Communities, Biomes and Ecosystems

1-13-15EQ: How do organisms interact with

their environment?

Chapter 2.1

• Ecology Study of interactions between organisms and their surroundings

Section 3-1

Figure 3-2 Ecological Levels of Organization

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Ecological Levels of Organization

Bioshphere

• The biosphere consists of all life on Earth and all parts of the Earth in which life exists.

Biome• Biome—a group of

ecosystems that share similar climates and typical organisms

Biological Levels of Organization

• Ecosystem—all the organisms that live in a place, together with their physical environment

• Community—an assemblage of different populations that live together in a defined area

Biological Levels of Organization

• Population—a group of individuals that belong to the same species and live in the same area

• Individual Organism– one organism of a species

Abiotic and Biotic Factors

What are biotic and abiotic factors?

Abiotic and Biotic Factors

• A biotic factor is any living part of the environment with which an organism might interact

Abiotic and Biotic Factors

• An abiotic factor is any nonliving part of the environment, such as sunlight, heat, precipitation, humidity, wind or water currents, soil type, etc.

Ecosystem Interactions

• Niche vs. Habitat

Habitat

• Habitat General place where an organism lives

Niche

• Niche—range of physical and biological conditions in which a species lives and the way the species obtains what it needs to survive and reproduce– How an organism interacts with biotic and abiotic

factors

Niche

• Instead of competing for resources species usually divide resources such as – Food, water, space,

nutrients, or light (necessity of life)

Community Interactions

• Competition Occurs when organisms attempt to use the same limited ecological resource in the same place at the same time.

Predator Prey Relationship

• Interaction in which one animal (the Predator) captures and feeds on another animal (prey)

• Predators can affect the size of prey populations in a community

Predator Prey Relationship

Camouflage to avoid predation

Mimicry

Symbiotic Relationships

• Symbiosis Living together• Three main types

– 1. Mutualism– 2. Commensalism– 3. Parasitism

Symbiotic Relationships

• Mutualism:– Organisms that benefit from a relationship with

each other– Example: Pollination, clown fish and anemone

• Commensalism:– One organism benefits from a relationship; the

other organism is neither harmed nor helped– Example: Barnacle and Whale

Symbiotic Relationships

• Parasitism:– Relationship in which one organism lives inside or

on another organism and harms an organism– Example: Fleas, ticks, leech, tapeworms

Communities 3.1

• Group of interacting populations that occupy the same area.– How does abiotic factors affect a community?– How does biotic factors affect a community?

Limiting factors

• Any abiotic or biotic factor that restricts organisms (numbers, reproduction or distribution)– Abiotic examples

• Water, temperature, fire, climate– Biotic examples

• Other plants or animals

Tolerance

• Tolerance—Ability to survive and reproduce under a range of environmental circumstances

• When environmental conditions, such as temp, goes beyond optimal range organism experiences stress

Tolerance

• When outside optimal range must expend more energy to maintain homeostasis

• Tolerance for environment helps determine habitatgeneral place where an organism lives

• J

Succession

• Ecological succession a series of more-or-less predictable changes that occur in a community over time

• Two types of succession– 1. Primary Succession– 2. Secondary Succession

Primary Succession

• Primary succession Life begins in an area where no community has existed before

• Examples volcanic islands, bare rock from retreating glaciers

• S

Primary Succession

• First species to colonize barren areas are called Pioneer Species– Examples lichen (mutualistic organism of fungus

and algae), moss and certain grasses• Pioneer species break down rock, and form

soil

Bare rockbare rock→lichens→mosses→grasses→shrubs→trees

Glacial retreat

Man-made structures

Secondary Succession

• Existing communities are not completely destroyed by disturbances. Then secondary succession occurs.

• Faster than primary succession because soil exists

Secondary Succession

• Occurs after natural disturbances– Wildfire, hurricane, human activities such as

logging and farming

Hurricane

Figure 53.18x1 Large-scale disturbance: Mount St. Helens

Figure 53.18x2 Forest fire

Climax Communities

• Climax Community Stable, mature community where little change in the composition of species

• Succession doesn’t always reproduce the original climax community

Biome 3.2

– The map shows the locations of the major biomes.

Tropical rain forest

Tropical dry forest

Tropical savanna Temperate woodlandand shrubland

Desert

Temperate grassland

Boreal forest(Taiga)

Northwesternconiferous forest

Temperate forest

Mountains andice caps

Tundra

Section 4-3

Figure 4-17 The World’s Major Land Biomes

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Color coded biomes of the World

Global Distribution of the Biomes

Section 4-3

Compare/Contrast Table

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Ten Major Biomes

Biome Precipitation Temperature Soil Diversity Trees Grasses

Tropical Rain Forest

high hot poor high dense sparse

Tropical Dry Forest

variable mild rich moderate medium medium

Tropical Savanna

variable mild clay moderate sparse dense

Desert low variable poor moderate sparse sparse

Temperate Grassland

moderate summer hot rich moderate absent dense

Temperate woodland and Shrubland

summer low, winter moderate

summer hot poor low medium medium

Temperate Forest

moderate summer moderate, winter cold

rich high dense sparse

Northwestern Coniferous Forest

high summer mild, winter cold

rocky, acidic

low dense sparse

Boreal Forest moderate summer mild, winter cool

poor, acidic

moderate dense sparse

Tundra low summer mild, winter cold

poor low absent medium

Freshwater Ecosystems 3.3– What are the major categories of freshwater

ecosystems?

Freshwater Ecosystems– What are the major categories of

freshwater ecosystems?

– Freshwater ecosystems can be divided into three main categories: rivers and streams, lakes and ponds, and freshwater wetlands.

Spoonbill

Duck

DragonflyPhytoplankton

FrogWater lilies Mosquito

larvae

SnailDivingbeetle

Trout

Pickerel

Duckweed

Snail Benthiccrustaceans

Hydra

Frogs lay eggs in the shallowwater near shore.The eggs hatch in the water as tadpolesand move to the land as adults.

The shore is lined with grasses that provide shelter and nestingplaces for birds and otherorganisms.

The roots of water liliescling to the pond bottom,while their leaves, on longflexible stems, float on thesurface.

The bottom of the pond isinhabited by decomposers andother organisms that feed onparticles drifting down from thesurface.

Fish share the pondwith turtles and other animals. Many of them feed on insectsat the water’s edge.

Plankton and the organisms thatfeed on them live near the surfacewhere there is enough sunlight forphotosynthesis. Microscopic algaeare among the most importantproducers.

Section 4-4

Freshwater Pond Ecosystem

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Crayfish

Freshwater Ecosystem

Marine Ecosystems– This diagram shows the different zones in

an ocean.

Open Ocean – The open ocean is divided into two

zones based on light penetration—the photic and aphotic.