Exercise 2 TERRESTRIAL SAMPLING TECHNIQUES (Preliminary Report)
December 6, 2007
Submitted by: Group # 2 Gerardo, Mary Antonette Maguslog, Justine Salumbre, 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
Sp. 1 Bryophyllum pinnatum
Sp. 2
Sp. 5 I. Quadrat Data
Sp. 6
Sp. 3
Sp. 7
Quadrat 1 Species Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7
Tally xxxxxxxxxx xxxxx x
Total # of species
ni 10 5 1 0 0 0 0 16 3
RDi 62.5 31.25 6.25 0 0 0 0
Quadrat 2 Species Species Species Species Species Species Species Species
1 2 3 4 5 6 7
Tally xxxxxxxxxxxxxxx xxxxxxxxxx xxxxxxxxxxx xxxxxxxxxxxxxxxx
x Total # of species
Sp. 4
ni
RDi
25 11 17 0 0 0 1 54 4
46.3 20.37 31.48 0 0 0 1.85
Relative Density of Plant Species in Quadrat 1 0% 0% 0% 6%
0%
31%
63%
1 2 3 4 5 6 7
Relative Density of Plant Species in Quadrat 2 2% 0% 0% 0%
31% 47%
20%
1 2 3 4 5 6 7
Relative Density of Plant Species in Quadrat 3
Quadrat 3 Species Species 1 Species 2 Species Species Species Species Species
3 4 5 6 7
0%
Tally xxx xxxxxxxxxxxxxx xxxxxxxxxxxxx xx
Total # of species
ni 0 3
RDi 0 9.375
27 2 0 0 0 32 3
84.375 6.25 0 0 0
0% 0% 0% 6%
9%
1 2 3 4 5 6 7
85%
Quadrat 4 Species Species 1 Species 2 Species Species Species Species Species
3 4 5 6 7
Tally
xxxxxxxxxxx xxxxxxxxx xxxxxxxxxx xx
Total # of species
ni 0 0
RDi 0 0
20 10 2 0 0 32 3
62.5 31.25 6.25 0 0
0% 0% 0% 6%
0%
31%
63%
1 2 3 4 5 6 7
Relative Density of Plant Species in Quadrat 5
Quadrat 5 Species Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7
Relative Density of Plant Species in Quadrat 4
Tally
xx xxxxx xx Total # of species
ni 0 0 2 5 0 2 0 9 3
RDi 0 0 22.22 55.56 0 22.22 0
0% 0% 0% 22%
22% 1 2 3 4 5 6 7
0%
56%
II.
Transect Data Transect 1 Species Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7
Tally xxxxxxxxxxxxxxx xxxx xxxxxxxxxxx xxxxxxxx
Total # of species
Frequency of plant Species (Transect 1)
ni 15 4 11 8 0 0 0 38 4
RDi 39.47 10.53 28.95 21.05
Relative Density of Plant Species in Transect 1
16 14
frequency
12 1 2 3 4 5 6 7
10 8 6
4 21% 1 39%
1 2 3 4
4
3 29%
2
2 11%
0 1
2
3
4
5
6
7
species
Transect 2 Species Tally Species 1 xxxxxxxxxxxxxxxxxx Species 2 xxx Species 3 xxxxxxxxx Species 4 xxxxxxxx Species 5 x Species 6 x 7 (Transect 2) xxxx Frequency ofSpecies Plant Species Total # of species
20
ni RDi 18 40.91 3 6.82 9 20.45 8 18.18 1 2.27 1 2.27 Relative Density 4 9.09 of Plant Species in Transect 2 44 7
18 16
1
Frequency
14
2
12
3
10
4
8
5
6
6
4
7
6 2%
7 9%
5 2% 1 42%
4 18%
2 0 1
2
3
4 Species
5
6
7
3 20%
2 7%
1 2 3 4 5 6 7
Transect 3 Tally xxxxxxx x xxxxxxxx xxxxxxxxx
Species Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7
xx
ni 7 1 8 9 0 2 0
RDi 25.93 3.7 29.63 33.33 0 7.41 0
Total # of species
27 5
Relative Frequency in Plant Species (Transect 3)
Relative Density of Plant Species (Transect 3)
10
6 7%
9 8 1 2 3 4 5 6 7
frequency
7 6 5 4 3
5 0%
7 0%
1 26% ç
4 33%
2 4%
2 1
3 30%
0 1
2
3
4
5
6
7
species
III.
Point Quarter Data Quadrat 4
Quadrat 1 I Species 1 Species 2
Quadrant II III IV 6 3 1 0 2 1 1 1
Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7 Total No. of Species
I 0 0 4 0 0 0 0 4 5
Quadrant II III IV 0 0 0 0 0 0 5 7 4 2 4 4 0 1 1 0 0 0 0 0 0 7 12 9
1 2 3 4 5 6 7
Species 3 Species 4 Species 5 Species 6 Species 7 Total # of species
0 0 0 0 0 8 3
0 0 0 0 0 4
Quadrat 2 I Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7 Total
10 2 2 0 0 0 0 14
# of species
1 0 0 0 0 3
Quadrant II III 8 6 6 1 7 5 0 0 0 0 0 0 0 0 21 12
0 0 0 0 0 1
IV 1 2 3 0 0 0 1 7
3 Quadrat 5 Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7 Total No. of Species
Quadrat 3 Species 1 Species 2 Species 3 Species 4 Species 5 Species 6 Species 7 Total No. of Species
I 0 0 3 0 0 0 0 3
Quadrant II III IV 0 0 0 2 1 0 11 9 4 1 1 0 0 0 0 0 0 0 0 0 0 14 11 4
4
Relative Density was computed using this formula: RDen= Total individuals species x 100
I 0 0 1 0 0 0 0 1 5
Quadrant II III IV 0 0 0 0 0 0 1 0 0 0 3 2 0 0 0 0 2 0 0 0 0 1 5 2
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
September 26, 2003 http://www.tamug.edu/seacamp/virtual/methods.htm http://www.countrysideinfo.co.uk/howto.htm
