Ecotone

Ecotone is a zone of junction between two or more different type of biomes that harbours different kind of species that are also not found on the either side of the actual biome. In this article, you will learn ecotone definition, ecotone characteristics, what is ecotone and edge effect, ecocline vs ecotone providing key insights for GS Paper-III Environment and ecology section of UPSC IAS Exam.

Table of Content

• What is Ecotone?
• Characteristics of ecotone
• Classification of ecotone              
• Importance of Ecotone
• Conclusion
• Frequently Asked Questions

What is Ecotone?

• Meaning: Ecotone is a zone of junction between two or more different type of ecosystems.
  • Ecotone Example: the mangrove forests represent an ecotone between marine and terrestrial ecosystem.
• Ecotone area is a transitional region where two communities meet and merge.
• Types of ecotones: grassland ecotone (between desert and forest), estuary ecotone (between saltwater and freshwater) and swamps or marshlands ecotone (between dry and wet ecosystem).
• Examples of ecotone species: snowshoe hare, mule varieties, robin, cottontail rabbit, blue jay etc.

Characteristics of ecotone:

• Ecotone has the conditions that are intermediate of the adjacent ecosystems or have characteristics of both.
• It occurs where water meets land, water of different type such as river meets water of another type such as ocean and land meets land with different features.  
• It may exist along a broad area or in a small region.
• It is a zone of increased competition or tension.
• It is linear as it shows progressive increase in species composition of incoming community but decrease in species of the outgoing adjoining community.
• Ecotone zone may contain many organisms which are entirely different from that of the adjoining communities.
• Edge effect ecotone: It contains more population density with more variety of species than either of the adjoining communities.
  • The organisms which occur primarily or abundantly in such zones are known as edge species or marginal species.
• In the terrestrial ecosystems, ecotone edge effect is applicable more for birds.
  • Example: the density of song birds is greater in ecotone between the forest and the desert.
• It can occur naturally or can be man- made.

Classification of ecotone:

• Climatic ecotones: includes Thermo-ecotone– when temperature is the main limiting factor and the Hygro-ecotone– when humidity is the main limiting factor.
• Edaphic ecotones: controlled by the effect of the edaphic factors and are subdivided:
  • Geo-ecotone: affected by the soil texture, depth or both.
  • Hydro-ecotone: affected by the water status in the soil.
  • Chemo-ecotone: affected by the soluble ions in the soil solution, including salinity.
• Biological ecotones:
  • External biological ecotone concerns the boundaries between adjacent ecosystems which need the same demands to survive.
  • Internal biological ecotone concerns the relations between the individuals within the same ecosystem, especially at the period of change from one aspect to another.

Importance of Ecotone:

• It contains many of the endemic and keystone species, so ecotone helps in sustaining many ecotype species.
  • Ecotype is a genetically distinct geographic race within a species, which is genotypically adapted to those specific environmental conditions.
• Many organisms require a transitional area for activities such as courtship, nesting, or foraging for food.
• It helps in gene flow when one population meets another population to result in greater genetic diversity.
• It is known as buffer zones as they protect ecosystem boundaries from many damages including climate induced hazards.
• It is very sensitive to global climatechange as climate change occurs when the boundaries between the ecosystem changes.
  • Thus, it acts as an indicator of such changes.

Conclusion:

There are abundant species in ecotone including the endemic ones, thus it becomes important for all the stakeholders including government, local population and international community to take appropriate steps in order to protect it from global climate changes and increase its area so as to contain more diverse species. Mangrove is one such that requires immediate steps for protection.

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