Food diagrams are visual depictions of species relationships. While similar to food chains, food diagrams offer more complex and realistic depictions.
Food webs often depict organisms moving through an ecosystem like this one; green algae (producers) are consumed by mollusks (primary consumers), who then become prey for slimy sculpin fish that, in turn, become food for salmon.
Components of Ecosystem
Ecosystems are complex environments made up of living organisms and non-living components that work together as one ecosystem. Living organisms known as “biotic components”, including populations of plants and animals, while nonliving things such as space, air, mineral soil and light make up what are known as “abiotic components.”
Abiotic components of an ecosystem determine what living organisms can survive in it, with desert environments often having very distinct abiotic characteristics from forests. Plants in desert environments must be drought resistant while those found in forests must tolerate moisture as well as plenty of sunshine.
Ecologists define biotic components of an ecosystem as autotrophs (living things that produce their own food) and heterotrophs (feeding on other living things), with organic material moving between levels to form what ecologists refer to as a food chain; should these chains overlap, they form what ecologists refer to as a food web.
Food Chain
Food chains, commonly used in schools, are linear diagrams that depict who eats whom. They usually start with plants before moving up to herbivores (animals that only consume plants), carnivores and finally top predators – also called apex predators – who consume both plants and animals.
Every organism plays an essential part in maintaining an ecosystem. If one species disappears from food chains, this may have lasting repercussions for other parts of the ecosystem – for instance if grasshopper populations decline and other organisms dependent on them for sustenance also decline.
Students can create food chains using strips of paper that illustrate a sun, producer, primary consumer, secondary consumer and tertiary consumer. Once completed, these can be interlocked and glued together into an organism-eating chain which they can hang from the rafters to demonstrate how a variety of food sources exist in nature.
Food Web
Food webs provide a visual representation of an ecosystem’s life forms and their interrelationships using arrows as symbols of feeding relationships, showing which organism eats which. Each step in an arrow represents one trophic level – for instance plants are producers (trophic level 1) that are consumed by primary consumers such as herbivores; then secondary consumers consume those consumers.
Food webs are more complex than simple food chains because many species consume multiple organisms at once and most animals have multiple sources of sustenance as backup should one source become unavailable.
Food webs may resemble connect-the-dots spirals with each organism a different hue. This visual can help introduce students to the idea that all living things are interdependent on each other and can be found both in children’s science books and academic journal articles that cover specific places or habitats.
Trophic Levels
Trophic levels refer to the position an organism occupies in a food chain or web. Their exact number depends upon their feeding relationship with other organisms in their ecosystem.
Organisms that produce their own food without feeding on other organisms are known as autotrophs. Examples include plants such as grass and algae. Other living things which rely on energy from other sources to obtain their sustenance – for instance rabbits, foxes and snakes are examples of heterotrophs.
Food chains or webs are networks of eating relationships between various animals. They can be organized into pyramid shapes and numbered with respect to how many organisms exist at each feeding level, from primary producers such as plants or algae through herbivores and carnivores that eat herbivores to secondary consumers which consume both primary and secondary consumers before finally culminating in tertiary consumers that feed off both groups simultaneously.