Question

Decomposers are associated with which class of food web? a. grazing b. detrital c. inverted d. aquatic

Short answer

Decomposers are associated with the detrital food web. Answer: b. detrital.

Step-by-step solution

Define decomposers

Firstly, we need to understand what decomposers are. In any ecosystem, decomposers are organisms that break down dead organic materials and wastes, converting them into simpler molecules, which can be absorbed by other organisms, thus releasing nutrients back into the environment.

Explain different classes of food webs

Now let's briefly discuss the four classes of food webs mentioned in the exercise: a. Grazing food web: A grazing food web consists of primary producers (plants) and their direct consumers (herbivores) at various trophic levels. b. Detrital food web: A detrital food web consists of detritus (dead organic matter), decomposers or detritivores that consume and recycle nutrients back into the environment. c. Inverted food web: An inverted food web starts with external nutrients (e.g. those provided by humans) and moves up the trophic levels, such that the initial source of energy may be higher up the food chain. d. Aquatic food web: An aquatic food web is a food web that occurs in water-based ecosystems (freshwater or marine).

Find the class of food web associated with decomposers

After understanding decomposers and the different food web classes, we can now determine the correct class of food web associated with decomposers. Since decomposers are organisms that break down dead organic material and recycle nutrients back into the environment, they are associated with the detrital food web.

Choose the correct answer

As we've identified that decomposers are associated with the detrital food web, the correct answer is: b. detrital

Key concepts

Detrital Food Web

When diving into ecosystem dynamics, the detrital food web plays a fundamental role in how energy and nutrients are recycled. Different from the food chains many of us learn about in primary school, detrital food webs are not as straightforward. They are characterized by their focus on detritus – the dead and decaying plant and animal matter, as well as feces. Decomposers, such as fungi and bacteria, are the backbone of this type of food web, as they break down this detritus into simpler substances.

The Importance of Decomposers

In the detrital food web, decomposers facilitate the breakdown process. Not only do they reduce organic matter back into essential nutrients, but they also play a key role in soil fertility and the continuation of life cycles within an ecosystem.

Circulating Energy

Detritivores, like earthworms and some insects, further contribute by consuming decomposed materials, releasing nutrients as they digest and excrete waste. This contributes to the soil nutrient pool, completing the cycle and allowing for new plant growth.

Ecosystem Nutrient Cycle

Central to life on Earth is the ecosystem nutrient cycle, a system that encompasses the movement and exchange of organic and inorganic matter back into the production of living matter. It's essential for maintaining ecological balance and ensuring that organisms have access to the substances they need to grow, reproduce, and survive.

Nutrients on the Move

The nutrient cycle includes several different processes such as the carbon cycle, nitrogen cycle, phosphorus cycle, and more. Each cycle describes how these various elements move through the living and non-living parts of ecosystems.

Role of Decomposers

Within this cycle, decomposers are the custodians of the nutrient cycle. They convert dead material back into its mineral form, making it available for plants and other autotrophs to absorb and turn into energy again, thus perpetuating the cycle of life.

Trophic Levels

Understanding the ecosystem's structure is made significantly clearer when we study the concept of trophic levels. Trophic levels categorize the various roles within a food web, providing a clear picture of who eats who and the flow of energy.

Stepwise Energy Flow

The base of all food webs begins with the primary producers, like plants and algae, which are at the first trophic level. They convert solar energy into chemical energy through photosynthesis. From there, the energy transfers up the ladder to herbivores (second trophic level), then to carnivores (third trophic level), and so on.

Decomposers' Unique Position

Rather than existing within a particular 'level,' decomposers intersect with all trophic levels by consuming dead organisms from across the food web. This unique role underscores the significance of decomposers in ecological processes, as they are a key factor in recycling nutrients and propagating energy flow.