from Africa Today Volume 48, Number 1Carrying Capacity's New Guise: Folk Models for Public Debate and Longitudinal Study of Environmental Change
Lisa Cliggett
Permission to CopyYou may download, save, or print for your personal use without permission. If you wish to disseminate the electronic article, or to produce multiple copies for classroom or educational use, please request permission from:
Copyright Clearance CenterFor other permissions or reprint use contact:
Professional Relations Department
222 Rosewood Drive
Danvers MA 01923 FAX: 978-750-4470/4744
Web address: www.copyright.com
Rights and Permissions, Journals Division
Indiana University Press
601 North Morton St.
Bloomington, IN 47404FAX: 812 855-8507
E-mail: journals@indiana.edu
Current public debates about the environment often assume a clear relationship between resource availability and population growth: more people mean fewer resources. Over the past three decades, scholars in the social and natural sciences have disassembled the notion of carrying capacity to demonstrate that relationships between humans and their ecosystems are more open, fluid, and complex than the concept allows. Despite scholarly recognition of the problems with carrying capacity, the term, and its underlying logic, endures. By reframing the concept as a folk model, we continue to highlight ecological relationships and advance arguments for conservation, but also acknowledge the complexity of human-environment links which formal applications of carrying capacity ignore.
Introduction
With increasing public concern about the environment, the human-environment link has moved from the realm of studies in the social and natural sciences to the center of public and political debate. To promote awareness of the impacts of markets and free trade on ecosystems in distant lands, western environmental activists stage protests at meetings of international organizations in the United States and Europe. Politicians take stands on the environmental debate, garnering support based on their proenvironment or proworker positions. Amid this hubbub of environmental awareness lurks a term that emerged in scientific discussion of the human impact on ecosystems: carrying capacity. The carrying capacity concept seems to have left the domain of academic consideration and been assimilated by the public as the natural explanation for the balance between nature and human populations.
In this article, I want to explore the usefulness of the carrying capacity concept for anthropological discussions in particular, but also for social science's contribution to environmental debates. By reframing the concept as a folk model, we can continue to use the phrase to highlight ecological relationships and advance arguments for environmental conservation, but at the same time acknowledge the complexity of the human-environment links which formal applications of carrying capacity ignore. The longitudinal Gwembe Tonga Research Project (GTRP), in Southern Zambia, offers one opportunity to look at how anthropologists have used a general notion of carrying capacity to understand social processes and the human-environment link over time.
The concept of carrying capacity relates the resources available in a given environment to the populations of particular animal species. Social scientists began using the term around the mid-1940s to assess human impacts on the environment, whether human populations in particular, or human-influenced populations, such as herds of cattle, goats, or camels. Over the past three decades, many scholars have offered detailed critiques of carrying capacity—particularly its formal application—by pointing out that the term does not successfully capture the multilayered processes of the human-environment link, and that it often has a blame-the-victim framework. These scholars most often cite the fluidity and nonequilibrium nature of this relationship, and the role of external forces in influencing environmental change, as key problems with the term.
Despite the critiques launched at the concept, I continue to ponder the question of whether or not "carrying capacity" can be at all useful in current social science and human ecology discussions. In particular, I wonder if it can provide a conceptual framework for describing some of the processes we see in Zambia's Gwembe Valley over the last fifty years, and perhaps more generally in describing human-environment relations as the general public, politicians, and international agencies become increasingly concerned with environmental issues. Before discussing carrying capacity in greater detail, I will give some background to the GTRP and the nature of human-environment links that the project has considered in this region of Southern Zambia.
GTRP HistoryThe GTRP is one of the longest and most systematic long-term studies in Africa, and is particularly remarkable in that it has followed a population as it has dispersed beyond the original study sites (Scudder and Colson 1978). Anthropologists Elizabeth Colson and Thayer Scudder initiated the Gwembe Study in 1956 in that portion of the Gwembe Valley that lies in Zambia, now comprised of Siavonga, Gwembe, and Sinazongwe Districts (all formerly one district). During the early 1990s, two new anthropologists (including this author) and one demographer joined the core team of the GTRP, and increasingly oversee the project activities and agenda.
At the outset, Colson and Scudder designed their investigation as a before-and-after study of the effects of large-scale development on local populations. In this case, development meant the building of Kariba Dam on the Zambezi River, and subsequent flooding of the river valley, causing the forced relocation of approximately 57,000 Gwembe Tonga people on both the Zambian and Zimbabwean (Northern and Southern Rhodesia during the period under discussion) sides of the river. Upon completion of the follow up study of the relocation in 1962, Colson and Scudder decided to continue the study indefinitely as a means to understand community continuity and change.1
At the time of its creation, Lake Kariba was the largest artificial reservoir in the world, and the local population the largest group ever to be forcefully resettled due to development activities. On the Zambian side of the lake, the majority of the resettled population moved up the escarpment from their old villages. However, due to last minute changes in the engineering of the dam, some villages were forced to move approximately 100 miles downstream from their original homes, and below the Kariba Dam wall. Six thousand people from these villages settled in an area known as Lusitu, among a different ethnic group with a population of approximately one thousand people, as well as a new ecological setting. These circumstances unfortunately created conditions in which to consider the classic notions of carrying capacity and the effects of human population density on local environments.
