Kai M. A. Chan

Modeling multiple ecosystem services, biodiversity conservation, commodity production, and tradeoffs at landscape scales

Nature provides a wide range of benefits to people. There is increasing consensus about the importance of incorporating these “ecosystem services” into resource management decisions, but quantifying the levels and values of these services has proven difficult. We use a spatially explicit modeling tool, Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), to predict changes in ecosystem services, biodiversity conservation, and commodity production levels. We apply InVEST to stakeholder-defined scenarios of land-use/land-cover change in the Willamette Basin, Oregon. We found that scenarios that received high scores for a variety of ecosystem services also had high scores for biodiversity, suggesting there is little tradeoff between biodiversity conservation and ecosystem services. Scenarios involving more development had higher commodity production values, but lower levels of biodiversity conservation and ecosystem services. However, including payments for carbon sequestration alleviates this tradeoff. Quantifying ecosystem services in a spatially explicit manner, and analyzing tradeoffs between them, can help to make natural resource decisions more effective, efficient, and defensible.

Conservation Planning for Ecosystem Services

Despite increasing attention to the human dimension of conservation projects, a rigorous, systematic methodology for planning for ecosystem services has not been developed. This is in part because flows of ecosystem services remain poorly characterized at local-to-regional scales, and their protection has not generally been made a priority. We used a spatially explicit conservation planning framework to explore the trade-offs and opportunities for aligning conservation goals for biodiversity with six ecosystem services (carbon storage, flood control, forage production, outdoor recreation, crop pollination, and water provision) in the Central Coast ecoregion of California, United States. We found weak positive and some weak negative associations between the priority areas for biodiversity conservation and the flows of the six ecosystem services across the ecoregion. Excluding the two agriculture-focused services—crop pollination and forage production—eliminates all negative correlations. We compared the degree to which four contrasting conservation network designs protect biodiversity and the flow of the six services. We found that biodiversity conservation protects substantial collateral flows of services. Targeting ecosystem services directly can meet the multiple ecosystem services and biodiversity goals more efficiently but cannot substitute for targeted biodiversity protection (biodiversity losses of 44% relative to targeting biodiversity alone). Strategically targeting only biodiversity plus the four positively associated services offers much promise (relative biodiversity losses of 7%). Here we present an initial analytical framework for integrating biodiversity and ecosystem services in conservation planning and illustrate its application. We found that although there are important potential trade-offs between conservation for biodiversity and for ecosystem services, a systematic planning framework offers scope for identifying valuable synergies.

Contributions of cultural services to the ecosystem services agenda

Cultural ecosystem services (ES) are consistently recognized but not yet adequately defined or integrated within the ES framework. A substantial body of models, methods, and data relevant to cultural services has been developed within the social and behavioral sciences before and outside of the ES approach. A selective review of work in landscape aesthetics, cultural heritage, outdoor recreation, and spiritual significance demonstrates opportunities for operationally defining cultural services in terms of socioecological models, consistent with the larger set of ES. Such models explicitly link ecological structures and functions with cultural values and benefits, facilitating communication between scientists and stakeholders and enabling economic, multicriterion, deliberative evaluation and other methods that can clarify tradeoffs and synergies involving cultural ES. Based on this approach, a common representation is offered that frames cultural services, along with all ES, by the relative contribution of relevant ecological structures and functions and by applicable social evaluation approaches. This perspective provides a foundation for merging ecological and social science epistemologies to define and integrate cultural services better within the broader ES framework.

Where are cultural and social in ecosystem services? A framework for constructive engagement

A focus on ecosystem services (ES) is seen as a means for improving decisionmaking. In the research to date, the valuation of the material contributions of ecosystems to human well-being has been emphasized, with less attention to important cultural ES and nonmaterial values. This gap persists because there is no commonly accepted framework for eliciting less tangible values, characterizing their changes, and including them alongside other services in decisionmaking. Here, we develop such a framework for ES research and practice, addressing three challenges: (1) Nonmaterial values are ill suited to characterization using monetary methods; (2) it is difficult to unequivocally link particular changes in socioecological systems to particular changes in cultural benefits; and (3) cultural benefits are associated with many services, not just cultural ES. There is no magic bullet, but our framework may facilitate fuller and more socially acceptable integrations of ES information into planning and management.

