- A food chain is a linear sequence of organisms, each of which eats the one below it. For example, grass grows, grasshoppers eat the grass, birds eat the grasshoppers, and hawks eat the birds.
- A food web is a more complex network of feeding relationships, in which multiple species may eat and be eaten by a variety of other species. For example, in a grassland ecosystem, grass may be eaten by grasshoppers, rabbits, and deer. Grasshoppers may be eaten by birds and spiders. Rabbits may be eaten by foxes and coyotes. Deer may be eaten by wolves and cougars. And so on.
Biomass refers to the total mass of living organisms in an ecosystem. It can be measured in terms of dry weight, wet weight, or carbon content. Biomass is important because it provides a measure of the amount of energy available to organisms in an ecosystem.
Here is a table summarizing the key differences between a food web chain and biomass:
| Feature | Food Chain | Food Web | Biomass |
|---|---|---|---|
| Structure | Linear sequence of organisms | Complex network of feeding relationships | Total mass of living organisms |
| Measurement | Number of organisms | Number of connections between species | Dry weight, wet weight, or carbon content |
| Importance | Provides information about the flow of energy through an ecosystem | Provides information about the structure and complexity of an ecosystem | Provides a measure of the amount of energy available to organisms in an ecosystem |
Here is an example that explains the difference between food web chain, biomass, and energy pyramid.
A grass is eaten by a grasshopper. The grasshopper is eaten by a bird. The bird is eaten by a hawk. This is an example of a food chain.
In a grassland ecosystem, there may be many different types of plants, animals, and other organisms. The interactions between these organisms can be represented as a food web. For example, grass may be eaten by grasshoppers, rabbits, and deer. Grasshoppers may be eaten by birds and spiders. Rabbits may be eaten by foxes and coyotes. Deer may be eaten by wolves and cougars. And so on.
The total mass of all the living organisms in a grassland ecosystem is its biomass. Biomass is important because it provides a measure of the amount of energy available to organisms in the ecosystem.
The energy pyramid shows the amount of energy that is available at each trophic level in a food chain or food web. The bottom level of the pyramid represents the producers, which are the organisms that make their own food. The next level up represents the primary consumers, which are the organisms that eat the producers. The next level up represents the secondary consumers, which are the organisms that eat the primary consumers. And so on.
The energy pyramid shows that there is less energy available at each higher trophic level. This is because some of the energy is lost as heat at each level. As a result, there are fewer organisms at each higher trophic level.