ECOLOGY: The study of the interactions between organisms, and the living and nonliving components of their

environment.

“TAIGA” Russian “little sticks”

Also known as a “Boreal Forest”It is the largest biome

in the world.The taiga is located

near the top of the world, just below the tundra biome.

Sunlight, temperature and precipitation determine the plants and animals that can survive in this biome

Characterized by coniferous, or (needle bearing trees) forest totaling about 30% of the worlds forest cover

Alaska’s Boreal forests

Subarctic climate with wide variations in

temperature ranges,(86°F to -65°F) and daylight

On average; 108 frost free days in the growing

season

Average 19in/year precipitation,but low evaporation due to indirect sunlight means enough water to

support lush growth

Soils are thin due to cold (permafrost in areas) roots are shallow

nutrient uptake is slowfallen leaves and moss can remain for a long time which

limits their organic contribution

Needles from spruce create acidic soil called

“Podzol” Al & Fe are leached out to lower horizons as well as clays and other minerals

Fires in 2004

Anchorage

Smoke

Brick red– fires pink—flames green--vegetation

SUCCESSION IN THE BOREAL FOREST

HERB STAGEGrasses and Flowering Plants

1-8 years after impact

Annual plants that grow, produce seeds and die in 1 year.

Sunlight penetrates to the ground

SHRUB STAGESitka Alder & Bebb Willow

6-25 years after impact

Shade intolerant perennial shrubs like Willow and Alder.

Provide good cover for animals.

Willow is primary moose browse

Direct sunlight available

Young Forest StageWhite Paper Birch

26-50 Years Deciduous trees (leaf

bearing)Birch, Aspen, & Poplar dominate

Shade intolerant shrubs begin to disappear except where direct sunlight is available

Shade tolerant plants dominate as ground cover (mosses, dwarf dogwood, low bush cranberry, wood fern)

Mature ForestWhite/Black

Sprucevs

Birch 51-150 years Spruce & Birch are

equal in abundance Lots of ground cover

diversity w/ shade tolerant plants

Small open areas at preceding stages

Climax Forest 150-300 plus years White Spruce is the

dominate tree Canopy more open

This stage will not change; only a disturbance will cause succession to repeat.

Energy through the ecosystems Ecology

ENERGY PRODUCTIVITY FOOD CHAINS

Is the source of biological energy for living

things. Is light energy that is changed to chemical

energy(sugar) by plants. 1 of 3 major components that determine the

plants, thus animals that can live in an ecosystem. Temperature & precipitation are the others

The SUN ..

Plants (producers) 1. Produce chemical

energy(sugar) from light energy by photosynthesis: thus they are “producers”

2. Are considered autotrophs or “self feeders”

3.Create biomass or stored energy for all other living organisms

Net primary productivity The rate at which plants

capture energy NPP varies depending on

seasons & locations. Winter=low to none Spring&summer= high

productivity Results in migration

patterns of animals seeking energy(in the form of food)

Biomass 1. The organic

material found in an ecosystem.

2. Represents stored energy available to other organisms

3. The rate biomass accumulates is net primary productivity

Consumersall heterotrophs

1. Any organism that gets its energy by “eating” biomass

2. Do not photosynthesize

3. Can be categorized by their diet as herbivore, omnivore, carnivore,detritivore. decomposer

Herbivores1. Consumers that rely

on eating plants to gain energy.

2. Are typically prey species for carnivores.

3. Often referred to as 1st order consumers orPrimary consumers

Omnivores 1. Animals that eat

both plants and other animals as part of their diet.

2. Maybe considered 1st order or 2nd order consumers

Carnivores1. Organisms that eat

other animals.(prey)2. Are considered

predators, & 3rd order or greater consumers.

3. Their populations are controlled by the number of prey species

Trophic levels

1.A trophic level is a feeding level where energy is passed from one level to the next; ie herbivore to carnivore

2. 90% of captured energy is lost in the transfer from one level to the next

3. Detritivores and decomposers are found in all trophic levels and are considerd the FINAL energy acceptors in

A pyramid is used to show relationships between organisms,Energy, and biomass. There is a 10% transfer(or 90% loss) from one level to the next. (going up the pyramid)

Detritivoresheterotroph

1. Detritivores are found in all trophic levels.

2. Detritivores(bugs, worms, millipedes) feed on dead;decaying matter, breaking it down but leaving behind some nutrients

Decomposers:heterotroph

1. Bacteria, molds, rusts2. Found in all trophic

levels3. They are considered

the FINAL energy acceptors: leaving only nutrients and molecules that are available for plants to take up again.

Bugs and bacteria

Food webs1. The relationship

many plants and animals have with each other.

2. These relationships are dependent on one another

3. The loss of one affects the survival of the others.