Ecotone and edge effect

Ecotone and edge effect

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  Ecotone and Edgeeffect Dr. Emasushan Minj Assistant Professor Department of Botany
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  Ecotone • An ecotoneis a zone of junction or a transition area between two biomes (diverse ecosystems). • Ecotone is the zone where two communities meet and integrate. • Example- the mangrove forests represent an ecotone between marine and terrestrial ecosystem. • Other examples are grassland (between forest and desert), estuary (between fresh water and salt water) and riverbank or marshland (between dry and wet).
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  Characteristics of Ecotone •It could be narrow (between grassland and forest) or wide (between forest and desert). • It has conditions intermediate to the adjacent ecosystems. Consequently it is a zone of tension. • Usually, the outgoing community number and population density decreases as we shift away from the community or ecosystem. • A well-developed ecotone contains some organisms which are entirely different from that of the adjacent communities.
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  Ecocline • Ecocline isa zone of gradual and continuous change -from one ecosystem to another when there is no sharp boundary between the two in terms of species composition. • It occurs across the environmental gradient [gradual change in abiotic factors such as altitude, temperature (thermocline), salinity (halocline), depth, etc.].
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  Edge Effect –Edge Species • Edge effect – “the changes in population or community structures that occur at the boundary of two habitats (ecotone).” • Sometimes the number of species and the population density of some of the species is much greater than either community, called edge effect. • The organisms which occur primarily or most abundantly in this zone are known as edge species. • In the terrestrial ecosystems edge effect is especially applicable to birds.  For example, the density of birds is greater in the ecotone between the forest and the desert.
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  Ecological Niche • Nicherefers to the unique functional role and position of a species in its habitat or ecosystem. • The functional characteristics of a species in its habitat are referred to as “niche” in that common habitat. • In nature, many species occupy the same habitat, but they perform different functions: ▫ Habitat niche – where it lives, food niche – what is eats or decomposes & what species it competes with, reproductive niche – how and when it reproduces, physical & chemical niche – temperature, land shape, land slope, humidity & another requirement. • Niche plays an important role in the conservation of organisms. If we have to conserve species in its native habitat, we should have knowledge about the niche requirements of the species.
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  Basis for comparisonHabitat Niche Meaning A habitat is an area, where a species lives and interact with the other factors. A niche is an ideology, of how organisms lives or survive in the provided environmental conditions. Consist of Habitats consist of numerous niches. A niche does not contain such components. It includes Affect of temperature, rainfall and other abiotic factors. Flow of energy from one organism to other through ecosystem. Examples Desrets, oceans, forest, rivers, mountains, etc. are examples of habitat. It is a part of habitat only, where shelter for living being furnished. Supports Habitat supports numerous species at a time. Niche supports a single species at a time. What it is Superset Subset Nature Habitat is a physical place. Niche is an activity performed by organisms. Specificity Habitat is not species specific. Niche is species specific.
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  Thank you