Definition of Pond or Lake Ecosystem
Structure having the abiotic and biotic components. Location, size, depth and substrates of a pond influence the biology of pond ecosystem. A pond ecosystem is a self sufficient and self regulating system. Also called Fresh water Ecosystem. These are two major components given below :
1. Abiotic components
2. Biotic components
1. Abiotic components : Temperature, light, pH of water and several basic inorganic and organic substances like H2O, CO2, O2, NO3, PO4, Ca, S and carbohydrates, proteins, lipids, etc., make the abiotic (physical) components.
1. Abiotic components
2. Biotic components
1. Abiotic components : Temperature, light, pH of water and several basic inorganic and organic substances like H2O, CO2, O2, NO3, PO4, Ca, S and carbohydrates, proteins, lipids, etc., make the abiotic (physical) components.
2. Biotic Component : The various organisms that constitutes the biotic component are as follow:
1. Producers
2. Consumers
3. Decomposers
Producers
These are autotrophic, green plants and some photosynthetic bacteria. The producers fix radiant energy and with the help of minerals complex organic substances as carbohydrates, proteins, lipids etc. Producers are of following types:
➤ Macrophytes are mainly rooted larger plants which include partly or are completely submerged, floating and emergent hydrophytes. The common plants are the species of Trapa, Typha, Eleocharis, Sagittaria, Nymphaea, Potamogeton, Chara, Hydrilla, Valiisneria, Ultricularia, Marsilea, Nelumbo, etc. Besides them some free-floating forms as Azolla, Salvinia, Wolffia, Eichhornia, Spirodella, Lemma etc. also occur in the pond.
➤ Phytoplanktons are suspended lower plants, Majority of them are such filamentous algae as Zygnema, Ulothrix, Spirogyra, Cladophora, and Oedogonium. Besides them there are also present some chlorococcales, Closterium, Cosmarium Eudorina, Pandorina, Pediastrum, Scendesmus, Volvox, Diatoms, Anabaena, some chroococcales, Gloeotrichia Microcystis, Oscillatoria, Chlamydomonas, Spriulina etc. and also some flagellates.
➤ Phytoplanktons are suspended lower plants, Majority of them are such filamentous algae as Zygnema, Ulothrix, Spirogyra, Cladophora, and Oedogonium. Besides them there are also present some chlorococcales, Closterium, Cosmarium Eudorina, Pandorina, Pediastrum, Scendesmus, Volvox, Diatoms, Anabaena, some chroococcales, Gloeotrichia Microcystis, Oscillatoria, Chlamydomonas, Spriulina etc. and also some flagellates.
They are heterotrophs which depend for their nutrition on the organic food manufactured by producers, the green plants. Most of the consumers are herbivores, a few as insects and some large fish are carnivores feeding on herbivores. Some fish also feed on other carnivores as well.
The consumers in a pond are distinguished as follows:
(i) Primary consumers (herbivores) : Primary consumers also known as primary macroconsumers, herbivores feeding directly on living plants (producers) or plant remains.
These may be large well as minute in size. The herbivores are further differentiated as:
➤ Benthos : These are -
(a) The animals associated with living plants (producers), labeled as 'a' in diagram and
(b) Those bottom forms which feed upon the plant remains lying at the bottom of pond. These are known as detrivores, labeled as 'b' in the diagram. Benthic populations include fish, insect larvae, beetles, mites, molluscs, crustaceans etc. Weight of benthic fauna is estimated in different zones of the pond, and the biomass expressed as g/m² of water.
Besides the above said herbivores, some mammals as cows, buffaloes etc. also visit the Macrophytes. Some birds also regularly visit the pond feeding on some hydrophytes.
Read more - Krebs cycle (TCA Cycle)
- Zooplanktons : These are chiefly the rotifiers as Brachionus, Asplanchma, Lecae etc., although some protozoans as Euglena, Coleps, Dileptus etc., crustaceans like Cyclops Stenocypris etc. are also present. They field chiefly on phytoplanktons. In the diagram these are labelled as 'c'.
(ii) Secondary consumers : Secondary consumers are carnivores which feed on the primary consumers (herbivores). These are chiefly insects and fish. Most insects as water beetles feed on zooplanktons. These are labelled as 'd' in the diagram.
(iii) Tertiary consumers : Tertiary consumers are also carnivores and include some large fish as game fish that feed on the smaller fish, and thus become the tertiary (top) consumers as shown in diagram.
➤ In a pond, fish may occupy more than one tropic levels. As shown in diagram. the smaller fish belong to herbivores levels, feeding on phytoplanktons as well as living plant parts (labelled as 'a'), and also on plant remains lying at the bottom (labelled as 'b'). Some fish may feed on some zooplanktons, thus occupying the secondary consumers level- the carnivores level (labelled as 'd'). Still, it is common to observe the large fish feeding on smaller fish, and thus occupying the tertiary consumers level.
Read more - What is Ecosystem
Decomposers
➤ They are also known as microconsumers, since they absorb only a fraction of the decomposed organic matter of both-producers (plants) as well as macroconsumers (animals) to simple forms. Thus they play an important role in the return of mineral elements again to the medium of the pond.
➤ These include a variety of heterotrophic microbes that are osmotrophs. These are sampled by the use of several isolation methods. They are chiefly bacteria, actinomcetes and fungi. Fungi are isolated by Warcup's method on Martin's actinomycetes on Jeson's medium. Among fungi, species of Aspergillus, Cephalosporium, Thielavia, Alternaria, Trichoderma, Saprolegnia etc. are most common decomposers in water and mud of the pond.
➤ These include a variety of heterotrophic microbes that are osmotrophs. These are sampled by the use of several isolation methods. They are chiefly bacteria, actinomcetes and fungi. Fungi are isolated by Warcup's method on Martin's actinomycetes on Jeson's medium. Among fungi, species of Aspergillus, Cephalosporium, Thielavia, Alternaria, Trichoderma, Saprolegnia etc. are most common decomposers in water and mud of the pond.
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