1 Syllabus • You are required only to study any one ecosystem, • and to know five animals • and five plants from your ecosystem. Biodiversity in Ireland Eco Eye, Series 9, Episode 2 3 The study of an ecosystem involves studying a number of sample habitats, as follows: 1. Mapping 2. identifying plants and animals 3. estimating the numbers of plants and animals 4. measuring the environmental (abiotic) factors 5. presenting the information What to observe in an Ecosystem Form a general overview of the area to be studied: Name the types of habitat within the ecosystem as each habitat will have its own populations of organisms which interact with each other and with the non-living environment. 5 Habitats within the Woodland Habitat: • • • • • • • Soil, ditch, oak aerial system, hedgerow, stone wall, oak root system. Page 1 of Ecology Report 6 Sketch of Ecosystem 1. Mark off the sample area by using poles with string or flags or by other visible markers 2. Draw a sketch of Ecosystem including features such as a road, wall, path, trees, bushes etc • Page 3 of Ecology Report 7 ecosystem-video 8 Organism Distribution 9 Plants Grasses Clover Buttercups Dandelions Daisies Nettles Poppies Thistles Dock Primrose Bluebell Animals H = herbivore, C = carnivore, O = omnivore, D = detritus feeder (detritus is dead and decomposing organisms) Earthworms (D) Caterpillars (H) Rabbits (H) Snails (H) Ladybirds (C) Badgers (O) Slugs (H) Bees (H) Foxes (C) Spiders (C) Wasps (H, C) Hedgehogs (O) Beetles (C, H, O) Butterflies (H) Thrushes (C) Aphids (H) Moths (H) Blackbirds (O) Qualitative survey A study determining the types of plants or organisms presence/absence in a habitat. 12 Carry out a qualitative study and note the diversity of flora and fauna in the ecosystem. 1. Use an identification Key to identify five animals and five plants 2. Note the habitat in which each organism was found. 3. Note a structural or behavioural adaptation of the organism. 4. Repeat this procedure to identify any five plants Identify •Page 4 of Ecology Report 13 Keys • A key asks questions which pinpoint one feature after another of an organism and, in a stepwise fashion enable us to identify it. • A simple key consists of pairs of questions to which you answer ‘yes’ or ‘no’ • You then look to the right of the set of questions, and using the number indicated, move down to the correct set of alternatives. • Continue to do this until a name is reached, often accompanied by a drawing, which matches your specimen 14 ECOSYSTEM FAUNA FLORA Woodland Owl, woodlouse, deer, centipede. Arum lily, oak tree, ivy, holly, moss Grassland Slug, snail, earthworm, Daisy, grass, field mouse, spider. dandelion, clover, plantain Hedgerow Butterfly, wren, rabbit, hover fly, hedgehog Herb Robert, blackthorn, cow parsley, goose grass, hawthorn. 15 Sampling 1. Random sampling – avoids bias and ensures that all areas within a habitat have an equal chance of being sampled by using a quadrat. 2. Systematic sampling – here samples are taken at regular intervals throughout the study area. This type of sampling is used where there is an obvious environmental gradient e.g. on a rocky seashore. 16 Quantitative survey • Quantitative Study provides a record of the numbers of plants and animals present in a sample area of the selected ecosystem • A quantitative study of plants and animals of a sample area of the selected ecosystem is carried out using 1. Percentage frequency and 2. percentage cover techniques. 