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Ecological System



"The Easter Islanders, aware that they were almost completely isolated from the rest of the world, must surely have realized that their very existence depended on the limited resources of a small island. After all, it was small enough for them to walk round the entire island in a day or so and see for themselves what was happening to the forests. Yet they were unable to devise a system that allowed them to find the right balance with the environment."
- Clive Ponting 1

"To paraphrase Ponting, we are aware that Earth is completely isolated from the rest of the universe and we realize that our very existence depends on the limited resources of this one small planet. After all, it is small enough for us to fly around in a day or so and see for ourselves what is happening to the forests (and plains and waters). Yet we seem unable to devise a system that allows us to find the right balance with the ecosphere."
  - Peter Miller and William Rees 2

Easter Island from Shuttle
  Image courtesy of Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center.

Easter Island is a relatively small island in the Pacific Ocean that was first settled by islanders of Polynesian descent in the fifth century. Easter Island had very few natural resources, and the only agricultural endeavor with which the settlers found success was the harvest of sweet potatoes. Because sweet potatoes are not a labor intensive crop, the population eventually had ample time to pursue other activities. The "other activities," in this case, turned out to be ceremonial activities among clans that included the construction of over 300 ahu, flat mounds or stone platforms that have advanced astrological alignments. At the site of each ahu, they placed huge stone monuments (called Moai), which were carved in distant quarries and transported to the site. There are several theories about the Moai, and what led to the collapse of the Easter Islander's society, but it is clear that the competition among clans for more and more monuments proved to be the key to their eventual demise as a society.


Moai at Rano Raraku
© Cliff Wassman,

One popular theory depends heavily on a probable method of transport for these monuments—rolling them on large tree trunks. Moving the monuments on tree trunks required massive amounts of timber harvest for nearly 200 years (approximately 1400-1600 CE), as competition between clans for more and more monuments became progressively more intense. The complete deforestation that eventually occurred led to lack of materials for shelter, cooking, and fishing; erosion and leaching of soil nutrients; societal and cultural collapse due to inability to construct these monuments; and competition/conflict between clans as resources became more and more scarce. By the time European settlers arrived in the 18th century, Easter Island society had decomposed to the point of near-constant warfare cannibalism.


We live on a planet with finite resources, with only one input from the outside -- the energy from the sun. While our technologies can rearrange matter to better suit our convenience, and extract energy by reaching farther and farther into the depths of the Earth, the limits to this process have become evident. A return to "ecological thinking" is necessary if we are to survive. Our deep involvement and preoccupation with technological thinking to the exclusion of ecological thinking has been a major contributor to environmental degradation.

In this unit, we look at ecology -- the understanding of living systems in relation to their environment. Ecology is the study of the patterns and relationships of these systems. In Greek, the word "oikos" means "house," and "logos" means "pattern." The word "oecologie" was coined by Ernest Haeckel, German scientist and follower of Darwin, in 1866. From that time and throughout the 1890s European botanists studied systems of plants and land and their interdependencies, giving rise to the science of ecology. Thus the science of ecology has always had a holistic approach to nature, connecting communities and systems. The philosophical roots of ecology and the land ethic of Aldo Leopold are discussed in detail in the unit on Ethical Systems.

The early study of ecology was tilted towards moral philosophy. As a science, it grew in parallel, more as a description of the distribution of plant communities, and their patterns of succession. In the 1920s and '30s ecology became more of a discipline of science. In 1927, Charles Elton, a colleague of Aldo Leopold, coined phrases such as "food chain" and "niche" and began to work on the way nutrition started with the sun, and on the natural dependencies of organisms and "communities of plants." The English ecologist Arthur Tansley proposed the term "ecosystem" for the total system of relationships.

A comparison of ecological thinking with technological thinking is important to our understanding of why conventional technologies have worked with little regard for the environment, except as a source of raw material or a place to dump -- or even as conditions and constraints to conquer. Table 1 contrasts features of conventional technological thinking with those of ecological or systems thinking.

