 An ecological system  consists of a living community and all of the physical aspects of its habitat  physical factors are known as abiotic factors and can include: ▪ light, temperature, precipitation, soil type, water availability, soil and water pH, etc  the members of the living community are known as the biotic factors in an ecosystem  include organism like animals, plants, mushrooms, and bacteria

 Ecosystems rely on energy -The amount of energy available in an ecosystem determines how many organisms can live in that ecosystem

 How does energy enter an ecosystem? - Sunlight is the primary source of energy for most ecosystems on earth No sun = No energy No Energy = No Life No Life = BUMMER!

 Divided into Trophic (feeding) levels.  Primary producers/autotrophs  Primary consumers/herbivores-plant eaters  Secondary consumers/carnivores –meat eaters  Tertiary consumers/carnivores  Detritivores/decomposers- vital part of the ecosystem. They recycle abiotic materials from dead organisms – without them, life would stop. - they play a role in nutrient cycling

 Primary producers are the first producers of energy rich compounds that are later used by organisms  Autotrophs: “self feeders”, organisms that can capture energy from nonliving sources and convert it into forms that living cells can use  Example: plants obtain energy from sunlight and turns it into nutrients that can be eaten and used for energy by animals such as a caterpillar

 Sunlight needs to be converted to be used in an ecosystem.  Who converts the sunlight? - plants, algae, some bacteria - organisms that convert the energy from sunlight into a useable form are known as producers - How do they do convert the energy? Photosynthesis

 Why is it important?  traps the sun’s energy and stores it in a sugar called glucose.  The stored energy is used by living things

6 CO H 2 O + Energy C 6 H 12 O O 2 Carbon Water Sunlight Glucose Oxygen Dioxide

 Who uses the energy trapped by producers?  All living things use the energy trapped by producers  producers use this energy themselves  Other living things, called consumers eat producers for their energy

Chemosynthesis: chemical energy is used to produce carbohydrates Primary producers like bacteria harness chemical energy from inorganic molecules such as hydrogen sulfide (hydrogen sulfide-bacterial breakdown of organic matter in the absence of oxygen)bacterialorganic matteroxygen

 Herbivore- plant eater  Carnivore- animal eater  Omnivore- eats both plants and animals  Decomposers- decay, chemical breakdown of organic matter  Scavengers- animals that consume the carcasses of other animals that have been killed  Detritivores- digest decomposers

Primary Consumers Producers Detritus Feeders Producers Primary Consumers Secondary Consumers Tertiary Consumers Decomposers

 Food Chain – the path of energy through the trophic levels of an ecosystem - all food chains begin with a producer

 = a series of multiple interconnected food chains.  in most ecosystems, energy doesn’t follow a simple path  many consumers eat at different trophic levels  food webs are representation of the complex relationships between organisms in an ecosystem

 Biomagnification – the concentration of toxins as they move through a food chain.  Ecological succession – changes in the composition of species found in a community over time  Ecosystem – a community interacting with its environment through a one-way flow of energy and the cycling of materials  Ecosystem stability – the ability of an ecosystem to return to a state of equilibrium following a disturbance

 Ecological pyramids: models that show the relative amount of energy or matter contained within each trophic level  Symbiosis – an ecological interaction between two organisms  Trophic level – position that organism(s) occupy in a food web, which is defined by its relationship to the primary energy source  Pioneer species – first species to populate an area during succession

 Ecological succession: a series of more or less predictable evens that occur in a community over time  Primary succession: begins in areas that have no remnants of an older community  Secondary succession: parts of old community survive, and can regrow rapidly

 90% of the energy available is lost as energy is transferred to the next trophic level - the energy is lost as heat  Only 10% is of passed on to the next level 100,000 J of sunlight 100 J Rats 10 J Snakes 1,000 J Grasshoppers 10,000 J wheat

Pyramids of energy show the relative amount of energy available at each trophic level of a food chain or food web Only 10% of energy is transferred to the next level

 Is the total amount of matter in the form of living tissue within a given trophic level  The amount of biomass a given trophic level can support is determined by the amount of energy available

A pyramid of biomass is a model that illustrates the relative amount of living organic matter available at each trophic level in an ecosystem.

 Autotrophs (producers) ▪ Algae ▪ Phytoplankton ▪ Plants ▪ Cyanobacteria ▪ Mosses ▪ Some protozoa

 Heterotrophs (consumers) ▪ Primary ▪ Secondary ▪ Tertiary ▪ Herbivores ▪ Carnivores ▪ Omnivores

 Decomposers ▪ Fungi ▪ Protists ▪ Bacteria

 Detritivores (detrivores) ▪ Millipedes ▪ Wood lice ▪ Types of earthworms

 What happens to the biomass and numbers as we move up trophic levels?  How does energy move through an ecosystem?  What amount of energy is available to each trophic level?