Week 11 - Biogeography III Flashcards
(138 cards)
1
Q
What is a biome?
A
A large, stable ecosystem characterized by specific plant and animal communities.
2
Q
What are biomes usually characterized by?
A
The dominant vegetation.
3
Q
What are the major terrestrial ecosystems named after?
A
Generally, the dominant plant communities.
4
Q
What is the major cause of biome disturbance?
A
Urban environments
5
Q
Are there any undisturbed biomes?
A
No, not really, especially considering air circulation and pollution.
6
Q
Why are temperature and precipitation considered “groups” of factors?
A
Because there are so many variables under each heading.
7
Q
What is convergent evolution?
A
The evolution of similar features in species of different lineage.
8
Q
What causes convergent evolution?
A
Natural selection combined with similar climatic conditions.
9
Q
Are bioregions historical or environmental?
A
Historical
10
Q
What are the primary controls on the geographical distribution and productivity of biomes?
A
Precipitation and temperature.
11
Q
What are the 8 main biomes?
A
Tropical Rainforest, Savannah, Desert, Chaparral, Grassland, Temperate Forest, Boreal Forest, Arctic and Alpine Tundra
12
Q
Why do biomes look a lot like the Köppen classification?
A
Because they are both defined by temperature and precipitation.
13
Q
What is the research focus on mapping and ecotones?
A
How to depict fuzzy lines.
14
Q
Are ecotones usually narrow or broad?
A
Climatic ecotones are usually quite broad, whereas ecotones based on soil or drainage can be very narrow.
15
Q
Is biodiversity high or low in ecotones, and why?
A
Usually quite high due to the overlap of two ecosystems.
16
Q
What were the continents previous to what we have now?
A
Originally one continent, Pangea, which split into a northern and southern continent, Laurasia and Gondwanaland respectively.
17
Q
What is the tropical rainforest biome like?
A
Consistent year round daylight, high temperature, high insolation, lots of precipitation, abundant species populations and diversity.
18
Q
How much of the world’s forests are tropical?
A
Roughly half.
19
Q
Why is biodiversity so high in tropical areas?
A
Very little climatic change, therefore lots of time to diverge.
20
Q
What is the rate of biodiversity in the tropics?
A
1 sq km may have over 100 species.
21
Q
What is the main species found in the tropics?
A
Insects.
22
Q
The tropics represent what percentage of Earth’s species?
A
Maybe 30-50%
23
Q
How has species identification happened in the past?
A
Kill it to identify it.
24
Q
How are ecological niches distributed in the tropics?
A
Vertically; the canopy is important here for light availability.
25
Why are tropical soils so devoid of nutrients?
It's mostly contained in the biomass, sucked up by the vegetation itself.
26
What to tropical trees need because of thin soils?
Buttresses.
27
What is the main problem with turning rainforest into agricultural land?
The soil is pretty nutrient-bare.
28
What are the issues with logging in the rainforest?
Major species loss, major carbon sink loss, timber is valuable but often burnt, and it's often pointless.
29
Where did apes develop?
In the savanna.
30
Why is the savanna good for apes?
Easy to see predators coming.
31
The savanna is a transition between...
...deserts and tropics.
32
What is the vegetation like in the savanna?
Grasslands with a few trees and shrubs.
33
Why is the savanna becoming less extensive?
Desertification.
34
How often does precipitation occur in the savanna?
Less than six months in the year.
35
What word means "a plant that has adapted for dry conditions"?
Xerophyte
36
What do fires do for the savanna?
Preserves the ecosystem by not allowing it to become forest.
37
Why are fires common in the savanna?
Because moisture deficits are common.
38
What kind of animals would you find in the savanna?
Large mammal; grazing animals provide food for many large predators.
39
What are soils like in the savanna?
More nutrient-rich than the tropics.
40
What is the difference between a desert as a climate and a desert as a biome?
Antarctica is not a desert as a biome.
41
How much of the terrestrial biomes are covered in deserts?
Roughly 1/3
42
Where are deserts usually located latitudinally?
Between 25 N and S
43
Why don't deserts have precipitation?
Descending air.
44
How do plants cope with deserts?
