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Flashcards in Biodiversity Deck (20)
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1
Q

Who was Alexander von Humboldt?

A

(1769-1859) A geographer, meteorologist and historian. He was an explorer.

2
Q

What was one of Alexander von Humboldt’s greatest discovery?

A

Mapping out the climatic zones of the earth using isothermal lines.

3
Q

What is the latitudinal diversity gradient?

A

The idea that the nearer you approach the tropics, the greater the increase in variety of structure, grace of form and mixture of colours.

4
Q

What is the altitudinal gradient?

A

There are more species at low and mid-altitude and fewer at higher altitudes.

5
Q

What is the depth gradient?

A

As you get further down into the ocean, there are fewer and fewer species.

6
Q

What are the different ways in which diversity can be measured?

A

Local (alpha) diversity, turnover diversity (beta), regional diversity (gamma), evenness, functional diversity and sampling.

7
Q

What does the idea of diversity cover?

A

The total species for a limited area, the abundance of species in a habitat, the difference of the habitat from others, the sum of everything in a region.

8
Q

What is alpha diversity?

A

The number of species found in a given habitat.

9
Q

What is beta diversity?

A

How distinct the fauna/flora is from other floras/faunas or turnover - how quickly do species turn over from one locality to another.

10
Q

What is the Jaccard similarity index?

A

An index used to calculate beta diversity.

11
Q

What is high tropical diversity a function of?

A

High alpha diversity and high beta diversity.

12
Q

What is gamma diversity?

A

Regional diversity.

13
Q

What is functional diversity?

A

Diversity of species based on their functions - size and locomotion.

14
Q

What is the intermediate disturbance hypothesis?

A

The idea that too much disturbance prevents species from becoming established. Too little disturbances mean a few species are able to crowd everyone else out.

15
Q

What is a goldilocks level of disturbance?

A

Where disturbance is low enough to let many species get established, but high enough that dominants get killed off frequently, preventing them from taking over.

16
Q

What is the mid domain effect?

A

The idea that if there is a lot of species with varying latitudinal ranges randomly arranged, the widely-distributed organisms wil include the tropics - wide-ranging things overlap in the middle.

17
Q

What is the species-area effects?

A

The idea that there is more land in the tropics.

18
Q

What is the problem with the species-area effects?

A

The biggest land mass is mostly temperate, and if species diversity was driven by area, Russia and Siberia would have a lot of species.

19
Q

What is the problem with the intermediate disturbance hypothesis?

A

There is no evidence that disturbance levels are that different in the tropical rainforests compared to other habitats.

20
Q

What is the problem with the mid-domain effect?

A

It assumes the tropics have organisms with large ranges, but this is not true - lots of organisms have small ranges.