Chapter 8 : dynamic ecosystem


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Chapter 8 : dynamic ecosystem

  3. 3. ABIOTIC COMPONENT The non living components of an ecosystem pH value Temperature Light intensity Humidity Water Topography Microclimate
  4. 4. pH value • the pH value of soil and water has important effect on the types of organisms • a drastic change in pH may kill the organisms Temperature • affects the physiological activities of organisms • most of organisms cannot tolerate extremes temperatures
  5. 5. Light intensity • affects the distribution and growth of organisms • the sun is the source of energy • some plants show adaptation to reach the light • most animal need sunlight but some show adaptation to live in the dark Humidity • is the amount of water vapour in the air • plant and animal that live in wet have special adaptation
  6. 6. Water • important for living process in all organisms • but some organisms are able to survive under condition where there is a limited supply of water such as camel and cactus Microclimate • Refers to local climate in a small area • Humidity, temperature and light intensity affect the microclimates
  7. 7. Topography • influence local climate and soil development • the main factor is altitude and aspect • higher altitude : lower atmospheric pressure and temperature so different plants growing at different altitude • sloppy areas receive more sunlight compared to valley •Gradient : steepness of a slope cause a faster drainage and run off the water
  8. 8. BIOTIC COMPONENTS The living components in an ecosystem Producers Consumers Decomposers
  9. 9. Producers • mainly green plants • manufacture complex organic food substances from raw materials •Convert light energy → chemical energy • affect the lives of other organisms because they start the food chain and food web
  10. 10. Consumers • Obtain their energy from the other organisms they feed on • Cannot make their own food : heterotrophs (herbivores, carnivores, omnivores, saprophytes or decomposers ) Decomposers • break down dead organisms through the decomposition process • the product in this process is returned to environment and will used again by green plants • saprophytic fungi and saprophytic bacteria
  11. 11. CLASSIFICATION OF BIOTIC COMPONENTS INTO TROPHIC LEVEL Food chain • A series of organisms through which energy is transferred in the form of food • trophic level - each stages in the food change and can be shown in the form of pyramid number • pyramid number show the interaction between a producers and consumers and the number of organisms • during food transfer from one trophic level to next level a lot of energy is lost ( through undigested matter, excretory products, lost as heat during respiration) • 90% : energy is lost • 10% : transfer from one trophic level to the next
  12. 12. Food web • in a community, food chains are linked together to form a food web • gives a more complete picture of the feeding relationship in a community
  13. 13. INTERACTION BETWEEN ORGANISMS Symbiosis Saprophytism Prey-predator Competition Commensalism Mutualism Parasitism
  14. 14. Symbiosis • Interaction in which there is a close and permanent relationship between two specific organisms • One species : benefits • One species : unaffected, harmed or helped
  15. 15. Symbiosis Commensalism • ( + , 0 ) • example - clown fish & sea anemones - pigeon orchid Mutualism • ( + , + ) • example - lichens - root nodules Parasitism • ( + , - ) • example - flea - tapeworm + : benefits 0 : neither benefit nor harm - : harm Epiphytes (plant) Epizoics (animal) Ectoparasite Endoparasite
  16. 16. Saprophytism A type of interaction in which living organisms obtain food from dead and decaying organic matter Enzymes are secreted onto the food and digestion occurs outside the cell Example : saprophyte (plant) : fungus saprozoite (animal) : earthworm
  17. 17. Prey-predator (+ ,- ) • predator - kills other animal for food - larger and fewer in number than its prey - the number of predator affects the size of prey population • prey - the animal that kill by the predator - must be able to protect itself from being killed • example : owls & snakes, frogs & snakes
  18. 18. prey predator Time Number
  19. 19. Competition An interaction between organisms which live together In a habitat and compete for the same resources that are in limited supply Intraspecific Competition between individuals of the same species Compete for light, water, space and nutrients Example : Bryophyllum sp Interspecific Competition between individuals of different species Example : paramecium aurelia & paramecium caudatum
  20. 20. Number the winner the loser Time
  21. 21. Interspecific competition
