Q.Among the ecosystem services are control of floods and soil erosion. How is this achieved by the biotic components of the ecosystem?
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Start your 14-day free trial to unlock the full solution →Biotic components, primarily plants, control floods by intercepting rainfall and enhancing soil water absorption, and prevent soil erosion by binding soil with roots and shielding it from direct impact.
Ecosystems provide a multitude of services essential for human survival and well-being, often categorized into provisioning, regulating, cultural, and supporting services. Among these, regulating services are crucial for maintaining environmental quality and stability. The control of floods and soil erosion falls squarely under these biotic regulation services, where the living components of an ecosystem actively mitigate natural hazards. This control is primarily achieved through the intricate interactions between vegetation, soil, and water.
The biotic components, predominantly plants, play a pivotal role in regulating water flow and preventing floods. When rain falls, the canopy of trees and other vegetation intercepts a significant portion of the precipitation, reducing the direct impact of raindrops on the soil surface. This interception slows down the water's descent, allowing some of it to evaporate directly from the leaves, while the rest drips down gradually. This process prevents the rapid accumulation of water on the ground, which is a primary cause of flash floods.
Furthermore, the root systems of plants are instrumental in enhancing the soil's capacity to absorb water. Roots create channels and pores within the soil, increasing its permeability and allowing rainwater to infiltrate deeper into the ground rather than flowing over the surface. This increased infiltration recharges groundwater tables and reduces surface runoff, thereby lessening the volume of water that reaches rivers and streams quickly. Forests, especially those in upper catchments, act as natural sponges, absorbing vast quantities of water and releasing it slowly, thus regulating river flow and mitigating downstream flooding.
The presence of a dense network of roots also improves soil structure, making it more porous and less compacted, which further aids water absorption.
Regarding the control of soil erosion, biotic components are equally indispensable. Soil erosion, the displacement of the upper layer of soil, is primarily caused by wind and water. Vegetation acts as a natural barrier against both.
- Protection from Water Erosion:
- Canopy Cover: The leaves and branches of plants shield the soil from the direct impact of raindrops. Without this cover, raindrops hit the bare soil with considerable force, dislodging soil particles and making them susceptible to being carried away by surface runoff.
- Root Binding: The extensive root systems of grasses, shrubs, and trees bind soil particles together, forming a stable network that resists dislodgement. This physical binding makes the soil much more cohesive and less prone to being washed away by flowing water.
- Increased Infiltration: As mentioned for flood control, increased water infiltration due to vegetation reduces surface runoff, which is the main agent of water erosion. Less runoff means fewer soil particles are transported. …
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