In addition to providing a context in which to examine the links between human populations and their environment, the longitudinal study offers a unique opportunity to consider change, adaptation, and resilience over time.2 The GTRP data, including field notes, interviews, census forms, and a variety of diaries kept by local people indicate that, compared to other periods in their history, Gwembe people lived relatively comfortable and materially secure lives during the 1960s and early 1970s (Scudder 1985, 1993). However, with the decline in Zambia's national economy in the mid-1970s, due to a drop in world copper prices and a decaying national infrastructure, combined with locally and globally induced environmental changes, Gwembe people's local economies also suffered, as did their health, nutrition, and general well-being (Clark et al. 1995; Colson 1995b; Gillett and Tobias, forthcoming). Since the 1970s, the Gwembe population has experienced fluctuations in quality of life, including access to basic food, access to cash for purchasing necessities and luxuries (such as soap), quality of education, and provision of medical services. All of these socioeconomic changes result in limiting people's coping strategies, conditions that can then exacerbate pressures on environmental resources.
The Ecological SettingIn addition to the problems associated with links to national and international economies, environmental fluctuations have impacted the Gwembe Valley in significant ways. The increasingly frequent drought cycles of southern Africa make the already drought-prone region even more risky for subsistence farmers. However, the longitudinal framework of the GTRP, with its frequent field visits, gives us a much better sense of environmental fluctuations and change. Despite seemingly increasingly frequent droughts and their environmental costs, we have found that drought does not lead inevitably to permanent ecological decline. Even in the Lusitu region, one of the most ecologically disturbed areas of the Gwembe Valley (and Zambia as a whole), we have seen change from year to year. The drought between 1994 and 1995, which was called the worst drought in the past decade, resulted in no harvest for people living in the Lusitu area. The following year, people told us they had a "good harvest" (although still not enough to feed the local population for the whole year). Apparently this drought had acted as a kind of fallow for the fields, allowing the soil to rest for a season, and then the following year produce better than in recent memory.
Of course, what local people might call a "good harvest" differs from what outsiders, including Zambians who live in areas with more consistent food production, might see as minimal survival. Indeed, the Gwembe Valley is notorious throughout Zambia as a drought-prone, impoverished, and backward region of scarcity. The region has a long history of droughts, famines, pest infestations, and crop failure that extends into the previous century, and the local population has an oral tradition documenting the most memorable of these crises.
The annual hunger season comes at the beginning of the rainy season, usually in October, and extends until the first harvest in February. During the hunger season, or nzala, people become accustomed to eating less, and collect wild foods from the surrounding bush. As mentioned above however, hunger years, or mwaka nzala, are becoming more common. The Gwembe Valley has been a food deficit area in thirteen of the last twenty-four years, and in the early 1990s, the Gwembe suffered the worst three droughts on record.
During the dry season, and often through the whole year during droughts, parts of the Gwembe Valley look like the Sahel. The population density and changing agricultural systems have combined to make agricultural production less than sufficient for people's needs. While soil scientists have not collected samples systematically over time, a variety of ecologists, as well as the local farmers themselves, tell us that the soil fertility is declining rapidly. Any visitor to the area can identify the growing problem of erosion. During the windy season, the topsoil blows through the air like ocean spray at the beach, and little or no wild grass grows on many abandoned fields. The lack of wild grasses and bush areas pose a problem for cattle and goat grazing. In the areas with the highest population, particularly along the lakeshore and in the Lusitu area, little unclaimed land exists where people can open new fields. The lack of fallowing periods for fields parallels the lack of open land; the rare occasion of a fallow period comes largely during severe droughts when people do not plant, or seeds do not germinate. With the severe droughts of the 1990s, both subsistence and commercial farmers in Zambia's Southern Province fear that the droughts in the south are becoming more permanent; many people move farther north to "chase rain" (Cliggett 1997b, 2000).
On top of these environmental conditions the Zambian economy has experienced upheaval since the 1970s, when the copper industry collapsed. More recently, the structural adjustment program started after multiparty elections in 1991 has lead to austere economic conditions for the Zambian nation, and for the poor majority of the population in particular. Maintenance of national infrastructures, such as health clinics, schools, and roads, have received little or no attention over the past two decades. The infrastructure in rural areas, where clinics have no aspirin or chloroquin, let alone antibiotics, and teachers often refuse their posts because they are too remote, seems to have been forgotten by the majority of decision makers in the cities. Under these circumstances, in rural areas such as the Gwembe Valley, extended family networks and kinship play a large role in the way people cope with scarcity in their physical and economic environments.
Carrying Capacity Revisited
Having established the Gwembe Valley context, I can move on to reconsider the concept of carrying capacity, and explore the way the concept has been used in the long-term Gwembe research. In a general sense, carrying capacity as used in human ecology refers to the link between populations and the environment. One of the more cited definitions, particularly with reference to Africa, states that carrying capacity is "the maximum number of people that a given land area will maintain in perpetuity under a given system of usage without land degradation setting in" (Allan 1949). Since then, most interpretations follow the general sense of this definition; carrying capacity relates population size to available resources, at given levels of extraction. This use of the term recognizes that decreasing returns to labor typically lead to new technology, such as the transition from extensive to increasingly intensive farming systems, and ultimately results in a new carrying capacity for a region.
