Download BIOL 2306 – Living Planet (hybrid)

BIOL 2306 – Living Planet (hybrid)
CONCEPTS FOR EPISODE 10 – Worlds Apart
I.
Island Ecology
A. Effects of isolation
1. “self-contained” fully-functional ecosystems with reduced input
from “outside” the system
2. increased rate of evolution (genetic change)
B. Island Biogeography
1. the larger the island, the higher the species diversity (# or
species)
a. more diverse habitats
b. higher probability of animals and plants colonizing from
mainland
c. more resources
d. larger habitat area
e. more genetic diversity
f. lower probability of chance disaster (i.e., hurricanes)
2. adaptations to limited resources
a. availability of fresh water – some birds are able to extract
salt from salt water
b. availability of food – seasonal variations may limit
permanent resident populations
II.
Types of islands
A. Barrier islands (examples: Padre Island, Matagorda Island, Mustang Island)
- in shallow waters adjacent to continents
- plants colonize and stabilize sandbars
- protect mainland from storms
- shallow water between island and mainland often fertile
and diverse ecosystem (example: Laguna Madre)
B. Mangrove islands
- in shallow tropical and sub-tropical waters
- mangroves trap sediments and soil builds up
C. Geologically-formed islands
1. volcanic activity (example: Galapagos Islands)
2. splitting off from continents (example: New Zealand)
3. glacial scouring (example: islands off western coast of Ireland)
D. Coral reefs -- form in shallow tropical clean waters
1. fringing reef – grows out from mainland or island
2. barrier reef – grows along shoreline, but is separated from it by
lagoon
3. coral atoll – forms around submerged volcanic island (example:
Great Barrier Reef off eastern coast of Australia)