Why is it not possible to have an ecosystem with only producers and no consumers or decomposers?
An ecosystem cannot function with only producers because the balance of nature requires all three types of organisms.
Producers (plants) make their own food through photosynthesis, but without consumers, there would be no mechanism to transfer energy through the food chain.
More importantly, without decomposers, dead plants and animals would accumulate without breaking down. Nutrients would remain locked in dead matter and not return to the soil.
Over time, soil would become depleted of essential nutrients, and new plants would not be able to grow.
The cycling of matter and energy that sustains life requires the combined action of producers, consumers, and decomposers working together.
Explanation
The chapter explains in Section 12.6 that 'decomposers play an important role in recycling nutrients' and that 'in nature, nothing is wasted—everything is reused.' Section 12.5 describes how food chains work with producers, consumers, and decomposers at different trophic levels. The chapter emphasizes that ecosystems depend on interactions among all biotic components and between biotic and abiotic components.
Solution Steps
An ecosystem requires all three types of organisms—producers, consumers, and decomposers—to function.
Producers make food through photosynthesis, but consumers are needed to transfer energy through the food chain.
Without decomposers, dead matter would accumulate and nutrients would not return to the soil.
Soil would eventually become depleted of essential nutrients, preventing new plant growth.
The cycling of matter and energy requires the combined action of all three types of organisms.