ce6460 ecology - amu.ac.in · terrestrial net primary productivity many factors influence primary...

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An ecosystem is a communityof living organisms inconjunction with the nonlivingcomponents of theirenvironment (things like air,water and mineral soil),interacting as a system. Thesebiotic and abiotic componentsare regarded as linkedtogether through nutrientcycles and energy flows.

ECOSYSYTEM

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Biomagnification, also known as bioamplification or biological magnification, is the increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain.


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Energy and Nutrient transfer in through Ecosystem

Nutrients (shown by light arrows) cycle through ecosystems in a closed loop, while energy (shown by dark arrows) is released at each stage.30‐11‐2019 UNIT I CE 623 Ecology and Environmental Microbiology 5

Concepts of Productivity

• Primary Productivity• Gross Primary Productivity• Net Primary Productivity• Net Community Productivity• Secondary Prouctivity


Terrestrial net primary productivity

Many factors influence primary productivity rates, but the most important on land are temperature and water availability.30‐11‐2019 UNIT I CE 623 Ecology and Environmental Microbiology 7

Ocean net primary productivity, 1997‐2002

© National Aeronautics and Space Administration.In contrast to land, where vascular plants carry out most primary production, most primary production in the oceans is done by microscopic algae.


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EcotonesAn ecotone is a transition area between two biomes. It is where two

communities meet and integrate. It may be narrow or wide, and it

may be local (the zone between a field and forest) or regional (the

transition between forest and grassland ecosystems).


Pacific crest ecotone. The peaks of the Cascade mountain range cast a rain shadow over eastern Oregon, instigating a harsh change from the wet, evergreen forests of the west to the dry, sparse, high desert of the east. Landsat 5satellite on 27 Oct 2011.



ECOTONES


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BIOMES

• A biome is a community of plants and animals that havecommon characteristics for the environment they exist in. Theycan be found over a range of continents. Biomes are distinctbiological communities that have formed in response to a sharedphysical climate."Biome" is a broader term than "habitat"; anybiome can comprise a variety of habitats.

•While a biome can cover large areas, a microbiome is a mix oforganisms that coexist in a defined space on a much smallerscale. For example, the human microbiome is the collection ofbacteria, viruses, and other microorganisms that are present ona human body.


Terrestrial biomes around the world30‐11‐2019 UNIT I CE 623 Ecology and Environmental Microbiology 15

TYPES OF BIOMES


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Ecological Succession

• Ecological succession is the process of change in the species structureof an ecological community over time. The time scale can be decades(for example, after a wildfire), or even millions of years after a massextinction.

• The community begins with relatively few pioneering plants andanimals and develops through increasing complexity until it becomesstable as a climax community. The "engine" of succession, the causeof ecosystem change, is the impact of established species upon theirown environments. A consequence of living is the sometimes subtleand sometimes over alteration of one's own environment.



Ecological Succession


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Freshwater Ecosystem


Zonation in Lake Ecosystem


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Planktons are the diverse collection of organisms that live in large bodies of waterand are unable to swim against a current. They provide a crucial source of food tomany large aquatic organisms, such as fish and whales



Benthos: the flora and fauna found on the bottom, or in the bottom sediments, of a sea or lake.


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Periphyton


Marine Ecosystem


Zonation in Sea


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Coral Reefs: Coral reefs are diverse underwater ecosystems held together by calciumcarbonate structures secreted by corals. Coral reefs are built by colonies of tinyanimals found in marine water that contain few nutrients.


Mangrove's Plantation


Biogeochemical Cycles

Nitrogen Cycle:Nitrogen is abundant in the atmosphere but occurs in an inert form thatliving organisms cannot use directly. In the nitrogen cycle, some of this supply is convertedto biologically useful forms.


Biogeochemical Cycles

Phosphorus Cycle: Phosphorus is found in water, soil, and sediments. Like nitrogen, it mustbe converted to biologically useful forms before plants and animals can take it up.


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ce6460 ecology - amu.ac.in · terrestrial net primary productivity many factors influence primary...

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