L4 - determinants of ecological variation Flashcards
why does productivity vary temporally and spatially?
- seasons
- environmental variability (temperature, moisture, light, nutrients)
- disturbances
- species composition and age.
What is the association between primary productivity and vegetation structure?
higher productivity = more complex structure
what are biomes based on?
structures of dominant vegetation.
how can biomes be predicted?
precipitation and temperature.
(remember the P&T diagram)
why do we care about variation at a global scale?
- global ecological feedbacks
- human livlihoods
- prediction
- decision making
list all the terrestrial biomes of Canada. (7 listed in class)
- temperate rainforest
- tundra
- temperate deciduous
- desert
- grasslands
- montane forest
- boreal forest
Describe a temperate rainforest
- mild temp
- wet
- structurally complex
- large disturbances uncommon
- conifer dominant
describe a temperate deciduous forest
- warm summers
- moderate precip
- deciduous tree dominant
- restricted range in Canada
Describe a boreal forest (tiaga)
- cold winters, short warm summer
- low precip
- sparse conifers
- high disturbance (bugs, fire)
- more than half of Canada is boreal
Describe a tundra Biome
- cold
- dry
- treeless areas, dominated by dwarfed shrubs
- perennial permafrost
Describe a montane forest biome
- forested area below mountain treeline
- dominated by conifers
- disturbances give it patchy structure
Describe a temperate grasslands biome
- dry
- warm
- soil moisture deficit prevents forest development
- herbaviours suppress tree establishment
- severely impacted by land-use change
describe a desert biome
- very dry
- variety of temperature
- soil moisture deficit limits most vegetation
what are some problems with biome maps?
- oversimplified
- cutoff point is subjective
- missing external factors like:
- proximity to water
- elevation
- land-use change
What is an Ecozone?
a classified region of distinct terrestrial and marine zones in Canada.
- 15 terrestrial
- 5 marines