  22. 22. ECOSYSTEM • An ecological system formed by the interaction of living organisms and their non-living environment • Example : Mangrove, swamp, desert, marine forest THE PROCESS OF COLONISATION AND SUCCESSION IN AN ECOSYSTEM COMMUNITY • A population of organisms living together within the same habitat • represent biotic components of an ecosystem •Example : various group of organisms living in forest
  23. 23. POPULATION • A group of individuals of the same species occupying the same habitat • expressed by density •The rate of change of a population density depends on birth rate, death rate and migration SPECIES •A group of closely related organisms which are capable of interbreeding to produce fertile offspring
  25. 25. HABITAT • The place where the organism lives • organism obtain its food, shelter and reproduces in its habitat • example : ponds, rivers, forests • within an ecosystem there will be several habitats • microhabitat : smaller division of an a habitat
  26. 26. NICHE • Is the function of an organism or the role it plays in the habitat • organisms can live in the same habitat but they occupy different niches • includes its habitat, its interaction, the types of food it consumes, the range of temperature it tolerate and the spaces it occupies •Example : a caterpillar and aphid live in the same habitat (caterpillar eats the leaf but aphid sucks sap from the leaf)
  27. 27. <> COLONISATION & SUCCESSION IN DISUSED PONDS How does a disused pond become tropical rainforest ?
  28. 28. Mangrove swampPond
  29. 29. LEARNING OUTCOMES  Explain the process of colonization,  Explain the process of succession,  Identify the successors in an ecosystem,  Identify the dominant species in an ecosystem  Identify the adaptive characteristic of pioneer species,  Identify the adaptive characteristics of successors,  Explain the changes in habitat caused by pioneer species,  Explain the changes in habitat caused by successors at every level of succession until a climax community is reached,  Relate the abiotic components with the biotic components in an ecosystem during the processes of colonization and succession.
  30. 30. COLONISASION  Occurs in newly formed areas where no life previously existed  The first colonisers : pioneer species  Special adaptation of pioneer species 1) hardy plant 3) have good dense root system (bind sand particles and hold water + humus) 4) have short life cycle 5) when die, their remains add to humus content  Examples : grasses, ferns & sedges
  31. 31. SUCCESSION  The process in which one community changes its environment so that it is replaced by another community  The gradual & continuous process  Leads to a final and stable community which is in equilibrium with its environment and is known as climax community  Successor species : a series of plant that replaced the pioneer species (herbaceous plant)  Successor : 1) grow bigger than pioneer thus reduced the amount of sunlight 2) have small wind- dispersable seeds (able to spread and grow rapidly) 3) can change the structure and quality of soil for larger plant to grow example shrubs
  32. 32.  Dominant species : grow faster and dominate the slower growing pioneer and successor species  Dominant species turn modify the environment which allows larger tree to grow  The larger trees provide shade and the shrubs cannot compete and are replaced by forest floor species  Ecological succession leads to a relatively stable community which is a climax community EXAMPLE : From bare ground → forest
  33. 33. COLONISATION & SUCCESSION IN DISUSED PONDS 1 Submerged/ sunken plant Plankton  Begin pioneer species which is submerged plant like Hydrilla sp., Cabomba sp., Elodea sp.  Submerged species are autotrophs (carry out photosynthesis)  When they die, they contributes debris/humus (which supplies nutrients for next group, successor)  The decomposition of dead pioneers species & soil erosion will add silt & reduce water level  The new environment is now suitable for 1st successor (floating plant)
  34. 34. 2  The floating plant like Lemna sp., Eichornia sp., Nymphea sp. will replace the pioneer group  They have broad leaves which cover the water surface  The pioneer group receive less light for photosynthesis  Thus, the population of pioneer group decreases  The accumulation of humus increases gradually  The pond become shallower  This leads to the growth of 2nd successor (emergent/amphibian palnt) Floating plant
  35. 35. 3  The emergent plant such as cattails & sedges (Thypa sp., Cyperus sp.) will replace the floating plants  They can live both water and on land  In earlier stages, these plant grow near the pond side  As the accumulation of humus and silt increases, they will dominate further in until the whole pond becomes land Emergent/ amphibian plant
