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Ecological Factors Influencing Distribution of Organisms - Coggle Diagram
Ecological Factors Influencing
Distribution of Organisms
Climate
Temperature
Range
most species live within
particular latitude with
specific latitude
adapt to live within
temperature range:
diurnal
(difference in temp
between night and day)
seasonal
fluctuation in temp
more extreme
in terrestrial habitats than aquatic
(water acts as buffer to temp change)
if temp too
high
, enzymes will denature
if temp too
low
, water will turn to ice in cells
Availability of
Water
Xerophytes - adaptions
to conserve water &
live in dry environments
Mammals have waterproof skin
& internal gas exchange surfaces
to reduce evaporation
in aquatic environments, organisms adapted to ensure don't gain too much water:
freshwater fish (e.g. perch) adaptions
to reduce osmotic water gain
marine (salt water e.g. mackerel) fish adaptions to conserve water since tendency H2O to move out osmotically due lower wp
Light
Intensity
plants require light
for photosynthesis
higher LI, greater the rate
of photosynthesis+ faster plant
growth rate
some plants adapted to grow in
low light environments
Examples:
bluebells grow on woodland floor
before leaf canopy develops above
water plants grow close to shore
where light penetrate through shallow
water/float on surface of deeper water
some cave dwelling animals adapted
excellent sense of smell + lose sense
of sight
- adaptions to low LI
Light
Quality
light made up of
different wavelengths
Red light absorbed by
water (which is colour blue)
blue light penetrates to deeper
parts so red seaweeds possess red
pigment that absorbs blue light
red algae found at greater depths
blue/green algae found at surface
Day
Length
greater day length (summer) =
more
time
for photosynthesis as more light
so greater plant growth
length of day will affect
nocturnal feeders
:
if day long, night short so less time
to feed and hunt
Edaphic
pH Values
influences
availability
or certain ions
Heather = acidic soils
so
likely to outcompete other
species in upland regions
& dominate
Orchids =
alkali soils
optimum pH for most
close to neutral
Availability of
Nutrients
MACRONUTRIENTS
D: ions required in large quantities
E.g. nitrates - synthesis amino acids
phosphates - synthesis nucleotide
calcium - synthesis cell wall lamellae
MICRONUTRIENTS
D: ions required in minute quantities
plants distribution depends on nutrient
balance of particular soil as **different
species make different demands on ions in soil**
Water
Content
different soil types contain different
amounts of water:
clay soil - lots of water
sandy soil - drain free so little water
most British plants adapted
for
moist, well drained soils
in waterlogged soils...
anaerobic conditions arise +
nitrogen levels
decrease
due to
denitrification converting nitrates back
to atmospheric nitrogen
rushes can tolerate these conditions
because spaces in root tissues that
allow oxygen from aerial parts to help
supply roots
many organisms cannot
survive anaerobic soil
zonation of plant species
on river bank show distribution
of plants due to gradient of
water availability in soil
Aeration of
Soils
spaces between soil particles
contain air where
roots obtain
oxygen for respiration
Peat formed in bogs where plant
matter does not decompose due to
water logged, acidic conditions
in these conditions, microorganisms
cannot carry out decomposition
Biotic
Factors
Competitors
organisms compete for
common resources in limited
supply (food/light/ions)
INTERSPECIFIC
competition -
between
DIFFERENT
species
range scavengers feeding of dead
animal carcass
INTRASPECIFIC
competition
between
SAME
species
young chicks compete mother's
attention to give them food - weaker
ones lose out to stronger ones
Competitive Exclusion Principle
where 2 species occupy same
ecological niche, interspecific
competition leads to local
extinction of one species
Predation
distribution of predator reliant on presence of its prey species
when
prey no. low = predators decline
when
predators no. increase = prey decline
Accumulation
of Waste
growth of microorganisms frequently
self limiting
because
accumulation of
waste products = toxic
in anaerobic conditions,
populations of yeast produce
ethanol
Ecological
Niche
D: where it lives and
what it does there
includes:
role in food chain
climatic & edaphic
requirements
competition with other
organisms
Measuring Factors that affect
Distribution of Organisms
(ABIOTIC FACTORS)
soil
moisture
use a
soil auger
to
collect a sample of soil
instrument allows taking
samples from a range of
depths
place soil in plastic bag
to prevent evaporation
before weighing
weigh sample
place in oven to dry to
constant mass @ 150*C
(high enough to evaporate
but not too high to burn)
use formula...
initial soil mass - soil mass after drying
x100
initial soil mass
soil organic
content
place oven dried soil in crucible
reweigh (set balance to 0)
use Bunsen to burn off organic content
mix soil to ensure all burnt off
allow cool + then reweigh
use formula...
dry soil mass - soil mass after burning
x100
initial soil mass
soil pH
measured using
pH electrode
attached
to digital meter
soil
temperature
measured using
thermometer
& protected within a metal cover
important to leave in soil
long enough to get an
accurate reading
reliability
-
thermometer placed into same
depth when sampling different
points
light
intensity
measured using
light meter
light intensity reaching ground level
x100
light intensity in the open (no shade)
valid + reliable readings:
no. of readings taken at point
readings taken over short time
(as sun changes position in sky)
better take full sunlight (not cloudy)