Multiple classification systems | My Assignment Tutor

Letter to the EditorEcosystem services: Multiple classification systemsare neededIn a recent paper in Biological Conservation, Wallace (2007) argues that the classification systems currently used for ecosystem services are inadequate because they mix ends andmeans. He then proposes a system to rectify this perceivedproblem. While there is much interesting material in Wallace’spaper, his basic premise is flawed and much of the paper suffers from a gross oversimplification of a complex reality. Wallace’s solutions to the classification problem might work if theworld had consistently crisp boundaries, static linear processes with no feedbacks, clear distinctions between meansand ends, little uncertainty, only one use for the classificationsystem, and people who always knew both everything aboutthe world and how it all affects their welfare – in other wordssome very different planet from the one we inhabit. In themessy world we do inhabit, we need multiple classificationsystems for different purposes, and this is an opportunity toenrich our thinking about ecosystem services rather than aproblem to be defined away.Let us start with definitions. Ecosystem services are defined as ‘‘the benefits people obtain from ecosystems’’ (Millennium Ecosystem Assessment, 2005). I think this is agood, appropriately broad and appropriately vague definition.This definition includes both the benefits people perceive, andthose they do not. The conventional economic approach to‘‘benefits’’ is far too narrow in this regard, and tends to limitbenefits only to those that people both perceive and are ‘‘willing to pay’’ for in some real or contingent sense. But the general population’s information about the world, especiallywhen it comes to ecosystem services, is extremely limited.We can expect many ecosystem services to go almost unnoticed by the vast majority of people, especially when theyare public, non-excludable services that never enter the private, excludable market. Think of the storm regulation valueof wetlands. How can we expect the average citizen to understand the complex linkages between landscape patterns, precipitation patterns, wetlands and flood attenuation, wheneven the best landscape scientists find this an extremely challenging task? We have to remain focused on the benefits provided by ecosystems, remembering that the degree to whichthe public perceives and understands them is a separate(and very important) question.A second problem is that ecosystem services are not ends,while ecosystem processes are means, as Wallace suggests.The end or goal is sustainable human well-being. Ecosystemservices are, by definition, means to that end. This does not imply that ecosystems are not also valuable for other reasons,but that ecosystem services are defined as the instrumental values of ecosystems as means to end of human well-being. Thedistinction Wallace (and also Boyd and Banzhaf, 2007) arereally trying to make, i believe, is one between intermediateservices and final services, not between means and ends. Itis true that for the purposes of certain aggregation exercisesadding intermediate and final services would be doublecounting. But that does not imply that intermediate servicesare not services. Think of the production of tires in an economy. Some tires are sold directly to consumers and are partof final demand, while others are sold to car companies andare intermediate products, sold to consumers as parts of cars.The tires themselves are indistinguishable from each other,the only difference being who buys them. When calculatingGNP (which is the aggregate of sales to final demand) it wouldnot be appropriate to count both the tires sold to final demand and the tires sold to car companies, since those tiresare already counted as parts of the cars sold to final demand.But tires in both cases, whether intermediate or final products, are means to the end of human well-being and are notends in themselves. Likewise, ecosystem goods and services,whether intermediate (or ‘‘supporting’’ in the MillenniumAssessment typology) services or final services are all contributors to the end of human well-being. Also, ecosystem processes and services are not mutually exclusive categories, asWallace seems to imply. Some processes are also services,others are not. Some services are intermediate, some are final, and some are partly both.In addition, there are other important and useful ways toclassify ecosystem services that are not captured in Wallace’stypology. I’ll mention just two: classification according to spatial characteristics and classification according to ‘‘excludability/rivalness’’ status.Table 1 groups the 17 ecosystem services listed in Costanza et al. (1997) into five categories according to their spatialcharacteristics. For example, services like carbon sequestraB I O L O G I C A L C O N S E R V A T I O N 1 4 1 ( 2 0 0 8 ) 3 5 0 – 3 5 2available at www.s ciencedirect.comjournal homepage: cate/bio contion (an intermediate input to climate regulation) is classifiedas ‘‘global: non-proximal’’ since the spatial location of carbonsequestration does not matter. The atmosphere is well-mixedand removing carbon dioxide (or other greenhouse gases) atany location is equivalent to removing it anywhere else.