Lec 4- terrestrial biomes Flashcards
biome
major divisions of land enviro based on specific climate w common plant species
- constantly evolving
- boundaries are subjective
terrestrial biomes
large terrestrial regions with similar climate and vegetation
- follow latitudinal arrangement of climate cells
- alignment is distorted in some regions due to tall mountain ranges and uneven distribution of water and land mass
- identified based on geography, mean annual temp and precipitation and predominant vegetation
geography
vary across latitudes based on:
- mean annual temp and precipitation sum (climate) (limits where organisms can survive and thrive)
- predominant vegetation (food and habitat for rest of ecosystem)
climate diagrams
- describe climate at locality
- Walter Lieth diagrams: display absolute and relative info about avg climate properties at location
- pack with info and can inform about climate of locality
What can we learn from climate diagrams?
absolute values:
how hot/cold across year?
how much yr was frost free?
how much precipitation?
how variable precipitation?
relative arrangement of curves:
when do periods of drought or extensive period of rain occur?
Yellow area
indicates drought
temp > 2x preciptation
temp above precipitation
Light blue area
lack of drought
- temp < 2x precipitation
Dark blue areas
excessively moist periods
- switches in scale and dark blue shading necessary for graphical reasons (too tall otherwise)
Canada biomes
temperate grassland
temperate forest
boreal forest
tundra
tropical rainforest
- high mean annual T
- high monthly mean T
- high mean annual precipitation sum
- low seasonality (almost no change in precipitation or temp across months)
- biomass-rich, evergreen (non-deciduous) forest vegetation
desert
- low or high mean annual temp (hot or cold)
- very low mean annual precipitation sum (v. dry)
- strong to moderate seasonality in temp
- sparse, short-stature, mostly tree-less, vegetation
temperate grasslands
- low mean annual t
- low mean annual precipitation sum
- strong seasonality in temp (hot summer and cold winters)
- tree-less vegetation dominated by grasses and shrubs
- v. fertile soils, biome with highest land loss (conversion to crop land)
temperate forest
- moderate mean annual t
- high mean annual precipitation sum
- moderate seasonality in temp
- forest vegetation (deciduous, broadleaf forests or coniferous forests
boreal forest
- v. low mean annual t
- moderate mean annual precipitation sum
- strong seasonality in temp
- conifer forest vegetation
- extensive wetland and peatland vegetation (muskeg)
tundra
- v. low mean annual t (cool summer, v. cold winters)
- moderate mean annual precipitation sum
- moderate seasonality in temp and precip
- low shrub and grass vegetation, tree-less and permafrost (ground remains frozen)
Whittaker diagram- purpose/fxn
- displays major biomes as a fxn of mean annual temp and mean annual precip
- each biome show map and mat
- considers climactic variation within biomes
Whittaker Diagram - deserts
desert biome: spans huge temp range bc of hot and cold deserts
- hot: influenced by warm and dry air of Hadley cells (warm throughout year)
- cold: dry bc of rain shadow effect and continentality (v. cold season) (higher latitudes)
Ecozones of Canada
gov’t of canada developed its own classification
soil
complex mixture of living and non-living material upon which most terrestrial life depends
mechanical weathering
breakdown of rock into smaller particles from combined action of water, wind and plants
chemical weathering
action of chemical processes such as solution, hydrolysis and oxidation
horizons of soil (5)
o (organic) also called LFH horizon: starts everything
a (surface): high organic content and root density
b (subsoil): less organic and root depth
c (substratum): little to no matter and roots, more large inorganic components
r (bedrock): inorganic
soil depth matters
influenced by slope, weathering, parent materials, and vegetation
the deeper the soil, the deeper root penetrate
deeper soils can also hold more water and minerals
soils
lots of species to describe and processes to understand
underappreciated biodiversity hotspots
why are soil organisms important?
- form soil strucutre
- regulate soil moisture
- perform gas exchange and carbon sequestration
- vital in nutrient cycling
- decompose dead matter
- control plant growth
