L2.1: Terrestrial Biomes Flashcards
GEOGRAPHY:
Found at 10 latitude
Tropical Rainforest
CLIMATE:
- Warm and wet year-round with little temperature variations
- Average temperature of 25-27C
- Annual rainfall of 2,000 to 4,000 mm
Tropical Rainforest
SOIL:
- Nutrients leached by heavy rains
- Rapid decomposition keeps soil organic matter low
- Nutrient-poor, acidic, thin, low in organic matter
- More nutrients are tied up in living tissue than in soil
- Mycorrhizae (symbiotic relationship between trees and fungi)
Tropical Rainforest
BIOLOGY:
- Vertical dimension provided by trees
- Trees often supported by buttresses
- Trees serve as trellises and growing sites for epiphytes
- Intricate, complex relationships between species
Tropical Rainforest
HUMAN INFLUENCES:
- Staple foods
- 25% of all prescription drugs
- Fast disappearing
Tropical Rainforest
GEOGRAPHY;
- 10-25 latitude
Tropical Dry Forest
CLIMATE:
- More seasonal than tropical rainforest
- Dry season of 6-7 months
- Abundant rainfall of 5-6 months
Tropical Dry Forest
SOIL:
- Of great age
- Less acidic and richer in nutrients
- High erosion rates
Tropical Dry Forest
BIOLOGY:
- Plants strongly influenced by physical factors
- Height is correlated with average precipitation
- Animals and wind disperse seeds
- Animals make seasonal migrations
Tropical Dry Forest
HUMAN INFLUENCES:
- Heavy human settling
- Agricultural conversion
- Decrease in biodiversity
Tropical Dry Forest
GEOGRAPHY:
- North and south of tropical dry forests
- 10-20 latitude
Tropical Savanna
CLIMATE
- Alternating dry and wet seasons
- Drought combines with fire
- Rain combines with lightning
- Drier than tropical dry forest
Tropical Savanna
SOIL:
- Low permeability to water
- Retains water near surface
- Little to no trees
Tropical Savanna
BIOLOGY:
- Greater portion takes place near ground level
- Fire resistant flora
- Wandering animals
Tropical Savanna
HUMAN INFLUENCES:
- Humans are a product and vice versa
- Fire plays a role in its ecology
- Where humans observed and learned to use, control, and make fire
- Hunting and gathering
- Pastoralism
- Livestock ranching
- Sahel: A region devastated by human populations, high density of livestock, and drought
Tropical Savanna
GEOGRAPHY:
- 20% of landmass of Earth
- 30 latitude
Desert
CLIMATE:
- 300 mm annual rainfall
- Evaporation and transpiration exceeds precipitation
- Drought conditions prevail
Desert
SOIL:
- Low in organic matter
- Under shrubs have large amounts of organic matter
- Kangaroo rats change the texture and elevate nutrient content by burrowing
- High salt concentration
- Caliche: Calcium carbonate-rich hardpan horizon that forms as soil ages
Desert
BIOLOGY:
- Plant cover absent
- Plants have dense plant hair covering
- Small leaves
- Seeds remain dormant until wet periods
- Low animal abundance, high diversity
Desert
HUMAN INFLUENCE:
- Concentrated near oases and river valleys
- Salt accumulation lessened irrigation
- Increasing in area
Desert
GEOGRAPHY:
- In all continents except Antarctica
- 30-40 latitude
Mediterranean Woodland and Shrubland
CLIMATE:
- Cool and moist autumn, winter, and spring
- Hot and dry summer
- Mild frost
- Prone to fires in summer
Mediterranean Woodland and Shrubland
SOIL:
- Low to moderate fertility
- Fragile
Mediterranean Woodland and Shrubland
BIOLOGY:
- Highly diverse flora and fauna with adaptations to drought
- Trees and shrubs are evergreen with small tough leaves
- Mutual relationship with microbes
- Slow decomposition in summer
- Fire-resistant plants
- Thick, fire-resistant tree barks
Mediterranean Woodland and Shrubland
HUMAN INFLUENCE:
- Wheat plantations once every 5 or 6 years
- Low intensity cultivation and long term stability
- Human settlements
- Clearing of forests for agriculture
Mediterranean Woodland and Shrubland
GEOGRAPHY:
- Largest biome in NA
- 30-55 latitude
Temperate Grassland
CLIMATE:
- 300 to 1000 mm annual rainfall
- Droughts may last several years
- Maximum rainfall in summer
- Cold winters, hot summers
Temperate Grassland
SOIL:
- Derived from wide variety of parent materials
- Deep, basic, fertile, high organic matter
- Black prairie soils have high amounts of organic matter
- Brown soils have less organic matter
Temperate Grassland
BIOLOGY:
- Herbaceous vegetation
- Trees and shrubs limited near streams and rivers
- Roving herbivores
Temperate Grassland
HUMAN INFLUENCE:
- Nomadic hunters became herders, then farmers
- Most fertile farmlands on Earth
- Prairie soil lost 35 to 40% of organic matter in 35 to 40 years
Temperate Grassland
GEOGRAPHY:
- 30-55 latitude
- Majority between 40-50 latitude
Temperate Forest
CLIMATE:
- Coniferous or deciduous
- Temperatures are not extreme
- 50 to 3000 mm annual rainfall
- Deciduous forest winters last 3-4 months
- Coniferous forest winters are more severe or summers drier
Temperate Forest
SOIL:
- Fertile
- Most fertile soil develop under deciduous forests
- Conifers grow on poor acidic soils
- Slow nutrient movement
Temperate Forest
BIOLOGY:
- Vertically stratified
- Fungi and bacteria the most important consumers
- Vital for recycling nutrients
Temperate Forest
HUMAN INFLUENCE:
- Human settlements along forest margins
- Agriculture
- Remaining 1-2% of old-growth forests in western NA
Temperate Forest
GEOGRAPHY:
- 50-65 latitude
Boreal Forest (Taiga)
CLIMATE:
- Long winters, short summers
- Moderate climates
- Moderate precipitation
- Low evaporation rates, infrequent droughts
Boreal Forest (Taiga)
SOIL:
- Low fertility, thin, acidic
- Low pH impede decomposition
- Nutrients tied up in a thick layer of plant litter
- Most trees have shallow root networks
- Mycorrhizal fungi
- Thin topsoil
- Permafrost subsoil
Boreal Forest (Taiga)
BIOLOGY:
- Evergreen conifers
- Larch dominates
- Willows along water sources
- Migratory mammals
- Wolves are major predators
- Epiphytes
- Trees are wind pollinated and do not produce fleshy fruits
Boreal Forest (Taiga)
HUMAN INFLUENCE:
- Ancient cave paintings
- Migratory humans
- Domestication of reindeer
- Berries
- Light human intrusion
- Lumber and pulp
Boreal Forest (Taiga)
GEOGRAPHY:
- Most of northern lands of Arctic Circle
- 66.5 latitude
Tundra
CLIMATE:
- Cold and dry
- Not as extreme as boreal forest
- Less severe winters, short summers
- 200 to 600 mm rainfall
- Soggy summers
Tundra
SOIL:
- Slow soil building
- Slow decomposition
- Solifluction: Moves soils downslope
- Permafrost
Tundra
BIOLOGY:
- One of the last biomes with large native mammals
Tundra
HUMAN INFLUENCE:
- Limited to small populations of hunters and nomadic herders
- One of the last pristine areas of Earth
- Intense oil extraction
- Chernobyl disaster passed radiation to food chain, rendering them unsuitable for consumption
Tundra