They may be ephemeral, have deep tap roots, spreading root systems, or toxins
45
When are animals active in the desert?
At night.
46
What is chaparral?
Grassy, shrubby, meadow
47
What grows on ice?
Algae
48
Who is the "other" guy, the not-Darwin?
Alfred Wallace
49
If the climate changes, a species must move. What are some problems?
Some species will move faster than others and is there even any place for them to go?
50
What parts of geological history are especially important when considering biogeography?
Shifting continents and climate change.
51
To whom is the theory of continental drift usually attributed?
Wegener
52
How is Wegener always depicted?
In a parka with a pipe in his mouth
53
What is the theory of continental drift based on?
The fit of continents if you cut out a map
54
What is the summer like in chaparrals?
Dry
55
Where do chaparrals occur latitudinally?
32-40 N and S
56
Where do chaparrals occur geographically?
Mediterranean, California, and Australia
57
How are chaparrals adapted to fires?
They have deep-rooted plants
58
What kind of trees are common in chaparrals?
Olive, acacia, eucalyptus, and cork oak.
59
Sclerophyllous -- what's that?
It means "hard-leaved", to withstand summer drought. They do not drop their leaves.
60
What kind of protective measures to plants in chaparrals generally have?
Thorns to protect from herbivores.
61
Are chaparrals good for agriculture?
Yes, but they require irrigation.
62
What is the decomp rate like in chaparrals?
Slow
63
What are the characteristics of grasslands?
Flat, prairie areas.
64
How abundant are natural grasslands?
Rare. They are the world's bread baskets and have been highly modified for grazing.
65
What do you call tall grasslands and where would you find them?
Prairies; found in the US and Argentina/Uruguay
66
What do you call short grasslands and where would you find them?
Steppes; found in US, E Europe, Veldt in South Africa.
67
What are the nutrients contents like in grasslands?
Extremely nutrient-rich
68
What kind of herbivores would you find in grasslands?
Small burrowing herbivores (dogs, jack rabbits, ground squirrels, and gophers) and larger running herbivores (. bison, pronghorn antelope, and elk)
69
What kind of carnivores would you find in grasslands?
Badgers, coyotes, ferrets, wolfs, and cougars
70
Why are many grassland species threatened?
Because of ecosystem changes.
71
What happened when Manitoba tried to create a natural grassland reserve?
They couldn't find a natural grassland.
72
What are the three types of temperate forests?
Mid-latitude broad-leaf and mixed forest;
Temperate rainforest;
Boreal forest.
73
What are the seasons like in mid-latitude broad-leaf and mixed forests?
Warm to hot summers, cool to cold winters.
74
What do mid-latitude broadleaf and mixed forests transition to in the north?
Boreal forest
75
Deciduous trees lose their leaves, but what do pines depend on?
Fires
76
Geographically, where would you find mid-latitude broadleaf and mixed forests?
N.America, Europe, and Asia
77
Where are temperate rainforests found latitudinally?
Mid to high latitudes.
78
Where are temperate rainforests found geographically?
Mostly along the Pacific coast of N.America.
79
What is the biodiversity of temperate rainforests like?
Low compared to tropical forests.
80
What are the characteristics of temperate rainforests?
Old and large, e.g. redwoods
81
What are the best shoes for a boreal forest?
Galoshes!
82
What should you bring to a Boreal forest?
Bug spray!
83
What is the name for the sub-Boreal forests?
Taiga
84
What kind of trees grow mostly in the Boreal?
Evergreen fir, pine, and spruce
85
Why is vegetation limited by in the understory of the Boreal?
Because of low light penetration.
86
What kind of plants would you find in the understory of the Boreal?
Cranberries, blueberries, orchids, roses
87
What is the climate like in Boreal forests?
Short summer, cold winter, fair amount of precipitation.
88
Where is the Boreal located geographically?
Fairly continuous band across N. America and Europe
89
What kind of mammals would you find in the Boreal?
Moose, bear, deer, wolverine, marten, lynx, wolf, snowshoe hare, voles, chimpmunks, shrews, and bats
90
What are soils like in the Boreal?
