Topic 10

Question 1

Colonisation

Answer 1

species grow that are capable of surviving difficult conditions such as bare rock. they begin to break down rock and add organic matter

Question 2

pioneer species eg lichens and mosses

Answer 2

are able to grow when colonisers have made conditions more hospitable

Question 3

pioneer

Answer 3

pioneer species produce soil as dead material accumulates. this allows larger herbaceous plants to outcompete pioneers.
shrubs and bushes can be supported when soil becomes deep enough

Question 3

climax community

Answer 3

forms when the largest plants can grow. there is then no further succession

Question 4

What is succession

Answer 4

Entire forests can be wiped out by natural disasters like fire. the day after the fire the forest will look abandoned. over time the forest would grow back. the predictable changes that occur in a community is called succession

Question 5

primary vs secondary succession

Answer 5

primary change starts with an empty inorganic surface, such as bare rock.
secondary succession begins on existing soil that is clear of vegetation. it occurs after fires and floods, for example.

Question 6

net primary productivity. and units

Answer 6

total chemical energy available for plant growth, plant reproduction and energy transfer to other trophic levels after respiratory losses.
kjm^-2 year^-1

Question 7

Explain why temperature has different effects on NPP at these two light intensities

Answer 7

At high light intensities, as temperature increases, NPP increases because light is not limiting photosynthesis

at low light, as temperature decreases, NPP decreases as photosynthesis is limited by light

Question 8

Suggest why an increase in temperature may cause an increase in NPP

Answer 8

Rate of photsynthetic reactions increases
increased movement of enzyme
more enzyme substrate complexes form

Question 9

Suggest two biotic factors that may influence NPP in this grassland

Answer 9

Disease
Trampling
shading
competition from other plants

Question 10

Light wavelengths

Answer 10

idea of (rate of) growth is linked to (rate of)
photosynthesis ;
2. idea of top of the shore is shallower water where
most wavelengths are available / lower shore is
deeper water where only green (and blue)
available ;
3. idea that red weeds {reflect / do not absorb} red
light OR green weeds {reflect / do not absorb}
green light ;
Ulva lactuca / green seaweed:
4. high(est) rates in {red / blue} light / eq / {very
low / lowest} in green light ;
5. would grow well if {all / (blue and) red} light
available ;

Question 12

gross primary productivity (GPP).

Answer 12

(rate at which) energy {incorporated / eq} into
{biomass / organic matter } ;
2. by { plants / producers} ;

Question 13

Using the information in the table, describe and explain the effects of temperature and precipitation on GPP.

Answer 13

dependent on photosnythesis
the mean tempeature rate is higher more enzyme substrate complexes can form due to more kinetic energy. higher the temperature higher the the rate of GPP. higher precipitate the higher the GPP, water in needed for the light deendet reaction.

Question 14

Give two reasons for the loss in mass between green plants and carnivores.

Answer 14

transfer of energy is lost too surroundings as heat is lost through respiration
some material is undigested and therefore lost to the animal in its faeces to be broken down by decomposers.