terrestrial sampling techniques

Exercise 2TERRESTRIAL SAMPLING TECHNIQUES

(Preliminary Report)

December 6, 2007

Submitted by:

Group # 2Gerardo, Mary Antonette

Maguslog, JustineSalumbre, Renz

Surquia, Joseph Michael

I. Introduction

II. Materials and Methodology Materials:

Worksheet (Appendix 3)

Barbecue sticks

Pencils and erasers

Straws

Scientific Calculator

Personal Computer

Methodology:

In this exercise, the groups are tasked to do sampling methods of three ways, the

transect, the quadrat and the point-quarter methods wherein groups are tasked to identify

how they interpret the data that will be collected. Procedures used to establish the said

methods are improvised for adaptation due to the unfavorable weather.

In the transect method, the group used the line intercept method as instructed in

the manual. The group designated three parallelling lines of straws across five plant

boxes measuring 30cm x 15cm or 150cm x 15cm and counted the species present per

individual line across and recorded it. The recorded data were then subjected for

computation via Related Density and interpreted the results.This method is illustrated in

Figure 1.

In the Quadrat method, the group made square plots in every plant box measuring

15cm x 15cm bounded by straws in a total of five or 75cm x 15 cm. The said square plots

covered only half of the plant boxes covered in the previous method. The group counted

present species, recorded it and treated the results via Related Diversity also. This method

is shown in Figure 2.

The quadrats were then divided into four each totalling twenty quadrants with a

measurement of 7.5cm x 7.5 cm of quadrants in each of the five quadrat. The species are

counted and recorded separately bounded by straws in all of the twenty quadrants. This is

the point-quarter method as shown in figure 3 and the data are interpreted thru the

computation of Relative Diversity.

III. Results and Discussion

Relative Density of Plant Species in Quadrat 1

63%

31%

6%

0%

0%

0%

0%

1234567


47%

20%

31%

0%

0%

0%

2%

1

2

3

4

5

6

7

Sp. 1 Sp. 2 Sp. 3 Sp. 4Bryophyllum pinnatum

Sp. 5 Sp. 6 Sp. 7

I. Quadrat Data Quadrat 1

Species Tally ni RDiSpecies 1 xxxxxxxxxx 10 62.5Species 2 xxxxx 5 31.25Species 3 x 1 6.25Species 4 0 0Species 5 0 0Species 6 0 0Species 7 0 0

Total 16# of species 3

Quadrat 2Species Tally ni RDi

Species 1xxxxxxxxxxxxxxx

xxxxxxxxxx 25 46.3Species 2 xxxxxxxxxxx 11 20.37Species 3 xxxxxxxxxxxxxxxx 17 31.48Species 4 0 0Species 5 0 0Species 6 0 0Species 7 x 1 1.85



0%

9%

85%

6%

0%

0%

0%

1234567


0%

0%

63%

31%

6%

0%

0%

1234567


0%

0%

22%

56%

0%

22%

0%

1234567

Quadrat 3Species Tally ni RDiSpecies 1 0 0Species 2 xxx 3 9.375

Species 3xxxxxxxxxxxxxxxxxxxxxxxxxxx 27 84.375

Species 4 xx 2 6.25Species 5 0 0Species 6 0 0Species 7 0 0



Species 1 0 0Species 2 0 0

Species 3xxxxxxxxxxxxxxxxxxxx 20 62.5

Species 4 xxxxxxxxxx 10 31.25Species 5 xx 2 6.25Species 6 0 0Species 7 0 0



Species 1 0 0Species 2 0 0Species 3 xx 2 22.22Species 4 xxxxx 5 55.56Species 5 0 0Species 6 xx 2 22.22Species 7 0 0


II. Transect Data Transect 1

Relative Density of Plant Species in Transect 1

139%

211%

329%

421%

1

2

3

4

Frequency of plant Species (Transect 1)

0

2

4

6

8

10

12

14

16

1 2 3 4 5 6 7

species

frequ

en

cy

1234567

Frequency of Plant Species (Transect 2)

0

2

4

6

8

10

12

14

16

18

20

1 2 3 4 5 6 7

Species

Freq

uenc

y

1

2

3

4

5

6

7

Species Tally ni RDiSpecies 1 xxxxxxxxxxxxxxx 15 39.47Species 2 xxxx 4 10.53Species 3 xxxxxxxxxxx 11 28.95Species 4 xxxxxxxx 8 21.05Species 5 0Species 6 0Species 7 0


Transect 2Species Tally ni RDi

Species 1 xxxxxxxxxxxxxxxxxx 18 40.91Species 2 xxx 3 6.82Species 3 xxxxxxxxx 9 20.45Species 4 xxxxxxxx 8 18.18Species 5 x 1 2.27Species 6 x 1 2.27Species 7 xxxx 4 9.09

Total 44# of species 7Relative Density of Plant Species in

Transect 2

142%

27%

320%

418%

52%

62%

79%

1234567

Relative Density of Plant Species (Transect 3)

126%

24%

330%

433%

50%

67% 7

0%

1

2

3

4

5

67

ç

Relative Frequency in Plant Species (Transect 3)

