Classification System (FEGS‐CS). Experts identified and documented the sensitive aquatic ecosystem ecological endpoints valued by humans, and the environmental pathways through which these endpoints may experience degradation in response to acidification. Beneficiary groups were then identified for each sensitive ecological endpoint to clarify relationships between humans and the effects of aquatic acidification, and to lay the foundation for future research and analysis to value these FEGS.