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Premise 4: "Health" and "Integrity"
Click below to view some of the premises from Karr and Chu (1999).
"Health" and "integrity" are meaningful for environmental management
FROM "Restoring Life in Running Waters" by James R. Karr and Ellen W. Chu. (Reprinted with permission from Island Press)
Webster's dictionaries define health as a flourishing condition, well-being, vitality, or prosperity. A healthy person is free from physical disease or pain; a healthy person is sound in mind, body, and spirit. An organism is healthy when it performs all its vital functions normally and properly, when it is able to recover from normal stresses, when it requires minimal outside care. A country is healthy when a flourishing economy provides for the well-being of its citizens. An environment is healthy when the supply of goods and services required by both human and nonhuman residents is sustained. To be healthy is to be in good condition.
Despite – or perhaps because of – the simplicity and breadth of this concept, the intellectual literature is rife with arguments on whether it is appropriate to use health in an ecological context. Is it appropriate to speak of "ecological health" or "river health"?
The arguments mounted against health as an ecologically useful concept go something like the following. Suter (1993)insists that health is an inappropriate metaphor because it is not an observable ecological property. According to Suter, health is a property of organisms, a position that acknowledges only the first, and narrowest, of the dictionary's definitions. Scrimgeour and Wicklum (1996) believe that no objective ecosystem state can be defined that is preferable to alternative states. Calow (1992) asserts that the idea of health in organisms involves different principles from the concept "as applied to ecosystems." He distinguishes between applying the concept in a weak form to signal normality (an expected condition) and in a strong form to signal the existence of an active homeostatic process that returns disturbed systems to normality. The strong form, he suggests, requires a system-level control that does not exist in ecosystems. Neither does such a homeostatic control exist in any dictionary definition of health. Why, then, must this notion be central to health in an ecological context?
"Societal values" also enter the discussion, sometimes as an essential, sometimes as an inappropriate consideration. Policansky (1993) and Wicklum and Davies (1995) contend that health is a "value-laden concept" and therefore inappropriate in science. Yet Rapport (1989) suggests that efforts to protect ecological health must consider "the human uses and amenities derived from the system." Regier (1993) and Meyer (1997) agree with Rapport about the importance of societal values in defining and protecting health. Regier speaks of "integrity" rather than health, saying that the concept of integrity is "rooted in certain ecological concepts combined with certain sets of human values."
Other authors have searched for more objective or scientific arguments for referring to health in ecological contexts, often equating health with properties such as "self-organizing," "resilient," and "productive." Haskell et al. (1992) suggest that an ecosystem is healthy "if it is active and maintains its organization and autonomy over time and is resilient to stress." But resilience of biological systems is difficult to define and even more difficult to measure (Karr and Thomas 1996). Resilient to what? The term must be defined in the context of specific disturbances. A biota can sustain itself – it is very resilient – when faced with normal environmental variation, even when that variation is large (e.g., variation in river flow). But the same biota may not be able to withstand even the smallest disturbance outside the range of its evolutionary experience. Does this concept add any objectivity to our concept of health? In fact, highly disturbed systems tend to be resilient to stress. Does this observation mean that these systems are healthier?
Costanza (1992) goes one step further, proposing an ecosystem health index as the product of system vigor (primary production or metabolism), organization (species diversity or connectivity), and resilience (the ability to resist or recover from damage). But are these criteria scientifically defensible? Applying them, we would define lakes with limited plant nutrients as less healthy than highly productive lakes with abundant plant nutrients. Would an increase in primary production caused by the addition of excess nutrients, such as from sewage, therefore be considered still healthier? Using maximum production as a measure of ecological health is the analogue of using gross national product as a measure of economic vitality. By Costanza's second criterion, a tropical forest might be calculated as healthier (more diverse and connected) than a spruce-fir forest. A community of sewage sludge worms (Tubificidae) at the outflow of a wastewater treatment plant would be healthy because it is very resilient to additional disturbance. These criteria all imply that "more is better" and can thus be turned too easily on their heads to justify human actions – from introducing species to adding fertilizers – that in fact degrade living systems.
Health as a word and concept in ecology is useful precisely because it is something people are familiar with. It is not a huge intuitive leap from "my health" to "ecological health." Cells; individual humans, animals, and plants; and complex ecological systems are all products of evolution. We understand that cells and individuals can be healthy or unhealthy; why is it unreasonable to extend the concept to ecosystems?
Of course we must "operationalize" the term – define it and find ways to measure it – but as a policy goal, protecting the health and integrity of our landscapes and rivers has a believable chance of engaging public interest and support. It is no accident that protecting biological or ecological "integrity" is the core principle of the Clean Water Act, Canada's National Park Act, and the Great Lakes Water Quality Agreement between the United States and Canada. Words like health and integrity are embedded in these laws because they are inspiring to citizens and a reminder to those who enforce the law to keep their minds on the big picture, the importance of living systems to the well-being of human society.
We contend that we can define health and integrity to make the terms useful in understanding humans' relationship with their surrounding ecological systems. Integrity applies to sites at one end of a continuum of human influence, sites that support a biota that is the product of evolutionary and biogeographic processes (Figure 3). This biota is a balanced, integrated, adaptive system having the full range of elements (genes, species, assemblages) and processes (mutation; demography; biotic interactions; nutrient and energy dynamics; and metapopulation, or fragmented population, processes) that are expected in the region's natural environment (Karr 1991; Angermeier and Karr 1994; Karr 1996). Adopting integrity as a management goal means aiming for a system that resembles this evolved state as much as possible (Angermeier 1998).
