Some students estimated the population of daisies in a school field - AQA - GCSE Biology Combined Science - Question 5 - 2019 - Paper 2

The area of the quadrat is calculated as:

$ext{Area of quadrat} = 50 ext{ cm} imes 50 ext{ cm} = 2500 ext{ cm}^2$

To convert this to square meters:

$ext{Area of quadrat} = 2500 ext{ cm}^2 = 0.25 ext{ m}^2$

Given that the mean number of daisy plants per quadrat is 7.65 and there are 15,744 quadrats in the field:

$ext{Total area of the field} = 62 ext{ m} imes 164 ext{ m} = 10,168 ext{ m}^2$

The number of quadrats in the field is:

ext{Number of quadrats} = rac{10,168 ext{ m}^2}{0.25 ext{ m}^2} = 40,672 ext{ quadrats}

So the total population of daisies is:

$ext{Population of daisy plants} = 40,672 imes 7.65 = 310,137.6 ext{ plants}$

Expressed in standard form, the population is approximately:

$3.1 imes 10^5 ext{ plants}$

Various factors contribute to the uneven distribution of daisy plants in the field:

Biotic Factors:

• Trees in the field: They can reduce light availability, affecting photosynthesis and ultimately leading to fewer daisies growing in shaded areas.
• Competition: Plants that compete for space, nutrients, and water can inhibit daisy growth in some areas.

Abiotic Factors:

• Soil quality: Variations in soil composition affect the availability of nutrients and water. Poor soil might not support daisy growth.
• Water drainage: Areas susceptible to waterlogging may hinder plant growth, leading to fewer daisies in such spots.
• Local climate: Microclimates within the field, such as differences in sunlight exposure and wind protection, can also affect plant distribution.

In summary, these factors could lead to patches where daisies thrive and areas where they are sparse.