  36. 36. 4  The accumulation of humus makes land more fertile  The creepers, herb plants and shrub will replace the emergent plants  The land now covered by bushes Grasses
  37. 37. 5  Over a period of time, the bushes will replaced by a primary forest  Finally, it reaches the climax community  Example : tropical rain forest in Malaysia
  38. 38. Hydrilla sp. (water weed) Elodea sp. (water weed) Cabomba sp. (fan wort) Submerged/ sunken plant
  39. 39. Lemna sp. (duck weed) Eichornia sp. (water hyacinth) Nymphaea sp. (water lily) Floating plant
  40. 40. Thypa sp. (cattails) Cyperus sp. (sedges) Fimbristylis sp. (sedges) Emergent / amphibian plant
  42. 42. MANGROVE SWAMP  Found in tropical & subtropical regions where freshwater meets salt water  Characteristics : 1) Soft & muddy soil 2) High concentration of salt 3) Low level of oxygen 4) Exposed to high intensities of sunlight & strong wind
  43. 43.  4 species of mangrove : 1) Avicennia sp. 2) Sonneratia sp. 3) Rhizophora sp. 4) Brugeria sp.  The mangrove plants are well adapted to the harsh conditions of these regions.
  44. 44. ADAPTATIONS OF MANGROVE PLANTS PROBLEMS ADAPTATIONS Soft, muddy soil Strong coastal wind Avicennia sp. : underground cable roots (long & branch) Rhizophora sp. : prop roots (aerial roots)- for anchor & aeration Waterlogged conditions of soil (↓ amount of O2) Avicennia sp. : breathing roots (pneumatophores), grow vertically upwards Gaseous exchange through lenticels (on the bark)
  45. 45. Direct exposure to the sun (↑ rate of transpiration) Leaves are covered by a thick layer of cuticle Leaves are thick & succulent (able to store water) High salinity of the sea water (soil hypertonic compared to the cell sap of the root cells) The cell sap in the roots cells has a higher osmotic pressure (hypertonic) than the soil. The excess salt is excreted as crystalline salt from hydatodes (pores on the lower epidermis) Seeds which fall onto the ground die (submerged in the soft & waterlogged) Viviparity : seeds are able to germinate while still attached to the mother plant
  46. 46. Props roots Excretion of crystalline salt from hydathodes Viviparity Pneumatophores Cable roots
  47. 47. Pioneer species Adaptations : • pnematophores • aerenchyma tissue • viviparous seedlings Successor species Adaptations: • props roots Successor species Adaptations : • buttress roots • viviparous seedlings • hydatodes • thick & succulent leaves • waxy cuticles
  48. 48. COLONISATION & SUCCESSION IN MANGROVE SWAMPS COLONISATION  The pioneer species : Avicennia sp. & Sonneratia sp.  The extensive roots system of Avicennia sp. & Sonneratia sp. collect sediments & organic matter  As times passes, the soil become more compact & firm SUCCESSION  Rhizophora sp. replaces the pioneer species  The arcing roots of Rhizophora sp. trap silt & mud, creating a firmer soil structure.  As times passes, the ground becomes higher & the soil becomes drier  Bruguiera sp. replaces Rhizophora sp.  The buttress roots of Bruguiera sp. Form loops which protrude from the soil to trap more silt and mud. The soil structure changes  Over time, terrestrial plants ( Nypa fruticans & Pandanus sp. replace Bruguiera sp.  As times passes, the tropical plants replace the terrestrial plants to form climax community
  49. 49. POPULATION ECOLOGY  Population ecology : a branch of ecology that studies the structure and dynamics of populations  Population density : the number of organisms per unit area of the habitat  Population density is affected by abiotic, biotic, birth rate, death rate immigration & emigration.  Sampling technique : estimate the total population size of the organisms  Type of sampling technique : 1) quadrat sampling technique (plant) 2) the capture, mark, release & recapture technique (animal)
  50. 50. Quadrat sampling technique (plant) • Used to estimating the size of plant populations • Made from a metal or a wooden frame • The quadrat is placed randomly in the ecosystem
  51. 51. FORMULA Frequency : the number of times a particular species is found present when a quadrat is thrown a certain number of times Frequency : Number of quadrats containing the species Number of quadrats X 100% Density : the mean number of individuals of a species per unit area Density : Total number of individuals of a species in all quadrats Number of quadrats X quadrat area Percentage coverage : an indication of how much area of the quadrat is occupied by a species. Percentage coverage : Aerial coverage of all quadrats (m2) Number of quadrats X quadrat area X 100%
