Study of plant population frequency

 Experiment No.                                    Date:

Aim of the experiment: To study the plant population frequency by quadrate method in Namrup College campus

Principle: Frequency is the number of sampling units (quadrat) in which a particular species occurs. It is determined by counting the total number of quadrat (sampling units) in which the species occur in a given time divided by total number of quadrat studied.

Frequency of each species is expressed in percentage-

Requirements: Square of 50cm x 50cm or 100cm x 100cm size, paper, pencil, preserving materials (hard board with papers fit)

Procedure: A 50 cm × 50 cm quadrat was placed randomly within the herbaceous vegetated area of the Namrup College campus. The plants of each species found in each quadrat were counted and recorded. In total, ten quadrats of identical size were laid at random in the study area, and the plant species present in them were identified. Unknown herbaceous species were collected and preserved for later identification with the guidance of the teacher. The total count of each species from all quadrats was then recorded separately.

Observation and calculation:

After the field observation, data are tabulated as follows and calculated the density as per the formula.

Sl. Nos.	Name of the plant species	Quadrate wise number of species recorded during the study										Total nos. quadrats in which species occurred (A)	Total nos. of quadrats studied (B)	Frequency F
		Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Q9	Q10
1	Ageratum conyzoides	10	-	-	30	-	-	-	14	-	4	4	10	40%
2	Axonopous compressus	14	10	-	24	-	12	14	8	-	-	6	10	60%
3	Borreria sp.	8	2	10	-	-	-	-	-	-	6	4	10	40%
4	Cynodon dactylon	6	-	28	-	-	-	-	-	-	-	2	10	20%
5	Phyllanthus niruri	4	-	-	-	-	4-	-	-	-	-	2	10	20%
6	Woodfordia fruticosa	4	2	2	-	-	-	-	4	-	-	4	10	40%
7	Digitaria sanguinalis	-	24	-	-	-	-	-	-	-	12	2	10	20%
8	Oplismenus sp.	-	2	8	12	12	-	-	-	-	-	4	10	40%
9	Oldenlandia diffusa	-	8	8	-	-	-	-	-	2	-	3	10	30%
10	Euphorbia hirta	-	-	14	-	-	-	-	-	-	-	1	10	10%
11	Alternenthera sessilis	-	-	8	-	-	-	-	-	-	-	1	10	10%
12	Centella asiatica	-	-	2	2	2	-	-	-	-	-	3	10	30%
13	Bulbostylis barbata	-	-	4	-	-	-	-	12	6	-	3	10	30%
14	Scaparia dulcis	-	-	-	2	-	-	-	-	-	-	1	10	10%
15	Kyllinga brevifolia	-	-	-	4	-	-	-	-	-	-	1	10	10%
16	Mikenia scandens	-	-	-	-	10	-	-	-	8	-	2	10	20%
17	Oxalis corniculata	-	-	-	-	-	-	-	-	14	-	1	10	10%

Result: From the field study, a total of 17 species of herbaceous plants were collected from the Namrup College campus. The names of the species are like Ageratum conyzoides, Axonopous compressus, Borreria sp, Cynodon dactylon,  Phyllanthus niruri, Woodfordia fruticosa,  Digitaria sanguinalis, Digitaria sanguinalis, Oplismenus sp., Oldenlandia diffusa, Euphorbia hirta, Alternenthera sessilis, Centella asiatica, Bulbostylis barbata, Scaparia dulcis, Kyllinga brevifolia,  Mikenia scandens and Oxalis corniculata density of species J is lowest in the college campus.

Inference: From the present study it is found that the frequency percentage of species Axonopus comressus is highest, whereas, several species like Euphorbia hirta, Alternenthera sessilis, Scaparia dulcis, Kyllinga brevifolia,  Mikenia scandens and Oxalis corniculata.

Precautions:

1. Pre-determined quadrat size or area should be measured appropriately,

2. Quadrats laid down or marked area in one field should not be very far from each other,

3. Quadrat should not overlap each other,

4. Number of plant species should be carefully counted,

5. Attention should be taken that all species encountered inside the quadrat must be recorded,

6. Proper safety measure should taken from leech, snake or other wild animals

 [Students must write actual species name and number in place of species given in the table]