Biotic and Abiotic Factors (pg 192-199,202) Flashcards
what are biotic factors
living things in an ecosystem
producers
plants use light energy from Sun to produce food
consumers
organisms that are not able make their own food; eat other organisms
decomposers
organisms that feed on dead matter, breaking it down and returning it to the environment
examples of producers
photosynthetic organisms (plants, algae)
who are the food makers in an ecosystem
producers
what do plants use to make food
light, water, carbon dioxide
how do consumers get their food
directly from plants or from animals that eat the plants
how are consumers classified
-herbivores (plants) eg. buck, sheep, cattle
-carnivores (animals) eg. snakes, vultures, lions
-omnivores (both) eg. baboons, warthogs, humans
examples of decomposers
fungi, bacteria, maggots
what are abiotic factors
non-living things that provide the basis of an ecosystem
examples of abiotic factors
soil, water, light, temperature, air, physiographic factors
silt
very fine particles of rock
humus
organic material found in soil formed by decomposition of organisms by decomposers
water-holding capacity
amount of water a soil can hold
what does soil consist of
particles of different sizes
how to separate soil layers
mixing it with water
what are the 3 types of soil
- sandy
- loamy
- clay
what does loamy soil consist of
mixture of sand, silt, clay and humus
what is the purpose of humus
hold soil particles together to from soil crumbs. helps soil hold water better. contains minerals and salts plants need for growth
how does each soil feel
- sticky = clay
- gritty = sandy
- soapy = loamy
how much water can each type of soil hold
- clay = a lot
- sandy = very little
- loamy = moderate
what is the important of water holding capacity in soils
plant growth
what type of plants grow in sandy soil
plants with large, shallow root system because absorb water quickly before it has ben drained
air content for different soils
- sand = large air spaces
- clay = small air spaces
- loamy = moderate amount air
what does more air content mean on soils
more oxygen available for plants
how does soil develop a pH
decomposers break down dead organic material, weak acids are produced. makes soil acidic
what pH level do plants grow best in
low pH (slightly acidic)
what plants grow better if the soil in alkaline (high pH)
highveld grasses, wheat, beans, onions
what plants grow better in acidic soil
maize, cane sugar, potatoes
what do living organisms need water for
body processes that keep them alive
what is the water cycle
natural cycle in which water is circulated through ecosystems by means of processes such as evaporation and condensation
where is the majority of earths water
seas and oceans
explain how water vapour is formed
heat energy from Sun causes some water from water bodies to evaporate and from water vapour. plants lose water from their leaves as water vapour during transpiration
how to plants absorb water
from the soil
how are clouds formed
water vapour rises in the atmosphere where it cools and condenses to from clouds
what are clouds made of
water and ice
explain rain
water droplets in clouds join and become too heavy to be held in suspension in the air and fall to Earth’s surface and rain
3 things happens to rain water
- soaked into land and stored groundwater
- runs off land into rivers
- returns atmosphere by evaporation
what happens to groundwater
water filtered through soil to bedrock, comes urface again in rivers
wetland
area covered by shallow water for most of the year
examples of wetlands
swamps, marshes, shallow lakes, vleis
south africa’s most famous wetland
st. Lucia wetlands in KZN
how has wetlands been lost
worlds population increased, need more land housing, agriculture and industry
why are wetlands important
- provide habitat and breeding ground plants and animals (birds, amphibians, fish)
- source water plants and animals
- filter and clean water
- act giant sponges and store water to prevent flooding during heavy rains
- dry season, helps keep rivers and streams flowing
how do wetlands filter and clean water
trap soil particles, pollutants and disease-causing organisms make water unsuitable or unsafe to use
how do people benefit from wetlands
- supply water people/domestic animals
- locals plant crops in soil and fish lakes
- natural materials found (reeds for housing), make items sell
- some plants used locals to make medicines
- popular wildlife and tourist areas
- trained and employed as tourist guides
photosynthesis
process using light energy to make food
photoperiod
