Lecture 4: Eudicots 1 Flashcards
How did the Pleistocene affect plant migration/extinctions?
Europe lost more species than North America, probably because the Alps blocked species from moving South
Asia did not get as strongly affected, and so is more diverse today
Southern hemisphere little impacted
Diversity patterns still reflect this glacial history: most families in East North America still south of glaciated zone
- Tree species diversity, many understory plants have higher diversity in South-East regions that were never glaciated
What is the most northern biome in Quebec?
Tundra (in the arctic zone)
- does not include any forest ecosystems
Where do we generally find the most diversity: canopy/sub-canopy, understory/shrub later, or ground vegetation later?
Ground vegetation later
Why do many understory/ground vegetation in the Northern temperate forest bloom in the spring?
The tree canopy in the spring is not yet formed, sunny at ground level –> many spring ephemeral species blooming
- example: trilliums, maianthemums
Ground level becomes shaded in the summer
Why is juvenile shade tolerance in trees important? Why is it not an important trait for plants that always have a short height?
Important in trees because they need to grow under the canopy
Plants with short height will either spend their whole life in the shade, or will not be found in the forest
Describe the North American boreal forest
28% of all of the US and Canada
Main tree species: Larix laricina, Picea mariana, Picea glauca, Abies balsamia, Pinus banksiana, Populus tremuloides, some Betula and Acers
What are the environmental conditions in the boreal forest?
Sunlight consistent in the growing season
- not as strong phenological-related changes in understory light, since canopy of evergreen species is always present
Colder overall
- minimum and and average temperatures are lower
- growing season length shorter
- late spring and earlier fall frost dates
Decomposition rates slow
- due to cold
- low nutrient content foliage
- decomposition-resistant foliage
Describe the Canadian shield environment
Large, exposed craton (very old rock)
Soils are young due to recent glaciation, most sites have thick humus layers because of slow decomposition
Bedrock/soil parent material is resistant to break-down. This leads to acidic soil with thick humus layer
How have trees and understory plants adapted to the environments of the boreal forest and Canadian shield?
Tree shapes help shed snow, reduce chance of branch breakage
- broad canopy to grab sunlight
Evergreen leaves take advantage of full growing season
Tissues have very good dormancy, cold adaptations (ex. able to have dormant buds, natural anti-freezing in leaves)
Understory plants are often sub-shrubs, evergreen or semi-evergreen
- Ericaceae family plants common, also many bryophytes and lichens
- understory plants protected by extreme cold from snow cover (snow acting as insulation)
What are the stem/leaf characteristics of the Ranunculaceae family (buttercup family)?
Herbacious plants or vines, rarely shrubs
Alternate, (usually) compound leaves usually without stipules
What is the floral structure of Ranunculaceae?
Bilateral or radial symmetry
Perfect
No fusion of flower parts
Superior ovary/ovaries
Usually many stamens and many distinct carpels
What type of fruit in the Ranunculaceae family?
Follicles, achenes, or rarely berries
Are Ranunculaceae plants economically important?
Not important, apart from a few horticultural species
Many poisonous plants
Many habitats
What order is the Ranunculaceae family a part of?
Ranunculales
What order is the Papaveraceae (poppy family) family in?
Ranunculales