17 Collecting plants and animals involves some of the methods shown in the table below Device Procedure Collected Knife Cut Plants, Trowel Dig Pooter Suck Plants, animals in soil Insects Beating Tray Shake bushes Crawling animals Pitfall trap Sink into soil or sand Crawling animals Sweep net Sweep through grass Insects A Quadrat • Usually square shaped • A frame that forms a known area usually 0.5m X 0.5m = 0.25m2 • Used for random sampling of plants or some slow moving animals 19 Gridded Quadrat Page 6 of Report 20 1. Determining the Percentage Cover of Sedentary Species • Can be measured using a gridded quadrat • An area of ground occupied by aerial parts of individual plants is examined and counted • Results are expressed as a percentage of the total quadrat area • Results can be presented as a pie chart or histogram. • More than one plant may be hit/ present in each grid, because plants overlap in layers 21 Percentage Cover procedure • Throw a quadrat at random • Record the plant hit at each sampling point • Repeat for a number of throws • Tabulate results Page 6 of Report 22 23 Quantitative % cover study of plants lant Name 1 2 3 4 5 6 Quadrat throw 7 8 9 10 Total Hits Total Points % Cove No. of hit s % Cover 100 Τot al no. of po int s 24 Tabulation of results Plant Name % Cover Buttercup 20% Daisy 12% Dandelion 14% Grass 46% Other 8% 1 10 1 2 12 0 2 6 6 6 5 2 3 1 2 6 12 4 Quadrat Throw 4 5 6 7 8 2 1 5 2 4 4 2 1 4 4 2 14 15 14 15 0 0 2 1 8 5 4 3 13 0 9 7 3 1 11 3 10 5 2 6 4 8 Total Hits 50 30 35 115 20 Total Points % Cover 250 20% 250 12% 250 14% 250 46% 250 8% Auto 25 Calculations Plot Graph % F r e q u e n c y X axis = Organisms Y axis = % Frequency Page 5 of Report Organisms 26 % Cover 8% 20% Buttercup Daisy 12% 46% 14% Dandelion Grass Other 27 2. Percentage Frequency • The probability of finding a named plant within the sample area in a number of quadrats • May be expressed as a percent of the total number of quadrats sampled 28 Percentage Frequency Procedure 1. Throw the quadrat randomly in the sample area 2. Record the presence or absence of a named organism within each quadrat 3. Repeat for a number of throws 4. Tabulate results Page 8 of Report 29 A quantitative study of plants Organism 1 2 3 Frequency 4 5 Frequency Quadrat throw 6 7 8 9 10 Total Frequency % Frequency No. of quadratscontainingorganism No. of quadratsthrown If percentage is required multiply frequency by 100 30 Tabulation of results Organism Name% Frequency Buttercup 50% Daisy 40% Dandelion 60% Grass 40% 1 Y N Y N 2 N Y N N 3 N N N Y Quadrat Throw 4 5 6 7 Y Y N Y N N Y Y Y Y Y N Y N N N 8 N N Y Y 9 Y Y Y Y 10 Total Frequency % Frequency N 5 5/10 50 N 4 4/10 40 N 6 6/10 60 N 4 4/10 40 % Frequency Auto Calculations 60% 50% 40% % Frequency 30% % Frequency 20% 10% 0% Buttercup Daisy Dandelion Grass Plant name 31 Conduct a Quantitative Survey of Plants and measure 3 abiotic factors Method: Line Transect 1. Put a measuring tape straight across the habitat 2. Walk beside the line and record the name of each plant touching the line at a certain point. 3. Repeat all along the length of the line transect. 4. Record 3 abiotic factors at each point 5. Combine the results to establish plant distribution. 6. Relate the distribution to the variation of the environmental factors. 32 33 To conduct a quantitative study of organisms along a belt transect Record % cover or number of a named organism in each quadrat along the transect Position of quadrat on belt transect Organism Name 0 % Cover = No. of hits 100 No. of points on quadrat 34 Measure Abiotic Factors Page 9 of Report 35 • Abiotic and biotic factors 36 Choice of Habitat Relationship between an organism’s suitability to its habitat and abiotic factors to include a measurement of any three abiotic factors: • pH • Temperature (air and ground or aquatic) • Light intensity • Water current • Air current • Dissolved oxygen • Mineral content • Percentage air in soil • Percentage water in soil • Percentage humus • Salinity • Degree of exposure • Slope 37 Observe the influential abiotic factors i.e. if it is exposed, sheltered, flat, on a slope, what direction does it face, influence of wind direction, intensity, drainage, etc. What is the influence of the nonliving(abiotic) components on the flora and fauna of the ecosystem? Page 9 of Report 38 Hygrometer - used to measure relative humidity – composed of a wet and a dry bulb thermometer. 