2.1 - StructureIB Topics 2.1.1-2.1.7

Topic 2 – The Ecosystem

Biotic and Abiotic ComponentsBiotic

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