Bio 20 Lesson 30: Factors that Affect Terrestrial Ecosystems

Soil Composition and Layers00:00:34

Soil is a critical factor for plant growth, with different ecosystems requiring specific soil characteristics. Soil is structured in layers: the litter layer (decomposing organic matter), topsoil (nutrients and rock particles), subsoil (less organic matter), and bedrock.

Abiotic Factors: Water, Temperature, and Sunlight00:03:02

Water availability through precipitation and groundwater is essential. Temperature and sunlight levels dictate plant adaptations, such as the evergreen needles of coniferous trees or the deep root systems of grasses in warmer climates.

Human Impact and Forestry00:05:04

Human activities, particularly forestry, significantly alter ecosystems. Clearing forests removes essential wildlife habitats and disrupts water and carbon recycling, impacting the overall stability of the environment.

The Role of Fire in Ecosystems00:05:55

Fire acts as an agent of change that can be beneficial when managed through prescribed burns, as it clears decaying matter and returns nutrients to the soil. Some species, like certain pines, are specifically adapted to rely on heat to release their seeds.