1. SEPTEMBER 28, 2016 BIOLOGY 10 DM MRS. HAUGHTON
AN ECOLOGICAL STUDY
SEPTEMBER 28, 2016
BIOLOGY
10 DM
MRS. HAUGHTON

2. WHY PERFORM SUCH A STUDY?
Ecological studies are performed to study the relationships which the plant and animal populations in a habitat or ecosystem have with each other and the abiotic elements.

3. WHICH ECOSYSTEM?
A small ecosystem which does not contain too many species should be chosen e.g. a pond, small woodland, a piece of wasteland, grassland, sand dune or rocky shore.

4. MAPPING THE ECOSYSTEM
A scale outline map of the ecosystem is usually drawn first. As the study progresses, positions of the most abundant species, quadrats, sweep nest and line transects should be marked on the map.

5. METHODS OF COLLECTING ORGANISMS

6. Try not to kill any organisms being captured
Try not to kill any organisms being captured. If possible practice capture and release method.
Also try and leave the habitat as undisturbed as possible.

11. METHODS OF SAMPLING ORGANISMS

12. These include
Observation over time
Quadrats
Line transects
Belt transects
Sweep nets
Capture-recapture

19. ANALYZING DATA FROM AN ECOSYSTEM

20. Information collected from the use of quadrats can be used to calculate the following:
Species density: the average number of individuals of each species per m2.
Species cover: the percentage of ground covered by a species; used if individual organisms are difficult to count
Species frequency: the percentage of quadrats in which a particular species was found.
The results can then be tabulated.

22. SPECIES LISTS

23. Using the estimates of species density or species cover, together with results obtained from sweep nets and capture-recapture, lists of plant and animal species, in terms of abundance, can be made using the following DACFOR key.
D- dominant
A -abundant
C- common
F- frequent
O- occasional
R- rare
N.B. Dominant does not necessarily mean the most abundant species. It may be one that has the greatest effect on the ecosystem, e.g. the large trees are the dominant species in a woodland.

24. GOING OUTSIDE
OCTOBER 6, 2015
BIOLOGY
10 DM

25. The places where a particular type of organism is found make up its distribution. If the distribution of organisms is to be examined, every single plant or animal in the habitat cannot be counted. Instead, a small, representative part called a sample is concentrated on and then conclusions are determined on the whole habitat. The area to be studied should be small, such as a tree, a small pond, a small area of a field or of grass etc.

26. Ecological studies in various habitats are important for the following reasons: to make a list of all the plants and animals found in a particular habitat, to determine the abundance of these organisms, to construct food chains and webs based on information gathered, to determine if any of the organisms are in distress or in need of care.

27. Many factors such as amount of light, temperature and amount of water are important in determining where organisms live. In this field experiment, the influence of the environment on the growth of Donkey weed will be determined.

28. Information gathered can be used to determine:
Species density: the average number of individuals of each species per m2.
Species cover: the percentage of ground covered by a species; used if individual organisms are difficult to count
Species frequency: the percentage of quadrats in which a particular species was found.

29. Two pieces of equipment that can be used to gather information from a habitat during and ecological study are the line transect and the quadrat.

30. The line transect is a horizontal line, usually made of string, placed across an ecosystem or parts of any ecosystem.
The species of plants or slow-moving animals that touch the line at fixed intervals are recorded.

31. The quadrat is a square frame of known area (in this case 1m2).
It is placed several times, at random, within the ecosystem and the number of each species of plant or slow-moving animals within the boundaries or touching the sides are counted.

32. AIM
AIM: To compare the distribution of Donkey weeds in two locations on the John Gray High School Campus.

33. METHOD
Form groups of 4 and collect a quadrat for the group (1m2 and divided into 100 squares).
Place a 10m line transect in a grassy area behind the Uniform shop (between the shop and the chain-link fence of the field).
Lay the grid on the ground and line it up with the line transect as shown below.
Count the number of squares, out of 100, which contain the Donkey weed. This is the FREQUENCY.

34. METHOD cont.

35. METHOD cont.
Estimate the number of squares of the quadrat filled by the weed. If a square is only partly filled with the weed, take this into account in making the estimate. (The final figure arrived at is the percentage cover.
Flip the quadrat twice as shown in the diagram. After the second flip, repeat steps 4 and 5.
Continue this until a total of five readings is taken.
Repeat steps 2-7 on the grassy area between the basketball courts.
Tabulate the results.

36. RESULTS

37. An example is done for you below.

38. Quadrat 1 and 2 – Determine what percentage of the quadrat contains the species.
Total of 2 Quadrats – Quadrat 1 + Quadrat 2
Species cover – Total of 2 quadrats ÷ 2
Species frequency - # of Quadrats the species is found in.
When you are doing your calculations remember that you are doing FIVE Quadrat throws instead of 2. So calculate accordingly.

39. THE ROCKY SHORE
A typical rocky shore can be divided into a spray zone or splash zone (also known as the supratidal zone), which is above the spring high-tide line and is covered by water only during storms, and an intertidal zone, which lies between the high and low tidal extremes.

41. FOLIOSE ALGAE

42. PERIWINKLE

43. PERIWINKLE

44. MUSSELS AND BARNACLES

45. KELP

46. SEA ANEMONE

47. SARGASSUM (BROWN SEAWEED)