Until the mid-1970s, many ecologists and social scientists tried to measure carrying capacity, transforming the concept into an analytical, methodological, and quantifiable tool (Birdsell 1953; Carneiro 1961; Rappaport 1967; Zubrow 1975). Even more recently, a few natural science scholars continue to apply the concept to current global concerns (Ehrlich and Ehrlich 1990; Mancl et al. 1999). These attempts at application have resulted in a growing outcry for a more flexible method to examine relationships between humans and their ecological settings, and ultimately, resource management. Since the late 1960s, the concept has received repeated critical attention, particularly from social scientists who have a variety of evidence suggesting that people, and their environments, adapt in oscillating periods of scarcity and sufficiency, if not always plenty (Boserup 1965; Street 1969; Netting 1981, 1993; Berry 1984; Dewar 1984; Agrawal 1995; Fairhead and Leach 1996). Critiques of the carrying capacity concept draw attention to a variety of problems in earlier attempts to measure a particular region's carrying capacity. A short list of some of the problems most often cited in the literature on carrying capacity include: (1) an assumption of equilibrium, (2) difficulty in measuring food resources, (3) inability to account for human preference in taste and labor expenditure, (4) assumption of full use of food resources, (5) assumption of homogeneity across the landscape, (6) assumption of an isolated group/region, (7) an ahistorical view of a process that in fact fluctuates in short- and long-term time frames, and lastly (8) the concept does not address the issue of standard of living
An Assumption of EquilibriumA variety of research during the 1990s focused on the open-ended nature of ecological systems (Berry 1993; Netting 1993; Moore and Vaughan 1994). Some of this literature even suggests that human populations can increase local biodiversity simply through their presence on the land, challenging the long-held assumptions that human habitation necessarily leads to deforestation and decreasing biodiversity (Fairhead and Leach 1996; Leach and Fairhead 2000; Leach and Mearns 1996). These findings can successfully end discussions that view ecosystems as static, balanced, and in check.
Difficulty in Measuring Food ResourcesMeasuring all potential food resources in a given environment poses a multitude of challenges for any investigator. How do we classify plants that could be eaten, but usually are not eaten? How do we include plants that appear on the landscape irregularly, over longer time periods than twelve-month cycles? Do we privilege caloric values over nutritional values (i.e., cassava versus beans)?
Inability to Account for Human Preference in Taste and Labor ExpenditureThis point relates to the previous critique in highlighting the role of the food consumers in establishing criteria for measurement. Humans have mysterious and deep relationships to what they eat; why one group of people will eat flying termites, while their neighbors in the same ecological niche refuse, can only be revealed, if at all, by sensitive exploration of world views, historical processes, and other cultural phenomena that gives food meaning.
Sometimes food preferences have more simple, pragmatic explanations; in the Gwembe Valley, people prefer to grow and eat maize, millet, or sorghum (with a strong preference for maize whenever possible). However, at the end of drought, when harvests have failed, a visitor can see old women in areas where wild grasses grow, collecting—grain by tiny grain—the small seeds atop the thin waving stalks of grass. Even when hungry, younger Tonga avoid the arduous and tedious labor that produces such a small harvest. An afternoon of collecting seeds in this manner offers only one small, tasteless (according to my informants) meal, and brief respite from hunger pangs. However, the same young people will hike almost eight hours to better fishing grounds, and then eight hours back with only enough fish for one meal. People make choices about investment of labor, and in many cases they will think the return does not warrant the increased work. Yet, at given moments that are difficult to predict, the same people will invest increased labor in getting their food. Assuming that one mode of production characterizes a given time period causes problems with a reliable measurement of carrying capacity. Accounting for this kind of variability within a quantifiable measurement seems as arduous and tedious as collecting grass seeds.
Assumes Full Use of Food ResourcesThis critique relates to the above point highlighting human preferences. In addition to conscious choices people make about what they will eat, and when, researchers and local populations may not recognize the same natural resources as potential food, leading again to a problem of measurement. Should all possible food resources be considered within a carrying capacity equation, or only foods local populations recognize? Whatever the answer to that question, the models will also need to account for seasonality of resources.
Assumption of Homogeneity across the LandscapeThis point, like the issues mentioned above, focuses on the subtlety that any models must include in order to claim close representation to an ecological reality. In the Gwembe Valley, for instance, ecological resources vary significantly within a ten-minute walk. A small sandy hill can drop into a moist dhambo where people keep small gardens to supplement their lakeshore gardens. However, these dhambo appear with no regularity or certainty throughout one particular village, let alone across the complete ecosystem from which people draw their food resources. A carrying capacity equation that seeks a clearly defined measurement could not successfully account for the significant, unpredictable variation found in any region large enough to support a local human population.
