Decomposition: Lecture 3 Study Notes

Function of Decomposers: Decomposers break down complex organic matter into simpler substances. This process recycles nutrients back into the ecosystem, making them available for use by plants and other organisms.

**Types of Microbes Involved:
- Bacteria:** The primary decomposers of organic matter, including dead animals. They are crucial for breaking down proteins, fats, and carbohydrates.
- Fungi: They decompose tough organic materials, especially lignin in plant cell walls and other recalcitrant organic matters.
- Actinobacteria: These bacteria also help degrade complex organic substances and contribute to soil health.

Regions Affected: Dung accumulation is a significant issue in many agricultural areas, particularly where livestock are raised in high numbers without adequate management.
Environmental Impact: The accumulation of dung can lead to nutrient runoff into waterways, promoting algal blooms and causing eutrophication, which depletes oxygen in aquatic environments and harms aquatic life.

Causes of Vulture Decline: India's vulture population has seen a dramatic decline due to several factors:
- Diclofenac Use: The veterinary drug diclofenac, used to treat cattle, is toxic to vultures that consume carcasses of treated animals.
- Habitat Destruction: Loss of habitat and food sources further exacerbates the decline in vulture populations.
- Other Threats: In addition to poisoning from medication in carcasses, vulture populations face threats from poaching and reduced reproductive rates.

Challenges to Decomposition in Aquatic Environments:
- Oxygen Availability: Decomposition is often retarded in water due to lower oxygen levels, especially in stagnant water bodies where anaerobic conditions prevail.
- Temperature: Cold water temperatures can slow down metabolic processes in decomposers, further slowing decomposition rates.
- Dilution of Nutrients: Decomposition can also be less effective in water due to the dilution of nutrients necessary for microbial activity.