Habitat and Ecological Niche for M.SC zoology students

Habitat and Ecological Niche for M.SC zoology students

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  ANDHRA UNIVERSITY DEPARTMENT OFZOOLOGY TOPIC: Habitat and Ecological Niche MENTOR DR.M.RATNA KALA MAM NAME: S. KEDARI SAI RED. NO: 723212244055
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  INTRODUCTION WHAT IS HABITAT? Definition: Habitat refers to the place where an organism or a species population lives. The word "habitat" has been used since around 1755 and comes from the Latin word habitāre. which means "to inhabit". The subdivision of a habitat is called a microhabitat. The specific environmental variable in the microhabitat is called microclimate or microenvironment. Examples: 1. A pond is the habitat of zooplankton, phytoplankton and fish. 2. Soil in a forest floor is the habitat of soil fauna comprising soil insects, their larvae and pupae, microarthropods, some molluscs, annelids, nematodes and proto- zoa and soil microflora comprising bacteria, fungi and actinomycetes.
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  HABITAT CLASSIFICATION AQUATIC HABITAT TERRESTRIAL HABITAT AERIAL HABITAT ARBOREAL HABITAT HABITAT CLASSIFICATION
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  TERRESTRIAL HABITAT Terrestrial habitatmay comprise forest, grassland, agricultural land, tundra, desert and so on. Here are some common types of terrestrial habitats with examples: 1. Forest habitat: There are different types of forest habitat they are Tropical Rainforests : Dense forests near the equator with high rainfall. (e.g., Amazon Rainforest, Congo Basin) Temperate Rainforests : Cool, moist forests with coniferous trees. (e.g., Pacific Northwest, Valdivian Rainforests) Temperate Deciduous Forests : Forests with trees that shed leaves seasonally. (e.g., Eastern North America, Europe) Boreal Forests (Taiga) : Cold, subarctic forests with coniferous trees. (e.g., Alaskan Taiga, Canadian Boreal Forest)
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  TERRESTRIAL HABITAT 2. Grasslands:Temperate regions with grasses and few trees. (e.g., Prairies, Savannas) 3. Tundras: Cold, treeless regions with low vegetation. (e.g., Arctic Tundra, Alpine Tundra) 4. Deserts: Arid regions with limited vegetation and rainfall. (e.g., Sahara Desert, Mojave Desert) 5. Mountain Ecosystems: Areas with unique adaptations to high elevations. (e.g., Himalayas, Rocky Mountains) These habitats support a wide range of plant and animal species, and each has its unique characteristics and adaptations.
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  AQUATIC HABITAT Aquatic habitatmay be fresh water, marine water and brackish water, or subdivisions of these larger habitats. Freshwater habitats : Fresh water habitat are aquatic ecosystems that contain little to no salt and include lakes, ponds, rivers, streams, springs, bogs, and wetlands. They are classified by factors like temperature, light penetration, nutrients, and vegetation. Marine water habitats: Marine water habitats are aquatic habitats with salt concentrations of more than one percent. Examples of marine water habitats: Coastal waters, Estuaries, Coral reefs, Mangrove forest, Mudflats. Brackish water Habitat: Brackish water is a mix of freshwater and seawater that has more salt than fresh water but less than ocean water. The salinity levels in brackish water habitats can vary and change over time due to tides, evaporation, rainfall, and drainage. These varying salinity levels can present unique challenges for aquatic life to adapt and thrive. Examples of habitats that contain brackish water: Mangrove forests and swamps, Baltic Sea, Seagrass beds, Estuaries, Lagoons.
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  AERIAL HABITAT Aerial habitatsare the skies and airspace where birds, insects, and bats live. Aerial animals are organisms that can fly, soar, or glide naturally in the air. Some examples of aerial animals include: Birds, Insects, Bats. ARBOREAL HABITAT Arboreal habitats are places in trees where organisms can live and feed, such as the roots, branches, leaves, and canopies of trees, and even holes within the tree. The word "arbor" is Latin for "tree". Many different organisms live in arboreal habitats, including mammals, marsupials, birds, insects, and fungi.
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  ECOLOGICAL NICHE  Anecological niche refers to an organism's place in the biotic environment and its functional role in an ecosystem.  The term was coined by the naturalist Roswell Hill Johnson but Grinell (1917) was probably first to use this term. The habitat and niche of any organism is called Ecotope.  Charles Elton (1927) regarded the niche as the fundamental unit of an organ- ism or a species population in the community.  It centered around the collection of food, involvement in the intraspecific and interspecific competition.  In simple terms, the habitat refers to the place where an organism lives and niche to the activity (functional aspect) of an organism. Examples: (a) there may be herbivore, carnivore and omnivore fish depending on their food habits, (b) there may be surface, column and bottom feeders with regard to the distributional patterns, and (c) there may be other kinds of distribution depending upon environmental gradients, such as tem- perature or pH.
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  TYPES OF NICHES Trophic Spatialor Habitat Multidimensional or Hypervolume TYPES OF NICHES
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  TYPES OF NICHES Spatialor habitat niche: As the name indicates, the spatial or habitat niche is concerned with the physical space occupied by an organism. It is broadly related to the concept of habitat, but differs from it, in the sense that while different species may occupy the same habitat, the activity of each organism may actually be confined to only a small portion of the habitat called micro- habitat. Tropic niche: This refers to the trophic position (food level) of an organ- ism. For example, in the Galapagos islands in South America, birds belonging to three genera, namely Geospiza (ground finches), Camarhynchus (tree finches), and Certhidia (warbler finches) are found. All these birds live in the same general habitat but differ in their trophic position. Multidimensional or hypervolume: The concept of hypervolume or multidimensional niche was developed by Hutchinson in 1965. He recognized two types of niches (a) fundamental and (b) realised niche (i) Fundamental niche :- The fundamental niche is the maximum abstractly inhibited hypervolume, when the species is not competing with others for its resources. (ii) Realised niche :- An individual or a species normally remains in competition (either interspecies or interspecies or both) and thus under biotic constraints only a part of the niche is realised by the species. This smaller hypervolume occupied by a species called the realised niche.
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  NICHE BREADTH ANDOVERLAP Niche breadth :- Niche breadth may refers to th width of the area. The species that utilized a broad spectrum of the environment are called habitat generalists. They usually have high niche breadth score. Some species are restricted in their distribution and live in a narrow range of environmental spectrum. They exhibits low niche breadth score. Niche breadth of each species can be calculated using Levine's formula (1967) :- 1/Bj = ΣP2 ij Where : Bj = niche breadth of species j Pij = proportion of occurrence of species j in plot i.
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  NICHE BREADTH ANDOVERLAP Niche overlap :- Niche overlap is a measure c the association of two or more species. In other words, how often any two species occurred together in a habitat or ecosystem. A high niche overlap value of two species indicates that they are found together more often than other species in a particular habitat. This indicates their similar habitat requirement and may also indicate competition if trophic or spatial niche is same food or space is limiting. Horn's (1966) formula can be used to calculate niche overlap score of each species :- Ljk = 2ΣPij Pik/ (ΣP2 ij + ΣP2 ik) Where :- Pij = Population of occurrence of species 'j' in plot 'i’ Ljk = over lap of species 'j', 'k' & Pjk = population of occurrence of species 'k’ in plot 'i'
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  References Books: Odum, E.P. Fundamentalsof Ecology. W.B. Saunders, Philadelphia. Websites: https://www.crestolympiads.com/topic/classification-of-animals-based-on-their-habitat
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  Thank you