Ecosystems Flashcards
define ecosytem
a unit that consists of plant and animal communities (biotic) that interact with each other as well as with the non living (abiotic) factors in a particular area
define community
all the populations of plants and animals living in an ecosystem that interact with one another
what are biotic factors?
living components, plants and animals and interactions between them
what are abiotic factors?
non living components of biosphere that have influence on distribution and survival of biotic components
What is aspect?
position of an area in relation to the sun (slope direction)
which slope will there be more sunlight and what will be its result?
more sunlight on north facing slopes in southern hemisphere and as a result it is warmer and drier with more light and plants thrive
What do slopes determine
rate of water run off
Steep slope=?
faster water= soil erosion= shallow and infertile soil= fewer plant and animals
What are different soil textures?
Clay- tiny soil particles
loam- slightly bigger particles
sand- coarser and larger particles
Air content in sandy soil and clay soil?
sandy soil= larger spaces= well aerated
clay soil= smaller spaces= poorly aerated
what is leaching?
when water filers through rapidly through and with large spaces taking away nutrients
why do plants rot in clay?
Too much water due to tiny spaces results in poor drainage
why is loam best for plant growth?
Medium water retention capacity and well aerated = sufficient nutrients for plant growth
what is Humus content and why is it good
Decayed animal and plant matter that increases soil fertility and water holding capacity
it makes soil darker
pH of soil
low pH= acidic= proteas and azaleas
high pH= alkaline= succulents
ph7 = neutral= Most plants
why do plants need light?
photosynthesis
What can too much light do
to much UV rays can damage tissues
What is Photoperiodism
effect of day length and duration of light exposure on plant
Give day lengths and examples(3)
short day- flower if day is less than 12 hrs
long day- flower if day is more than 12 hrs
neutral- unaffected by day length
what is migration and hibernation and when does it occur?
Migration- animals move to other areas
hibernation- animals slow hart rate and metabolism to fall in deep sleep
occur due to decrease light hours in day ( season changes)
difference between sun loving and shade loving plants?
sun loving- require high light intensity to photosynthesise
shade loving- survive/ photosynthesise in low light intensity
what is stratification?
layering of vegetation in forests
what are ectothermic animals?
body temperature depends on environmental temperature. become inactive in cold winter temperatures and hibernate to survive. (active at moderate temps)
what are endothermic animals?
keep body temperature constant regardless of environmental temperature to operate efficiently and all the time. may also hibernate or migrate to warmer habitats in the winter
what are annuals?
complete life cycle in one season and survive winter with seeds
what are deciduous plants?
lose leaves in winter to reduce metabolism to survive
What are evergreen plants?
function all year round
what do atmospheric gasses do?
traps heat and allows life to exist
what does nitrogen do?
manufacture protein
what does oxygen do?
allows for cellular respiration
what does carbon dioxide do?
Photosynthesis
difference between hydroscopic and capillary water?
hydroscopic: water attached tightly around soil particles (not easily absorbed)
capillary water: water stuck between soil particles (easily absorbed)
What are hydrophytes?
plants adapted to grow in water
what are mesophytes?
plants adapted to grow in area of moderate water supply
what are Xerophytes?
plants adapted to grow in extremely dry conditions (succulents)
What is the water cycle?
Continuous cycle movement of water between the earth and the atmosphere.
Name 5 steps of water cycle and explain?
Evaporation: water from large water masses and soil reaches atmosphere becoming water vapour
Transpiration: Plants lose water vapour from leaves, stems and flowers to atmosphere
Condensation: Large amounts of water vapour condense to form clouds
Precipitation: water moves from atmosphere to earth in form. of rain, snow, fog, hail, dew and frost.
Infiltration: water absorbed by upper layers of soil to form hydroscopic and capillary water
where does water reach after infiltration?
water table
why are wetlands important?
- Maintains biodiversity and support variety of plants and animal life
- provides regular water supply.
- Helps reduce effects of droughts and floods
what are autotrophic components(Producers and which trophic level)?
Green plants that can photosynthesise to produce their own organic nutrients. first trophic level
what are heterotrophic components?
organisms that cannot produce own carbohydrates and depend on producers = CONSUMERS
What are primary consumers and which trophic level?
herbivores and omnivores. Second trophic level
What are secondary consumers and which trophic level?
carnivores and omnivores. Third trophic level
What are tertiary consumers and which trophic level?
Carnivores. 4th trophic level
What are decomposers and which trophic level?
Bacteria and fungi that feed on dead organic material. (saprophytic)
any trophic level.
What are trophic levels?
different feeding levels of living organisms
why are decomposers important?
Breaks down organic compounds into simple inorganic materials which return to soil for process to continue.
What is the food chain?
The transfer of energy
What happens in a longer food chain?
less energy will be available for next trophic level
what energy is available and what energy is not from one trophic level to next?
growth (metabolism)- available energy to next trophic level
Urine, respiration and faeces is lost/ released energy that is not available to next trophic level
what is a food web?
different food chains linked together
Define ecology
the study of the relationship between living organisms and the environment in which they live