Technological Thinking

Ecological Thinking
Focus on parts and how they connect for immediate performance

Focus on patterns, context, connectedness, and relationships

Problems reduced or taken apart for understanding

Whole = sum of parts


Need understanding of parts in context of larger whole

Whole > sum of parts

World as collection of objects; relationships secondary.   Objects are networks of relationships
Gives sense of rigid structures of domination and control   Multileveled order of interdependence
Product- oriented thinking, often in terms of closed systems  

Contextual thinking or weaving together to make sure there is free flow in network; structure follows.

Often open systems.

Table 1: Technological Thinking vs. Ecological Thinking (adapted from FRITJOF CAPRA).

Technology is the result of human effort to transcend limits placed on us by space and time. Population explosion has made us aware that the extent to which we can overcome space constraints is limited.

Speed and efficiency are the main metrics of success in technology, which has led to a lack of appreciation of time -- that it takes time to build the complex intricate system that houses and nurtures us as part of it. This lack of respect for time that is embedded in our technological thinking has been one of the most salient factors in degrading environmental quality. To feed our technological ways of life, we currently destroy 24.7 million acres of ancient forest, pump 6.6 billion metric tons of CO2 into the air, and pump 24.9 billion barrels of oil out of the Earth each year.3, 4, 5

Technologies have typically focused only on narrow segments of the entire system to which the specific technology relates. For example, the design and marketing of the automobile had no forethought about the disruptions large numbers of automobiles would have on land, on air, on energy use, on social units such as cities and families, on all aspects of our ways of life. Technological thinking has traditionally had characteristics that are contrary to holistic, systems thinking -- but this has slowly begun to change. The emerging practice of industrial ecology looks at products as part of a larger cycle and attempts to reduce the environmental impacts of production, consumption, and disposal.

Ecology has traditionally dealt only with natural systems. The new field of industrial ecology is beginning to study industrial behavior and biogeochemical cycles as a part of a system, using the results to design environmentally friendly products and processes. For true integration, however, we need to merge the two ecological systems -- natural and industrial -- with the right consideration of space and time. We are still a long way off from this undertaking!

The sensitivity and response of various organisms to nature's cues is beautifully illustrated in a flower clock designed in 1751 by Carl von Linnaeus, who is considered the father of botany. Noticing that different flower species opened during different times of the day, Linnaeus designed a clock (Figure 1) using the characteristic time of opening and closing of the flowers. He found that once bees had found the flowers they preferred, they would return to the "clock" at the appropriate time, rain or shine! This is a beautiful example of the temporal behavior deeply embedded in the ecological system, including animal physiology. It has also been shown through experiments that certain medications or treatments for human illnesses are more effective at different times of the day (for reasons not fully understood by science). Technology has often tended to ignore these time-linked behaviors and effects.

Figure 1: Representation of the flower clock proposd by Linnaeus. The 12 hours
of the clock run from 6 a.m. to 6 p.m.. Click for larger image.
Source: The Clocks That Time Us, by Moore-Ede, Sulzman, and Fuller. 6



[1] Ponting, Clive. Green History of the World, Oxford University Press, 1991. p. 7

[2] Miller, Peter and William Rees. Ecological Integrity: Integrating Environment, Conservation, and Health. (Edited by D. Pimentel, L. Westra, and R.F. Noss). Island Press, 2000. p. 3

[3] Source: Greenpeace Video, Magnificent 7. Greenpeace USA Media Center,

[4] Global CO2 Emissions from fossil-fuel burning, cement manufacture, and gas flaring in 1998, as measured by weight of carbon. Source: Carbon Dioxide Information Analysis Center,

[5] Global Crude Oil Production, 2001. Source: Energy Information Agency,

[6] Moore-Ede, M.C., F.M. Sulzman, and C.A. Fuller. The Clocks That Time Us, Harvard University Press, 1982. p. 12



  ©Copyright 2003 Carnegie Mellon University
This material is based upon work supported by the National Science Foundation under Grant Number 9653194. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.