Ecosystems Chapter 3 PDF

 Chapter 3 1olslao29 Ecosystems Chapter Objectives In this cha...

 Chapter 3 1olslao29 Ecosystems Chapter Objectives In this chapter, you will learn about: Abiotic components Ecosystem Biotic components Forest ecosystem Interdependenceamong organisms 'AlNVing things are natural, but all natural things cannot be living'. Discuss in class. INTRODUCTION TO ECOSYSTEM Al the living organisms in a particular area, In other words, our environment means a surroundings. Our environment interacting witheach other, andalsotheir non-living consists of environments (weather, Earth, Sun, soil, climate, iving things astwellasnon-living things. Living organisms such as plants and animals form the atmosphere, ett) comprise the ecosystem. biotic components (living components)of an ecosystem.Non-living things such as soil, ait INFO HUB water and light are the abiotic components The term 'ecosystem' is derived from the Greek word Oikos, meaning a house'. (non-living components) of our ecosystem. The below shows the pond ecosystem. ponds and grasslands are examples of picture Forests, List from the picture, the: ecosystems. a variety of thingsaround us. The a. biotic components There exists around us constitute our environment. b. abiotic components things 40 Fig. 3.1 Pond ecosystem  BioticComponents and scavengers are consumers. Omnivores The biotic componcnts ofa forest are in thec two other type of consumers. following sequence of food or trophic such as human beings and levels. /Omnivores Producers on both plants and flesh of peacock feed The green plants make animals. their own food by the proces of photosynthesis. Some carnivores and omnivores, known as Hence, they are called producers, They are also do not hunt other called are animals that Theyforn the trophic autotrophs. scavengers, level 1. fedon theflesh of deadanimals.They animal, but are Cxtremely important for the environment as Plants absorb and convert the solar into chemical energy energy. This by eating up the dead chemical energy they help to keep it clean is transferred to other Vulture,crow, jackal organisms as food. bodies of various animals. Producers are the foundation of an and hyena are well-known scavengers. as they are ecosystem the main source of energy and food to other organisms. Consumers Animals and human beings cannot malke their own food and obtain it from other sources. Such organisms are called Fig. 3.2 Hyenas feeding on flesh consumers or heterotrophs (beteros means 'another and Decomposers trophe means nourishing).They are of three Decomposers are organisms that rypes based on their feeding habits. down and break feed on dead and decaying organisms. When a The animals that feed on green plants are called plant or an animal dies, its decaying body is herbivoresorprimary consumers.The chemical broken down or decomposed by energy of food from plants is decomposers. directly passed The nutrients present in the dead body are returned on tothem. Herbivores comprise the trophic the soil o by the action of decomposers. Bacteria and level 2. fungiare the most important decomposers. Theherbivores are then eaten by carnivores or secondary consumers. The chemical energy of food from plants is indirectly on to passed them through herbivores.Carnivorescomprise the trophic level 3. The carnivores are then eaten by tertiary consumers.They arce animals that feed on the flesh ofotherorganisms (primaryand secondary consumers). The chemical energy is passed Fig. 3.3 Mushroom (a fungi)growing on on to them through primary or secondary a broken twig 41  State whetherthe follewing statementsare TrB G Eals, 1. Autotrophs belong to the trophic leve 1 2 Plants are also refered to as heterotrophs 3. Scavengers are tertiary consurners 4 Bacteia are scavengerS S. Vulture and crovw areexarnples of herbivoes FOOD CHAIN ln nature, some animalseat plarnts whereas some eat other anitnas link them with cach other, Consider the followiny, link between phate Plants Grasshopper frog Fig.34 A sirnple fochait Notethat sequence.A grasshopperfeeds nn the link follows a een pharts, kis etes sy fo Thefrog becomes the food for a snake, and finally the sake is eten byan ege The fs gives us an idea about the transfer of food energies froTn the herbivnns tthe catsivN d A food chain a sequence which shows how iving hinys is in an