Estimating
a plant population
The plant population we are
going to estimate is juvenile (young) mangrove trees. We estimate
the number of trees by using the random quadrat method. A 1 metre
square quadrat was placed randomly in an area containing juvenile
mangrove trees. A stick was thrown over the shoulder and where the
stick landed was the bottom corner of the quadrat. The number of
mangrove seedlings in the quadrat was counted and the results put in
the table below.
| Quadrat |
No. of juvenile
mangroves |
| 1 |
4 |
| 2 |
3 |
| 3 |
8 |
| 4 |
0 |
| 5 |
7 |
| 6 |
5 |
| 7 |
2 |
| 8 |
6 |
| 9 |
5 |
| 10 |
6 |
| Total |
46 |
Questions
Work out the average number of juvenile mangroves by
dividing the Total by 10
Average =
Check answer 1
The total area where
the juvenile mangroves grow is 20m x 100m =
Check Answer 2
Therefore your estimate
for the number of juvenile mangroves is Check
Answer 3
Distribution
of a plant and animal species
You have been looking at the abundance
of organisms. The distribution of the
organism is another important part of the ecosystem. The
abiotic factors of the ecosystem in conjunction with the
biotic factors control the distribution of organisms. To look at the
distribution of the species you have just been studying click
here.
Answer
1 The average is 46/10 = 4.6 mangroves per square metre
Back to questions
Answer 2 2000 sq metres
Answer 3 2000 x 4.6 = 9200 juvenile
mangrove trees.
