Ecology and Functions of an Ecosystem

2020-04-29 10:42:03

Ecology and Functions of an Ecosystem
Ecology

Ecology

Ecology - interaction of organisms w/ each other and env
the branch of biology that deals with the relations of organisms to one another and to their physical surroundings.
Env is biotic+ abiotic component
study all kinds of interactions simple and complex such as pollination, predations, amenalism etc.

Levels of Organisation in an Ecology :

Individual
Population of same species
Community
further divided into Major large sized independent organism that depend only on Sun’s energy and Minor are dependent on others.
Consumers aka Heterotrophs or Phagotrophs - divided into Macro and Micro/saptrotrophs/decomposers/osmotrophs

Ecosystem

structural and functional unit of Biosphere its components are either Biotic or Abiotic
Ecosys are Terrestrial and Aquatic. Ex Lakes, rivers, ponds, Tundra, taiga etc
Ecotone is junction b/w 2 or more ecosys - intermediate condition, contain unique organisms.
Edge effect - when one species pop is more than others
Regional and local variations -> formation of habitats ex physical and chemical conditions viz Temp, Water, Light and Soil. Habitats also contain biotic elements.
defined range of conditions that it can tolerate eg diversity in resources, distinct roles etc comprise to form its Niche(unique functional role)
Various types of Niche are Habitat, Food, Reproductive, Physical & Chemical

Terrestrial Ecosys :

Image unavailable in web version: Ecology-and-Functions-of-an-Ecosystem

Aquatic systems/Zones

not called biomes but are divided into distinct life zones.

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Biosphere is absent at extremes of the North and South poles, highest mountains, deepest oceans etc due to hostile conditions but they do have dormant life eg bacteria etc.
Thick aerosols present in North IN Himalayan edge.
Nagar Van Udyan Yojana - City forest. School Nursery Yojana, ENVIS - CSS, integrate collection, storage, retrieval of data.
Organism that tolerate wide range of temperatures called eurythermal.
narrow range of temperatures called stenothermal.
tolerant of a wide range of salinities (euryhaline) narrow range (stenohaline).

Homeostasis

Process by which organisms maintain the constancy of their internal, physical and chemical condition is called Homeostasis

Homeostasis is maintained through :

Regulation : most mammals, all birds and few lower vertebrates do it through thermoregulation or osmoregulation.
- Osmoregulators actively control salt concentration despite the surrounding salt concentration.
Conform : All plants and 99% of animals cannot maintain constant internal env.
- they are also called as ectotherms ie they depend on external sources of body heat as they cannot regulate their body temperature.
- Are mostly cold blooded animals ex amphibians, reptiles, fishes insects etc.
Migration : Organisms move to places where favorable condition exists.
Suspend : or reduce their metabolic activity until favorable condition arise.
- Microbes such as bacteria, fungi and lower plants etc produce thick walled spores that help them survive in unfavorable condition.
- Production of seeds that remain dormant until favorable condition causes germination.
- Hibernation and aestivation. Aestivation takes place during summer but and hibernation during winters.
- Aquatic organisms inter into diapause ex zooplanktons.
small animals are not found in polar regions - have large surface area relative to their volume, lose body heat very fast during cold they have to expend much energy for thermoregulation/ through metabolism.
Allen’s Rule : Mammals from colder climate have shorter ears and limbs to minimise heat loss.
Nearly 25% of all insects are phytophagous (feeding on plant sap).
Parasites that feed on the external surface of the host organism are called ectoparasites. Ex lice, ticks.
Endoparasites : inside the host body at different sites.
Brood Parasitism : Parasitic bird lays its eggs in the nest of its host and lets the host incubate them this is called.

Glossary

Lichens : are symbiotic partnership of a fungus and an alga can be found in deserts and tundra regions too.

Fungus is the dominant partner that gives it its major characteristics. Fungi do not have cholorphyll so they depend on other organisms for their nutrients which is alga in this case.
alga here could be green alga or blue green alga aka cyanobacteria. Alga are from Protista kingdom. #important #PrelimsPYQ
Lichens are different from mosses which are non vascular plants. ![[Pasted image 20220210152530.png |300 x 200]]

Mosses : are non vascular flowerless plants in Bryophyta division. That form dense green clumps on walls and mats. They can absorb liquids 20 times their weight.

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Sedges : are monocotyledons ie a single embryonic first leaf that appears from a germinating seed.

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Spruce : are coniferous evergreen trees found in termperature and boreal/taiga regions. They are different from pines in that their needles(adult leaves) are attached to stems in bundles not individually like in spruces trees.

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Fir trees : Are evergreen coniferous trees mostly occuring in mountains.

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Lemmings : are small rodents found in tundra biomes and very similar to voles and muskrats.

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Ptarmigan : are mid sized birds that are reared for meats and eggs or hunted as game birds.

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Elk : One of the largest species within the deer family native to north america and also found in Central and East Asia.

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Prairie Dog : are herbivorous burrowing rodents native to grasslands of north america. They are called dogs due to their warning calls that sound like a dog’s bark.

![[Pasted image 20220210160845.png |300 x 300]]

Ground Nesting Brids : Certain examples of ground nesting birds om India are Lapwings, Malabar Crested Lark.