Ecology (Part 2) PDF

ECOLOGY (Part – 2)  Homeostasis  The ecosystem , by itself, tries to resist the change and maintain itself in equilibrium.  Homeostasis is the inherent property of all living systems to resist change.  Homeostatic plateau - System can show this tolerance or resistance only...

ECOLOGY (Part – 2)  Homeostasis  The ecosystem , by itself, tries to resist the change and maintain itself in equilibrium.  Homeostasis is the inherent property of all living systems to resist change.  Homeostatic plateau - System can show this tolerance or resistance only within a maximum and a minimum range, which is its range of tolerance.  Negative feedback  If any stress tries to cause a deviation, then the system has its own mechanisms to counteract these deviations Positive Feedback If the stress is too high and beyond the range of homeostatic plateau, then another type of mechanisms Positive feedback mechanisms add to the stress conditions and tend to take the system away from the optimal conditions. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Ecological Succession  Ecological succession is the gradual process by which ecosystems change and develop over time.  One type of a community is totally replaced by another type of community over a period of time and simultaneously several changes also occur.  An orderly process of changes in the community structure and function with time mediated through modifications in the physical environment and ultimately culminating in a stabilized ecosystem known as climax.  Each stage/temporary community is called a successional stage or seral stage.  The whole sequence of communities which are transitory are known as Seral stages or seres  The community establishing first of all in the area is called a pioneer community.  Each step prepares the land for the next successional stage.  All habitats are in the state of constant ecological succession. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Types of Succession  Primary succession  Primary succession refers to a series of community changes which occur on an entirely new habitat which has never been colonized before. For example, a newly quarried rock face or sand dunes. (pioneer and climax community).  Secondary succession  Secondary succession refers to a series of community changes which take place on a previously colonized, but disturbed or damaged habitat. For example, land obtained after felling trees in a woodland, land clearance, or fire. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Succession  An established species and impact of external natural forces, which try to alter the environmental condition of that area. Ex. Hardwood tree replacing red pine  Ecosystem is continuously changing and reorganizing as well as ecological succession refers to orderly that changes happening in composition or structure of ecosystem This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Succession starting on different types of area  Hydrarch / Hydrosere  Starting in watery area like pond, swamp, bog  Mesarch / Mesosere  Starting in an area of adequate moisture  Xerarch / Xerosere Starting in a dry area with little moisture.  Lithosere: starting on a bare rock  Psammosere: starting on sand  Halosere: starting on saline soil This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Process of ecological succession  Nudation  It is the development of a bare area without any life form.  The bare area may be caused due to landslides, volcanic eruption etc. (topographic factor), or due to drought, glaciers, frost etc. (Climatic factor), or due to overgrazing, disease outbreak, agricultural/industrial activities (biotic factors). This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Invasion  Migration (dispersal) - It is the successful establishment of one or more species on a bare area through dispersal or migration,  Ecesis (establishment) – Followed by establishment.  Aggregation – Dispersal of the seeds, spores etc. is brought about by wind, water, insects or birds and then the seeds germinate and grow on the land.  As growth and reproduction start, these pioneer species increase in number and form groups or aggregations.  Competition - As the number of individuals grows there is competition, both inter-specific (between different species) and intra-specific (within the same species), for space, water and nutrition.  They influence each other in a number of ways, known as coaction.  Reaction - The living organisms grow, use water and nutrients from the substratum, and in turn, they have a strong influence on the environment which is modified to a large extent.  Stabilization - The succession ultimately culminates in a more or less stable community called climax which is in equilibrium with the environment. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Forest ecosystem  Abiotic Components  Inorganic and organic substances found in soil  Temperature, humidity, rainfall, light  Biogenic gases (CO2, O2)  Biotic components  Producers: Large trees, herbs, lianas (climbers), Orchids  Primary consumer: Deer, Elephant, moles etc.  Secondary consumer: Snake, Lizards etc.  Tertiary consumers: Tiger, Lion etc.  Decomposers This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Tropical rain forest  Notable features:  Found in tropical region (near the equator).  High rainfall, humidity and temperature- growth of trees  Large leaves  Rich in biodiversity  Fauna of these rainforests includes the jaguar, tapir, okapi, boa constrictor, African grey parrot, keel-billed toucan, crowned eagle, three-toed sloth, spider monkey, large flying fox and more.  Example: Amazon Rainforest, Congo Rainforest, Southeast Asian Rainforest etc.  Silent Valley in Kerala is the only tropical rain forest lying in India This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Layers  Emergent layer- topmost layer of the tallest broad-leaf evergreen trees  Canopy - top branches of shorter trees form an umbrella like cover  Understory - smaller trees, receive very dim sunlight, dark green leaves with high chlorophyll content  Forest floor - receives almost no sunlight and is a dark layer (Shrub layer or ground layer) This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Tropical deciduous forest  Notable features:  Tropical deciduous forests form a natural cover almost all over India.  They are found a little away from the equator and are characterized by a warm climate  They are of two types-moist and dry.  Moist forests are found on the eastern slopes of Western Ghats, North eastern parts of the Peninsular Chhota Nagpur plateau and along the Shiwaliks.  They shed there leaves for a particular period of time.  