Objectives: Understand the elements that make up ecosystems and significance Make thorough observations of the elements of an ecosystem Make contributions to the construction of a food web Demonstrate comprehension of the interaction abiotic and biotic factors in ecosystems

Environmental Interactions Ecology- scientific study of the interactions between organisms and their environment Environment- surroundings The environment consists of 2 parts: 1. biotic factors- all living things thatinhabit the environment ex. Plants, bacteria, animals 2. abiotic factors- nonliving parts of the environment ex. Temperature, light, soil, air Must have abiotic factors in order for biotic factors to exist Limiting factors- factors that restrict the size of a population. ex. The amount of food, space

Organization of Life (simplest to largest) 1.organism- 1 living thing 2.Population- group of organisms of the same species living in the same area -they compete for resources like food 3.community- all organisms living in the same area (all populations in an area) -each population affects others ex. Fox affects rabbits 4.ecosystem- all living organisms plus their surroundings in an area 2 general types of ecosystems terrestrial- land ex. Forest aquatic-water 5. biosphere- highest level-all living and nonliving parts of the earth-all living things are found here

How do organisms live in the same community without running out of resources? -they feed on different types of food -illustrated by food chain and food web All organisms feed in 1 of 3 ways: 1.producers- makes own food (ex. Plants) 2.Consumers- ingest food from other organisms (ex. Human) 3.decomposer- breaks down organic matter to nutrients (ex. Bacteria)

Types of feeding relationships in a community: 1.Autotroph (self-feed)- get energy from the sun to make own food 2.heterotroph- organism that consumes other organisms for food types of heterotrophs: a. herbivore- eats plants b. carnivore- kills and eats animals c. scavenger- feeds on animals already dead (ex. Buzzard) d. omnivore- feeds on plants and animals ex. Human 3.decomposer- breakdown and absorb nutrients from dead organisms (ex. Bacteria, fungi)

How is energy moved or cycled through the ecosystem? By the food chain and food web Food chain- model used to show how energy is moved from 1 organism to another -shows one feeding relationship ex. autotroph > heterotroph> carnivores (arrow points to the animal that is doing that the energy is going to) Each link on the food chain is called a trophic level

Food web Shows multiple feeding relationships in an ecosystem It is the more reliable than the food chain

Each link in the food chain has 3-5 links only (no more). Why? Energy is used at each link (each transfer) *Only 10% is passed on to the next level Ex. Plant > grasshopper> fish> human 1000 cal100 cal 10 cal1 cal energy pyramid- shows less energy transfer with each link of the food chain -organism number decreases with each level

Components of an energy pyramid Producers- always at the base/beginning of food chain ex. Grass (bottom of pyramid) Primary consumer- consumes plants directly man ex. grasshopper fish Secondary consumer- eats primary consumer grasshopper ex. Fish plant Tertiary consumer- eats secondary consumer ex. man

Niche-role a species plays in its community (job) habitat-place where an organism lives out its life (ex. Aquatic habitat)

Questions for review: What is an ecosystem? What elements make up an ecosystem? How are the elements of an ecosystem related? What is the relationship between producers and consumers in an ecosystem? How do organisms coexist in an ecosystem? What is a food web?

Examples of organism interactions: Predation Competition Symbiotic relationships

Predation Predation-when one organism kills another predator- organism that kills prey- organism killed Each affects the size of the other’s population

competition 2 organisms strive to obtain the same limited resources (ex. Food) Both organisms are harmed somewhat Competition may be between the same species or between different species “survival of the fittest”- the stronger of a species wins which weeds out the weaker ones

Close feeding relationships: Symbiosis-close feeding relationship in which one lives in or on another organism Types of symbiosis: 1. commensalism- relationship in which one organism benefits and the other is not affected ex. Moss on tree ex. Cowbird on cow 2. mutualism- relationship in which both organisms benefit ex. Bacteria in cows ex. Bee and flower 3. parasitism- relationship in which one benefits and the other is harmed ex. Tapeworm in stomach ex. Mosquito sucking blood

Involves 4 processes: 1. evaporation- changing from liquid to a gas (evaporation from plants is called transpiration) 2. condensation- changing from a gas to a liquid droplets (occurs in clouds) 3. precipitation- liquid returns to earth as rain, sleet, snow, hail 4. respiration- water is breathed out from the lungs

Carbon cycle Source of carbon is Carbon dioxide in atmosphere It is converted by plants to glucose by photosynthesis Animals ingest the glucose and then die. When they die carbon is returned to the air as carbon dioxide by bacteria when the matter decays.

student lab home student lab home Nitrogen cycle Nitrogen makes up 78% of atmosphere. Problem: we cannot use it unless it is converted to nitrate. Only 2 things can convert nitrogen to the form we use. These are: lightning and nitrogen fixing bacteria.

Do not copy—this is review Example of Food chains

Example of food web

Food web Everglade web

Consumerevolutionhost symbiosis Decomposerextinctionlimiting factor trophic level Detritusfood chainmutualism Ecologyfood webomnivore Ecosystemhabitatparasite Environmentherbivorepredation