Assumption of an Isolated Group/RegionDefining a region for a carrying capacity measurement assumes that a human population relies only on the resources within their territory. The !Kung San of Botswana, often imagined to be the ideal example of a "natural population" living solely from their environment, have in fact been in contact, and exchanging with neighbors and outsiders for centuries (Wilmsen 1989), suggesting once and for all that isolated populations exist only in the minds of romantic scholars searching for a pristine past.
An Ahistorical View of a Process that in Fact Fluctuates in Short- and Long-Term Time FramesAlso related to the point above, if we see ecosystems as nonstatic and changing, then we must look for change over time—both long-term and short-term. One easily identified problem with applications of carrying capacity is the assumption that a population has already reached its carrying capacity—which people are already using all of the resources they can. This type of assumption occurs most frequently with short-term studies. Longitudinal research provides the antidote to any naïve conclusions drawn from slice-of-life and moment-in-time studies.
The Concept Does Not Address the Issue of Standard of LivingAt an ethical and moral level, a quantifiable measurement of carrying capacity cannot account for the varying "standards of living" within which humans can survive. One way Gwembe people adjust to increasing food scarcity is through malnutrition (Gillett and Tobias, forthcoming). Humans can eat less and less, and less nutritionally valuable food, yet still continue to survive in a given environment. As social scientists concerned with the well-being of the people with whom we work, do we want to argue that a particular region's carrying capacity has not been exceeded yet, simply because people still get their food from the local environment and continue to survive there?
In terms of specific measurement then, an investigator needs so much precision in data collection tools—to capture all the variation in time, space, ecological resources, technology, and all the social, cultural and material components that go into how humans work with, and adapt to, their environment—that it renders the term quite limited. With an obligation to collect such a level of detail in data, if in fact that detail can be measured, and if we decide that measuring such data does not compromise our ethical commitment to the local populations where we work, most researchers would (wisely) choose another research topic, particularly in this age of rapid appraisal studies that seek answers quickly.
My Concern with Carrying Capacity
The well-founded critiques of formal application and measurement of carrying capacity strongly suggest that the concept, as a quantifiable phenomenon, proves more cumbersome than revealing. For the most part, the majority of social sciences, such as anthropology and geography, as well as many scholars in the natural sciences of biology and ecology, have dispensed with the concept because they see humans and culture as highly adaptable. These scientists argue that carrying capacity generalizes a complexity of interactions that should not be glossed over.
The optimists among social scientists, who follow arguments of Boserup (1965) and Netting (1993), have suggested that humans and cultures are almost infinitely adaptable, so that human groups can overcome limitations set by the environment through technological, institutional, and social change. Using this framework of adaptation, through human energy and investment, the ability of a given environment to support growing human populations, that is, the carrying capacity, can actually increase through social and technological change.
The pessimists among social scientists, who find inspiration in the neo-Malthusian models proposed by Paul Ehrlich (Ehrlich et al. 1989; Ehrlich and Ehrlich 1990) and Garret Hardin (Hardin 1959; Hardin and Baden 1977), tend to see human populations growing beyond an environment's ability to provide resources, and ultimately decreasing the carrying capacity of a region, and the planet as a whole, through overuse of limited resources.
Although my training in anthropology emphasized the optimist's appreciation for the amazing creativity in human adaptability, particularly in regard to their ecosystem relationship and coping strategies, at a more abstract level, I believe our planet holds limited resources that risk destruction and extinction if we do not take steps to curb their overconsumption. In this way then, I find myself considering a very general concept of carrying capacity.
My reconsideration of the topic arose in part because of courses I teach in ecological anthropology. When we address carrying capacity in readings and lectures, undergraduate students demonstrate an intuitive understanding of the concept. And in my last two undergraduate courses, I conducted a brief survey on the first day of class to get a sense of my students' baseline knowledge. Carrying capacity was one of the few terms they knew prior to taking the course. Dewar (1984) also recognized the common sense facet of carrying capacity as he offered his critique of the concept and attributed its appeal to its simplicity. For scientific purposes, we know that carrying capacity poses irreconcilable problems and misleads us into believing in the simplicity of the relationship between humans and the environment. However, that simplicity helps the idea persist for a broader public.
This type of generalized public knowledge also appeared in a recent scientific journal. In a survey of Ohio adults testing their environmental literacy, the study found that the majority of respondents had a good understanding of the principle of carrying capacity (Mancl et al. 1999). The environmental scientists who developed this questionnaire rephrased the old themes of environmental resources and human population in a new way: "carrying capacity of an area is limited by the food and space available, and the pollution potential of increasing populations" (Mancl et al. 1999: 58), thus highlighting the negative impacts that humans have on their population. It is interesting to note that these environmental scientists continue to adhere to the principle of carrying capacity although scholars from both the social and natural sciences have critiqued the concept for at least two decades.
The generalized knowledge that the public shares of this concept suggests that perhaps the term has moved beyond an issue of measurement and quantification. As my students and the Ohio adults offer their understanding of carrying capacity, I hear them expressing something more akin to a "folk model" of how humans and their ecosystems interact, rather than a research method to produce empirical data on calories in the environment. This folk model provides an explanation for a complex relationship whose many facets remain beyond popular knowledge. Carrying capacity has become the story we tell ourselves about what our environment can offer to us, and how we must behave toward our environment. The term, though originating from the natural and social sciences, has moved beyond our academic boundaries into the public domain.
