Chapter 4: Terrestrial and Aquatic Biomes

what is a biome

geographic region that contain communities of organisms with similar adaptations

convergent evolution

species not closely related look similar because they evolved under similar selective forces

example of biomes and convergent evolution

similar environmental conditions in deserts have selected for similar water conserving life forms in all deserts

types of terrestrial biomes

tundra and boreal, temperate, and tropical

what is a climate diagram

graphs of average monthly temperature and precipitation for a specific location

what is a growing season

months with temperatures greater than 0 degrees Celsius

tundras

the coldest biome characterized by a treeless expanse above permanently frozen soul (permafrost)

precipitation in tundras

less than 600 mm

soils in tundras

acidic and nutrient poor

plans in tundras

grow low to the ground to gain protection under snow and ice

tropical rainforests

a warm and rainy (at least 2 m annually) biome, with multiple layers of lush vegetation

species diversity in tropical rainforests

higher than anywhere else in the world

matter in tropical rainforests

organic matter decomposes quickly, vegetation rapidly takes up nutrients

soils in tropical rainforests

soils are devoid of humus and clay, and retain nutrients very poorly

subtropical deserts

a biome characterized by hot temperatures, scarce rainfall, and sparse vegetation

what are subtropical deserts associated with

dry, descending, air of Hadley cells

soils in subtropical deserts

soils are shallow and devoid of organic matter, and neutral in pH

characteristics of aquatic biomes

flow (fast moving or still water), depth (shallow or deep), salinity (salt or freshwater)

ponds and lakes

aquatic biomes with nonflowing freshwater with lakes larger than ponds and often formed by glacial retreat or geological activity

littoral zone

shallow area around the edge with rooted plants

limnetic (pelagic) zone

open water beyond the littoral zone where the dominant photosynthetic organisms are floating algae (phytoplankton)

profundal zone

too deep to receive sunlight, low oxygen

benthic zone

bottom area with sediments; is habitat for burrowing organisms

what happens to circulation in ponds and lakes as surface waters cool during the autumn

they begin to sink

what happens to circulation in ponds and lakes during winter

water less than 4 degrees celsius floats beneath the ice

what happens to circulation in ponds and lakes as surface waters warm during the spring

they begin to sink

what happens to circulation in ponds and lakes as surface waters continue to warm during the summer

they gain heat faster than deeper waters and float on the surface

what are salt marshes

a saltwater biome that contains non-woody emergent plants

where are salt marshes and estuaries found

salt marshes are often found at continental coasts and in estuaries where the mouths of rivers mix with salt water from oceans

what do estuaries contain

abundant nutrients and sediments carried downstream by rivers which supports extremely high biological productivity

what is a coral reef

a marine biome found in warm shallow waters that are 20 degrees celsius year round

what are corals

tiny animals in a mutualistic relationship with algae where corals produce CO2 and algae produce sugars

where do corals live

in colonies, their exoskeleton contributes to the structure of reefs

what are rising temperatures causing in coral reeds

causing algal symbionts to leave resulting in coral bleaching and death

why are the same biomes found on multiple continents

convergent evolution results in plant communities that are similar when environmental conditions are similar

what information can be gained from a climate diagram

the months of the year when temperature and precipitation are not adequate for plant growth

what conclusions can you draw from the climate diagram for Santiago Chile

plant growth is limited by lack of precipitation Nov - April