Ecosystems PDF

Ecosystems  Introduction The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley. Ecosystem: A self-regulating group of biotic communities of species interacting with one another and with their non-living enviro...

Ecosystems  Introduction The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley. Ecosystem: A self-regulating group of biotic communities of species interacting with one another and with their non-living environment exchanging energy and matter The term oekologie (ecology)was coined by the German biologist Ernst Haeckel in the year 1866. Greek word “Oikos” meaning “home” and “logos” meaning “study” Ecology: The study of organisms in their natural habitat interacting with their surroundings This material is for reference only. Points present in the slides are only for assistance and their elaboration are present in book. Examination quesions will be in depth and can be solved by following text book only. Classification of Ecosystems Natural Ecosystems Terrestrial Ecosystems Man-made Ecosystems (aquaria, garden, dams & cropland of Forest maize, wheat, rice). Ecosystems Grass land Aquatic Ecosystems Ecosystems Desert Ecosystems Fresh water Ecosystems Standing water Running water Marine Ecosystems (lentic) Ecosystems (lotic) Ecosystems Natural Ecosystems Man-made Ecosystems Structure of Ecosystem Ecosystem Structure  Biotic Components of Ecosystems Producers (or autotrophs) Green plants and some bacteria which manufacture their own food. Consumers (or heterotrophs) Animals which obtain their food from producers Primary consumers = herbivores (rabits, insects) Secondary consumers = carnivores (Frog) Tertiary consumers = top canivorous (Snake, big fish) Omnivores = Humans, rat, fox Decomposers Bacteria and fungi that decompose dead organic matter and convert it into simpler parts  Functions of an Ecosystem  Food chain and food web ( food chain is a series of organisms that eat one another so that energy and nutrients flow from one to the next. Many food chains interacts to form food web)  Energy flow (The ( energy flow takes place via the food chain and food web)  Ecological pyramids (An ( ecological pyramid is a graphical representation designed to show the biomass or bio productivity at each trophic level in a given ecosystem)  Food Chain The transfer of food energy from the source (plants) through a series of organisms by repeated eating and being eaten up is referred to as food chain. Types: Grazing food chain-a common chain starting with plant or plant product Detritus food chain-chain derived by the organic wastes and dead matter from grazing food chains Trophic Level  Food web The interlocking pattern formed by several food chains that are linked together is called a food web.  Energy Flow in Ecosystems First Law of Thermodynamics energy can neither be created nor destroyed but only is transformed from one form to another. Second Law of Thermodynamics-The second law of thermodynamics states that no energy transformations are 100% efficient. 10 Percent Rule of Energy As a rule of thumb, 90 percent of the energy involved is degraded at each tropic transfer and only 10 percent of the energy is conserved in the organism's tissue.  Ecological Pyramid The graphical representations of different tropic levels in an ecosystem where producers occupy the base and the top consumer occupy the apex of the pyramid, is known as ecological pyramid. They are used to illustrate the feeding relationships between organisms. Types of Ecological Pyramids Pyramid of number = no of individual at each tropic level is considered Pyramid of biomass = biomass at each tropic level is considered Pyramid of energy = energy at each tropic level is considered  Pyramid of Number Pyramid of number is used to show the number of individuals in each tropic level. It is upright in case of grassland and pond ecosystems. Pyramid of Number Pyramid of Biomass tertiary consumers 75 g/m2 Pyramid of biomass records the total dry organic matter of organisms at each trophic level in a 150g/m2 given area of an ecosystem. secondary consumers The pyramid of biomass is used to show the total biomass of individuals primary at each trophic level. consumers 675g/m2 It is better than the pyramid of number for showing the relationships between organisms. producers 2000g/m2 18 Pyramid of energy Pyramid of energy is used to show the amount of energy transferred between tropic levels. It provides the best representation of the overall nature of an ecosystem. The pyramid of energy flow is always upright because there is always loss of energy while moving from lower tropic level to higher tropic level. Therefore, the energy reaching the next tropic level is always less compared to that in the previous tropic level. Ecological pyramids Energy flow Energy flow Production of biomass  Primary production  Biomass production using photosynthesis  Secondary production  Biomass production by consuming producers Succession  Ecological succession is the gradual process by which ecosystems change and develop over time.  It is therefore a series of predictable temporary communities or stages leading up to a climax community.  Each stage/temporary community is called a successional stage.  Each step prepares the land for the next successional stage.  All habitats are in the state of constant ecological succession.  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 Succession starting on different types of area  Hydrarch / Hydrosere  Pond, swamp, bog  Mesarch / Mesosere  Area with adequate moisture  Xerarch / Xerosere  Lithosere: On bare rock  Psammosere: On sand  Halosere: On saline soil Process of ecological succession  Nudation  Invasion  Migration (dispersal)  Ecesis (establishment)  Aggregation  Competition  Reaction  Stabilization Nutrient cycles  Nitrogen Nutrient cycles  Carbon Nutrient cycles  Phosphorus 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  Tropical rain forest  Notable features:  Found in tropical region (near the equator).  High rainfall, humidity and temperature  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.  Layers  Emergent layer  Canopy  Understory  Forest floor  Example: Amazon Rainforest, Congo Rainforest, Southeast Asian Rainforest etc.  Tropical deciduous forest  Notable features:  Tropical deciduous forests form a natural cover almost all over India.  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.  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.  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.  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.  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 hawks etc. 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, 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 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) 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  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, Mexican deserts, 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  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 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) 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  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)  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) https://youtu.be/xwFr2hWjo5s https://youtu.be/NeK5-mJhWeg  Exercise 1. The natural place of an organism or community is known as a. Niche b. Biome c. Habitat d. Habit 2. Which of the following require maximum energy a. Secondary consumer b. Decomposer c. Primary consumer d. Primary producer  Ocean acidification is caused by which of the following gases? a. Sulfur Dioxide b. Carbon Dioxide c. Nitric Oxide d. Ozone Which one following is the example of man-made ecosystem “Ecosystem” term was coined by------- A Lindeman B AG Tansley C Grinnel D Turesson What are the edaphic factors for the abiotic components? a) Sunlight, temperature, Wind b) Soil type, soil moisture, soil mixture c) Longitude, latitude d) Rainfall, humidity  The food chain which starts with green plants is called a) Food web b) Detritus food chain c) Grazing food chain d) None of the above Which is/are below the abiotic components of an ecosystem? A Light B Water C Carbon D All of the above Which are the following are two basic classes of ecosystem are: a) Aquatic and forest b) Ponds and lakes c) Rivers and forests d) Aquatic and terrestrial