factors affecting species distribution Flashcards
1
Q
abiotic factors
A
- geographical isolation
- temperature
- water
- physical structure
- chemical composition
- light
- aspect
2
Q
geographical isolation
A
- physical barriers prevent the movement of species
- some barriers are obvious, some are not
3
Q
geographical expansion
A
- widespread international travel and trade by humans has introduced species both deliberately (African honey bee) and accidentally (Dutch elm disease)
4
Q
species introduction, the African honey bee
A
- introduced in South American to supplement native populations
- spread across Americas
- forms aggressive swarms
- suitable environment, but South Atlantic ocean prevented spread, human intervention needed
5
Q
species introduction, Dutch elm disease
A
- elm logs with bark transported from Netherlands to UK
- contained fungal pathogen and bark-boring beetle vector
- uninentional introduction
- not international but resulted in loss of much of the elms in the UK
6
Q
temperature, Lovage
A
- grows on sea cliffs around the British Isles
- mostly in the North West as prefers cool temperatures
- global warming is squeezing range Northwards
7
Q
temperature, Olive
A
- deep roots, can survive in very arid conditions
- frost sensitive, so found in coastal areas
8
Q
temperature, small-leaved lime
A
- Fenno-Scandinavia
- thermophilic, only occurs in south
- will increase range Northwards from global warming
9
Q
Navelwort
A
- found in west of UK and Ireland as favours wet conditions
10
Q
garden pea
A
- very sensitive to high and low fluctuations in temperature and water
- 64 days active life cycle, sensitivity to temperature changes across life cycle
- upper and lower threshold temperature
- optimum temperature is highest for seed and seedling then decreases after germination
- also sensitive to high and low temperatures when blossoming
11
Q
acclimation
A
= recent history of a species may affect the responses of a plant or animal to an environmental situation
e.g. lethal temperature, previous temperature exposure dictates subsequent tolerance
12
Q
water
A
- species distribution depends on water availability
- too much or too little water is a problem (drought stress, water logging)
- water availability changes with altitude, latitude and distance from coast
- fluctuations in water availability can be from natural phenomena or human activity
e.g. trees found in river valleys in Iraq, trees found around irrigation systems in Oman
13
Q
Opuntia
A
- prickly pear
- cactus from Colorado
- can last 1,000hrs without water (oak ~15hrs)
14
Q
shade tolerant plants that like nitrogen
A
e.g. nettles
- grazing animals sheltering and defecating in shaded areas transfers nutrients
15
Q
physical structure of the soil, pocket gophers
A
- only tolerant of deep soils of fine sands
- can use species distribution to determine soil structure of area
16
Q
chemical composition of soil
A
- derived from acid rocks (e.g. granite)
- derived from basic rocks (e.g. limestone, dolomite)
- influences soil moisture, nutrients, pH and temperature
- determines vegetation distribution which in turn determines animal distribution
17
Q
aspect
A
- north or south facing
- impacts light availability and wind exposure
e.g. seabirds always face the wind, lichen responds to guano. bryophytes found on north side as more shaded
18
Q
animal distribution
A
- more complicated as they move
- can be affected by changes in behaviour brought about by environmental factors
19
Q
chipping sparrow experiment
A
- small North American bird
- normal habitat = coniferous forest
- wild caught animals spent 71% of time in pine forest, 29% in oak
- lab reared, no foliage exposure spent 67% time in pine, 33% time inn oak
- lab-reared, oak foliage exposure only spend 46% pine, 54% oak
- conditioning from previous exposure
- still innate preference for pine
20
Q
North Uist
A
geographically isolated island so no grazers
