Lesson 9 Flashcards
(90 cards)
What is the definition of biodiversity?
The number of species that occupy a certain area, genetic variations or the role that species play within an ecosystem.
What is one of the most important factors supporting high species biodiversity in mountains?
The diversity of habitats that result from a rapid change in elevation on mountain slopes. Otherwise known as microclimates that lie along the vertical elevation gradients.
Who was one of the first people to document the patterns of mountain biodiversity?
Alexander Von Humboldt - a Prussian geographer and naturalist, in the 1800s.
The cross-section sketch of Chimborazo (a Stratovolcano in Ecuador) depicts what phenomenon?
The distribution of species along gradients of varying physical conditions - drawn by Alexander Von Humboldt.
Who laid the foundation for the entire field of biogeography?
Alexander Von Humboldt
What is the highest mountain in Ecuador?
Chimborazo - a Stratovolcano.
What is speciation?
Speciation - occurs when populations genetically diverge to the point where they are no longer able to interbreed.
What must happen for speciation to occur?
Populations must be isolated, so there is no movement of individuals from one place to another.
What is allopatric speciation? Where is this a common occurrence and why?
The isolation of a species through geographic isolation. It is common in mountains because these rugged landscapes impose topographic barriers that isolate smaller populations.
What can be explained as the cause of genetic and morphological variations in the Tyrian Metaltail (humming bird)?
Geographic isolation or allopatric speciation
What factors contribute to the high diversity of bell flowers?
Combined effects of climate oscillations, rugged alpine habitats and variable floral morphology as well as geographical isolation between multiple mountain refugia.
What are refugia?
Refugia are places in the mountains that have maintained favourable conditions during periods of past environmental change - often associated with periods of glaciation.
What are the three measures of biodiversity?
1 - Species richness
2 - Evenness
3 - Species diversity
What is species richness?
The simplest measure of biodiversity - which is the count of the total number of species present.
What is evenness?
Measures how similar species are in their relative abundances.
What is species diversity?
A measure of biodiversity that accounts for both species richness and and evenness.
What is DNA barcoding?
An increasingly popular way to assess biodiversity. It is a technique used to characterize species, using a short DNA sequence. It also provides a measure of genetic diversity within populations and communities.
True or False: If there are large differences in the abundance of species, then a community has high evenness.
False - A large difference would indicate a low evenness.
True or False: mountain regions contain a low proportion of endemic species.
False - endemic species are unique species. These species are found in mountain regions and nowhere else in the world.
What small endemic species is found only in the Rocky Mountains? Describe this species.
The Banff Spring Snail or Physella johnsoni. This is a small freshwater snail. It is unique because it has adapted to life in thermal springs, where water is low in oxygen and high in hydrogen sulfide. They are omnivores!
When was the Banff Spring Snail first identified?
In 1926 at sulfur mountain in Banff National Park - they have not been found anywhere else.
What is threatening the Banff Spring Snail?
The ponds they live in are prone to drying up. Now the snails are listed as endangered, so they are highly protected.
What is a diversity hotspot?
Regions containing high concentrations of endemic species that are also facing threats of rapid species loss.
How many biodiversity hotspots have been identified throughout the world? How many of them are located in mountain regions?
35 - half of which are located in mountain regions.