Figure 3
This definition of integrity takes into account three important principles: (1) a biota spans a variety of spatial and temporal scales, (2) a living system includes items one can count (the elements of biodiversity) plus the processes that generate and maintain them, and (3) living systems are embedded in dynamic evolutionary and biogeographic contexts. This breadth is important because human society depends on, and indeed values, both elements and processes – that is, both structure and function – in these systems (counter to Meyer's [1997] argument).
As human activity changes biological systems, they – and we along with them – move along a continuum, ultimately to a state where little or nothing is left alive (see Figure3). Whether such as shift is acceptable to society is certainly a "value" decision – do we value the elements and processes that are lost? – but those decisions ought to be grounded in broad understanding of the consequences of loss, which include the loss of our own basis for existence (Westra 1998). Two criteria would help set the thresholds for whether a loss is acceptable (Karr 1996). First, human activity should not alter the long-term ability of places to sustain the supply of goods and services those places provide. Second, human uses should not degrade off-site areas, a provision that requires a landscape-level perspective in modern decision making. Such criteria in decisions about environmental policy – from land use to setting fish harvest quotas – would avoid the depletion of living systems.
Like health and integrity generally, river health can take on multiple definitions. To irrigators, rivers are healthy if there is water enough for their fields. For a power utility, rivers are healthy if there is water enough to turn their turbines. For a drinking-water utility, healthy means enough pure or purifiable water throughout the year. To fishers, rivers are healthy if there are fish to harvest. For recreationists, rivers are healthy if swimming, water skiing, or boating do not sicken people. But every one of these viewpoints is only part of the picture. Each trivializes the other views of the river – not to mention nonhuman aspects of the river itself – while assigning value only to its own. To protect all river uses and values, we need broader definitions of river health.
Water bodies with integrity, especially rivers, have persisted in, even modified, their region's physical and chemical environment over millennia. The very presence of their natural biota means that they are resilient to the normal variation in that environment. Still, the bounds over which the system changes as a result of most natural events are narrow in comparison with the changes that result from human actions such as row-crop agriculture, timber harvest, grazing, or urbanization. Normal, or expected, conditions constituting integrity vary geographically because each river's biota evolves in the context of local and regional geology and climate and within the biological constraints imposed by the organisms with access to that region (see Premise 6). Understanding this baseline must be the foundation for assessing change caused by humans. Only then can we take informed decisions in response to the question, Is this level of change acceptable?
When human activities within a watershed are minimal, the biota is determined by the interaction of biogeographic and evolutionary processes. As human populations increase and technology advances, landscapes are altered in a variety of ways. Those changes alter the river's biota and thus the entire biological context of the river, causing it to diverge from "integrity." In some cases, the changes are minor. In others, they are substantial; they may even eliminate all or most of the plants and animals in a river. That much divergence from integrity is not healthy for humans or nonhumans.
Consideration of river health or integrity rarely entered decision making by societies bent on conquering some frontier. Water was simply there, a potable liquid to be used. It was there to be allocated, to be consumed, and to be discarded and, as likely as not, carrying society's unwanted wastes with it. When the goal is to conquer, everything else is in the way. This attitude has threatened and continues to threaten the tenuous balance between water and human society, between rivers and the people who depend on rivers. In some instances, water is at the center, even a weapon, in age-old power struggles among humans: between the powerful and the weak in a single society – downstream populations of Hokoham in arid Southwest fortified themselves against upstream neighbors to retain control over the flow of water (Pringle 1998) – and between the societies of haves and of the have-nots (Donahue and Johnston 1998). The consequences for human culture and values, as well as for human and ecological health, have been catastrophic.
Society – oblivious to either human-health or ecological risks of radically altering rivers – has chronically undervalued their biological components. We have behaved as if we could repair or replace any lost or broken parts of regional water resource systems, much as we replace toasters, cars, jobs, and even hearts or livers. This disregard has only worsened the lack of coherence in water law and in regulations regarding water use. The result is a body of federal, state, and local law that fails to make the connections between water quality and quantity, surface water and groundwater, headwater streams and large rivers, and the living and nonliving components of aquatic ecosystems. This disconnectedness was one thing when there were few people living on a vast North American continent; now it is quite another.
We need a new approach, one based on new conceptual models of how rivers, landscapes, and human society interact. Mental models guide much that we do. But models – whether conceptual, physical, or mathematical – can be wrong when they make inappropriate assumptions or focus on the wrong endpoint. They can mislead when they contain inappropriate levels of detail, or they can be irrelevant if they do not apply to the real world. The first rule of modeling is to recognize that "all models are wrong, but some models are useful" (Anderson and Woessner 1992). Models are most useful when they are routinely evaluated to determine if expectations are being met and if policies based on those models are accomplishing the goals of the society using those models.
A new model, with biological integrity and ecological health at its core, should inform society not only about the condition of rivers and the landscapes they run through, but also about the lives of people living in those landscapes. That model should focus on biological endpoints as the most integrative measures of river health. Because they can be defined on the basis of objective criteria (Karr 1996; Westra 1998) and used systematically to diagnose ecological condition (Rapport 1998), the concepts of biological integrity and ecological health can and should be central to that model (Rapport et al. 1998). Biological monitoring with these concepts at its core integrates the influence of all forms of degradation caused by human actions and can thus guide diagnostic, curative, restorative, and preventive management actions.
References
Karr, J. R. 1991. Biological integrity: A long-neglected aspect of water resource management. Ecol. Appl. 1: 66-84.