Chapter 4: Interactions of Life Lesson 1: Living Earth

Ecosystem An area where organisms interact with one another as well as with the nonliving parts of the environment Each organism interacts with other organisms in one or more ecosystems

The Biosphere The part of Earth that supports life Includes the top portion of Earth’s crust, the waters that cover Earth’s surface, and the atmosphere that surrounds Earth

Ecosystem An ecosystem contains both biotic and abiotic factors The living parts of an ecosystem An abiotic factor The nonliving parts of an ecosystem

A Place to Live Community Population All of the populations living together in ecosystem Populations in a community interact, using one another for food and shelter Population A group of organisms of the same species living together in an ecosystem

Habitat Habitat The part of the ecosystem in which an organism lives Each organism has its own habitat The habitat supplies everything the organism needs

Niche Niche An organism’s role in its environment Includes everything an organism needs, as well as everything it does, as well as how it interacts with its environment Two populations with similar needs can share a habitat, however, two populations cannot share the same niche

Habitat Ecosystem Ecosystem

Broad and Narrow Niches Organisms can have broad or narrow niches Broad Niche Organisms are able to live in a variety of places and eat many different foods Narrow Niche Organisms that live in one particular habitat, eat only a certain food, and live only in a particular range of conditions

Diversity Refers to the variety of species in an ecosystem, not necessarily the number of species in an ecosystem A population does not have to be big to be diverse                                        

Which group is more diverse?

Why are some ecosystems more diverse than others? Climate and Location Ecosystems closer to the equator have more species, so they are more diverse Coral Reefs, Tropical Rain Forest Ecosystems closer to the Earth’s poles have fewer species, so they are less diverse

High Diversity Areas                                           Tropical Rain Forest Coral Reef

Less Diverse Areas                                             Antarctica Snowy Tundra

Human Interaction The actions of humans are making ecosystems less diverse Removing forests and grasslands, draining swamps, building new roads, houses, and shopping centers

Getting Energy All living things need energy to live, eath, and grow The sun is the source of energy in almost all ecosystems This makes the Sun the first step in most food chains.

Getting Energy Producers An organism that can make its own food Usually Green Plants Responsible for Photosynthesis

Getting Energy Consumers Organisms that eats other organisms for energy 2 Types of Consumers Primary Consumer Herbivore—animal who eats only plants Secondary Consumer Carnivore—animal who eats other animals Omnivores Get energy from primary and secondary consumers.

Getting Energy Scavengers Decomposers Eat the remains of dead animals Vultures Decomposers Consumers that break down plant and animal remains Return nutrients to the soil Completes energy cycle Bacteria and Fungi

Steps of the Energy Cycle Sun—Producer—Primary Consumer—Secondary Consumer—Scavenger—Decomposer—Producer

Getting Energy Food Chain Sequence of connected producers and consumers Shows how energy flows through an ecosystem

Food Webs Food Web A group of connected food chains in an ecosystem A change in one population in an ecosystem can affect other populations

Energy Pyramid Shows that energy is lost at EACH LEVEL of the food chain. 90% of energy is lost at each level. 10% of energy is passed on. Why are there fewer organisms higher on the energy pyramid? Less energy to support organisms at the top.

Population Interaction Chapter 4 Population Interaction

Limiting Factors Factors in an environment that can become limited Space, light, food, water, air, and nutrients Can cause competition

Carrying Capacity The largest number of individuals of one species that an ecosystem can support over time When areas exceed carrying capacity leads to competition for resources

Competition The struggle among organisms for limited resources in an area When organisms have the same environment, they have different niches or roles

Predator-Prey Relationship Animal that feeds on living things Prey Animals that predators eat More Prey = More Predators More Predators = Less Pray Less Prey = Less Predators

Predator-Prey Relationships

Symbiosis Close relationships between organisms of different species in which one or both of the organisms benefit 3 Types Parasitism Mutualism Commensalism

Parasitism One organism is helped and the other is harmed Parasite An organism that lives in or on another organism Host Organism that a parasite lives in

Mutualism Type of symbiosis in which both organisms benefit Both are helped

Commensalism Type of symbiosis in which one organism is helped and the other is not affected in any way