Human Ecology - Basic Concepts for Sustainable Development
Environmental success stories from around the world with their lessons on how to turn from decline to restoration and sustainability.
Author: Gerald G. Marten
Publisher: Earthscan Publications
Publication Date: November 2001, 256 pp.
Paperback ISBN: 1853837148
Hardback SBN: 185383713X
This book explains why we have environmental problems and what we can do about them. The explanation employs a “systems perspective” that:
- Shows how human society and the environment function as self-organizing, adaptive systems;
- Explains why the combined human-environment system that prevails today has become unsustainable;
- Points to what it takes for humans to create sustainable relationships with their environmental support system.
The concepts below are abstract, but they are very real. The book brings them to life with engaging stories and examples.
- The ways that people interact with the rest of the ecosystem come from their social organization as a system. The way that the rest of the ecosystem responds also comes from its organization as a system. Human actions that impact one part of an ecosystem generate a chain of effects that reverberates back and forth through ecosystem and social system.
- Biological systems at all levels, including ecosystems and human social systems, are the product of selective processes (“chance and choice”) that adapt them for survival. Each level has its own “emergent properties” that are a consequence of that level as whole rather than any of the component parts.
- As a consequence of this selective process, the chains of effects are structured into feedback loops that stabilize (negative feedback) and generate rapid change (positive feedback). There is a tension between the forces for stability and forces for change that creates “switches”.
- Ecosystems can withstand considerable change and still continued to function OK, but if changed so much that they are not able to function, ecosystems adapt by undergoing drastic and irreversible change, which may not be OK for people who depend on the ecosystem's services. Examples are desertification of grazing lands and replacement of commercially valuable fish by “trash fish”.
- Switches are organized into “complex system cycles” of “growth”, “equilibrium”, “dissolution”, and “reorganization”. Sustainable societies are attuned to the cycles in their own society and in their environmental support system.
- Complex adaptive systems are self-organizing. The fundamental organizing processes for ecosystems are coadaptation of component species and “community assembly”, a process that ensures that all the parts of an ecosystem fit together functionally on a sustainable basis. Natural ecosystems have a diversity of plant, animal, and microorganism species to cover (with redundancy) the diversity of roles necessary for a functioning and sustainable ecosystem.
- People impose organization on ecosystems to better meet their needs (ecosystem services). This doesn’t happen free. It requires inputs of materials, energy, and information. Major modification of ecosystems is limited by the fact that (a) we may not be able to maintain the inputs and (b) we don’t have the means to conceive functional and sustainable designs that work as well as nature.
- Ecosystems are spatially hierarchical. Regional ecosystems consist of component ecosystems whose inputs and outputs all fit together if the ecosystems are formed by natural processes. Human-dominated ecosystems are sustainable only if in proper balance with natural ecosystems on which they depend for inputs and outputs.
- Just as different species adapt to one another by biological evolution, social systems and ecosystems also coevolve and coadapt. Ecosystems adapt by natural processes and by changes that people impose on ecosystems to make them fit their social systems. Traditional societies are typically well coadapted because they have a strong local connection to their environmental support system that allows them to know it well. They know where the services come from and they know the impact of their actions on the services. Coadaptation of traditional societies includes (a) designing their human-dominated ecosystems to mimic or fit with nature (“letting nature do the work” and recognizing natural cycles), (b) avoiding overexploitation or damage to natural ecosystems, and (c) making changes in a “precautionary” manner.
- Coadaptation between social systems and ecosystems is reinforced by human “biophilia” (an inborn affinity for nature) and “sense of place”. Children explore nature as they grow up, “imprinting” on the local landscape in a way that leads to deep emotional attachment and detailed knowledge of their home area and nature within it. The local ecosystem takes on a sacredness that inhibits local people from damaging it.
- Urban societies tend to be alienated from their environmental support system, and in general, poorly coadapted with ecosystems. This happens in part because many urban people have limited childhood experience with nature. Even more important, the diffuse global reach of environmental support systems for contemporary cities makes it impossible for anyone, child or adult, to imprint on them or even comprehend them.
- Historically, urban societies have followed a complex system cycle of growth and collapse. The main problem is separation and alienation of urban societies from their environmental support system. Excessive social complexity has also contributed to collapse by reducing adaptiveness and wasting resources on the “overhead” to maintain social complexity. In the past, growth and collapse has been on a local or regional scale, and reorganization consisted in moving to a new place and starting again. Now globalization is extending and synchronizing this process throughout the planet. There will be nowhere to move after collapse.
- Humans use inputs of energy, materials, and information to modify ecosystem organization, material cycles, and energy flows to extract useful services for people. Excessive demands for ecosystem services can damage or diminish the natural capital necessary for material cycles and energy flows that underlie ecosystem services. If demand is too great, the ecosystem can switch irreversibly to providing little or none of the services.
- Humans have increased their carrying capacity by increasing their share of the planet’s biological production (primary production) more than a thousand times. There is little scope for further increasing carrying capacity because there is little scope for increasing the planet’s biological production and there is little scope for increasing the human share of biological production beyond the large percentage that human’s already consume. Food production has never been greater, but much of today’s food production may not be sustainable and may be at the expense of future food production because of damage caused by inappropriately intensive food production on marginal lands.
