5.3 Soil Degradation & Conservation

What is succession in soil ecosystems?

Changes in the composition and structure of the ecosystem over time

What influences succession?

• Climate

• Vegetation

• Interactions between abiotic and biotic factors

How does primary succession arise?

Where soil development starts from bare rock where there is no organic matter

What is the role of pioneer species in ecological succession?

(Lichens and mosses) colonise hare substrate, starting process of soil formation by breaking down rocks and organic matter

Why are pioneer species well suited for harsh conditions?

Pioneer species can tolerate low nutrient availability and harsh environmental conditions

How do pioneer species contribute to soil formation?

They break down rocks and organic matter, creating a thin, nutrient-poor soil layer over time

What happens as the soil layer develops?

Accumulated organic matter and weathering deepen soil allowing the colonisation of herbaceous plants/shrubs

How do herbaceous plants and shrubs contribute to succession?

These plants have higher nutrient requirements than pioneer species and further enrich the soil

How does soil fertility affect plant growth during succession?

As the soil becomes more fertile, larger plants, including trees can grow

What are climax communities in ecological succession?

Climax communities are stable ecosystems where trees are established, marking the later stages of succession

How do soil characteristics change during succession?

Soul becomes enriched with nutrients, organic compounds and microbial communities

What are the initial characteristics of soil during succession?

Soil is nutrient-poor and has low organic matter content

How does soil improve as succession progresses?

As vegetation and organic matter increase, the soil becomes enriched with nutrients, organic compounds and microbial communities

How does soil pH change during succession?

Soil pH may change as different plants and microbes affect nutrient cycling processes

How does soil erosion risk change as succession progresses?

Soil erosion becomes less of a risk as the soil becomes more stabilised and protected by vegetation