39 Wind speed - Anemometer 40 Rainfall – Rainfall gauge is used to measure the amount of rainfall in mm. 41 Soil Temperature - Thermometer 42 Air Temperature - Thermometer 43 Light meter Used to measure the light intensity in units called lux. 44 Adaptations of Organisms to their Environment • Need to know structural, competitive or behavioural adaptation by organisms • Note an adaptation feature by any organism in your selected ecosystem 45 An adaptation is a process, change, method, characteristic or feature that an organism or species possesses, develops or evolves that suits/adjusts the organism to its environment to increase its chances of survival and reduce competition. Examples: • Ladybird warning colouration • Field mice are nocturnal: predator avoidance. • Page 11 of Report 46 Adaptation Benefit Beak Shape adapted to method of feeding e.g. pointed beak suitable for probing the ground for earthworms e.g. blackbird Slimy mucus Prevents e.g. snails, earthworms, etc. from drying out as it travels across dry terrain Body colour Provides camouflage and protects animals from predators e.g. woodlice Sharp claws For digging e.g. badger Tail Aids balance e.g. Squirrel on tree tops Bright body colour Deters predators e.g. ladybird (also releases toxic 47 fluids to deter predators) Hairy skin and fur Traps a layer of air – insulation Long canine teeth Kill prey and tear flesh Speed of predator Usually faster than its prey Long/big ears Good hearing to detect predator Nocturnal Predator avoidance e.g. field mice 48 Look for inter-relationships between the various living organisms in the ecosystem Explain and identify the role of the organism in energy transfers. Construct 1. food chains 2. A food web 3. A pyramid of numbers Page 10 of Report 49 Identify and use various apparatus required for collection methods in an ecological study Collection apparatus •Name: •How used: •Type of organism collected : Page 12 of Report 50 Biodiversity 51 Cryptozoic trap • A piece of wood or stone which is left on the ground. • After a suitable interval, animals such as slugs, woodlice, centipedes and millipedes will be found underneath. 52 Pitfall Trap • Jam jar buried in ground and covered with raised flat stone. • Used to collect ground surface animals insects, nocturnal and diurnal • e.g. spiders, centipedes, woodlice, beetles, etc. 53 Mammal Trap • Used to collect small mammals • e.g. mice, voles, etc. 54 Insect net • Used for catching flying insects. • The net part should be sufficiently long so that the mouth frame seals off the end of the net which contains the catch when the net is laid flat. 55 Sweep Net • Used to collect insects from tall grass 56 Beating tray • This is a white tray, cotton sheet or large sheet of white paper. • It is placed under a bush or tree branch. • The tree branch is shaken suddenly and vigorously. • Insects and other invertebrates fall onto the tray. 57 Pooter • Used for picking up very small animals. • Suck through mouthpiece (end of which is covered with muslin) and the animal is taken into jar through the hose. 58 Sieve • Organisms that live in leaf litter can be extracted by using a sieve with a mesh size of about 5 mm. 59 Tullgren Funnel • Used to extract animals from soil by heating the soil on one side • The animals are driven out of the soil by heat from a lamp and fall through a wire gauze 60 Collection Methods Method Used for collecting Small nocturnal animals e.g. slugs, woodlice Small animals that walk along Pitfall the surface of the ground e.g. beetles, spiders Tullgren Small animals from leaf litter and funnel soil samples e.g. worms, spiders Insects and spiders from the surface Pooter of leaves and leaf litter Sweep Insects from long grass and vegetation Mammal trap Small mammals e.g. mice , shrew Cryptozoic 61 Conduct a Quantitative Survey of fast moving Animals, e.g. fieldmouse population Day 1 1. Capture field mice using small mammal traps. 2. Record the number of captured mice e.g. 20. 3. Mark each with a dab of red paint on the belly surface. 