Vegetation Adaptation | Tropical Rainforest

Adaptation of Trees

How have temperate coniferous trees adapted to the natural environment?

• Trees are evergreen therefore they are able to photosynthesise whenever temperatures rise above 3ºC, important in spring and even on some sunny winter days. This gives them an advantage over deciduous species that have to use precious energy growing new leaves every spring.

• The conical shape enables trees to shed snow which might break branches.

• Flexible trunks prevent snapping in high winds, common in these regions.

• Needle leaves have a small surface area and are waxy which reduces water lost by transpiration. Both of these adaptations are important as these trees grow in low rainfall areas, often less than 500mm per year.

• Dark forest floor and acid pine needles limit ground vegetation and competition for nutrients.

• Cones protect seeds from extreme winter cold and summer forest fires.

• Resinous bark protects trees from extreme winter cold.

• Wide, spreading roots to:

• collect nutrients from the shallow soil. The soils are thin and most of the nutrients are held within the litter layer

• provide anchorage against strong winds

• avoid the subsoil which is frozen for much of the year

How have rainforest trees adapted to the natural environment?

• Trees grow to 50 metres in height to reach the sunlight in the canopy

• Large canopy layer to maximise photosynthesis

• Evergreen trees due to the continous growing season. This means the tree can shed leaves at any time, but always be able to photosynthesise.

• Straight trunks and few branches to save energy in the race upwards towards the sun. Branches below the canopy would receive little sunlight.

• Shallow infertile soil results in:

• buttress roots for anchor and support

• shallow spreading roots to obtain nutrients from the decomposing vegetation

• Lianas climb up the trees to reach the sunlight

• Leaves have drip tips or holes that assist photosynthesis in allowing the water to drain off

• Leaves under the main canopy have adapted to the lack of light by growing large to assist photosynthesis

• Leaves in the canopy layer are small and leathery to protect against the strong sunlight

• Epiphytes grow in branch hollows where nutrients and water can collect

• Fungi on the roots help supply the trees with nutrients

• Stilt roots to protect against river floods