1.1 – Biomes and Earth’s Spheres
an ecosystem is the term used for the interaction between
living and non-living things in a set area
o ecosystems come in all sizes
o ecosystems combine to make biomes
biome = large geographic regions that contain similar
ecosystems
there are 5 main terrestrial (land) biomes in Canada:
o tundra far North
o mountain (aka coniferous) forest western Canada
o grasslands Prairies
o boreal forest spans all across Canada
o temperate deciduous forest southern Ontario
there are 2 main aquatic (water) biomes in Canada:
o marine oceans
o freshwater lakes, streams, ponds, rivers, wetlands
biomes combine to make up the 4 major spheres on Earth:
i. biosphere = the part of the Earth where living things
exist
ii. lithosphere = the hard part of the Earth’s surface
(ex: stones, rocks, mountains)
iii. hydrosphere = the part of the Earth that is water
(includes salt and fresh, water vapour)
iv. atmosphere = the layer of air above the Earth’s
surface (gases)
Biosphere
Earth is the only planet with a biosphere that we know of
this is the sphere that interacts the most with the other 3
(is not distinct from the other 3 spheres)
Illustrating the interconnectedness of the 4 spheres:
The water cycle
Sun’s rays evaporate huge amounts of water from oceans
and other bodies of water within the hydrosphere
as water vapour rises in the atmosphere, it cools and
condenses, forming clouds
eventually the water falls back to the lithosphere as
precipitation (liquid or solid)
as water returns to the oceans by river systems, it erodes
rocks and picks up other materials (nutrients, minerals)
it’s absorbed by plants in the biosphere so they can
undergo photosynthesis
it’s consumed by animals in the biosphere
water plays a critical role in the survival of animals (cell
respiration, body cooling, hydration, etc.)
without water, the biosphere couldn’t exist!