envirmment at rdatd to t according to their feeding babits. AIl food chains begin wth plarts, as plants make theie esfod by photosynthesis. Aninals eat either plants or other anirnals. The atrows in a foodd chais skw s direction. All animalsdepend upon plants either directly o inditeetty Thus, a simple food chain can also be gíven as: ProducerPrinary Secondary Tertiary Consumer Consumer Corsurner (Plants) (Snait) (Fro) (Kingfishe) Vultute Let us consider another example of a food chain (Fig, 3.5).Here, the grassis eaten by the grasshopper. The grashopper is eaten by a rat. Therat is eaten by a snake, The snake gets eatern by an eaple or vulture. An eayle or vulture when dies is decomposed by the deconposers,such as mushrooms. VWhat do you think will happen if Mushoo there are no green plants? 42  Quick check 2 Ruild the food chains by numbering the living things correctly. 1>2>3>4 a) b) Mouse 2 Lion Plants Goat 2 Owl Grass 2 Caterpillar Jackal ( Food Web Food web basically several is interlocking and independent, food chains in an organism in the ecosystem. Each living ccosystem is a part of multiple (different food) instance, a grasshopperchains. For and giraffe are herbivores. Similarly, different herbivores we seethat there are a lot can be eaten by different carnivores. Thus, of food chains that prevail in an ecosvstem overlapping and which are interdependent in nature. Hence, interconnecun chains that are wecan describe food web linked as a network of food togetherin one form or the other. solar Producers energy (green plants making nutrients with photosynthesis) Scavengers (vulture) red-tailed hawk Secondary Consumers e(carnivores) squirrel fox Primary Consumers (herbivores) Producers (green plants) (fungi) rabbit mouse decomposers (fungi and bacteria) detritus feeders (insects and worms) Fig. 3.6 A forest food web Detritus: The remains of something that has been destroyed or broken up 43  PYRAMID OFNUMBERS 7he pyamid of numbers a grapbical Carnivores ypreniatien that depicts tberelationship in terms f ohe mumber ofprotucers, berbivores and the Herbivores Hdeer Secondary sne, cGarniSat tbeis suecesie trophic level, You will observe that there is a decrease in the number Producers of individuals from the lower to the higher Irsect trophic levels. Different ccosystems have (Prirnary orer different pyramids of number. The three types ofpyramid of numbers are: Upright pyramid of number Partly Upright Oak tree Pyramid of Nurnber (Producer Partly upright pyramid of number Fig.3.8 Partly upright pyrarnid of number Invertedpyramid of number Inverted Pyramid ofNumber Upright Pyramid of Number This type of ecological Aquatic and grassland pyrarnid is seen in ecosystemshave thiS ype food chainwhere one parasitic of pvramid of number. The pyramid is upright primaryproducer supports numerous parasites because these ecosystems have numerous which support more hyperparasites. small autotrophswhich in turn support lesser herbivores. The herbivores supporta still smaller number of carnivores. Hyperparasites Tertiary consumer (Lion) pyramid Secondary consumer Parasites (Fox) Primary consumer Upright (Deer) Herbivores Producers (Grass) Pyramid of Number Producers Fig.3.7 Upright pyramid of number Partly Upright Pyramid of Nunber This type of pyramid of number is seen in the forest ecosystem.Here, the number of producers are lesser in number and support a greater number of herbivores. These herbivores in turn Inverted pyramid of number support a fewer number of carnivores. Fig. 3.9 Invertedpyramid of number 44 Ecology: The environment as it relates to lving organisms  But how do you think plants benefit from INFO HUB animals? on orinside the Organisms thatttive bodies of other living organSMs.are called parasites The different organisms in the forest alongwith Eor tapeworms are parasitesthat example, plantsand animalsare all interdependent. ive inside the bodies of some animals aad They the food digested bythese animals. depend on each other for feed on food,protection and The organismthat provides food and shelter shelter. Hence,it is IS called host. important to control this to a parasite biodiversity by managing the balance between thetwo. Eoeroy is transferred along food chains from Some of the ways of interdependence are one trophic level to the next. However, the predation, parasitism and symbiosis. amount available energy decreases from of one Predation: In tropbic level to the next. an ecosystem, predation is a biologicalinteraction where a predator (anorganism Energy flow in an ecosystem starts from the Sun that is bunting) feeds on its prey (the auhich produces all the energy needed for organism life. Then that is attacked). For example, in the food chain comes the producers, the autotrophs.These (Fig- 34),frog is the predator organisms harness the energy of the Sun for grasshopper, and the prey. While, frog is the prey for the convertit into sugars.These snake, organisms obtain the predator. 