What is Ecology? Greek Word Roots: “eco” come from “oikos” which means “house” “logy” means “study of”

What is Ecology? Ecology – study of the interactions of living organisms with one another and with their physical environment.

Ecology Terms Habitat – a place where a particular population of a species live. Community - the groups of many different species that live together in a particular habitat.

Ecology Terms Ecological system or ecosystem – consists of a community and its habitat.

Ecosystem Terms Biotic Factors – all of the living organisms that belong in a habitat. Examples: a) animals b) plants c) fungi d) protists e) bacteria

Ecosystem Terms Abiotic Factors – all of the physical (non-living) aspects that belong in a habitat. Examples: a) soil (mineral), water, wind (air) b) energy such as light or sound c) climate, weather, temperature

The Tropical Rainforest is the most diverse ecosystem. Ecosystem Terms Biodiversity – a measure of the number of species living in a certain ecosystem. The Tropical Rainforest is the most diverse ecosystem.

All members of an ecosystem are interdependent. Ecosystem Terms Niche – an ecological role that an organism fulfills in an ecosystem. All members of an ecosystem are interdependent.

Ecosystems Change Over Time When a new habitat is created (fire, earthquake, logging, etc) the change is somewhat regular Natural, gradual changes in the types of species that live in an area; can be primary or secondary

Primary Succession Begins in a place without any soil Sides of volcanoes Landslides Starts with the arrival of living things such as lichens that do not need soil to survive Called PIONEER SPECIES

Primary Succession Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil

Primary Succession Simple plants like mosses and ferns can grow in the new soil

Primary Succession The simple plants die, adding more organic material The soil layer thickens, and grasses, wildflowers, and other plants begin to take over http://www.cwrl.utexas.edu

Primary Succession These plants die, and they add more nutrients to the soil Shrubs and tress can survive now http://www.rowan.edu

Primary Succession Insects, small birds, and mammals have begun to move in What was once bare rock now supports a variety of life http://p2-raw.greenpeace.org

Secondary Succession Begins in a place that already has soil and was once the home of living organisms Occurs faster and has different pioneer species than primary succession Example: after forest fires

Climax Community A stable group of plants and animals that is the end result of the succession process Does not always mean big trees Grasses in prairies Cacti in deserts

Energy Flow in Ecosystems A) The primary source of energy is the sun. B) Producers are organisms that capture light energy and convert it into chemical energy. C) Consumers are organisms that consume producers or other consumers for energy. D) Decomposers are organisms that consume producers, consumers, and other decomposers for energy once they have died.

Energy Flow in Ecosystems Producers - organisms that make energy-storing molecules, such as glucose, from light or chemical energy. They are the first and the most important link in an ecosystem, they are sometimes called: Autotrophs - produce food for themselves. Examples: some bacteria, few protists, and all of the green plants

Energy Flow in Ecosystems Consumers - organisms that consume plants or other organisms to obtain energy. They are the second and less important links in an ecosystem, they are sometimes called: Heterotrophs – rely on other organisms for food. Examples: some bacteria, most protists, some fungi, all plants not green, and all animals

Consumer Types: 1) Herbivore – feed directly on green plants. Examples: deer, cattle, zooplankton, turtles 2) Carnivore – feed on other animals. Examples: lions, hawks, fish, frogs 3) Omnivore – feed on plants and animals. Examples: bears, raccoons, crayfish, humans

Energy Flow in Ecosystems Decomposers – organisms that consume organic wastes and dead bodies of other organisms. They are the last and much needed link in an ecosystem, they are sometimes called: Heterotrophs – rely on other organisms for food. Examples: some bacteria, few protists, and some fungi

Energy Flow in Ecosystems Every living organism requires energy. Trophic Level - shows how energy gets transferred from organism to organism. Sun  Producer  Consumer  Decomposer

Energy Flow in Ecosystems Food Chain – the path of energy through the various trophic levels of an ecosystem.

Food Chains: 1st level Producers - make their own food. 2nd level Herbivores - eat primary producers. 3rd level Carnivores - eat herbivores. Omnivores - eat both herbivores and carnivores. 4th level Decomposers - eat all dead organisms.

Energy Flow in Ecosystems Food Web – all of the interconnected groups of organisms that make up many food chains.

Ecosystem Energy The energy that is stored at each trophic level is about 1/10 that of the level below it. By showing the declining amounts of energy in each of the trophic levels an ecological pyramid can be formed.

Symbiotic Relationships Symbiosis- two species living together 4 Types of symbiosis: 1. Commensalism 2. Parasitism 3. Mutualism 4. Predation Cleaning shrimp 28

1. Predation Predation- when one organism eats another

Symbiotic Relationships Commensalism- one species benefits and the other is neither harmed nor helped Ex. orchids on a tree 30

Symbiotic Relationships Parasitism- one species benefits (parasite) and the other is harmed (host) Ex. lampreys, leeches, fleas, ticks, tapeworm 31

Symbiotic Relationships Mutualism- beneficial to both species Ex. cleaning birds and cleaner shrimp The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos. The plover has also been observed taking leeches from the open mouths of crocodiles! In this association the plover receives a supply of food and the other animal rids itself of unwelcome pests 32

= 1 species Type of relationship Species harmed Species benefits Species neutral Commensalism Parasitism Mutualism = 1 species 33

Ecosystem Terms Limiting Factor – any biotic or abiotic factor that restricts the existence of organisms in a specific environment. Examples of limiting factors Amount of water Amount of food Temperature

Limiting Factors Density Dependent- depend on how many organisms live in an area Example: disease; food shortages Density Independent – do NOT depend on how many organisms live in an area Example: tornado; earthquake

Ecology Terms Carrying capacity: the number of organisms that can be supported by a particular ecosystem

Cycling maintains homeostasis (balance) in the environment. Nutrient Cycles Cycling maintains homeostasis (balance) in the environment. 3 cycles to investigate: 1. Water cycle 2. Carbon cycle 3. Nitrogen cycle 37

Evaporation, transpiration, condensation, precipitation Water cycle Evaporation, transpiration, condensation, precipitation 38

Carbon cycle- Photosynthesis and respiration cycle carbon and oxygen through the environment. 39

Nitrogen cycle- Atmospheric nitrogen (N2) makes up nearly 78%-80% of air. Organisms can not use it in that form. Lightning and bacteria convert nitrogen into usable forms. 40