Leaky prezygotic isolation and porous genomes: rapid introgression of maternally inherited DNA.

Abstract Accurate phylogenies are crucial for understanding evolutionary processes, especially species diversification. It is commonly assumed that “good” species are sufficiently isolated genetically that gene genealogies represent accurate phylogenies. However, it is increasingly clear that good species may continue to exchange genetic material through hybridization (introgression). Many studies of closely related species reveal introgression of some genes without others, often with more rapid introgression of maternally inherited chloroplast or mitochondrial DNA (cpDNA, mtDNA). We seek a general explanation for this biased introgression using simple models of common reproductive isolating barriers (RIBs). We compare empirically informed models of prezygotic isolation (for pre‐ and postinsemination mechanisms of both female choice and male competition) with postzygotic isolation and demonstrate that rate of introgression depends critically upon type of RIB and mode of genetic inheritance (maternal versus biparental versus paternal). Our frequency‐dependent prezygotic RIBs allow much more rapid introgression of biparentally and maternally inherited genes than do commonly modeled postzygotic RIBs (especially maternally inherited DNA). After considering the specific predictions in the context of empirical observations, we conclude that our model of prezygotic RIBs is a general explanation for biased introgression of maternally inherited genomic components. These findings suggest that we should use extreme caution when interpreting single gene genealogies as species phylogenies, especially for cpDNA and mtDNA.

A social–ecological approach to conservation planning: embedding social considerations

Many conservation plans remain unimplemented, in part because of insufficient consideration of the social processes that influence conservation decisions. Complementing social considerations with an integrated understanding of the ecology of a region can result in a more complete conservation approach. We suggest that linking conservation planning to a social–ecological systems (SES) framework can lead to a more thorough understanding of human–environment interactions and more effective integration of social considerations. By characterizing SES as a set of subsystems, and their interactions with each other and with external factors, the SES framework can improve our understanding of the linkages between social and ecological influences on the environment. Using this framework can help to identify socially and ecologically focused conservation actions that will benefit ecosystems and human communities, and assist in the development of more consistent evidence for evaluating conservation actions by comparing conservation case studies.

Opinion: Why protect nature? Rethinking values and the environment

A cornerstone of environmental policy is the debate over protecting nature for humans’ sake (instrumental values) or for nature’s (intrinsic values) (1). We propose that focusing only on instrumental or intrinsic values may fail to resonate with views on personal and collective well-being, or “what is right,” with regard to nature and the environment. Without complementary attention to other ways that value is expressed and realized by people, such a focus may inadvertently promote worldviews at odds with fair and desirable futures. It is time to engage seriously with a third class of values, one with diverse roots and current expressions: relational values. By doing so, we reframe the discussion about environmental protection, and open the door to new, potentially more productive policy approaches.

Ecosystem-service science and the way forward for conservation.