1009% of the energy they produce.The primary Parasitism: It is a consumers which eat the non-mutual relationsbip autotrophs get the between species, where one species, the parasite, next most but energy, this is only 10% of the benefits at the expense of the original energy that the autotrophs other, the host, get. Next, sometimeswithout the secondary killing the host organism. Fleas consumers, which eat the primary or ticks that live on consumers get nutrients, dogs and cats are parasites. but this is only 1% They live on theblood of the host animal. of the energy that was originally in the plant. Tertiary consumers, at the top of the food chain eatsecondaryand primary consumers, and they only get 0.1% of the energy. INFOHUB At every Flea eggs level of the energy pyramid, the Definitive host organisms only get 10% of the energy from LIFE CYCLE the previous level. OF DOG FLEA Flea larva INTERDEPENDENCEBETWEEN ORGANISMS We Flea pupa knowthat plants are very useful to humans Flea adult and Fig.3.10 An example animals. of parasitism Definitive host: An organism that supports a parasite 45  Symbiosis: It is an interation between two eof Dependence Plants on Animals dierent organisms living in dose physical Carbon dioxide: Animals take in of/ both. carbon oxyyen and association, typically to the advantage release dioxide while carbon breathing,This Symbiosis is a mutually beneficial relationship. dioxide in turn is utiliscd bytheplants For cxample, a group of soil bacteria called in the process of photosynthesis and oxygen i released. Rbizobia live in the root nodules of leguminous fix atmospheric Pollination: Animals help crops. In turn,these bacteria plants to reproduce usable form of nitrogen through Animals Such such as nitrogen turning it into pollination. insects, for the plants. birds and other animals help the plants by carrying the pollen grains to various places for pollination. Secd dispersal: The animals hclp the plants with the process of seed dispersal. The fruits are caten by animalsand birds.They then walk or fly to distant places and spread the sceds Root which cone out with their droppings. Some nodules seeds stíck to the furs of the animals or birds and are carried from one place to the other. ABIOTIC COMPONENTS OF THE symbioticrelationship ENVIRONMENT Fig. 3.11 An example of Abiotic' mean 'non-living' components on Plants and Dependence ofAnimals components. Sunlight, air, water, soil or indirectly, the abiotic components - Food: All anímals, directly temperature are some of depend on plants for their food. For cxample, of the environment.These components torm an and carnivores and habitat. important part of herbivores plants, cat the organism's oTnnívores feed on herbívores. carbon dioxide Sunlight Oxygen: The plants take in for all living organisms Sunlight is essential give out oxygen in for photosynthesis and in plants photosynthesise take in this oxygen on the Earth. Green the atrnosphere. Aniímals depend the presence of sunlight. All animals while breathing, for food, cither directly or indirectly. such as monkeys and on plants Shelter:Someanimals animals feed on plants. Flesh shclter. Some Plant-cating birdsdepend on plants for animas. the trees and live there. cating animals,in turn, cat plant-cating animalsmake holes in for all is the ultimate source of ofenergy There So, sunlight Birds build their nests on the trees. Length ofa day also influences living organisms. are anumber of insects such as grasshopper, and birds. poultry the reproductivecycle of noths and antsthat live on the trees. Poultry:Dorrestic fows,incuding hickens, ducks, geese, etc.  water that nutrients and waste materials move throughout the body. Water is one of the