Lecture 2:Biomes Flashcards
What do biomes represent?
Large regions e.g. deserts with distinct climate and specific species adapted to it that form complex communities.
The equivalent term for aquatic biomes?
Aquatic life zones
Aquatic life zones are divided into?
- Freshwater life zones
- Marine/Ocean life zones
What is common across different biomes?
Food webs that facilitate the transfer of energy from producers that harness energy from the sun.
There is an agreed upon classification for the biomes of the world. (true or false)
False.
1. It is contested between different studies
2.Existence of small scale variations and transition zones.
Which two major factors determine a biome?
- Average temperature
- Average precipitation
(these are then determined by latitude and altitude)
What makes a region a desert?
Low and unevenly scattered annual precipitation.
Deserts cover about 30% of earth’s land surface. (true or false)
True
Vegetation that may be found in deserts is?
Sparse
List 4 types of deserts.
- Tropical
- Temperate
3, Cold - Semi-deserts
What causes the different types of deserts to occur?
Difference in average temperatures
Remember latitude zones
———————- 90N (polar)
polar zone
———————- 66.5N (artic zone)
temperate zone
———————- 23.5N (tropic of cancer)
tropical zone
———————— 0 (equator)
Topical deserts are? (keep in mind tropical and sahara as an example)
Hot and dry. (hot since located within the tropics)
Temperate deserts are characterized by? (keep in mind seasons of temperate zones like US)
High summer temperatures, low winter temperatures
Do temperate deserts experience more precipitation than tropical deserts? (Yes or No)
Yes
Describe vegetation in temperate deserts. (think movies you have seen deserts in US)
Sparse drought resistant shrubs and succulents. e.g. sagebrush- from mint family
Where are semi-desert biomes located?
In semiarid zones between deserts and grasslands
Give two characteristics of semi-desert biomes
- have thorn trees and shrubs adapted to long dry spells
- experience short and sometimes heavy rains (recall documentary seen in class about Kalahari)
How much precipitation do grasslands receive?
Enough to support grasses but not large stands of trees
Name 3 factors keep trees from growing in grasslands
- Seasonal drought (amount of precipitation)
- Grazing and browsing by herbivores
- Occasional fires
Name three types of grasslands. (think latitude regions)
- Tropical
- Temperate (prairies or steppes)
- Polar (tundra)
(remember precip constant but temp variable)
Name one type of tropical grassland.
savanna
Climate characteristics of savannas. (think climate here in Ngong)
- Warm-hot temperatures year round
- Two dry seasons
- rain in rest of seasons
Why do African tropical savannas contain enormous herds of browsing and grazing animals?
Have higher net productivity.
Describe climate of temperate grasslands
cold winters with hot and dry summers
Why go temperate grasslands have deep and fertile soils?
soil is packed with the roots and rhizomes (underground stems) of grasses for anchorage and absorption. during winter when water is unavailable grasses die and their structures decay.
Due to their high fertility many of the world’s natural grasslands are being lost to crop farming. (true or false?)
True
Where do polar grasslands occur?
Just south of the artic polar ice cap
What is another name for polar grasslands?
Artic tundra
Describe climate of polar grasslands.
long dark winters with low snowfall. i.e. freezing desert
Describe vegetation of polar grasslands.
thick spongy mat of low growing plants