  52. 52. Capture, mark, release & recapture technique (animal) • Used to estimate the populations of mobile animals • The method : 1) A specific animal sample is captured 2) The animal is marked (a ring, a tag or waterproof coloured ink/paint). 3) The marked animals are released into the general population 4) After suitable period of time, a second sample are recaptured 5 ) The number of marked animal is recorded
  53. 53. FORMULA Population size : (no of individuals in the 1st sample) X (no of individuals in the 2nd sample) no of marked individuals recaptured
  54. 54. 8.4 BIODIVERSITY  Refers to the diverse species of plants and animals interacting with one another on Earth  Taxonomy : a branch of biology concerned with identifying, describing and naming organisms  Organism are classified into 5 major kingdoms : 1) Monera 2) Protista 3) Fungi 4) Plantae 5) Animalia
  55. 55. Monera N : Monera C : - prokaryotic organisms (unicellular organisms) - no distinct nuclear membrane - The cell wall is present but lack of both membrane-bound nuclei and organelles - No tissues formation - They can be photosynthetic and non-photosynthetic E : Bacteria and cynobacteria
  56. 56. Protista N : Protista C : - have a nuclear and organelles that surrounded by membrane - may be unicellular or multicellular (algae and protozoa) - they can either be heterotrophic or autotrophic or even both - the cell of multicellular, are not specialised to perform specific functions in the organisms - some have both plant and animal characteristic E : Amoeba, Paramecium, Spirogyra and Chlamydomonas
  57. 57. Fungi N : Fungi C : - heterotrophic multicellular and some are unicellular - the cell walls of fungi contain chitin - the main bodies consists of network of thread-like hyphae called mycelium - do not chlorophyll - produce spores for reproduction - become saprophytic and some are parasitisms E : Mould (Mucor), mushrooms and yeast
  58. 58. Plantae N : Plantae C : - include all land plants - have a chlorophyll and carry out photosynthesis - multicellular - cells are specialise into tissues E : mosses, fern, conifers and flowering and non-flowering plant
  59. 59. Animalia N : Animalia C : - multicellular, heterotrophic and eukaryotes - animal cell do not have cell wall - mobile - do not have chlorophyll E : invertebrate, fish, reptiles,, bird and mammals
  60. 60. Kingdom Phylum Class Family Order Genus Species A group of organisms sharing certain basic features A group of organisms has closely related classes A group of organisms has closely related order A group of organisms has closely related families A group of organisms has closely related genera A group of organisms has closely related species A group of organisms are very similar, but they still have individual different The Hierarchy in the Classification of Organisms
  61. 61. Linnaeus Binomial System Classification 1. The modern system of naming animals and plants is based on the Linnaeus Binomial System develop by Carolus Linnaeus 2. The Linnaeus Binomial System of classification uses two words to name every species of organisms found. i) the first word in the name refers to the genus ii) the second word is the specific name 3. The characteristics of the system are as follows: i) both names are in Latin words ii) the name of the genus is written first and the first letter should be in upper case. The name of the species is written in lower case iii) both names are in italics if typed or underlined if written
  62. 62. Common name Scientific name Paddy Oryza sativa Durian Durio zibethinus Oil palm Elaeis guineensis Rambutan Nephelium lappacium Sugar cane Saccharum officinarum Chicken Gallus domesticus Toad Bufo melanosticus Frog Rana erythraeu Scientific names of some local organisms
  63. 63. Kingdom Phylum Class Family Order Genus Species Animalia Animalia Chordata Chordata Mammalia Mammalia Carnivora Carnivora Canidae Canidae Canis Canis familiaris lupus The Hierarchy in the Classification of Organisms Dog Wolf
  64. 64. The Importance of Biodiversity Importance of Biodiversity Shelter Clean drinking water Economic resources Clean air Sources of food Sources of medicine
  65. 65. 8.5 The impact of microorganisms on life  Microorganisms are tiny organisms that can only seen clearly under the microscope  Microorganism are classified into 5 major types : 1) Virus 2) Bacteria 3) Algae 4) Protozoa 5) Fungi
  66. 66. Bacteria N : Bacteria C : - unicellular organisms which have basic cell structure that includes a cell wall, plasma membrane and DNA that is not enclosed in a membrane - have a cell walls made of a polymer called peptidoglycan - certain bacteria form spores under unfavourable conditions - their shape may be spherical (coccus), rod shape, (bacillus) or spiral (spirilium) E : Lactobacillus sp. and Staphylococcus sp.