4. Release each at their capture site. 5. Allow time for the mice to readjust to normal conditions. 62 Day 2 1. Capture field mice as before. 2. Record the number captured e.g. 18. 3. Record the number of recaptures (marked mice) e.g. 6. 4. Return the mice to the habitat at their capture site. 63 • the capture–recapture method, i.e. Number = C 1st × C 2nd _____________ M 2nd Calculation: Population = Day 1 Captures x Day 2 Captures Number of Recaptures = 20 x 18 6 = 60 mice 65 Analysis Prepare a brief report of the results obtained Identify possible sources of error in such a study. 66 Errors During Fieldwork 1. Bias: purposely choosing sample sites to get ‘good results’ or avoid work. 2. Too Few Sample Sites: may not give accurate representative results. 3. Surveyor Variation: students vary in ability, commitment and interest. 4. Equipment Quality: measurement and trapping success will be affected. 67 5. Changing Nature: results may depend on the time of day, season or year. 6. Chance: cannot survey every square centimeter so even with many sites some species may be missed. 7. Improper Trapping Techniques: all evasive species may not be captured and/or insufficient numbers captured in follow up surveying. • The study of an EcT 68 CHAPTER 6 STUDY OF AN ECOSYSTEM • A suitable key is used to identify and name organisms. • A qualitative study records the presence or absence of species. • A quantitative study records the number of each species. • Quantitative studies can be: • subjective (i.e. a personal judgement is made as to the number) • objective (i.e. an independent method of calculating numbers is used) • Subjective methods are not recommended, because they depend on individual judgements, which may vary from person to person. CHAPTER 6 STUDY OF AN ECOSYSTEM • Errors may arise in the study of an ecosystem in the following ways: • mistakes may be made in judgement and recording • conditions change in the ecosystem over time • accidental discoveries may be made • the habitats studied may not accurately reflect the overall ecosystem CHAPTER 6 STUDY OF AN ECOSYSTEM • A quantative study of plants in a habitat involves using: • quadrats, which are examined for: (a) Percentage cover of plants or stationary animals. (b) Frequency • transects: (a) Line transect (rope marked at intervals – record what touches the line). (b) Belt transect (equivalent to quadrats taken in a line – methods used are the same as for quadrats). CHAPTER 6 STUDY OF AN ECOSYSTEM Three sample abiotic factors Ecosystem Sample factors Rocky seashore Measured by Exposure to air Air temperature Wave action and exposed habitats Position on shore Thermometer Compare sheltered CHAPTER 6 STUDY OF AN ECOSYSTEM Three sample abiotic factors Ecosystem Sample factors Measured by Grassland Air temperature Thermometer Soil pH indicator Light intensity pH meter or universal Light meter CHAPTER 6 STUDY OF AN ECOSYSTEM Effects of abiotic factors Ecosystem Abiotic factor Influence Rocky seashore Exposure Different species of wrack and animals are found on different zones of the shore Temperature Periwinkles are arranged along a temperature gradient Wave action High wave action forces plants higher on the shore, and favours species with narrow fronds CHAPTER 6 STUDY OF AN ECOSYSTEM Effects of abiotic factors Ecosystem Abiotic factor Grassland Air temperature differences in different grassland plants (and animals) Influence Temperature parts of the will affect how well the grow Soil pH Soil pH will favour some plants and therefore some animals Light intensity at higher light Grasses grow better intensities CHAPTER 6 STUDY OF AN ECOSYSTEM • Organisms show many adaptations that allow them to survive in their habitat. • The results of a study can be presented in tables, lists, charts, graphs, diagrams, etc. • The results of a study should include food chains, food webs, and pyramids of numbers. • The work carried out in Activities 2–5 should be presented in a portfolio.