They are economically very important because of timber like sal and teak.  The animals found here are tiger, wolves, rabbit etc. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Sub-tropical forest  Notable features:  Subtropical forests are within or bordering the tropical zone.  temperatures may vary only slightly over a year  Subtropical rainforests occur in Central America, the West Indies, India, Madagascar, mainland Southeast Asia, and the Philippines.  Small deciduous trees and shrubs are found. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Temperate rain forest  Notable features:  The world's largest temperate rain forests are found on the Pacific coast of North America.  Temperate rain forests are also found in coastal Chile, Norway, the United Kingdom, Japan, Australia and New Zealand.  The mild weather conditions  Adequate rainfall  Coniferous trees dominate the forest  tall evergreen trees are also found  Animals: black bears, lynx, wolves etc. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Temperate deciduous forest  Notable features:  Located in the mid-latitude areas (between the polar regions and the tropics). E.g.- Northeast China Plain (China), The Manchurian mixed forest (Asia), The European Temperate Deciduous Broadleaf Forest (Europe)  The temperature varies widely from season to season with cold winters and hot, wet summers.  During the fall, trees change color and then lose their leaves.  Most of the trees are broadleaf trees such as oak, maple, beech, hickory and chestnut.  Animals: toad, chipmunk, gray squirrel, Yellow-breasted chat etc. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Evergreen coniferous forest  Notable features:  They are found just in south of arctic tundra  Winters are long, cold and dry  Sunlight is available for few hours only  Soil has less nutrient and acidic  Major trees are Pine, Fir, Cedar etc.  Animals: moose, deer, reindeer, squirrels, wolves, bears, foxes, owls, woodpeckers etc. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Grassland ecosystem  Abiotic components:  Inorganic elements (C, H, O, N, P, S)  Temperature, humidity, rainfall, light  Biotic components:  Producers: Some scattered trees, Grass  Primary consumers: Grazing animals, This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Tropical grassland  Notable features:  Located near the equator, between the Tropic of Cancer and the Tropic of Capricorn.  Although these areas are overall very dry, they do have a season of heavy rain.  Dominated by grasses  May have some drought-resistant, fire-resistant trees  Animals: giraffes, zebras, buffaloes, kangaroos, mice, moles, gophers, ground squirrels, snakes, worms, termites, beetles, lions, leopards, hyenas, and elephants.  Examples:  Savannas  Found in Africa, South America, Australia, Myanmar-Thailand region in Asia This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Temperate grassland  Notable features:  Trees and shrubs are completely absent or rare.  cold winters (-40⁰C) and hot summers (38⁰C)  Gentle slope  Animals: Rodents, bisons, wolves, hawks, owls etc.  Examples:  Prairies (South America)  Pampas (Africa)  Velds (Central Europe)  Steppes (Asia) This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Polar grassland  Notable features:  Severe cold and strong wind  Arctic wolf, arctic fox, reindeer, migratory birds and insects are found.  Examples:  Arctic Tundra  Permafrost: Permafrost is soil, rock or sediment that is frozen for more than two consecutive years. In areas not overlain by ice, it exists beneath a layer of soil, rock or sediment. This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Desert ecosystem  About 1/3rd of the worlds’ land area is covered with desert  Tropical desert  Notable features:  It is the driest and hottest place on earth.  Rainfall is sporadic and in some years no measurable precipitation falls at all.  Examples: Sahara, Kalahari, Thar, Great Australian desert.  Temperate desert  Notable features:  Temperate deserts can be much colder than tropical deserts  The floor of the temperate desert is often covered by rocks and small pebbles  Examples: Mojave, Sonoran Deserts  Cold desert  Notable features:  cold deserts occur in temperate regions at higher latitudes  hot summers but extremely cold winters.  Examples: Atacama,  Gobi, Great Basin, Namib, Iranian, Takla Makan, and Turkestan This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Pond ecosystem  A pond ecosystem refers to the freshwater ecosystem where there are communities of organisms that are dependent on each other and with the prevailing water environment for their nutrients and survival.  Notable features:  Small freshwater ecosystem  Water is stagnant  Can be seasonal  Exposed to anthropogenic activities This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Lake ecosystem  Organisms of aquatic ecosystem  Planktons (Algae, rotifers)  Nektons (Fishes)  Neustons (Water flea)  Benthos (Snail)  Periphytons (Crustaceane)  Zonation (Stratification)  Epilimnion (Warm, lighter, circulating surface layer)  Hypolimnion (Cold, viscous, non-circulating bottom layer) This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Types of lakes  Oligotrophic lakes (Low nutrient content)  Eutrophic lake (High nutrient content)  Dystrophic lake (Low pH)  Endemic lakes (Ancient, deep, having endemic fauna)  Desert salt lakes (High salt content)  Volcanic lakes  Mermictic lakes (Permanently stratified)  Artificial lakes This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Streams  Notable features:  flowing water that is mostly unidirectional  a state of continuous physical change  many different (and changing) microhabitats  variability in the flow rates of water  plants and animals that have adapted to live within water flow conditions.  Stages  Mountain highland (Young River)  Second phase (Middle Aged River)  Third phase (Old River) This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Oceans  Notable features:  Marine ecosystems support a great diversity of life and variety of habitats.  The ocean is a major influence on weather and climate.  Plants: seaweeds, or marine algae (brown, green, red), sea grasses, phytoplankton  Animals: protozoans, marine invertebrates (echinoderms, mollusks, segmented and non-segmented worms, jellies, coral, sea anemones, hyroids) marine vertebrates (fishes, birds, mammals), and zooplankton.  Zones  Coastal zone  Open sea  Euphotic zone (Abundant sunlight, high photosynthetic activity)  Bathyal zone (Dim light)  Abyssal zone (Dark zone) This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of  Thank You This PPT should be used as reference only. Reading books (mentioned in syllabus) is mandatory for the preparation of