  67. 67. Algae N : Algae C : - photosynthetic eukaryotic plant-like organisms in the kingdom protista - have a chlorophyll and chloroplast - cell walls are made of cellulose - do not have leaves, stems or roots E : phytoplankton and Spirogyra sp.
  68. 68. Fungi N : Fungi C : - heterotrophic multicellular or unicellular - do not have chlorophyll - have a cell walls made up of chitin - fungi feed by secreting enzymes that break the surrounding organic material down into simple molecules before they are absorbed E : Mucor sp. and yeast
  69. 69. Protozoa N : Protozoa C : - unicellular organism - have nucleus, cytoplasm and plasma membrane - capable carry out living processes such as respiration, reproduction and excretion - they have flagella, cilia or pseudopodia to move E : Euglena sp., Paramecium sp., Amoeba sp.
  70. 70. Viruses N : Viruses C : - is not a living cell because it cannot survive or reproduce on its own outside the host - is composed of DNA and RNA, surrounded by a protein coat - can be crystallised E : T4 bacteriophage and tobacco mosaic virus
  71. 71. The Effect of Abiotic Components on the Activity of Microorganisms 1. Concentration of nutrient: - all microorganisms except viruses need nutrient and water for reproduction and growth. - without nutrient and water, microorganisms will die or form spores 2. pH - most bacteria prefer slightly alkaline condition (pH around 7.4) - moulds, yeast and protozoa (pH between 4.5 and 5.0)
  72. 72. 3. Temperature - most microorganisms are inactive at low temperatures - optimum temperature for most microorganisms is between 35 ⁰C and 40 ⁰C - beyond 60 ⁰C the growth of microorganisms is inhibited - microorganisms and their spores can only be destroyed when they are sterilized at a temperature of about 121 ⁰C 4. Light intensity - microorganisms prefer place which are dark or have a low light intensity - a high intensity of sunlight and ultraviolet rays can kill microorganisms - however, algae and photosynthetic bacteria need light to photosynthesis
  73. 73. The Role of Useful Microorganisms in the Ecosystem 1. Digestion: - in stomach, intestine or caecum of herbivors – have a bacteria that produce cellulases enzymes to digest cellulose to simple sugars - simple sugar absorbed by the herbivore and symbiotic bacteria - Termite have a Trichonympha sp. (flagellated protozoan) which is help to digest cellulose from the wood 2. Medicine - fungi – produce antibiotic (prevent the growth of bacteria) - Examples: Penicillium notatum – gonorrhoea, syphilis, lung infection Streptomycine – tunerculosis (TB) - dead bacteria or viruses – produce vaccine
  74. 74. 3. Decomposition: - bacteria and saprophytic fungus are microorganisms that feed on dead organic matter to get energy for their life processes. - play an importance role in the natural cycles of the elements such as the carbon cycle and nitrogen cycle 4. Industry - production of alcohol – using yeast through the fermentation process of sugar, starch or grains - production of vinegar – the bacterium, Acetobacter, acts on alcohol to produce vinegar (ethanoic acid) - Making bread – using yeast and sodium bicarbonate to produce carbon dioxide to rises the bread dough - Production of butter – cream is made sour by the action of bacteria. Bacteria split protein from the fat of the cream. This will enable the fat molecules stick together when the mixture is stirred strongly