Conservation biology began life as a crisis discipline, its central tenet to understand and help reverse losses of biodiversity and habitat. Those losses continue unabated, implying that, as a discipline, we are failing in our central charge. A growing number of conservation biologists are therefore looking for a new way forward, and we believe that an increased focus on ecosystem services provides it. Yet the conservation community remains deeply, and sometimes very publicly (McCauley 2006), divided over how much emphasis ecosystem-service approaches should receive relative to those based solely on moral suasion. Put bluntly, will we achieve greater conservation success by protecting nature for its own sake or for our own sake? This dichotomy highlights extremes of a continuum that was prominent a century ago. Nature for nature’s sake, often blended with aesthetic appeals, can be traced most notably to the preservationist John Muir. Conservation through utilization can be traced to another icon, forester Gifford Pinchot. These complementary strands, each valid, powerful, and deeply rooted in the conservation movement, clashed long ago, especially in the United States. But just as Muir’s writings acknowledge a role for utilitarianism and Pinchot’s a keen awareness of the intrinsic value of nature, pluralism between the two schools of thought is the norm in conservation practice. For example, in a survey of current projects underway in major conservation nongovernmental organizations, it is proving difficult to distinguish those focused on biodiversity for its own sake and those focused on ecosystem services and human well-being. Most projects mix the two approaches, drawing on the diverse ways in which people perceive and interact with nature to motivate action. We see an expanded role for ecosystem-service approaches in conservation not because these approaches are more valid in some way, but because they have not yet come close to reaching their conservation potential and because people from all walks of life can contribute to the realization of that potential. Despite past successes, the rate of biodiversity loss has not slackened, making it urgent that we broaden and strengthen the foundation for conservation. Nature for nature’s sake resonates only with the already converted. Business interests, farmers, and the billion humans living in rural poverty remain unwilling or unable to move. We need these people as partners in conservation, and ecosystem-service approaches provide a means of motivating and enabling them. If human dependence on nature becomes widely recognized, society will demand greater environmental stewardship. The resulting investments in conservation promise to outweigh select instances in which the two approaches conflict. Arguing for a greater focus on ecosystem services is not “selling out” biodiversity (McCauley 2006)—quite the opposite. By emphasizing the many ways nature sustains and enriches people’s everyday lives, ecosystem-service programs turn traditional conservation approaches, which are based on separating people from nature, on their heads. Conservation efforts premised on protecting a small number of places or species from people are necessary but far from sufficient. Conservation efforts must be interwoven throughout entire land and seascapes and must place greater emphasis on preserving population numbers and diversity if they are to sustain biodiversity. Arguments for ecosystem-service approaches drive us toward this vision of conservation. Already, ecosystem-service advocates are finding allies and enjoying traction in places where ethical arguments for biodiversity conservation are given short shrift. For example, ecosystem-service ideas embed concerns about the environment and biodiversity in the heart of broader policy debates concerning global poverty reduction (Sachs & Reid 2006). In much of the world, conserving nature out of moral obligation is a luxury most simply cannot afford. Nevertheless, human well-being is intimately linked to the immediate environment and natural capital is a vital part of the economic base. In the face of a sea of poverty, demonstrating the ignored links between nature and elements of well-being—safe drinking water, food, fuel, flood control, and aesthetic and cultural benefits that contribute to dignity and satisfaction—is the key to making conservation relevant and, if we are lucky, possible. As a community conservation biologists must refocus research efforts to deliver the science to support ecosystem-service conservation. The Millennium

Modeling benefits from nature: using ecosystem services to inform coastal and marine spatial planning

People around the world are looking to marine ecosystems to provide additional benefits to society. As they consider expanding current uses and investing in new ones, new management approaches are needed that will sustain the delivery of the diverse benefits that people want and need. An ecosystem services framework provides metrics for assessing the quantity, quality, and value of benefits obtained from different portfolios of uses. Such a framework has been developed for assessments on land, and is now being developed for application to marine ecosystems. Here, we present marine Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), a new tool to assess (i.e., map, model, and value) multiple services provided by marine ecosystems. It allows one to estimate changes in a suite of services under different management scenarios and to investigate trade-offs among the scenarios, including implications of drivers like climate. We describe key inputs and outputs of each of the component ecosystem service models and present results from an application to the West Coast of Vancouver Island, British Columbia, Canada. The results demonstrate how marine InVEST can be used to help shape the dialogue and inform decision making in a marine spatial planning context.

Ecosystem Services and Beyond: Using Multiple Metaphors to Understand Human–Environment Relationships

Ecosystem services research has been focused on the ways that humans directly benefit from goods and services, and economic valuation techniques have been used to measure those benefits. We argue that, although it is appropriate in some cases, this focus on direct use and economic quantification is often limiting and can detract from environmental research and effective management, in part by crowding out other understandings of human—environment relationships. Instead, we make the case that the systematic consideration of multiple metaphors of such relationships in assessing social—ecological systems will foster better understanding of the many ways in which humans relate to, care for, and value ecosystems. Where it is possible, we encourage a deliberative approach to ecosystem management whereby ecosystem researchers actively engage conservationists and local resource users to make explicit, through open deliberation, the types of metaphors salient to their conservation problem.