Food Chains

• The basic components of a food chain are sunlight, producers and consumers. Plants are producers. They store energy they produce by photosynthesis and pass the energy through the ecosystem in a series of steps. In each step, or trophic level, an organism is eating or being eaten. Consumers are organisms that obtain energy by eating other organisms. Food chains are presented in a diagram with pictures of the species involved and arrows between the organisms to show the direction that energy flows. Food chains are not linear, because animals usually eat more than one type of plant and in turn are eaten by more than one type of predator. Food chains within a community, such as a deciduous rainforest, are linked to form a food web that represents the interconnected feeding relationships between organisms.
  
  

Producers

• Plants introduce energy from the sun into the ecosystem and make up the first trophic level of a food chain. Temperate rainforests contain coniferous or deciduous trees, depending on temperature. Deciduous species dominate in warmer temperate rainforests. Deciduous trees such as big-leaf maples in North America and members of the Nothofagus genus in Chile are the biggest contributors of energy to the food chain because the tree canopy absorbs the most sunlight. Other producers include smaller trees, shrubs and woody plants in the understory and ferns, mosses and flowering herbaceous plants on the forest floor.
  
  

Consumers

• Three types of consumers are herbivores, carnivores and omnivores. Herbivores make up the next trophic level in a food chain and obtain energy by eating plants. Herbivores typically found in temperate deciduous forests include herbivorous insects and birds, small mammals and deer. Carnivores belong to another trophic level and feed on other consumers. These predators include carnivorous insects, salamanders, insect-eating birds, pythons, owls, hawks and bobcats. Omnivores are consumers that feed on both plant and animal matter depending on the season or life-cycle stage. Many bear species are omnivores.
  
  

Decomposers and Detritus

• Decomposers are another type of consumer in temperate forest food chains. Decomposers such as mushrooms, molds and bacteria feed on detritus such as animal droppings and the remains of dead organisms on the forest floor, breaking them down and returning nutrients to the soil. Organisms that feed on detritus in the leaf litter sometimes make up their own separate food chain within a forest community that includes fungi, snails, spiders and insects.