  75. 75. 4. Industry - production of fermented milk – tairu and yogurt - the bacteria, Lactobacillus sp. and Streptococcus sp. and yeast - the milk will become sour and has smell of alcohol - production of vitamins – Vitamin B2 – yeast - Vitamin D – yeast and bacterium - textile industry – bacteria are use to decomposed the soft plant tissues leaving the plant fibres 5. Nitrogen cycle
  76. 76. List the function of microorganism in the nitrogen cycle above  Nitrogen-fixing bacteria Process: Nitrogen Fixation 1. Rhizobium sp. (in root nodule) Clostridium sp. Anabaena sp. Nostoc sp. (cyanobacteria) Azotobactor sp. (live freely in soil)  fix atmosphere nitrogen into nitrate (absorb by plant & animal)
  77. 77.  Putrefying bacteria and fungi Process: Decomposition 2. Help in putrefaction and decomposition of organic matter into ammonia NH3
  78. 78.  Nitrifying bacteria Process: Nitrification 3. Nitrosomonas sp. Nitrococcus sp. Changes ammonia into nitrite, NO2 - 4. Nitrobacter sp. Changes nitrite into nitrate, NO3 -
  79. 79.  Denitrifying bacteria Process: Denitrification 5. Denitrifying bacteria, changes nitrate into nitrogen
  80. 80. Pathogens, Vectors and Symptoms of Some Diseases Disease Pathogens Vector Symptoms Method of infection TB Bacteria - -Feeling tired -Constant coughing -Coughing out blood Droplet infection, dust, food and drinks that are contaminated Cholera Bacteria (Vibrio sp.) House fly -Vomiting -Serious diarrhea Water or food that is contaminated Food poisoning Bacteria, fungi House fly -Vomiting -Diarrhoea -Abdominal pains -Fever Water or food that is contaminated Cold Virus - - Fever, Headache - Muscle pain Through the air Ringwor Fungi - - Red spot on the skin - Itchiness Touch
  81. 81. Pathogens, Vectors and Symptoms of Some Diseases Disease Pathogen Vector Symptoms Method of infection Dengue Virus Mosquito, Aedes aegypti - High fever - Headache -Rashes - Pain at the joint -Bleeding from the nose, gums and tooth sockets Mosquito bite Mumps Virus - - Fever - Painful feeling when eating -Difficulty opening the mouth -Soft swelling in front and and below the ears Through the air
  82. 82. Disease Pathogens Vector Symptoms Method of infection AIDS Virus (HIV 1 and HIV 2) - - Fever -Loss of body weight -Tiredness -Candidiasis around the mouth and throat -Pneumonia -Kaposis’s sarcoma -Through sexual contact with a person infected with HIV - Transfusion of blood from a HIV victim -Sharing of injection needles Malaria Protozoa (Plasmodium) Mosquito - Fever -Headache - Muscle pain -Shivering Mosquito bite SARS Virus - - High fever -Cry cough -Shortness of breath or breathing difficulty -Pneumonia -Headache, muscular stiffness -Loss of appetite -Rash, diarrhoea -Droplet infection touch - Close contact with someone who has SARS -Body secretion
  83. 83. Transmission of Microorganisms 1. Through five ways : i) the air ii) touch iii) food iv) vectors v) water
  84. 84. Controlling Pathogens Methods of controlling pathogens Antibiotics Penicillin and streptomycin are chemicals produced by microorganisms which inhibit the growth or kill other microorganisms, especially bacteria Vaccines Are modified or weakened forms of bacteria or viruses. Is a suspension of dead bacteria or viruses which is inoculated into our body to induce the production of antibodies. Examples of vaccine are Sabine vaccine and BCG Antiseptics Are used on cuts and wounds to kill and inhibit the growth of microorganisms. Examples of antiseptics are acriflavin and iodine solution Disinfectants Use to kill microorganisms on the floor, buildings or furniture and sterilise surgical equipment. Example : phenol, formaldehyde and carbolic acid