important factors for seed germination.Water is the habitat for many organisms such as \otus, water whalc,shark and scahorse.Some lily, fish, organisms nccd oxygen dissolved in water to survive. Plants make their food in the presence Fig. 3.12 of sunlight Air of Air is a mixture several gases. Oxygen and carbon dioxide are two main gasesthat support ife on the Earth.Plants need carbon dioxidefor preparing their food by photosynthesis.Both Fig.3.13 Deer ts and animals drinking water use oxygen for respiration. Carbon dioxide is exhaled by animals. It Humidity is a quantity it is representing the added of water vapour amount also to the environment by burning of in the atmosphere or in a gas. fuels. Oxygen is given out by Humidity also affects the type of plants during organisms in an area. photosynthesis. What is the percentage of following Soil gases in the atrnosphereOxygen and Carbon dioxide? Soil is the top layer of the Earth's surface in which Moving air is called wind.VWind is one of the plants grow.It is a mixture of finerock particles, agents of dispersal of seeds.Air also helps birds minerals, microorganisms and decomposed to fly. bodies of plants and animals. Soil also contains Name one seed dispersed by vwind. water. Soil provides the medium for plant growth.It Water is the habitat for many animalssuch as snails, earthworms and The human body is about 60 %water by weight. ants. Soil can be of various blood and even bones Ypes clay, sand,silt and loam. Our body cells, tissues, contain water. Like human beings, bodies of all Temperature living organisms contain water. Plants absorb Temperature a is measure of warmth or coldness water from the soil through their roots. Water of a substance or environment. Sun's heat reaches 1S a raw material essential for photosynthesis. the Earth and makes it warm. Being just at the Water acts a medium of transport in the as right distance from sun,our the planet Earth bodies of both plants and animals.It is through has a temperaturethat favours the growth and Teaching Tip: lt can be explained to students that fat tissue does not have as much water as lean tissue. In adult 47 women, fat makes up more of the body than men, so they have about 55% of their bodies made of water.  the FOREST ECOSYSTEM of living oganisms, Moreovet, survival the heat oie third of the Farths around it helps fo retain Foreets cover of air land. T layer ot let it ecape. Wihout air, the Earth Tand arva odmolly ty trea andplent f and the Earth, places plants ard too cold to live' On vast varicty of forct. A arinrals e would be cold while those ncar scen in a forest. Depending on the kin near thepoles are very That is why, very few vegetation, forests can be classifiedinto the middlepart are hotter tropic rainforest, temperate and boreal forests. organisms live in polar regions, Temperature of plants and animals attects the distribution Tropical Raintorest onthe Earth, The climatein a tropical rainforest is hot and receives heavy rainfall. The heavy rainfall caUs flooding, soil erosion and rapid lcaching f nutricnts from thc soil. INFO HUB Tropical rainforests are found along the between Tropic of Cancerand equator, Sbjet Tropic of Capricorn C life that favours Earth has a temperature Fig.3.14 The plant-mutrimyfrom te saluble changes with Chelossafaatu a body temperature irrigation, is rferrod ta cobose and Animals soil, due to rain are called cold-blooded the outsde temperature most reptiles and leacbing insects, aninals,For cxample, and quickly use up any Plants grow rapidly body temperature docs amphibians. Animals obose material lett from decomposing plants are called organic outside temperature the not change soith and animals.As a result, soil is nutrient-deficient For example, birds and suarm blooded animals. isvery thick, and most iamal FlorThe tropical rainforest to penetrate theforest comnponents notmuch sunlightis able Thus,we nowknow that the biotic the top of the components. floor.However, the plants at ate closcly dependent on abiotic Quick Check 3 Fill in the blanks. 