Cerrado Ecosystem Overview

Cerrado Ecosystem Overview

• The Cerrado is a vast biome, primarily located in Brazil (99%).
• It's a biodiversity hotspot, with at least 1,500 endemic plant species and 12,000 plant species in total.
• Critically important for hydrological reasons, supporting three major river basins.
• Represents a significant portion of Brazil's territory (¼).
• Classified as a grassland and wooded savannah biome.
• Characterized by deep, thick soils holding vast amounts of water and carbon.
• Vegetation is often twice as extensive underground as aboveground.
• The health of the Cerrado depends on the health of surrounding ecosystems.

Human Impact on the Cerrado

• Significant landscape change due to agriculture and urbanization.
• Widespread loss of Cerrado vegetation.
• Conversion to pastureland often indistinguishable from grasslands.

Ecological Succession and Fire Dynamics

• Ecological succession describes the recovery process after disturbance, like deforestation, fires, or agricultural abandonment.
• Secondary succession is faster and easier when soil is present.
• Seral stages depict the ordered shifts in species communities.
• Fire is a critical natural element defining the Cerrado.
• Frequent fires in the wet season, mainly caused by lightning strikes—but dry season fire spread further.
• Cerrado species have evolved adaptations like thick bark and extensive root systems to survive fires.
• Burrowing animals and migration to less-flammable areas are other strategies for survival.
• There's a balance of fire, with mostly grass landscapes, and various succession stages.
• Controlled burns are needed to maintain the delicate balance, but there are concerns about uncontrolled fires and public perception.
• Agricultural activity and fire suppression have impacted successional patterns.

Invasive Species

• Invasive alien species, like wild boars (introduced by Europeans) disrupt ecosystems and deplete native species.
• Wild boars thrive in human-altered environments (agricultural areas).
• Invasive grasses (introduced in the 1960s-70s) outcompete native species and contribute to fire intensity.

Feedback Mechanisms in the Cerrado

• Feedback mechanisms highlight the constantly changing nature of ecosystems after disturbances.
• Positive feedback amplifies change, while negative feedback mitigates it.
• Population growth and agricultural practices have positive feedback on invasive grasses.
• Cattle grazing impacts fire intensity and the spread of invasive grasses.
• Evidence suggests Cerrado clearing impacts local climate, increasing wind speeds, rainfall, and fire frequency.

Conservation Considerations

• Maintaining the balance between economic activity and environmental preservation is crucial.
• The Cerrado's dynamic nature requires a flexible approach to ensure sustainability.
• Understanding the complex interplay of natural and human-induced changes is essential for conservation efforts.