Principles of EcologyUnit 5

ECOLOGY WARM-UPPut the following in order from smallest to largest:ecosystem, biome, organism, population, community, biosphere

Ecosystem AssignmentDraw a picture of your "ideal" ecosystem. In other words, if you could live in anywhere in the world, where would it be and what would it look like. List the biotic and abiotic factors around you. Also, write down the levels of organization in your ecosystem. (organism, population, community, ecosystem, biome)

What is Ecology?

Ecology is the study of the interactions among living things, and between living things and their surroundings.

Biologically_Speaking__Ecosystems_and_the_Cycles_of_Nature.asf

Levels of Organization

An organism is any living thing.

Ex: an alligator

A population is a group of the same species that lives in one area.

Ex: a group of alligators that live in the same place at the same time.

Organism

Population

A community is a group of different species that live together in one area.Ex: alligators, birds, frogs, grass, trees, insects, etc…

An ecosystem includes all of the organisms as well as the climate, soil, water, rocks and other nonliving things in a given area

Ecosystem

A biome is a major regional or global community of organisms characterized by the climate conditions and plant communities that thrive there

Ex: Savanna

Every ecosystem includes both living and nonliving factors:

Biotic Factors: are the living things in a ecosystem.Examples:Plants, animals, fungi,bacteria, and protists

Abiotic Factors are the nonliving things in an ecosystem.Examples: rainfall, temperature, sunlight, soil, & wind

Biodiversity is the assortment, or variety, of living things  in an ecosystem.A keystone species is a species that has an unusually  large effect on an ecosystem.Ex: Beavers lead to major changes in an ecosystem.

ENERGY IN ECOSYSTEMS

Producers and Consumers

Type Also Called Description

Producer Autotroph Gets energy from nonliving resources

Consumers Heterotrophs Get energy by eating other organisms

Processes by Which Produces Obtain Energy

Both:All producersmake own energy

-Example of cyanobacteria

Types of Consumers

Name of Consumer: Role:

Herbivore Eats only plants

Carnivore Eats only other animals

Omnivore Eats both plants and animals

Detritivore Eats dead organic matter

(Examples: decomposers & scavengers)

Examples of each???

carnivore decomposer

A food chain is a model that shows a sequence of feeding relationships. *Trophic level s are the nourishment levels of a food chain.

Food Webs

A food web shows the complex network of feeding relationships and flow of energy.Example in notes:Producer: phytoplankton & algaePrimary Consumer: zooplankton, shrimp, etc…Secondary Consumer: sponge, jellyfishTertiary Consumer: Reef Shark

Pyramid Models

Energy pyramid shows the distribution of energy among trophic levels

Tertiary Consumer

Secondary Consumer

Primary Consumer

Producers

Between each tier of an energy pyramid, up to 90 percent of the energy is lost into the atmosphere as heat.Only 10 percent of the energy at each tier is transferred from one trophic level to the next.

Two other pyramid models:

1. Biomass Pyramid:   measures: total dry mass of organisms in a given area.

tertiaryconsumers

secondaryconsumers

primaryconsumers

producers

75 g/m2

150g/m2

675g/m2

2000g/m2producers 2000g/m2

2. Pyramid of Numbers: Measures: the number of individuals at each trophic level*Numbers in populations decrease as you go up.

500.000

5000

5

INTERACTIONS IN ECOSYSTEMS

A habitat is the place where an organism lives.

*A niche is an organism’s role in its environment.

*A niche includes all of the factors that a species needs to survive, stay healthy, and reproduce.foodabiotic conditionsBehavior

Madagascar

South America

Ecological equivalents are species that occupy similar niches but live in different geographical regions

Community Interactions

Important organism interactions include competition, symbiosis, and predation.

Symbiosis.asf

Competition

Competition occurs when two organisms fight for thesame limited resource

Symbiosis

Symbiosis: relationship between 2 different species where at least one species benefits.

Predation

-PredationProcess by which one organism hunts and kills another organism for food.

Types of Symbiotic Relationships

*Mutualism is a symbiotic relationship in which both species benefit.

Commensalism

One species benefits and the other is not affected.

Parasitism

Parasitism is a symbiotic relationship in which one species benefits and the other is harmed.

Organism benefits

0

_

Organism is not affected

Hornworm caterpillarThe host hornworm will eventually die as its organs are consumedby wasp larvae.

Braconid waspBraconid larvae feed on their host and release themselves shortly before reachingthe pupae stage of development.

_

Parasitism +

0

ECOLOGICAL SUCCESSION

*Ecological succession is the natural replacement, over time, of one community of organisms by another. .

-

*Ecosystems are always changing due to natural events or by human action.*After any disturbance, organisms replace other species through the gradual, predictable process of succession.

PRIMARY SUCCESSION:

Primary succession is the gradual development of a new community from nothing..

*It occurs on bare terrain, without soil or pre-existing plant or animal life.)

*Volcanic eruptions or floods that carry away the soil can lead to primary succession.

*Any species to move into a devastated area is a pioneer species.*They must be able to live on limited resources.*Examples include bacteria and tiny plants.*Lichens are common pioneer species because they can live on bare rocks.*The formation of soil is the first step in primary succession.

Primary Succession Animation

SECONDARY SUCCESSION:*Secondary succession occurs when a disturbance changes or partially destroys an ecosystem, but leaves the soil.

*Examples: abandoning farmland, leaving a logged forest to regrow, or burning down a forest

Secondary succession

Succession Eventually Slows:*Succession does not continue indefinitely. *A more stable community called a climax community eventually forms.*A climax community has organisms that are well adapted to the environmental conditions and can survive and reproduce.*Examples include the swamps of Florida and the old growth forests of the Pacific Northwest.*Climax communities can restart due to natural disasters or human impact.

Populations:

*A population is a group of organisms of one species that live in the same place at the same time. Organisms in a population compete for   -food -water -mates

Population Density: is the number of individuals that live in a defined area.

Factors that affect the size of a population:

Immigration-movement of individuals into a population.BirthsEmigration-movement of individuals out of a populationDeath

Types of Population Growth:

Exponential Growth: J-curve graph:

A population grows rapidly because of an abundance of resources.Birth rate exceeds death rate

Logistic Growth:

S-curve:

A population begins with a period of slow growth followed by a brief period of exponential growth before leveling off at a stable size.The carrying capacity is the point at which the population growth becomes stable. (max. number of indiviudals an environment can support)

Limiting Factors: ecological factors limit pop. growth.

Density-Dependent Limiting Factors:

CompetititionPredationParasitism/Disease(affected by the number of organisms that live in a given area)

Density-Independent Limiting Factors

Unusual weather (droughts, floods)Natural disasters Human activities

(affect the populations regardless of their size)

Attachments

Biologically_Speaking__Ecosystems_and_the_Cycles_of_Nature.asf

Symbiosis.asf