Energy transferred through an ecosystem is measured in kJ m-2 year-1.
(a) What is an ecosystem?
[ 1 ]
(b) Light trapped by producers is considerably less than light measurements over a given area. Give two reasons for the reduction in light trapped by the producers.
1.
2.
[ 2 ]
(c) The biomass of producers is determined as being higher than that of consumers. Explain why.
[ 2 ]
(d) Oxygen is a by-product of photosynthesis. Where in the chloroplast does the light-dependent reactions occur?
[ 1 ]
(e) An area of a field is to be sampled for the frequency of Ragwort. The area chosen measures 100m x 50m. Explain how the area should be sampled using a 0.5m quadrat.
[ 3 ]
(f) The field also has a thick hedgerow which is a habitat for the banded and white-lipped snail (Caepea spp). A group from a local wildlife trust used the Mark & Recapture method of sampling. 26 snails where captured and marked on day one. The next day, the group returned and captured 7 marked snails.
Suggest one criticism of the group's method. Identify how their method would reduce accuracy of an estimate of population number.
[ 2 ]
[Total: 11]