number of hours of light that a plant gets everyday
diurnal
active during day and inactive at night
nocturnal
active at night and inactive during day
how do living organisms depend on light
plants - growth
animals - daily routine
what does photosynthesis produce
food for plants, oxygen
what happens when a plant gets more light
photosynthesis speeds up
how many light hours does chrysanthemums need to flower
10 hours light each day
when will namaqualand flower
only in bright light
examples of nocturnal animals
bushbabies (galagos), moths
how do nocturnal animals see at night
eyes many light receptors, sensitive dim light. big eyes lets in more light
when does southern hemisphere receive more light
november, december, january
how does the tilt of the earth effect direct sunlight
causes sun to be higher in the sky during summer months, increases amount sunlight falling onto earths surfaces
why are reptiles more active during the day
cannot regulate own body temperature, active during day when warmer and not cooler at night
why do some plants open during the day and some open at night
temperature difference
why do deserts have distinct periods of activity
large temperature variations between day and night
winter tempreture
lower, shorter periods of daylight
summer tempreture
higher, longer periods daylight
migration
seasonal movement of animals from one area to another in response to climatic conditions such as temperature and rainfall
when do animals usually migrate
start of winter
where do swallows migrate to
leave south africa to northern africa or europe
what does seasonal temperature effect
amounts food and water available to animals
what happens inland areas during winter(temperature)
less grazing and water because lower temperatures and lack of rain. animals migrate areas more grazing and water
examples animals migrate
locusts, butterflies, whales ,penguins, turtles
hibernation
slowing down of body processes when temperatures drop and food becomes scarce. some animals become inactive in winter
what happens during hibernation
animal’s body temperature drops, heart beat slows and become totally inactive
where does the horseshoe bat live
Sudwala caves in Mpumalanga
what happens horseshoe bats heartbeat in winter
slows 4 beats per minute, body temperature drops to temperature of environment, wakes up warm days increase body temperature
aestivation
slowing down of body activity and processes in response to high temperatures
what happens during aestivation
weather very hot and dry, animals hide keep cool and prevent water loss, body temperatures slow down and become inactive until temperature drops
how do bullfrogs aestivate
bury themselves mud at bottom of lakes and rivers, dry up in summer. body processes slow down and use air stored air sac provide oxygen for respiration until river/lake fills up again
what happens plants in arctic
small, close ground so dont freeze by cold wind
what plants track the sun
sunflowers, Namaqualand daisies, artic plants
which plants need low temperatures to germinate
peaches and plums, peas and beans
why do some plants germinate in low temperatures
ensures seeds do not germinate during autumn but after winter when seedling have chance to survive
what plants need high temperatures grow
tomatoes and many fruits and vegetables
when do plants that prefer lower temperatures grow
winter and early spring
deciduous trees
lose leaves winter and become dormant. new buds do not grow and are covered for protection against cold
pollination
transfer of pollen from the anther to the stigma
physiographic-factors
factors relate to the physical features of land such as altitude, aspect and slope
what er the three main gases found in the atmosphere
nitrogen (78%), oxygen (21%) and carbon dioxide (0,03%)
what is nitrogen needed for
formation of proteins
wind
moving currents of air
what does wind play a role in
pollination, seed dispersal, animal dispersal
how does wind affect rate of transpiration
plants lose more water through transpiration when it is windy
how does wind effect lakes, rivers and seas
speeds up evaporation
altitude
height above sea level
slope
how steep or flat an area is
aspect
direction a slope faces
higher altitude
lower temperatures, less oxygen and more intense sunlight - affects types of plants grow there
what does steepness effect
how quickly water flows away from surface and kind of plants whether exposed wind and sunlight
aspect in southern hemispshere
north-facing slopes warmer, sun rays come north. ferns grow south-side
aspect effecting rain
wind blows rain onto south-east slopes, north-west slopes less rain
