Flow of Energy Through the Trophic Levels WHAT

Flow of Energy Through the Trophic Levels

WHAT IS ECOLOGY? Ecology- the scientific study of interactions between organisms and their environments, focusing on energy transfer Ecology is a science of relationships

The environment is made up of two factors: • Biotic factors- all living organisms inhabiting the Earth • Abiotic factors- nonliving parts of the environment (i. e. temperature, soil, light, moisture, air currents)

• Niche - the role a species plays in a community; its total way of life • The niche of the organism is the job the organism has in the environment. (Ex. Bees help plants reproduce by pollination. ) • Habitat- the place in which an organism lives out its life Habitat vs. Niche

A niche is determined by the tolerance limitations of an organism, or a limiting factor. Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment. Habitat vs. Niche

Habitat vs. Niche Examples of limiting factors - • Amount of water • Amount of food • Temperature • Amount of space • Availability of mates

Feeding Relationships • There are 3 main types of feeding relationships 1. Producer - Consumer 2. Predator - Prey 3. Parasite - Host

Feeding Relationships Producer- all autotrophs (plants), they trap energy from the sun • Bottom of the food chain

Feeding Relationships Consumer- all heterotrophs: they ingest food containing the sun’s energy ØHerbivores ØCarnivores ØOmnivores ØDecomposers

Feeding Relationships CONSUMERS 1. Primary consumers • Eat plants • Herbivores • Secondary, tertiary … consumers • Prey animals • Carnivores

Feeding Relationships Consumer-Carnivores-eat meat • Predators – Hunt prey animals for food.

Feeding Relationships Consumer- Carnivores- eat meat • Scavengers • Feed on dead animals • Vultures are scavengers

Feeding Relationships Consumer- Omnivores -eat both plants and animals

Feeding Relationships Consumer. Decomposers • Breakdown the complex compounds of dead and decaying plants and animals into simpler molecules that can be absorbed

• A trophic level is the position occupied by an organism in a food chain. • Each link in a food chain is known as a trophic level. • Trophic levels represent a feeding step in the transfer of energy and matter in an ecosystem. Trophic Levels

• Organisms that share a trophic level get their energy from the same source. • Producers are found at the base of the energy pyramid and comprise the first trophic level of the food chain. • Producers capture energy as sunlight and converts it into usable forms. Trophic Levels

• Above producers are the primary consumers that make up the second trophic level. • Above the primary consumers are the secondary consumers that occupy the third trophic level. • Finally, there are the tertiary consumers at the top trophic level. • This group is often called the “top” of the food chain. • They are generally omnivores, like humans, or carnivores, like lions. Trophic Levels

E N E R G Y Trophic Levels Tertiary consumerstop carnivores Fourth Tropic Level Secondary consumers-small carnivores Third Trophic Level Primary consumers- Herbivores Second Trophic Level Producers- Autotrophs First Trophic Level

• It takes a large number of producers to support a small number of primary consumers • It takes a large number of primary consumers to support a small number of secondary consumers – Amount of available energy decreases for higher consumers or/energy decreases the farther you move from the primary producer. Energy Pyramid

• Some energy in the primary consumer is STORED & not lost to the atmosphere or used by the consumer itself. • What happens to all energy as it moves up the pyramid? – Some energy is used by that trophic level for metabolism, some of the energy is lost as heat, and some energy is stored and can passed on to the next trophic level (10%). Energy Pyramid

• The Ten Percent Law states that the amount of energy available to organisms at a particular trophic level is ten percent of what it was at the previous level. • Some of the energy is stored in tissue, some is used for metabolism, locomotion, reproduction and homeostasis. 10% Law

10% Law

Trophic Levels Food chain- simple model that shows how matter and energy move through an ecosystem

Food web- shows all possible feeding relationships in a community at each trophic level • Represents a network of interconnected food chains Trophic Levels

• Organic material produced in the ecosystem is referred to as Biomass. • Producers add biomass to an ecosystem by making organic molecules. • The stored biomass is what is passed on to other organisms in the ecosystem. • Energy is measured in kilocalories (kcal) – kcal – the heat required to raise the temperature of one kilogram of water by one degree – kcal represents 1000 true calories of energy Measuring Biomass

• Food Chain 1: – Phytoplankton – zooplankton – smelt – trout – humans • 10, 000 kcal – 100 kcal – 1 kcal • Food Chain 2: – Phytoplankton – smelt – humans • 10, 000 kcal – 100 kcal • Which food chain gives the human more energy? • How much more energy? Calculating Available Energy