Carrying Capacity in the GTRPCarrying capacity also has meaning for me because when I joined the GTRP in 1994, I was told simply that "on the day of relocation in 1958, the carrying capacities of some of the resettlement areas were exceeded by almost three times." In a recent GTRP document, Scudder and Colson state that in the Lusitu area, where six thousand Tonga were settled, "we estimate that the capacity of the land base to support those people, as well as approximately 1000 hosts, under existing systems of land use was exceeded by a factor of two or more at the time of resettlement" (Scudder and Colson 1997: 5).
As I look at these statements now, I find two things particularly interesting. First, I was given this statement as a fairly solid fact, and second, I did not question the use of carrying capacity in that statement. My students' and the public's intuitive grasp of the concept, my colleagues' use of the term, and my naÔve acceptance of its use, forces me to reconsider carrying capacity.
Since 1994, I have undertaken four research trips to the Gwembe Valley, including a year and half of residence. Until this last year, I had generally accepted that the Gwembe Valley's carrying capacity has, at some level, been exceeded. Although I was aware of the critiques of, and general problems associated with, the concept of carrying capacity, I still did not question its use. I simply operationalized carrying capacity as "an environment of scarcity," and I focused (and continue to focus) my research on how people cope with living in a harsh environment that cannot consistently provide enough food and natural resources for their basic subsistence.
This research focus has included a study on support systems for the elderly, a look at household decision making, the processes of domestic migration—both to urban areas and frontier farming—areas and the impact of secondary education on families and households (Cliggett 1997a; 1997b; 1997c; 2000; Cliggett in press; n.d.-b). This coming year I will start analysis on diaries kept by our village research assistants, looking at domestic violence over time, and linking it to economic and ecological factors in the Gwembe Valley. At some level, my attention, and the GTRP's longitudinal attention, to coping with scarcity gives an implicit acceptance of a general concept of carrying capacity.
Some Examples of Coping with Scarcity
Since its inception, the GTRP has paid close attention to Gwembe people's adaptation to their ecosystem, which includes a wide array of coping strategies when environmental conditions become less hospitable. As I mentioned above, malnutrition represents one adaptation to the region's food scarcity (Gillett and Tobias n.d.; Gillett 1995). Colson (1979) has identified at least three more flexible strategies that people employ during periods of scarcity, both in the Gwembe and in other agrarian-based societies.
First, when preferred food resources disappear, Gwembe people shift to alternative food sources, things they call "famine foods," such as tamarind seeds mixed with ash, or the grass seeds mentioned earlier. Second, people also decrease their domestic group size so that they are more mobile and have fewer mouths to feed. This mobility also allows finding food sources, both in the environment and through pleading with kin, in distant areas not plagued with the same problems. And finally, Gwembe people also limit sharing with outsiders during periods of scarcity. During bad droughts, families do not repair or rebuild homestead granaries. Instead they let them continue to disintegrate, despite still holding grain. In this way families can appear to have no food stores, so that passersby will not come pleading for grain. Families also begin to eat indoors, as opposed to in public view near the cooking hearths; again, this prevents neighbors from seeing how much food a family has to eat.
These examples of adaptation demonstrate that Gwembe people know how to, and do, cope with the conditions of scarcity they face, both seasonally and cyclically. These ethnographic findings suggest that resource availability in the environment does not limit Gwembe populations' ability to survive, or at least not yet; that is, perhaps the carrying capacity model does not apply in a formal sense.
At the same time, our study has operated implicitly under the assumed notion of carrying capacity as a general framework, not a quantifiable phenomenon. In fifty years of field research, Colson and Scudder, and more recently other project colleagues, have seen changes in the environment. In general, the changes tend toward decreasing resources: little to no wild game in regions of human population, decreasing forest areas, increasing agricultural areas, smaller harvests tied to long-term field use and erosion, among other indicators.
We see local people's adaptive strategies as responses to lack of resources, which we believe are increasingly caused by environmental degradation and economic decline. At moments we may even anticipate a generalized collapse of social institutions and coping abilities, particularly as they fulfill resource and consumption needs (Scudder 1983, 1984).
In a recent article, Scudder and a group of ecologists working with satellite data analyze land cover change from 1986 to 1997 in the Lusitu region of the Gwembe Valley (Petitet al. n.d.). The findings suggest that the spread of bare soils and erosion in this region has increased more rapidly in the five years from 1992 to 1997 than in the six preceding years, suggesting that the rate of change is increasing. Furthermore, they suggest that without technological and/or institutional changes, natural vegetation in this area could drop from forty-five to twenty-one percent and bare soils could increase from five to twenty-one percent over the next twenty-four years (Petit et al. n.d.: 24).
