important component in studying ecology

1. Field work • important component in studying ecology • enables us to find out the numbers and species of plants and animals living in a community and to gain information about the ecological interactions there • the emphasis is on investigation rather than collecting samples

2. Safety and ethical guidelines on field study

3. Dos 1. Before setting out, listen to the weather forecast and wear suitable clothing. Go through a personal checklist and an equipment checklist. Bring enough water and some food. Prepare a journey plan and let others know where you are going and the time you are expecting to return home.

4. Dos 2. Follow existing paths. Repeated trampling of areas other than paths can be harmful to the ecosystem and can prevent the regeneration of vegetation which may result in soil erosion. 3. Bring a pen and a notebook. Observation and good data records are the keys for successful field studies.

5. Don’ts 1. Litter – take home all your rubbish or dispose of it properly in litter bins. Plastic bottles and plastic bags are reusable containers, so please reuse them if possible. Remember the 3R-principles for treating litter: Reduce, Reuse and Recycle. 2. Light fires – fire is destructive to the ecosystems, and may threaten your own life.

6. Don’ts 3. Harm any wildlife – each creature, however small, has a role in the ecosystem and should be respected. Do not kill insects or snake just because of their unpleasant appearance. It is illegal to kill or wilfully disturb any living organisms inside country parks or special areas.

7. Don’ts 3. Do not collect anything from the countryside without permission. If you come across injured wildlife, report it to the Agriculture, Fisheries and Conservation Department or the Kadoorie Farm & Botanic Garden.

8. Don’ts 4. Interfere with natural structures that are made by wildlife – spiders’ webs, termite mounds, birds’ nests are parts of the ecosystem and are essential for the survival of these animals (e.g. most birds cannot breed without nests).

9. Distribution and abundance of organisms

10. Sampling • the study of a defined area (e.g. a habitat) by studying parts of the area • take several samples from a habitat, making the assumption that these samples are unbiased and representative of the habitat • to ensure that the samples are unbiased, they are selected randomly  random sampling

11. Sampling using a quadrat • one of the simplest ways of sampling a habitat • a quadrat: a square frame made of wood or metal • A quadrat

12. Sampling using quadrats • to use the quadrat… • Generate a random coordinates of the site • put the quadrat at the random location • Count the plants and animals inside it, ignore anything outside the quadrat • repeat the process again in different parts of the field

13. Sampling using quadrats • to use the quadrat… • calculate the average number of individuals per unit square for each species and measure the area of the habitat under study to estimate the density of each speices

14. Activity 19.5 Sampling using quadrats • limitations • it will be hard to count fast-moving animals, this method is limited to vegetation and slow-moving or stationary animals • the quadrat must also be placed on a fairly flat piece of land

15. Sampling using a line transect • this method is used to record exactly where each species or type of organism is found • a line transect can be made from a string marked at regular intervals • it is stretched across the habitat you want to examine • all the organisms touching the string are recorded with their distance from one end of the line called the ‘origin’

16. Sampling using a line transect • How to make a line transect, and illustrate the results with a profile diagram stake regular internal marks line transect 1 m origin graph paper height(m) soil 1 m 0 1 2 3 4 5 6 7 8 distance from origin (m)

17. Sampling using belt transects • a better method than line transect • belt transect is made by: • laying out two parallel strings, perhaps one metre or less apart and record the plants between them • or placing quadrats continuously or in regular intervals along a transect line Quadrat 1 Quadrat 2 Quadrat 3 Quadrat 4 Quadrat 5 • A belt transect 1 m

18. Sampling using belt transects • the distribution and relative abundance of different species along the belt transect can be studied • the results can be represented by a ‘kite’ diagram or histogram

19. Think about Sampling using belt transects • kite diagrams • histograms species 4 species 3 species 4 Percentage cover species 3 species 2 Percentage cover species 2 species 1 species 1 Distance along transect line (m) Distance along transect line (m)

20. Measurement of abiotic factors

21. Common instruments for measuring abiotic factors pH Light intensity Air movement • Light meter • pH meter • Anemometer

22. Humidity • Thermohygrometer Common instruments for measuring abiotic factors Dissolved oxgen Temperature Salinity • Refractometer • Electronic thermometer • pH meter

23. Field study

24. Field study 1 Studying a woodland Woodland is one of the three major types of vegetation in Hong Kong (the other two are grassland and scrubland). Most ecological processes, such as energy flow, materials cycling, effects of human impacts, relationships between organisms and adaptations, are available in woodland.