Deep litter, slow decomp, thin and acidic.
91
Why are soils thin and acidic in the Boreal?
Because of large quantities of water and subsequent leaching.
92
What does tundra mean?
Marshy plain.
93
Where would you find tundra, both geographically and latitudinally?
Extreme north of North America and Russia, mostly north of 60N
94
What is the difference between tundra and alpine tundra?
Alpine tundra has no permafrost and better drainage.
95
What kind of plant life can be found in the tundra?
Treeless, dwarf shrubs, mosses, lichens and short grass
96
What is species diversity like in the tundra?
Low
97
What are the principal herbivores in the tundra?
Caribou, musk ox, arctic, hare, voles and lemmings.
98
How do birds handle the tundra?
They migrate for the winter.
99
What are the main carnivores in the tundra?
Fox, snow owl, polar bear, and wolves.
100
What is the ground surface like in the tundra?
Spongy and hummocky
101
What is the climate and soil like in the tundra?
Cold, poor drainage, permafrost, and low rates of evapotranspiration.
102
What acts as a physical barrier to plant growth in the Arctic?
The permafrost line.
103
When did the dinosaurs die out?
65 million years ago
104
What is some of the evidence for continental drift?
The existence of similar fossils on different continents
105
What is a classic example of a fossil found on multiple continents?
Glossopteris, an extinct fern.
106
Where are Glossopteris fossils found?
S.America, Africa, India, Oz, and the Antarctic
107
When and why was the idea of continental drift accepted?
1960, with the development of plate tectonics
108
What is interesting about continental drift and fossil groupings?
You find groupings similar to biomes.
109
What is the period of time that we are currently in?
The Quaternary
110
How long has the Quaternary period lasted?
About 2 million years
111
When did the last glaciation terminate?
About 20,000 years ago
112
Which ice sheet covered present day BC?
The Cordilleran ice sheet.
113
What use to be where the Bering Strait is now?
The Beringia land bridge
114
What is dispersal?
The movement of species from one area to another.
115
What is the point of species dispersal?
To escape inhospitable environments and reach new habitats.
116
What is colonization?
When a breeding population is set up
117
What is passive dispersal?
Outside forces causing dispersal, e.g. wind, water, birds, animals, people
118
What is active dispersal?
Providing your own movement, e.g. flying, walking, swimming
119
What are irruptions?
Temporary explosions, e.g. locusts
120
The limit of individuals that can live in an area, be stable, and support itself is called what?
Carrying capacity.
121
Which factors limit colonization?
Biological and environmental factors
122
What is another name for exponential population growth^
Geometric growth.
123
When does geometric growth happen?
It's usually only possible in the early stages of colonization.
124
What is the more general kind of growth seen after the initial stages of colonization?
Logistic growth
125
What is logistic growth related to?
Carrying capacity
126
What is a supertramp?
An animal that follows the strategy of high dispersion among many different habitats, towards none of which it is particularly specialized. (think, literally, of a tramp)
127
What is a corridor?
A path from one place to another.
128
Which corridor facilitated the Great American Interchange?
The Isthmus of Panama
129
What do corridors promote?
Dispersal and colonization
130
How are exotic species introduced?
By humans
131
Why are some species introductions deliberate?
Agriculture or gardens
132
What percentage of flora is thought to be introduced in Canada and America?
10-25%
133
What happened during the Great American Interchange?
Species were exchanged across North and South America when the Isthmus of Panama opened up.
134
What is Cope's rule?
The trend in evolution is toward larger size, but many exceptions exist. Also toward more species, but we have an incomplete fossil record to prove or disprove this.
135
What causes extinction?
Normally, it's caused by change events (e.g. dry periods) where there is a lack of genetic diversity to cope. There is also competition from evolving species and overspecialization.
136
Which animals are more susceptible to extinction?
Large animals because they require more resources.
137
What is the difference between a biogeographic region and a biome?
A biogeographic region is an historic division, where as a biome is an environmental division. Think deserts in Oz and Cali.
138
What are the six major biogeographic realms?
Nearctic, Neotropic, Palaearctic, Ethiopic, Madagassian, Oriental, Australian