- Many animals, as well as traditional human societies, have evolved mechanisms to maintain their population below carrying capacity in a way that ensures a sustainable relationship with their environmental support system. Contrary to this, the present human population is near, or possibly beyond, the carrying capacity of the planet. Excessive population means a lower quality of life. Severe overpopulation damages the environmental support system (i.e., diminishes natural capital) in ways that close off options for pursuing a sustainable relationship with the environment.
- People convert natural capital to other forms of capital if they expect larger economic returns from investment in other sectors of the economy. This is a source of unsustainable human/ecosystem interaction.
- The way that contemporary urban society extracts economic value from natural capital can be characterized as the “Tragedy of Serial Degradation”. For example, the "hamburger connection" on tropical forest lands: Forest is clear-cut for timber extraction and resulting pastureland is grazed until the fragile soil can no longer support grazing or any other economic activity (including return of the forest). Deforestation then moves to a new location, followed by grazing, and so on. This process, which makes renewable resources non-renewable, is driven by global markets and extends to every natural resource from which economic value can be extracted: for example, cash crops on fragile soils; unsustainable aquaculture ponds replacing mangroves; tourism and commercial fishing that irreparably damage coral reefs and move on to new ones. The Tragedy of Serial Degradation is also prominent in urban areas: for example, expansion of the American metropolis by conversion of undeveloped land to attractive new suburbs that eventually fall into decay, causing inhabitants to flee to new suburbs.
- To prevent the Tragedy of Serial Degradation, traditional societies employ renewal processes that mimic natural ecological cycles and repair ecological damage before it becomes irreversible: for example, nomadic pastoralism and slash-burn agriculture. The corresponding process for preventing Tragedy of Serial Degradation in urban areas is design for urban and suburban self-renewal.
- People will overexploit or abuse an ecosystem if there is no social constraint and the ecosystem is large enough for destructive activities of a single individual to have no negative consequences for that person, even though the consequences for everyone are serious if everyone does it. This is the “Tragedy of the Commons”. Group ownership and control of “common property resources” can prevent Tragedy of the Commons. Conditions at the local level are most conducive to sustainable use of common property resources. A major challenge of our times is how to prevent Tragedy of the Commons in a global free-market economy.
- Sustainable human/ecosystem interaction is not simply a matter of “balance with nature”. Ecosystems and societies constantly change, and coping with unexpected changes is a key to sustainability. This is “resilience”, which is weak in contemporary society. Resilience is enhanced by properly structured diversity, but it can be in conflict with stability and efficiency, which have become high priorities for contemporary society. A key to resilience and ecologically sustainable development is to enhance the adaptiveness of contemporary society and its interaction with its environmental support system. Food security is an example of a major resilience issue in today’s world.
- Another key to sustainable development is for local communities to be in charge of their interaction with local ecosystems. This requires (a) social institutions within the community and at higher levels of social organization to ensure community participation and authority (b) citizen knowledge to guide effective action, and (c) active support from higher levels of government.
- The future of wealthy nations is closely linked with the environmental fate of poor nations. This is not only because wealthy nations are dependent on resources from poor nations but also because global peace and security are strongly linked to the ecological health of poor nations.
Human Ecology Concepts
- Ecosystem and social system
- Chain of effects through ecosystem and social system
- Sustainable development
- Quality of life, material consumption, and demands on ecosystems
- How human ecology is useful
- Positive feedback
- Exponential growth
- Negative feedback
- Population regulation and carrying capacity
- Agricultural Revolution, Industrial Revolution, and history of human carrying capacity
- Human population explosion and quality of life
- Social regulation of population below carrying capacity
- Self-organization of ecosystems and social systems (assembly process)
- Hierarchical organization of biological systems (emergent properties)
- Complex system cycles
- Stability domains
- Ecosystem design
- Ecosystem homeostasis
- Input/output characteristics of natural, agricultural, and urban ecosystems
- Landscape mosaics
- Natural ecological succession
- Human-induced ecological succession
- Irreversible changes in ecosystems (e.g., desertification)
- Urban succession
- Co-evolution and co-adaptation of ecosystems and social systems
- Changes in agriculture since the Industrial Revolution
- Material cycling in ecosystems
- Ecological energy flow
- Ecosystem services
- Relation of ecosystem services to intensity of use
- Perceptions of nature (OK/Not OK, capricious, indestructible, fragile)
- Attitudes of spirit religions, Eastern religions; and Western religions toward nature
- Unsustainable human/ecosystem interaction (human migrations and new technologies)
- Fallacy that economic supply and demand protect the environment
- Relation of portable capital to sustainable use of natural resources
- Tragedy of the Commons
- Sense of place and alienation of urban societies from nature
- Social complexity and the reasons for collapse of complex societies
- Precautionary Principle
- Resilience (including the conflict between stability and resilience)
- Coexistence of urban societies with natural ecosystems
- Social institutions for sustainable use of common property resources
- “Doing things nature’s way”
- Use of fire by North American Indians
- Traditional agriculture
- Traditional forest management in Japan
- Biological control of mosquitoes
- Adaptive development
- Community participation for sustainable development
- Regional environmental management (including strategic planning)
“EcoTipping Points” are levers that turn environmental decline to a course of restoration and sustainability. This simple idea pulls together many of the concepts in the book in a way that makes them understandable while pointing to what people can do to solve the problems. Click here to see a hundred environmental success stories from around the world that illustrate how EcoTipping Points work.