25. In this study, identification of all encountered animals and plants to species level is not necessary. Identify to species level only for those important species. For others, use common names or assign number to different species such as tree 1, shrub 1, shrub 2, spider 1 and so on. On the other hand, vary accurate data and a very large sample size is not necessary.

26. A. Aims of studying the living organisms on a slope 1. To understand the composition of a woodland. 2. To measure and record the abiotic factors that affect life. 3. To examine how organisms are adapted to the environment. 4. To investigate any interrelationships among living organisms in the habitat.

27. 5. To investigate how biotic and abiotic factors are related to each other, and how abiotic factors affect the distribution and abundance of organisms.

28. B. Precautions 1. Wear trousers and long-sleeved shirts. 2. Beware of swarm of wasps, bees and snakes. Do not irritate hives of wasps, bees or other wild animals. 3. Impose minimum disturbance to the woodland. Collect samples only when necessary. Whenever possible, identify the organisms in the field, or you may take photographs and identify them later.

29. 4. Wear gloves when collecting litter to protect your hands from certain invertebrates such as centipede.

30. C. Equipment (per group) Transect line 1 Measuring tape 1 Quadrat (50 x 50 cm) 1 Ranging poles with spirit Air net 1 level thermometer 1 Light meter 1 Compass 1 Plastic bags 5 Forceps 2 Digital camera 1 Beakers (100 cm3) 2 Sorting tray (white) 1 Digital hygrometer 1 Anemometer 1 Spade 1 Labels Protractor 1 Calculator 1 pH paper Evaporating dish 1 Sieves

31. D. Procedures Field work 1. Walk around and examine the habitat. Draw a sketch map of the woodland showing the location of the studied site. 2. Run a 20 m transect line across the area which can represent the woodland. 3. Along the transect line, measure the gradient of the slope at 2 m intervals. Use the results to draw a profile diagram.

32. 4. Select a suitable area of ground that is representative. Put a quadrat (50 x 50 cm) on the area. 5. Use the air net to catch flying animals near the transect line. Search for small animals in different micro-habitats such as under or inside a rotten log, on leaf surfaces, in flowers or in fruits etc. Whenever possible, identify and count the animals in the field (or you may take photographs). Presence of spider web and animal damage on leaves may provide useful information of animal distribution. Free the animals after the identification.

33. Collect all the litter within the quadrat and put it into a plastic bag with labels. Bring it back to school for further investigation. • Measure the abiotic factors: • (a) Use the light meter to measure the light intensity • (i) above canopy layer (you can measure this at open space outside the woodland), • (ii) below the canopy layer but above the shrub layer, and • (iii) below shrub layer.

34. (b) Use the thermometer to measure the temperature • (i) on the surface of litter layer, • (ii) in open air within the woodland, and • (iii) in open air outside the woodland. • (c) Use the digital hygrometer to measure the humidity • (i) on the surface of litter layer, • (ii) in open air within the woodland, and • (iii) in open air outside the woodland.

35. (d) Use the anemometer to measure the average wind speed inside and outside the woodland. • 8. Use a spade to dig up the top 5 cm of soil within the quadrat. Place the soil on the sorting tray and sort out the animals for identification. • 9. Collect about 1 kg of soil and put it into a plastic bag. Bring it back to school for further investigation.

