Common edge patterns
Sharp transition horizontally and vertically
Sharp
Wide and regular
Gradual transition vertically
Wide and convoluted
Perforated *Degree of perforation influences flow rates of materials, energy, and information
Wide transition horizontally (supports more diversity than sharp transition)
nature’s design ecotone fosters social diversity An example of an ecotone, or edge, is the transition between a wet meadow system and a drier upland wooded system. Such meadow-forest edges are rich, diverse habitats where species interact. The complexity and interdependency of relationships in ecotones, as well as the physical structure of the transition zone, result in an accumulation of energy, materials, and information, providing food, mates, communication, and shelter.
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Horizontally, the ecotone transition can be narrow (a sharp change, as in a forest abutting an agricultural field), or it can be wide (gradual change, as in natural meadow-to-forest transition). Vertically, ecotones show transitions in vegetation height from grasses and herbaceous ground cover in the wet meadow to woody shrubs and herbs with variable soil moisture, to dry upland canopy species in the forest.
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The degree of “perforation” in an ecotone inhibits or enhances dispersal of energy, materials, and information across the edge. For example, an expansive patch of brambles inhibits dispersal, whereas a large tree fall or flowing stream create space and enhance dispersal. A wet meadow to upland forest can buffer flood damage or resource depletion resulting from prolonged drought. The greater the contrast between transitions, the more robust and diverse the ecotone. When there are wider transitions, there is more capacity to support diversity and buffer disturbances.
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SOCIAL DESIGN A WELL-FUNCTIONING SYSTEM • ECOTONES
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Ecotones are “hot spots” where organisms interact to get food, find mates, communicate, rest, and take shelter. Ecotones are diverse, robust systems. Perforation in an ecotone inhibits or enhances the flow of material, energy, and information. Ecotones help the ecosystem buffer disturbances.