Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
16 Cards in this Set
- Front
- Back
|
continental islands*
|
• Located on continental shelves or detached fragments of continents
• Geologically related to continents • Usually separated from continents by shallow sea passages • May have been physically connected to continent during periods of low sea level (land-bridge islands) • Inhabited by some mammals and amphibians of continental origin • Variety of natural resources similar to that of continents • Resource limitations not so significant • Relatively accessible Examples: Cuba, Trinidad, England, Madagascar, Borneo |
|
|
oceanic islands*
|
• Originated in the ocean, not geologically related to continents
• (Almost) always volcanic • Often remote, isolated, small • Separated by deep water from continents • Have limited resources and less varied environments • Accessible to people only in the last 2,000 yrs. Examples: St. Lucia, Barbados, Ascension, Iceland, Mauritius, Maldives, Tahiti, Hawaii |
|
|
island colonization
|
Q: How do things get there? (“colonization vectors”)
• wind • floating (currents) • rafting • birds • human introduction (intentional and accidental) Colonization is a rare and random event. Not only must a plant or animal survive the journey, but a reproductive pair must arrive at more or less the same time in order to establish a viable population. It all happens entirely by chance (“sweepstakes routes”). Q: What influences the chances of arrival and successful colonization? • area (size) • relief (high vs. low islands) • distance from source region • direction of prevailing winds and currents • the distance across intervening ocean gaps (“filter gaps”) |
|
|
source region
|
where the plant or animal originally came from (colonization)
|
|
|
adaptive radiation
|
when a species successfully colonizes an island and survive it evolves to fill the many available ecological niches
|
|
|
dispersal vectors
|
wind, birds, human introduction (intentional: horses; accidental: rats), rafting (iguana), currents
|
|
|
filter effect
|
something about different islands have different species
|
|
|
Wallace's line
|
deep water seperates islands
|
|
|
endemism*
|
concentrated in one area
* species residing on insular islands are endemic |
|
|
endemic species*
|
very vulnerable because endemic species are on insular islands
|
|
|
disharmonic (unbalanced) biota*
|
- loss of verterbrae animals (predators on the island)
- loss leads to a loss of defensive traits |
|
|
theory of island biogeography
|
In The Theory of Island Biogeography (1967), Robert McArthur and Edward Wilson proposed a model that islands are in a state of “dynamic equilibrium” between immigration and extinction of species.
The rate of immigration is faster for islands near a mainland source and that rate of extinction faster for small islands. Thus, a small and remote island will have the smallest number of species. |
|
|
insular/insularity*
|
the isolation of islands
- related to endemic species |
|
|
colonial legacies
|
the last effects that a former "island owner has on a community," think of the Francophone community
|
|
|
Small Island Developing States
|
banded together in the common interest of surviving economically against vastly larger nations; mauritius, maldives, haiti, dominican republic, jamaica
|
|
|
Alliance of Small Island States (AOSIS)
|
a coalition of small island and low-lying coastal countries founded in 1990. The main purpose of the alliance is to consolidate the voices of small island developing states to address global climate change
|