36. 10. Examine the plants: • (a) Trees which touch or have their perpendicular crown projections overlying the transect line should all be included in you investigation. • (b) For each tree included in your investigation, measure its height, diameter of trunk (at breast height), crown length, crown width and also record its corresponding position on the transect line. crown width crownlength treeheight perpendicularcrown projection

37. (c) Epiphytes on a particular tree along the transect line should also be recorded. Brief description is enough. • (d) Record all shrubs which touch, overlie or underlie the transect line. For each type of shrub, only record their heights and corresponding positions on the transect line. • (e) Include all fungi, herbs, grasses, mosses, ferns growing near the transect line. Record only the approximate number of species encountered and notice the most abundant species.

38. Laboratory work • Soil analysis • (a) Place the soil sample on a sorting tray and sort out the animals for identification. • (b) Record the colour, smell and nature (hard, soft, loose or sticky) of the soil. • (c) Add a little soil sample to a beaker. Add some distilled water and test its pH.

39. 2. Place the litter in a tray and use forceps or glass rod to sort out the animals. Identify and count them. 3. Try to find out the adaptive features shown by the living organisms collected from the site.

40. E. Discussion 1. Construct a slope profile of the woodland. 2. Use the plant data to draw a profile diagram. The diagram should be able to show the position and relative sizes of the plants including trees, shrubs, herbs and grasses. 3. How can we explain the distribution pattern of organisms in terms of the physical limiting factors?

41. 4. Propose food webs for the woodland. 5. How do the organisms adapt to living in the woodland? 6. Are there any effects of human impact on the woodland?

42. Field study 2 Studying a freshwater stream The major factor influencing the distribution and abundance of living organisms in a freshwater stream is the directional flow of water from upstream. In order to survive in streams, organisms there may have different morphology and physiology compared to those in terrestrial habitats. Teachers should ensure that any stream is not polluted with faecal matters before allowing students to work on it.

43. A. Aims Refer to the aims of Field study 1, try to list the aims of studying a stream. B. Precautions 1. Wear canvas shoes with adequate soles. 2. Wear trousers instead of shorts. Wear long-sleeved shirts. 3. Be careful of slippery rock surfaces.

44. C. Equipment Metre-rule 1 Hand lenses 2 Compass 1 Light meter 1 Thermometer 1 Rubber gloves 1 pair Flow meter 1 Fish nets 2 Trowel 1 Forceps 4 Soft brushes 2 Plastic bags 2 Sorting tray (white) 1 Transect line Beaker (100 cm3) 2 Reagent bottles 2 Vials of different sizes 6

45. D. Procedure Field work 1. With the help of your teacher, select a section of a stream for study. Fix a transect line across the stream. Record the nature of the bottom and depth at suitable intervals along the line. Be sure to put any rocks you have moved back to their original position. Use the data to draw a cross sectional profile diagram.

46. 2. Draw a sketch map of the area in which you are working. Indicate the flow direction, composition of substrates (sand/gravel/pebbles/boulders), position of the trees which are related to the habitat (Do the trees provide shading to the stream bed?). 3. Record the appearance of the area of your study, including water colour, smell and any floating material or foam.

47. 4. Measure the abiotic factors: • Light intensity (on the water surface and at the bottom of the stream) • Temperature (both air and water) • Average current speed (For each factor, measure at different points and consider taking an average) 5. Fill bottles with stream water and bring them back to school for chemical analysis.

48. 6. Use a trowel to collect about 1 kg of sediment from different parts of the bottom of the stream. Put the samples in plastic bags and bring them back to school for further investigation. 7. Record approximate numbers of plants (including algae if possible). Note down their roles in the ecosystem. Collect some specimens for further microscopic investigation.

49. 8. Find, identify and record animals found on the water surface, in the water, on the surface of rocks at the bottom and beneath the sediment at the bottom and on the water plants. Put them in a white sorting tray for identification and observation. Record their external features, classification and ways of adaptation. All animals should be placed back into the water before leaving the site.

50. Laboratory work 1. Analyse the water sample in the laboratory. Measure the pH, dissolved oxygen, ammonium content, phosphate content, total suspended solids and chemical oxygen demand. 2. Analyse the particle sizes of the sediment. Use the information to write a report. Concept Map