Topic 9: Ecosystems Biotic and abiotic factors

1. Core content

Ecosystems

The concept of ecosystem, structure and ecosystem functioning:

• Abiotic factors:

- physiographic factors (aspect, slope, and altitude)

- soil (pH, humus content, texture, water retention capacity and air content)

- light (day length and seasonal changes)

- temperature (effect of day/night and seasons)

- water (water cycle and the importance of wetlands)

- atmospheric gases (link to pollution-Grade 12);and

- wind (link to transpiration).

• Biotic factors, which include: (Links to Grade 8)

- producers

- consumers

- decomposers.