Ecology

Principles of Ecology

Organization in the biosphere Biosphere-

portion of the Earth that supports life

Abiotic factors- non-living parts of the environment

Ex.- air temp.,water, light, soil

Biotic factors- all living organisms that inhabit an environment

Parts of the Biosphere

Organization of the biosphere

Ecosystem- interactions among the populations in a community and the communities’ physical surroundings ( or abiotic factors)

Parts of an Ecosystem Habitat- place where organism

lives Niche- role and position a

species has in its needs for food and shelter -all interactions with biotic and

abiotic parts of its environment

Biosphere

Ecosystem

Community

Population

Organization of the biosphere Community

a collection of interacting populations

a change in one population causes a change in another

Biosphere

Ecosystem

Community

Population

Organization of the biosphere

Population group of organisms

of one species that interbreed and live in the same place at the same time

Biosphere

Ecosystem

Community

Population

Organization of the biosphere Ecosystem

Community

Population Ecology Population growth- increase of the size of a group

over time ZPG = Zero Population Growth birthrate = death rate Population Growth = birthrate-death rate x 100

1000

Population Ecology  Exponential

Growth- as population gets larger, it grows faster

J-curve graph

Population Ecology Carrying capacity- number of organisms of

one species that an environment can support S-shaped curve

Human Population Growth

Factors effecting population growth rate Age structure see fig. 4.11 p. 107

Immigration- movement

into a population

Emigration- movement

from a population

Relationships in the community

Symbiosis- relationships between organisms where there is a close and permanent association among organisms

Three types Mutualism Commensalism Parasitism

Types of Symbiosis Mutualism- both organisms benefit

Lichens are formed by algae and fungi living together. Algae can photosynthesize and make food which is shared by the fungus. The fungus in turn shelters the algae from a harsh climate.

Types of Symbiosis Mutualism #2

Bright and colorful clown fish live in and amongst the tentacles of the sea anemone, which look like beautiful aquatic flowers, but bear poisonous stinging cells called nematocysts. A slime layer covering the clownfish make them immune to the stinging cells, and the stinging tentacles of the sea anemone deter potential predators. The clownfish in turn protect the sea anemone from other fish that would feed on the anemone. Clownfish lay eggs within the sea anemone, which offers protection during their incubation and development.

Types of Symbiosis Commensalism- one organism benefits, the

other is unaffected

Barnacles attach to a whale or scallop shell. The barnacles get a home and transport, and the whale or scallop is not affected.

Types of Symbiosis Commensalism #2

The Cattle Egret (Bubulcus ibis) forages in pastures and fields among livestock such as cattle and horses, feeding on the insects stirred up by the movement of the grazing animals. The egrets benefit from the arrangement, but the livestock, generally, do not. However as in most cases of commensalism, there is a "but". Cattle Egrets have been observed perching on the top of cattle picking off ticks, lending a slight tinge of mutualism to the arrangement.

Types of Symbiosis Parasitism- one organism benefits, the other is

harmed

A tapeworm lives inside another animal, attaching itself to the host's gut and absorbing its host's food. The host loses nutrition, and may develop weight loss, diarrhea and vomiting. Usually parasites do not kill the host before they move on, as this would cut off their food supply.

Types of Symbiosis Parasitism #2

Nutrition and Energy Flow The ultimate source

of energy is…

the SUN!

Nutrition and Energy Flow

Autotroph/Producers use sun’s energy to create chemical compounds (photosynthesis)

Ex. – plants and algae

Food Chains- shows how matter and energy flow from autotroph to heterotroph to decomposer

Herbivores/1st Order Consumers- feeds on plants

Carnivores/ 2nd and 3rd Order Consumers- feed on other animals

Heterotrophs/Consumers- organisms that feed on other organisms

Nutrition and Energy Flow

Decomposers- break down and absorb nutrients from dead organisms

Ex.- fungi and bacteria

Nutrition and Energy Flow Other members of a

food chain Omnivores- feeds

on plants and animals

Nutrition and Energy Flow Other members of a

food chain Scavengers- eats

animals that have already died

Nutrition and Energy Flow Food Webs- all

possible feeding relationships in a community

Nutrition and Energy Flow Aquatic food web

Nutrition and Energy Flow Trophic Levels- a

feeding step in a food chain

only pass on approximately 10% of energy to next trophic level

Nutrition and Energy Flow

Pyramid of Energy- shows loss of energy at each trophic level

Nutrition and Energy Flow

Nutrition and Energy Flow

Nutrition and Energy Flow

Cycles in Nature

Carbon Cycle

Cycles in Nature Water Cycle