Biomes Flashcards
What is a biological realm
the broadest divisions of the earth’s land surface – subdivided into ECOREGIONS/ ECOZONES
What is an ecoregion
an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm.
Ecoregions cover large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species
What is a biome
A broad, regional type of ecosystem characterised by distinctive climate and soil conditions as well as a distinctive kind of biological community adapted to those conditions
What can biome classifications be useful for
as a way of classifying the Earth’s terrestrial communities into major ecological units – correlates with regional climate types
What are biological realms characterised by?
Evolution history of the organisms within it
Floristic kingdoms
Zoogeographic regions
What are the size orders of: bio realms, ecoregions, biomes
Realm = biggest
Realms divide into ecoregions that may contain a number of biomes
Name 3 bio REALMS
Any from: Australian Oceanian Oriental Sino-Japanses Palearctic Sahro-Arabian Nearctic Panamanian Neotropical Madagascan Afrotropical
What is the key idea behind biomes/ realms?
Similar regional climates produces morphological adaptations in plants - so plants have similar plant physiognomy and similar structure in vegetation regardless of actual species
What climate type is Af in classification
Tropical wet climate/ rainforest biome
What climate type is Dfb in classification
sub-arctic climate / boreal forest biome
What factors are plant physiognomy
size shape leaf structure stem size thorns
What is the law of tolerance
for each abiotic factor, an organism has a range of tolerances within which it can survive
How much precipitation is there in a tropical biome
no less than 100mm per month
what type of soil is found in tropical biomes
Laterites
high clay content
Excessive leaching
Acidic and naturally infertile soils
What are the 3 types of desert
True desert
Semi desert
Extreme
How do true, semi and extreme deserts differ by definition
Amount of rainfall and plant coverage
True = less than 120mm semi = 150-400mm extreme = 70mm
Which type of plant is most dominant in deserts
Shrub - drought deciduous or evergreen
Which type of plant is most dominant in tropical biomes
Broad leafed evergreens (forest)
Name 3 types of plants found in deserts
True xerophytes
Phreatophytes
Halophytes
Succulents
How are xerophytes adapted to deserts?
Have shallow root system and extent well beyond canopy
How are succulents adapted to deserts
Store water well in tissues
Waxy leaves prevent waterloss
CAM photosynthesis
What are soils like in deserts?
Poorly developed due to lack of leaching
What is a tundra
is a type of biome where the tree growth is hindered by low temperatures and short growing seasons (usually colder, rocky climates)
What is a taiga?
a forest of the cold, subarctic region - small number of tree species (but lots of them)
Describe 5 features of a tundra
Any from: treeless-ness short growing season Shallow soils Low precipitation dry winds nutrient poor conditions mosses, lichens, sedges, dwarfshrubs young, thin soils Gleying clumped vascular plants
Where are taigas mostly found?
Subarctic and cold continental climates
It’s northern most limit is were the taiga meets the tundra
What kind of trees are found in a taiga?
mainly evergreen
Where are tundras normally found?
encircling the arctic ocean (polewards of Taigas)
What are soils like in taigas
young, shallow Podzols - low in natural fertility
How much of the Earth is covered by water?
75%
Are aquatic or terrestrial environments more stable ?
Aquatic are more stable, less variable
What are the 4 features aquatic biomes are defined on
Depth
Salinity
Temperature
Nutrients
What 5 factors affect the distribution of aquatic organisms
Light penetration Temp Nutrients Distance from shore/ depth Position in water colum (i.e: open water or bottom)
What are the 2 freshwater biomes
Standing bodies of water (lentic)
Moving bodies of water (lotic)
What is a lotic biome
A freshwater, moving body of water
What is a lentic biome
A freshwater, standing body of water
Give an example of lotic and lentic freshwater biomes
Lentic = lakes, ponds, wetlands
Lotic = rivers, streams
What 2 factors limit primary production in marine biomes
Light
Nutrients
What is the photic zone
The certain depth of marine biomes that solar radiation penetrates
How much solar radiation is absorbed in the first meter of water
more than 50%
What are the two main nutrients in marine biomes
Nitrogen
Phosphorous
What are the 3 types of coral reefs
Fringing
Barrier
Atolls
Name 3 types of organisms that build coral reefs
Coralline algae Sponges Stony corals Hydrocorals Formaniferans
What are polyps?
Coral animals
Which biome is coral reef usually found?
tropical distributions
above 18 degrees C
