L8 Biome Concepts Flashcards
What defines a biome
The main vegetation
What is a biome
A large scale (regional or continental) distinct community of plant and animas, adapted to the regions physical environment (inc climate, topography and soil)
What determines the regional extent of a biome
Climate
How are biomes classified
According to structural character if vegetation
How is climate controlled
How much solar energy is intercepted by Earth and its atmosphere
What part of earth does solar energy warm up
The land
Land then heats up the air
What is denser, cold or warm air
Cold air is denser
Explain how air cycles
Hot air rises as it is less dense
Once it has risen, it is further away from the hot land, so it cools down and falls again
What causes the Coriolis effect
The earths rotation
Which direction do the Northern and Southern hemisoheres deflect to
N hemisphere delflects to the right
S hemisphere deflects to the left
What does the Coriolis effect do to an object
Deflects an objects intended direction
Where do Hadley cells meet
What is the name for this
At the equator - intertopical convergence zone (ITCZ)
What winds meet at the intertropical convergence zone
What climatic events are common here
NE and SE trade winds come together
Monsoons and tropical cyclones
As distance from the equator increases, what happens to the duration, amount and reliability of precipitation
All decrease
What is the most productive ecosystem
Tropical rainforest
What is the growth rate in tropical rainforests
Quick
Where is biodiversity highest and why
Around the equator
Things grow faster so there is increased speciation
What are some local scale drivers of biomes
Human impact
Disturbance
Topography
Microclimates
What are top down processes acting on biomes
Climate
What bottom up processes affect biomes
Topography, human influence etc.
What is the fourth dimension in 3 dimensional space
Time
What can topography affect
Airflow
Climate
Soil (run off, erosion)
Drainage
Species adaptation
Species composition
How can altitude alter local climate (what changes can be seen as you go up and over a mountain)
Prevailing wind
Rising, cooling air
Descending, warming air
Rain shadow
What do changes in altitude show a similar relationship do
Changes in latitude
How can soil affect plant communities
Nitrogen, drainage, sand/clay
What produces more mineral rich soil: deciduous forest or evergreen pine forest
Deciduous forest
What fcators can influence soil
Climate
Organisms
Topography
Parent materials
Time
Environmental interactions
Define a disturbance
An event in time that disrupts the ecosystem or physical environment
In what dimensions can disturbance vary
Why is disturbance important
Can vary on scale, frequency and type
It can promote succession and diversity
Give some examples of disturbance
Fire
Disease
Drought
Human exploitation
Wind (that causes trees to fall)
How does functional classification split plants
Depending on structure, traits and biochemical processes
How does evolutionary classification split plants
Depending on their evolutionary history and how close they are geentically related to eachother
Taxonomic grouping is based on generic differences
How can plants be split by life cycle
What are the 3 life cycles
Annual - lifecycle within 1 year
Biennial - every 2 years
Perennial - 3 years or more
How does the Raunkiaer system classify plants
What are groups based off
Plant life form classification
Groups based on the place of the plants bud growth form
When was the Raunkiaer system proposed
1904
Where does bud growth occur in phanerophytes and give an example plant
From main stem into air above 50cm from ground
trees
Where does bud growth occur in chsmaephytes and give an example plant
Persistent shoots near ground, no more than 50cm above soil
Small woody shrubs, herbaceous
Where does bud growth occur in hemicryptophytes and give an example plant
At or near soil durface
Single stemmed herbs - Aperacae
Where does bud growth occur in cryptophytes give an example plant
What 2 groups are they split into
Below ground, buds lie beneath surface
Bluebells, wild garlic, daffodils
Geophyte - rhizomes and bulbs
Helophyte - under water
What is the growth form of attached hydrophytes and give an example plant
Shoot system entirely underwater, leaves underwater or floar on surface, influorescence may emerge above water surface
Water lily
What is the growth form of free-floating hydrophytes and give an example plant
Entire plant can exist in water column or on surface, no connection to secument
Water cabbage
What is the growth form of epiphytes and give an example plant
Plants grow on one another, depending on other plants for mechanical support, can exist entirely above ground
Ferns, mosses and lichens
Are epiphytes parasitic
No, but sometimes so many can grow on one plant that they kill it
What does Raunkiaers system not show
Adaptations and evolutionary histories
What is Raunkiers classification good for
Observing differences in functional diversity
How can plants be classified in terms of large general plant characteristics (what groups are they split into)
What is this method useful for
Evergreen - tropical
Evergreen - temperate
Deciduous - tropical
Deciduous - temperate
Tree or shrub
Grasses or herbaceous plants
Global climate and carbon models
What are the 3 photosynthetic pathways and when are they used
C3 - most common
C4 - shade intollerent
CAMs - hot and arid desert regions
What is used in biological classification of plants
Grouping species with shared characteristics
Revised to reflect evolutionary theories of common descent
What does a predominantelty C4 system tell you about the environment
Evolved in an area of low carbon dioxide e.g. Tropical grassland
What does a high prescence of bryophytes tel lyou about the environment
Wet and moist
What are some ways of classifying plants
Family groups
Biological (linked to Linnaeus)
Photosynthetic pathways
General plant characteristics
Raunkiaer system
Life cycle