Conclusion: Carrying Capacity's New GuiseIn my mind, these findings suggest ominous prospects for the future of the Lusitu in particular, and the Gwembe Valley more generally. Although I strongly support the critiques launched at attempts to formally measure any region's carrying capacity, my general sense of the limits of the land in this region tells me that population and natural resources in an ecosystem are linked. And using popular language, the concept of carrying capacity generally expresses this relationship. Of course, using the term glosses over profoundly important processes such as the World Bank's structural adjustment program, which has resulted in worker layoffs, soaring food prices, (which decreases quality of life for the majority of Zambia's population) shifting agricultural activities focused on export crops, and the impact of chronic disease on household labor.
However, using carrying capacity in a general sense highlights the environment as a topic that needs attention. As academics, we develop skills in critiquing terms and definitions. We focus our attention on particular terms, such as "race" (Gates 1986; Appiah and Gates 1995; Gould 1996), and "household" (Guyer 1981; Netting et al. 1984; Dwyer and Bruce 1988; Wilk 1989), and point out why those terms do not describe the multitude of processes subsumed under the term. We spend great energy taking apart terms, ideas, and concepts in order to clarify our meanings, reveal social constructions, and ultimately promote better understanding of our social world. And yet, despite the critiques, other scholars who may well have agreed with the arguments against use of those terms, as well as the same authors who drew critical attention to them in the first place, continue to use them, although with new definitions, qualifications, and clarifications (for "household" see, for example, Wilk 1991; Netting 1993; Kertzer 1997; Townsend 1997). By critically examining such terms, we free ourselves to use them, as long as we reflect on the complexity the terms represent.
Carrying capacity may well have become another one of these terms, recreated through scholarly critique and launched into the public domain through increasing environmental consciousness. Who would argue against concern for our environment, both global and local? Carrying capacity offers a general, and yes, flawed, view of the interrelationship between humans and their ecosystems. But it also provides a general framework for asking more important questions. Why do some areas and some groups of people seem to draw on their natural resource reserves more than other areas and people? How do local populations in small-scale farming economies respond to national and international forces that encourage particular, and often destructive, forms of resource use? Under what conditions will farmers resist overextraction of resources? Our jobs as social scientists should not be simply to question whether or not the environment has limits, and whether or not humans have exceeded those limits, but to look more closely, and with a more subtle lens, at populations and regions most vulnerable to the impacts of this relationship.
Acknowledgements
Thanks are due to University of Kentucky students in my course in Ecology and Social Practice during spring 1999 and 2000, and the graduate students in my Seminar on Ecological Anthropology during fall 1999, for their curiosity and discussion on this topic. The Work Group in Development Anthropology, and The Eco-lunch group of the Department of Biology also offered valuable comments on the themes presented in this paper. I would like to give special thanks for thoughtful critique from George Alter, Gracia Clark, Jim Vaughn, and Nora Haenn, and to Clark Gibson for his comments and the opportunity to present this material for the African Studies Seminar at Indiana University.
NOTES1. In addition to the study of forced relocation and its repercussions, project foci have included: exploration of community and individual response to economic opportunities, national impoverishment, ecological impacts of population growth, agricultural and other practices, impacts of economic differentiation and changing lifestyles on community relationships, health and physical well-being, incipient ethnic mobilization as people relate themselves to the national system, the biology of poverty, and demographic trends, including the impact of AIDS in one of the five most heavily affected countries in the world (Clark et al. 1995; Colson 1960, 1964, 1967, 1970, 1971, 1974, 1979, 1995a, 1995b, 1996; 1999; Colson and Scudder 1975, 1979, 1981, 1988; Scudder 1962, 1968, 1972, 1985; Scudder and Colson 1971, 1981; Scudder and Habarad 1991).
2. Colson and Scudder's theory of social adjustment to forced relocation outlines the four stages of adjustment that local populations undergo as they adapt to new locations and circumstances (Scudder 1981; Scudder and Colson 1982).
REFERENCES CITEDAgrawal, Arun. 1995. Population Pressure=Forest Degredation: An Oversimplistic Equation? Unasylval 181 (46): 50–8.
Allan, William. 1949. Studies in African Land Usage in Northern Rhodesia. Rhodes Livinston Papers no. 15. Manchester: Manchester University Press.
Appiah, Kwame Anthony, and Henry Louis Gates, eds. 1995. Identities. Chicago: University of Chicago Press.
Berry, Sara S. 1984. The Food Crisis and Agrarian Change in Africa. African Studies Review 27 (2): 59–112.
———. 1993. No Condition Is Permanent: The Social Dynamics of Agrarian Change in Sub-Saharan Africa. Madison: University of Wisconsin Press.
Birdsell, J. B. 1953. Some Environmental and Cultural Factors Influencing the Structuring of Australian Aboriginal Population. American Naturalist 86: 171–207.
Boserup, Ester. 1965. The Conditions of Agricultural Growth. Chicago: Aldine.
Carneiro, Robert L. 1961. Slash and Burn Cultivation among the Kuikuru and Its Implications for Cultural Development in the Amazon Basin. In The Evolution of Horticultural Systems, edited by J. Wilbert. Caracas: Sociedad de Ciencias Naturales La Salle.
Clark, Sam, Elizabeth Colson, James Lee, and Thayer Scudder. 1995. Ten Thousand Thonga: A Longitudinal Anthropological Study from Southern Zambia 1956–1991. Population Studies 49: 91–109.