0

1

2

3

4

5

6

7

8

9

10

1 2 3 4 5 6 7

species

frequ

en

cy

1234567

Transect 3Species Tally ni RDi

Species 1 xxxxxxx 7 25.93Species 2 x 1 3.7Species 3 xxxxxxxx 8 29.63Species 4 xxxxxxxxx 9 33.33Species 5 0 0Species 6 xx 2 7.41Species 7 0 0


III. Point Quarter Data

Quadrat 1 Quadrant I II III IVSpecies 1 6 3 1 0Species 2 2 1 1 1Species 3 0 0 1 0Species 4 0 0 0 0

Quadrat 4 Quadrant I II III IVSpecies 1 0 0 0 0Species 2 0 0 0 0Species 3 4 5 7 4Species 4 0 2 4 4Species 5 0 0 1 1Species 6 0 0 0 0Species 7 0 0 0 0Total 4 7 12 9No. of Species 5

Species 5 0 0 0 0Species 6 0 0 0 0Species 7 0 0 0 0Total 8 4 3 1# of species 3

Quadrat 2 Quadrant I II III IVSpecies 1 10 8 6 1Species 2 2 6 1 2Species 3 2 7 5 3Species 4 0 0 0 0Species 5 0 0 0 0Species 6 0 0 0 0Species 7 0 0 0 1Total 14 21 12 7

# of species 3


Relative Density was computed using this formula:RDen= Total individuals species x 100

Total individuals all species

Results and Discussions

Line transect sampling is a popular method used to estimate population density.

The probability density of perpendicular sighting distances from randomly placed

transect lines are modeled to derive an estimate of population density.


For all three transects performed, species 1 is the most dominant plant

constituting 36.70% of the total population of species followed by species 3, 25. 69%,

species 4 22.94% and the rest. 14. 67%.

A quadrat is a frame of any shape that can be placed over vegetation so that cover

can be estimated, plant counted or species listed. Quadrats are used to define sample

areas within the study area and are usually made from strips of wood, metal or rigid

plastic which are tied, glued, welded or bolted together to form the quarat.

The quadrat method allows the user to define a fixed area, called a plot, within

which plant characters can be measured. Usually, a rectangular quadrat frame is used to

define the sampling area, although a quadrat can also be a permanently established area

within a site. Although the exact experimental design will determine where and how

many samples are taken, the procedure always involves measuring plant characters of

only those plants inside the quadrat. Quadrat sampling usually attempts to define plant

community characteristics for an area much larger than the actual area sampled. For this

reason, care must be taken to obtain samples that represent the entire habitat and that

eliminate the human factor. Usually this means employing an experimental design that

ensures random placement of the frame or permanent quadrat.

The purpose of using a quadrat is to enable comparable samples to be obtained

from areas of consistent size and shape.

For this exercise, five quadrats were surveyed and the following results were

obtained:

Species 1 is dominant in quadrats 1 and 2. On the other hand, species 3 is

dominant in quadrats 3 and 4. Quadrats 4 and 5 constituted 5 different species, quadrats 2

and 3 with 4 kinds of species and the least, quadrat 1 with 3 kinds of species.

Conclusion

The transect method simply refers to the establishment of a baseline along which

sampling is conducted. This method is typically used when there are apparent vegetation

differences from one point of interest to another within a sampling site. For example,

when sampling an area containing a river, wetlands, and uplands, establishing a transect

line that traverses these distinct habitats is a reliable means of collecting representative

data.

There are factors to be considered in relation to the use of quadrats. First,

distribution of plants, second, shape and size of the quadrat and third, the number of

observations needed to obtain an adequate estimate of density.

Regarding the shape, one should take into consideration the Edge effect. It is

minimal in a circular quadrat and maximal in a rectangular one. The ratio of length of

edge to the area inside a quadrat changes as circular>square>rectangular.

Edge effect is important because it leads to possible counting error. A decision

must be made every time an animal or plant is at the edge. For plants or animals that are

partly in and partly out of the quadrat, you have to adopt some reasonable convention.

For example, plants that are more half in are included and ones less than half in are

excluded. Include all the edge plants on the north and east side and exclude all those on

the south and west side.

Long thin quadrats are better than circular or square ones of the same area. The

reason for this is habitat heterogeneity: long quadrat cross more patches.

Different vegetation types requires different quadrat sizes. Vegetation with

smaller plants, greater plant density or greater species diversity need smaller quadrats.

The results of quadrat sampling are often related to the size and shape of the plots

used. The method is also very time consuming. Methods that do not use plots are often

useful and much faster for plant and sessile animal sampling.

The point-quarter method relies upon a random distribution of the organisms in

the area to be sampled. Uniform or clumped distributions will yield erroneous results.

However, this method is one of the most favored for sampling in several habitats

including intertidal and coastal scrub.

References:

http://www.psychology.ex.ac.uk/lundy/quadrat.htm

http://www.olemiss.edu/depts/mathematics/Departmental%20Seminars/Statistics/gerard.pdf

http://www.olemiss.edu/depts/mathematics/Departmental%20Seminars/Statistics/gerard.pdf

September 26, 2003

http://www.tamug.edu/seacamp/virtual/methods.htm

http://www.countrysideinfo.co.uk/howto.htm

http://www.countrysideinfo.co.uk/howto.htm

http://www.tamug.edu/seacamp/virtual/methods.htm

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