Aartee Mishra is teaching live on Unacademy Plus
Environment Book Summary Presented B Aartee Mishra
2. Micro consumers -Saprotrophs (decomposers or osmotrophs) Natural Ecosystem They are bacteria and fungi which obtain energy and nutrients by decomposing dead organic substances (detritus) of plant and animal origin. Aquatic Fresh Waters Marine Waters Terrestrial . The products of decomposition such as inorganic nutrients which are released in the ecosystem are reused by producers and thus recycled. Forests GrassandsSaline Waters Deserts
Aquatic Biomes . Freshwater Lakes and Ponds Streams and Rivers - Marshes and Swamps Marine - Oceans Coastal wetlands
Goods and Services provided by ecosystems include: Provision of food, fuel and fibre Provision of shelter and building materials Purification of air and water Detoxification and decomposition of wastes Stabilization and moderation of the Earth's climate Moderation of floods, droughts, temperature extremes and the forces of wind Generation and renewal of soil fertility, including nutrient cycling. Pollination of plants, including many crops Control of pests and diseases .
Ecotone is a zone of junction between two or more diverse ecosystems. For e.g. the mangrove forests represent an ecotone between marine and terrestrial ecosystem. Other examples are - grassland, estuary and river bank Grass Land Forest Characteristics of Ecotone Ecotone It may be very narrow or quite wide has conditions intermediate to the adjacent ecosystems. Hence it is a zone of tension. It is linear as it shows progressive increase in species composition of one in coming community and a simultaneous decrease in species of the other out going adjoining community. A well developed ecotones contain some organisms which are entirely different from that of the adjoining communities.
EDGE EFFECT Sometimes the number of species and the population density of some of the species is much greater in this zone than either community. This is called edge effect. The organisms which occur primarily or most abundantly in this zone are known as edge species. In the terrestrial ecosystems edge effect is especially applicable to birds Land ecosystem Transitional ecosystem Aquatic ecosystem Ecotone marshland EcosystemI Ecosystem I
Niche. A niche is the unique functional role or place of a species in an ecosystem. It is a description of all the biological, physical and chemical actors that a species needs to survive, stay healthy and reproduce. A niche is unique for a species, which means no two species have exact identical niches. If we have to conserve species in its native habitat we should have knowledge about the niche requirements of the species and should ensure that all requirements of its niche are fulfilled. Types of Niche 1. Habitat niche where it lives 2. Food niche-what is eats or decomposes & what species it competes with 3. Reproductive niche -how and when it reproduces. 4. Physical & chemical niche temperature, land shape, land slope, humidity & other requirement