Cliggett, Lisa. 1997a. The Cattle for Land Exchange: Elderly Women's Negotiations in the Gwembe Valley, Zambia. Working Paper. Population Institute for Research and Training, Indiana University, Bloomington.
———. 1997b. Economic and Social Components of Migration in Two Regions of Southern Province, Zambia. Center for Development Studies, Bath, United Kingdom. Report.
———. 1997c. My Mother's Keeper: Changing Family Support Systems for the Elderly in the Gwembe Valley, Zambia. Ph.D. diss., Indiana University.
———. 2000. Social Components of Migration: Experiences from Southern Province, Zambia. Human Organization 59 (1): 125–35.
———. n.d.-a. Gender, Subsistence, and Residential Arrangements for the Elderly in the Gwembe Valley, Zambia. Journal of Cross Cultural Gerontology. In press.
———. n.d.-b. Male Wealth and Claims to Motherhood: Gendered Resource Access and Intergenerational Relations in the Gwembe Valley, Zambia. In Gender in Economic Life: Annual Readings in Economic Anthropology, edited by Gracia Clark. New York: Academic Press, forthcoming.
Colson, Elizabeth. 1960. Social Organization of the Gwembe Tonga. Manchester: Manchester University Press.
———. 1964. Social Change and the Gwembe Tonga. Human Problems in British Central Africa: The Rhodes Livingstone Journal 35: 1–13.
———. 1967. Competence and Incompetence in the Context of Independence, and Comments. Current Anthropolgy 8: 92–111.
———. 1970. Converts and Tradition: The Impact of Christianity on Valley Tonga Religion. Southwestern Journal of Anthropology 26 (2): 143–56.
———. 1971. Social Consequences of Resettlement. Manchester: Manchester University Press.
———. 1974. Tradition and Contract: The Problem of Order. Chicago: Aldine.
———. 1979. In Good Years and Bad: Food Strategies in Self-Reliant Societies. Journal of Anthropological Research 35 (1): 18–29.
———. 1995a. The Contentiousness of Disputes. In Understanding Disputes, edited by P. Caplan. Oxford: Berg.
———. 1995b. War and Domestic Violence. Cultural Survival 19 (1): 35–8.
———. 1996. The Bantu Botatwe: Changing Political Definitions in Southern Zambia. In The Politics of Cultural Performance, edited by D. Parkin, L. Caplan, and H. Fisher. Providence, Rhode Island: Berghahn.
———. 1999. Gendering those Uprooted by Development. In Engendering Forced Migration: Theory and Practice, edited by N. Indra. New York: Berghahn Books.
Colson, Elizabeth, and Thayer Scudder. 1975. New Economic Relationships between the Gwembe Valley and the Line of Rail. In Town and Country in Central and Eastern Africa, edited by D. Parkin. London: Oxford University Press.
———. 1981. Old Age in Gwembe District, Zambia. In Other Ways of Growing Old: Anthropological Perspectives, edited by P. Amoss and S. Harrell. Stanford: Stanford University Press.
———. 1988. For Prayer and Profit: The Ritual, Economic, and Social Importance of Beer in Gwembe District, Zambia 1950–1982. Stanford: Stanford University Press.
Dewar, Robert. 1984. Environmental Productivity, Population Regulation, and Carrying Capacity. American Anthropologist 86 (3): 601–14.
Dwyer, Daisy, and Judith Bruce, eds. 1988. A Home Divided: Women and Income in the Third World. Stanford: Stanford University Press.
Ehrlich, Paul R., G. C. Daily, Anne H. Ehrlich, P. Matson, and P. Vitousek. 1989. Global Change and Carrying Capacity: Implications for Life on Earth. In Global Change and Our Common Future, edited by R. DeFries and T. Malone. Washington, D.C.: National Academy Press.
Ehrlich, Paul R., and Anne H. Ehrlich. 1990. The Population Explosion. New York: Simon and Schuster.
Fairhead, James, and Melissa Leach. 1996. Misreading the African Landscape: Society and Ecology in a Forest-Savanna Mosaic. Cambridge: Cambridge University Press.
Gates, Henry Louis, ed. 1986. "Race," Writing, and Difference. Chicago: University of Chicago Press.
Gillett, Rhonda. 1995. Growth and Physical Status: Biocultural Measures of Long-Term Underdevelopment among the Gwembe Tonga of Zambia. Ph.D. diss., Indiana University.
Gillett, Rhonda, and P.V. Tobias. n.d. Human Growth and Development in Southern Zambia: A First Study of Tonga Children predating the Kariba Dam, as a Baseline for Comparison with Contemporary Zambians. American Journal of Human Biology, forthcoming.
Gould, Stephen Jay. 1996. The Mismeasure of Man. New York: Norton.
Guyer, Jane. 1981. Household and Community in African Studies. African Studies Review 24 (2/3): 87–137.
Hardin, Garrett. 1959. Nature and Man's Fate. New York: Rinehart.
Hardin, Garrett, and John Baden, eds. 1977. Managing the Commons. San Francisco: W. H. Freeman.
