120 likes | 352 Vues
Rising Sea Levels. Rising Sea Levels. Food Webs and Pyramids. What is a food web?. Several food chains connected together Shows many different paths of how plants and animals are connected Each level of animal represents a different trophic level
E N D
What is a food web? • Several food chains connected together • Shows many different paths of how plants and animals are connected • Each level of animal represents a different trophic level • Which is an organisms position on the food web
Parts of a food web • Primary Producer: produces own food by photosynthesis • Usually green plants • Primary Consumer: animals that consume only plant matter • Aka herbivores-rabbits and cows • Secondary Consumer: animals that eat primary consumers (herbivores) • Aka carnivore- owls and foxes • Tertiary Consumer: animals that eat secondary consumers • Carnivores that eat other carnivores
Energy Pyramids • Model of energy flowing in a community • They are measured from the bottom trophic level to the top • Primary Producers • Primary Consumers • Secondary Consumers • Tertiary Consumers
Ten Percent Rule • An average of only 10% of the energy in one trophic level is passed to the next trophic level • 90% is used by previous trophic level
Why only 10%? • Energy is used up for daily life activities • Not all organisms that die are eaten by animals on the next trophic level • Not all parts of organisms are eaten and digested for energy
Biomass Pyramids • Amount of energy available in the form of organic matter of organisms • There is a gradual decrease in biomass from producers to higher trophic levels • 2 common types • Terrestrial • Aquatic
Aquatic Pyramid • Why is it inverted (upside down)? • Smaller weight of producers are supporting consumers of a large weight
Human Impact • Destroys the environment in which the organisms eat or make their food • Removes food source for other organism • Could lead to extinction of species • Hunting • Overfishing • Deforestation