Lecture 22

Question 1

Ecosystem

Answer 1

A community of organisms an the physical and chemical interactions they have with their environment

• Consist of living (biotic) and non-living (abiotic) components
• Abiotic components include air, water, soil, temperature, salinity, and nutrients

Question 2

Two major Ideas of ecosystem ecology

Answer 2

• Flow of energy and cycling of nutrients
• Energy flows through ecosystems (Cannot be recycled)
• Nutrients cycle through ecosystem (can be recycled)

Question 3

Ecosystem productivity

Answer 3

The amount of biomass (dry weight of biological material) that is added to a system during a given period of time by plants in that system
-Rate
-Varies among biomes
-Units include:
lbs/acre/year
kg/ha/year
g/m^2/year
kcal/m^2/year

Question 4

Biomes

Answer 4

A region of similar climate and dominant plant types

Question 5

Insolation

Answer 5

Measure of solar radiation energy received on a given surface area in a given time

Question 6

Productivity

Answer 6

The rate at which a new biomass is produced

Question 7

Biomass

Answer 7

Organic matter produced by plants and other photosynthetic producers; total dry weight of all organic matter in plants and animals in an ecosystem
-Snapshot in time

Question 8

Relationship between productivity and biomass

Answer 8

In many systems the two are positively correlated, but this is not always the case

Question 9

Humans and productivity

Answer 9

Humans use about 20% of Earth’s total net primary productivity (Food, construction materials, fuel, fibers)

• We also reduce the productivity of our planet by converting forests, grasslands to agriculture, urban areas
• Direct impact on biodiversity decline
• Crowding out and eliminating habitats and food supplies of many other species