Kertzer, David I., and Tom Fricke, eds. 1997. Anthropological Demography: Toward a New Synthesis. Chicago: University of Chicago Press.
Leach, Melissa, and James Fairhead. 2000. Challenging Neo-Malthusian Deforestation Analyses in West Africa's Dynamic Forest Landscapes. Population and Development Review 26 (1): 17–44.
Leach, Melissa, and R. Mearns, eds. 1996. The Lie of the Land: Challenging Received Wisdom on the African Environment. London: James Curry.
Mancl, Karen, Kathleen Carr, and Michele Morrone. 1999. Environmental Literacy of Ohio Adults. Ohio Journal of Science 99 (3): 57–61.
Moore, Henrietta, and Megan Vaughan. 1994. Cutting Down Trees: Gender, Nutrition, and Agricultural Change in the Northern Province of Zambia 1890–1990. Portsmouth, New Hampshire: Heinemann.
Netting, Robert. 1981. Balancing on an Alp: Ecological Change and Continuity in a Swiss Mountain Community. Cambridge: Cambridge University Press.
———. 1993. Smallholders, Householders: Farm Families and the Ecology of Intensive, Sustainable Agriculture. Stanford: Stanford University Press.
Netting, Robert, Richard Wilk, and Eric Arnould. 1984. Households. Berkeley: University of California Press.
Petit, Carine, Thayer Scudder, and Eric Lambin. n.d. Understanding Land-Cover Change Processes from Remote Sensing Observations: Resettlement and Rapid Land-Cover Changes in Southeastern Zambia. International Journal of Remote Sensing. In press.
Rappaport, Roy A. 1967. Ritual Regulation of Environmental Relations among a New Guinea People. Ethnology 6 (1): 17–30.
Scudder, Thayer. 1962. The Ecology of the Gwembe Tonga. Manchester: Manchester University Press.
———. 1968. Social Anthropology, Man-Made Lakes and Population Relocation in Africa. Anthropological Quarterly 41: 168–76.
———. 1972. Ecological Bottlenecks and the Development of the Kariba Lake Basin. In The Careless Technology: Ecology and International Development., edited by M. T. Farvar and J. P. Milton. New York: Natural History Press.
———. 1981. What It Means to be Dammed: The Anthropology of Large-Scale Development Projects in the Tropics and Subtropics. Engineering and Science 44 (4): 9–15.
———. 1983. Economic Downturn and Community Unravelling. Culture and Agriculture 18: 16–19.
———. 1984. Economic Downturn and Community Unravelling, Revisited. Culture and Agriculture 23: 6–10.
———. 1985. A History of Development in the Zambian Portion of the Middle Zambezi Valley and Lake Kariba Basin. Institute for Development Anthropology, Binghamton, New York. Report.
———. 1993. Development Induced Relocation and Refugee Studies: Thirty-Seven Years of Change and Continuity among Zambia's Gwembe Tonga. Journal of Refugee Studies 6 (2): 123–52.
Scudder, Thayer, and Elizabeth Colson. 1971. The Kariba Dam Project: Resettlement and Local Initiative. In Technical Innovation and Cultural Change, edited by R. Bernard and P. Pelto. New York: Macmillan.
———. 1978. Long-Term Field Research in Gwembe Valley, Zambia. In Long-Term Field Research in Social Anthropology, edited by G. M. Foster, T. Scudder, E. Colson, and R. V. Kemper. New York: Academic Press.
———. 1981. Secondary Education and the Formation of an Elite: The Impact of Education on Gwembe District, Zambia. London: Academic Press.
———. 1982. From Welfare to Development: A Conceptual Framework for the Analysis of Dislocated People. In Involuntary Migration and Resettlement: The Problems and Responses of Dislocated People, edited by A. Hansen and A. Oliver-Smith. Boulder: Westview Press.
———. 1997. Gwembe Tonga Farmers and their Environment: A Century of Change and Continuity. Unpublished manuscript.
Scudder, Thayer, and Jonathan Habarad. 1991. Local Responses to Involuntary Relocation and Development in the Zambian Portion of the Middle Zambezi Valley. In Migrants in Agricultural Development, edited by J. A. Mollett. London: Macmillan.
Street, John M. 1969. An Evaluation of the Concept of Carrying Capacity. The Professional Geographer 21 (2): 104–7.
Townsend, Nicholas. 1997. Men, Migration, and Households in Botswana: An Exploration of Connections over Time and Space. Journal of Southern African Studies 23 (3): 405–20.
Wilk, Richard, ed. 1989. The Household Economy. Boulder: Westview Press.
———. 1991. Household Ecology: Economic Change and Domestic Life among the Kekchi Maya in Belize. Tucson: University of Arizona Press.
Wilmsen, Edwin N. 1989. Land Filled with Flies: A Political Economy of the Kalahari. Chicago: University of Chicago Press.
Zubrow, Ezra. 1975. Prehistoric Carrying Capacity: A Model. New York: Academic Press.
IU Press Journals
Home PageMore about Africa Today
Library
RecommendationTables of
ContentsAdvance
InformationSubmission
Guidelines