Biomes Flashcards
How do we characterize dominant plants in relation to biome?
Plant growth form and characteristics of the leaves
Tell us why these plants are adapted to environment
We can classify biomes by their
dominant plants
Plant growth forms from increasing to decreasing investment in woody biomass
- Deciduous trees
- Shrubs
- Grasses/sedges and Forbs (wild flowers)
Other plant growth forms for water limiting areas
Cacti and succulents
Sclerophyllous shrubs and leaves
Deciduous trees say about plant growth
Most woody biomass
invest a lot of carbon into main woody stem to gain access to light and store lots of carbon and energy in woody structure
Shrub say about plant growth
Medium woody biomass
woody stem to access some light and store some carbon and energy
2 categories with no woody biomass
Grasses/sedges
Forbs
How do cacti and succulents adapt to live in water limited areas?
Succulent structure found in stems or leaves stores water
How do sclerophyllous shrubs and leaves adapt to live in water limited areas?
tough leathery leaves that is adaption to water limited conditions, minimize water loss to conserve
What are the variation in leaf characteristics?
- Deciduous trees
- Broadleaf decidous - Evergreen trees
- Needle evergreen
Broadleaf evergreen
Deciduous trees
Broadleaf
Trees flush new set of leaves in spring
Drop leaves every year
Evergreen trees
keep leaves for more than one year or growing season
Needle evergreen trees
Needle shape conserves water during summer for winter seasons
Why characterize biomes by plants?
Plants are immobile so must cope with full environment (yearly variation and extremes) and biotic conditions
More visible than animals
Broad leaved evergreen trees
Often found in tropical areas where there is no winter
Broad leaf shaped
Photosynthesize year round
Plants coping with environment reflects
Climate
Biome
climatically and geographically defined areas of ecologically similar climatic conditions
What predicts a biome?
Precipitation and temperature
Whittaker 1975 plot
x axis is average annual precipitation and y axis is average annual temperature
Climate diagram
temperature on right y axis and precipitation on left y axis
If temperature line exceeds precipitation line,
insufficient precipitation and climate for plant growth
Tropical rainforest
Precipitation never falls under temperature
No variation in temperature
ITCZ causes wet and dry seasons
Super diverse species
Broad leaved evergreen
Canopy trees
Tall trees as competition for light
Tropical Seasonal forest and Savannah
Little variation in temperature
Wet season and dry season
Trees less dense and often deciduous
Savanna have intermixed species with trees (need water) and grasses (no water)
Disturbances in Savannah
Determine structure of vegetation
Fire helps grasses grow
Elephants knock down trees to reduce tree density
Deserts
Low precipitation and under temperature line
Variation in temperature cold winter, hot summertime
Never enough rainfall to support plant growth
Plants adapt use succulents, cacti, short lived annuals
What causes low water availability to deserts?
Descending air from Hadley cells
Temperate Grasslands
Warm wet summer and cold dry winters
Mid precipitation
Winter have freezing temperatures –> deciduous trees
Excellent for agriculture
Fires, herbivores, mowing can maintain grasslands
Temperate Shrublands and Woodlands
Mediterranean climate: asynchrony between precipitation and warm temps (winter rain)
Small Region where precipitation falls under temperature
Wet season during cooler times
Grass, shrubs, tough vegetation
Sclerophyllous leaves: tough and leathery which help low water availability
Fire common
Hyperdiverse, interesting plants (olives, wine, avocados)
Temperate Deciduous Forests
Synchrony between temperature and variation
Cold dry winters and warm wet summers
Soils fertile enough for deciduousness
Canopy, understory, shrubs, forbs
Temperate evergreen forests
Flipped: winter in june and july, sumer in january and december
Still have synchrony between temperature and precipitation
Precipitation varies
Nutrient poor soils: evergreen
Fire
Not as diverse as other forests
Boreal forests (Taiga)
Some deciduous and evergreen
Often contain permafrost: subsurface soil layer that stays frozen year to year which keeps water from draining
Conifers: needle leaved evergreen trees
Resist freezing
Long lived, nutrient efficient
Tundra
Majority: Below freezing temperatures
No more trees
Grasses, forbs, growing shrubs
Lichen, moss
Short growing season and long days
Biome you would see needle leaves
Boreal forests (taiga)
Biome you would see sclerophyllous leaves
temperate grassland/ woodland
Biome you would see broad leaved deciduous leaves
Temperate deciduous forest
Biome you would see broad leaved evergreen
Tropical rainforest