‘‘Local proximal’’ services, on the other hand, are dependenton the spatial proximity of the ecosystem to the human beneficiaries. For example, ‘‘storm protection’’ requires that theecosystem doing the protecting be proximal to the humansettlements being protected. ‘‘Directional flow related’’ services are dependent on the flow from upstream to downstream as is the case for water supply and water regulation.And so on for the other categories listed in Table 1.Another way to classify ecosystem services is according totheir ‘‘excludability and rivalness’’ status. Table 2 arrays thesetwo characteristics against each other in a matrix which leadsto four categories of goods and services. Goods and servicesare ‘‘excludable’’ to the degree that individuals can be excluded from benefiting from them. Most privately owned,marketed goods and services are relatively easily excludable.I can prevent others from eating the tomatoes i have grown,or the timber i have harvested or the fish i have caught unlessthey pay me. But it is difficult or impossible to exclude othersfrom benefiting from many public goods, like a well-regulatedclimate, fish in the open ocean, or the aesthetic benefits of aforest. Goods and services are ‘‘rival’’ to the degree that oneperson’s benefiting from them interferes with or is rival withother’s benefiting from them. If I eat the tomato or the fish,you cannot also eat it. But if I benefit from a well-regulated climate, you can also do the same. Excludability is largely afunction of supply (to what extent can producers excludeusers) and is related to the cultural and institutional mechanisms available to enforce exclusion, while rivalness is afunction of demand (how do benefits depend on other users)and is more a characteristic of the good or service itself. Table2 places ecosystem services into the four categories that thistwo by two matrix creates.These two examples should be enough to indicate thatthere are many useful ways to classify ecosystem goods andservices and our goal is not a single, consistent system asWallace implies, but rather a pluralism of typologies that willeach be useful for different purposes.Finally, ecosystems are complex, dynamic, adaptive systems with non-linear feedbacks, thresholds, hysteresis effects, etc. Wallace’s Fig. 1 ignores this complexity andconceives of the system as a linear chain from production(means) to direct benefits by people (ends) with no feedbacksor any of the other complexities of the real world. As I havesaid, all ecosystem services are in fact means to the end ofhuman well-being, ecosystem processes can also be services(they are not mutually exclusive categories), and the sameservices can be both intermediate and final, The real worldis complex and messy and our systems of classification anddefinition of ecosystem services should recognize that andTable 1 – EcoServices classified according to their spatial characteristics1. Global non-proximal (does not depend on proximity)1&2. Climate regulationCarbon sequestration (NEP)Carbon storage17. Cultural/existence value2. Local proximal (depends on proximity)3. Disturbance regulation/ storm protection9. Waste treatment10. Pollination11. Biological control12. Habitat/refugia3. Directional flow related: flow from point of production to point of use4. Water regulation/flood protection5. Water supply6. Sediment regulation/erosion control8. Nutrient regulation4. In situ (point of use)7. Soil formation13. Food production/non-timber forest products14. Raw materials5. User movement related: flow of people to unique natural features15. Genetic resources16. Recreation potential17. Cultural/aestheticTable 2 – Ecosystem services classified according to their excludability and rivalnessExcludable Non-excludableRival Market goods and services (most provisioning services) Open access resources (some provisioning services)Non-rival Club goods (some recreation services) Public goods and services (most regulatory and cultural services)B I O L O G I C A L C O N S E R V A T I O N 1 4 1 ( 2 0 0 8 ) 3 5 0 – 3 5 2 351work with it, not ignore it in a misguided attempt to imposeunrealistic order and consistency.R E F E R E N C E SBoyd, J., Banzhaf, S., 2007. What are ecosystem services? The needfor standardized environmental accounting units. EcologicalEconomics 63, 616–626.Costanza, R., d’Arge, R., de Groot, R., Farber, S., Grasso, M.,Hannon, B., Naeem, S., Limburg, K., Paruelo, J., O’Neill, R.V.,Raskin, R., Sutton, P., van den Belt, M., 1997. The value ofthe world’s ecosystem services and natural capital. Nature387, 253–260.Millennium Ecosystem Assessment, 2005. Island Press,Washington DC.Wallace, K.J., 2007. Classification of ecosystem services: problemsand solutions. Biological Conservation 139, 235–246.Robert CostanzaRubenstein School of Environment and Natural Resources,The University of Vermont,617 Main Street,Burlington,VT 05405-1708,United StatesTel.: +1 802 656 2974; fax: +1 802 656 2995E-mail address: [email protected]lable online 30 January 20080006-3207/$ – see front matter2008 Elsevier Ltd. All rights reserved.doi:10.1016/j.biocon.2007.12.020352 B I O L O G I C A L C O N S E R V A T I O N 1 4 1 ( 2 0 0 8 ) 3 5 0 – 3 5 2


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