2.1 - StructureIB Topics 2.1.1-2.1.7

Topic 2 – The Ecosystem

Biotic and Abiotic Components

Biotic All living

components of the ecosystem

Ex:

Abiotic All non-living

components of the ecosystem

Ex:

Food Chains The position an organism occupies in a

food chain is called the trophic level.

Local Food Chain Example:

Food Webs Ecosystems

contain many interconnected food chains

Pyramid of Numbers A graphical model

of the number of organisms in a food chain

Pyramid of Biomass A graphical model

of the amount of biomass present in a food chain at a certain point in time

Pyramid of Productivity A graphical model

of the rate of energy production over time

Key Words (define and provide a local example of each) Species Population Habitat Niche Community Ecosystem

Parasitism Mutualism Predation Herbivory

2.2 – Measuring Abiotic ComponentsIB Topics 2.2.1-2.2.2

Topic 2 – The Ecosystem

Significant Abiotic Factors Terrestrial

Ecosystem Marine

Ecosystem Freshwater

Ecosystem

2.3 – Measuring Biotic ComponentsIB Topics 2.3.1-2.3.5

Topic 2 – The Ecosystem

Estimating abundance of organisms Counting the

number of organisms is almost always done using an estimate

Lincoln Index A mathematical

model to estimate population size

Capture-mark-release-recapture

Example 1

13 deer were caught and marked

14 deer were caught the second time and 5 were marked

Example 2

75 Ladybugs were caught and marked

80 Ladybugs were caught the second time and 3 were marked

Quadrats A square of area

used to measure the population of non-mobile organisms Can help to

calculate population density and percentage cover

Diversity1. The number of

different species

2. The number of individuals of each species

Simpson’s Diversity Index Used to compare

diversity between areas

High value of D implies stable ecosystem

Low value of D implies unstable ecosystem

2.4 – BiomesIB Topics 2.4.1-2.4.2

Topic 2 – The Ecosystem

Biomes A collection of

ecosystems that share similar climactic conditions

Rainforest

Desert Tundra Temperate Forest

Grassland

Prevailing Climate

Location

Sun Exposure

Precipitation

Limiting Factors

Rainforest

Desert Tundra Temperate Forest

Grassland

Prevailing Climate

Hot, Humid, Rainy

Hot, Dry Cold Seasonal Varied by location

Location Near Equator

Varied, where no

precip

Poles 40-60o N Latitude

Varied, where some precip

Sun Exposure

High Varied, usually

high

Low Medium, Seasonal

Varied

Precipitation

High None Snow Medium, Seasonal

Low

Limiting Factors

Too much precip.

Not enough water

Too cold, permafrost

Seasons Low precip

2.5 – FunctionIB Topics 2.5.1-2.5.7

Topic 2 – The Ecosystem

Photosynthesis

Respiration

Gross Primary Productivity (GPP)

The amount of energy produced by producers

Net Primary Productivity (NPP)The amount of

energy stored by producers and available to consumers

Gross Secondary Productivity (GSP)

The amount of energy consumed by consumers

Net Secondary Productivity (NSP)The amount of

energy stored by consumers and available to the next trophic level