Identify the dominant plant phylum in the boreal forest.

In some areas there are gaps in the boreal forest where trees fail to grow and peat tends to accumulate. Suggest reasons for this.

An increase in global temperatures poses a critical threat to boreal forests. Explain the consequences of climate change to this northern ecosystem.

Suggest one advantage for the evergreen trees of the boreal forest being pollinated by wind.

Discuss the advantages of the production of seeds enclosed in fruit.

The boreal forests are situated close to the north pole and even in summer the intensity of sunlight is lower than at the equator. Sketch a graph showing the effect of light on the rate of photosynthesis, labelling the axes.

In some boreal species, Rubisco is down-regulated during the winter months. Describe the role of Rubisco in photosynthesis.

coniferophyta/conifer/coniferous/gymnosperms/pinophyta ✔

a. waterlogged soils/poor drainage
OR
acidic soil
OR
anaerobic conditions/soil ✔

b. organic matter not «fully» decomposed «leading to peat formation»
OR
decomposers/saprotrophs less active/fewer in cold «temperatures» ✔

a. higher temperatures so more transpiration/droughts/dehydration/water shortage ✔

b. more forest fires ✔

c. more/new pests/diseases because of the changed conditions ✔

d. competition from trees/plants «that colonize/spread to boreal forests» ✔

e. trees/«named» organisms «of boreal forests» not adapted to warmer conditions
OR
trees/«named» organisms migrate/change their distribution due to warmer conditions ✔

f. trees die so loss of habitat for animals ✔

g. faster decomposition/nutrient cycling «so conditions in the ecosystem change» ✔

h. standing water/floods due to more snow/permafrost melting ✔

animals/insects/mutualistic «relationships» not needed «for pollination»
OR
pollen not eaten by animals/insects ✔

a. seeds are protected «inside the fruit» ✔

b. seed dispersal by fruits ✔

c. example of a strategy for seed dispersal by a fruit ✔

d. dispersal reduces competition/spreads seeds away from parent plant/to colonize new areas ✔

For mpc suitable strategies are dispersal by wind, by animals ingesting/carrying away succulent fruits, by animals being attracted to colourful/sweet/tasty fruits, by animals burying nuts, by burrs or other hooked fruits sticking to animals and by self-explosion.

a. x-axis labelled as light intensity/amount of light AND y-axis labelled as rate of photosynthesis/rate of oxygen release/rate of carbon dioxide uptake ✔

b. curve starting at/slightly to the right of the x-axis origin and rising rapidly and then more slowly and plateauing but never dropping ✔

a. carbon fixation/fixes carbon dioxide/carboxylation
OR
rubisco is used in the Calvin cycle/light independent stage ✔

b. carbon dioxide linked to RuBP/ribulose bisphosphate «by rubisco» ✔

c. glycerate 3-phosphate/glycerate phosphate produced «by rubisco» ✔