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| Ecosystem characteristic | Trends in ecological development | Complex Ecosystem Theory |
| Species composition | Changes rapidly first, slower later | |
| Species diversity | Increases initially, then becomes stabilised or declines in old stages, as size of individuals increases |
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Total biomass (B) |
Increases | Larger ecosystem biomass |
| Non-living organic matter | Increases | |
| Food chains | From linear chains to more complex food webs | Longer food chains |
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Energy flow (Community metabolism) |
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| Ecosystem characteristic | Trends in ecological development | Complex Ecosystem Theory | ||
| Gross production (P) | Increases during early phase of primary succession, little or no increase during secondary succession | More exergy capture | ||
| Net community production (yield) | Decreases | |||
| Community respiration (R) | Increases | Higher transpiration in terrestrial systems
More energy flow activity within the system |
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| P/R ratio | From P > R to P = R | Higher respiration | ||
| B/P and B/R ratios (Biomass supported / unit energy) | Increases | More effective exergy consumption | ||
| Overall efficiency of energy utilisation | Increases | Increases | ||
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| Ecosystem characteristic | Trends in ecological development | Complex Ecosystem Theory |
| Mineral cycles | Becomes more closed | Less leaking (export) of material from the system |
| Overall efficiency of nutrient utilisation | Increases | Increases |
| Turnover time and storage of essential elements | Increases | Longer cycles (Longer average cycle length) |
| Internal cycling | Increases | Turnover time of cycles or cycling rate diminishes,
The proportions of material flowing in cycles increases. |
| Nutrient conservation | Increases | |
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| Ecosystem characteristic | Trends in ecological development | Complex Ecosystem Theory |
| Life cycles | Increasing specialisation, length and complexity | More types of organisms (higher diversity) |
| Symbiosis | Increasingly mutualistic | More articulated food web, Species will occupy higher average trophic levels |
| Information | Increases | Increased organisation and diversity increase the information content of the community. |
Trends in ecological development:
Odum, E. P., 1971,1997. Ecology Sinauer, Sunderland, Mass.
Odum, E. P., 1989. Ecology and Our Endangered Life-support System Sinauer Associates
Complex Ecosystem Theory:
Schneider, E.D and J.J. Kay, 1994, Life as a Manifestation of the Second Law of Thermodynamics Mathematical and Computer Modelling, Vol 19, No. 6-8, pp.25-48.