1. Pants are (teriary consumersproducers) upright pyramid of number (uprightipartiy 2 Aquatc ecosystems have is a mutually beneficial relationship Prgdatiorn/Symbiosis) 4 Annas help the plagswith the process of (seeddispersal'photosynthesis 5 The aoutof water vapour in the atrmosphere is called (humtáitysoil) The measue of warmth or coidress of a substarnce is called (sunlighttemperature) Leaching: eproess ofpecolaung *Nute: Cuick Check 3 1s before the topic Forest ecosystem rainforest get about 12 hours of intense every day sunlight Temperate Forests throughout the year. In a rainforest, Temperate forests correspond to forest many trees such have special aS mangroves. concentration formed in the northern and supporting roots like Due tothe stilt roots. southern hemispheres or in temperate regions. thick The main characteristics include: wide leaves, Canopy of large trees, small plantsclimb on others to reach the large and tall trees, large wild canopy and non sunlight. Many creepers and seasonal vegetation. The temperate deciduous The plants cimbers grow in a in a rainforest. rnforest have a forest has four smooth bark seasons--winter,spring, summer and leaves. Rain falling on and autumn. Animals and plants have special down from the the forests drips leaves and trickles down adaptations to cope with these yearly changes. trunks to the the tree ground. The plants roots to help have shallow Adaptation meansthe ways in which plants and capture nutrients level of the from the top animals change to suit the conditionsin which soil. they live. A rainforest has many Flora: The word deciduous' means epiphytes such as that the epiphytic orchids. Epiphytes areplants leaves on these trees change on other plants thatlive colour in autumn, and insteadof fall off in collecting winter and grow back with roots, water again in they obtain ln from water and pring. winters, these forests get rain and from debris minerals snow that collects and hail so deciduous on the plants lose_their supporting plants through leaves to conserve hair on water. their leaves. Deciduous trees Fauna: Rainforests have broad are leaves to capture tremendously rich in from the energy animal life. Sun and convert it to Rainforests are populated with Some food by photosynthesis. insects like of the food is butterflies; used for growth arachnids like spiders; and reptiles like snakes; some is stored.They store amphibians like frogs; food in the roots birds for the like parrotsand mammals ikesloths. winter when the tree has no and cannot make any leaves food.Some deciduous trees are black walnut,red maple, poplar, birch and willow. Faüna: Animals living in these forests adjust to cold winters by hibernating or During winter, leaves migrating, fall off trees, leaving animalswith less covers to hide themselvesfrom predators. Some of the animals found here are a. Mangrovetrees the black bear, raccoon,wild boar, turkey and rat snake. b. Sloth Fig. 3.15 Flora and fauna of tropical rainforests Trickle: Run or flow |Debris: The remains of something that has been destroyed or broken up 49  droop downward to help shed excess snow am3 the branches from breaking. to keep that live in the Fauna: Someanimals coniferous are hawks, owls, lynxes, snowshoe forest rabbits Most of the animals and wolverine. migrate on the onset ofwinters. a. Red maple a. Fir tree b. Rat snake forests temperate Flora and fauna of Fig.3.16 Boreal forests forest or snow also known as taiga Boreal forests by coniferous characterised forest is larches. of pines, sprucesand mostly has consisting The are evergreen. taiga trees Most of these Some parts b. Lynx and warm summers. cold winters boreal forests frozen sub of 3.17 Flora and fauna have a permanently Fig. of the conifers Drainage is poor called permafrost. layer of soil due to layers of rocks Quick Check4 the permafrost or statements due to acidic and the following The soil is State whether below the soil surface. False (F). just a deep layer of are True (T) or by It is covered rainfal. mineral-poor. receive heavy rainforests conifer needles. 1. Tropical partially decomposed of the Earth's trees one-third a taiga forest have 2. Forests cover Most trees in Flora: Surface. which prevent water loss leaves leaves. with needle-like trees have narrow snow more casiy 3. Deciduous freezing weather and shed as snow forest. in is known Waxy coating on needles 4. Boreal forest than broad leaves. is very colour boreal forests The leaves aredark in 5. The drainage in prevents cvaporation. heat to be absorbed. Coniferous well maintained. allowing more solar spruce)have branches that trees (pine, fir and 50