Tremendous Trees From written in partnership with One Tree per Child

Plants have several basic needs for survival. These needs include light, water, air, minerals and nutrients. They also need to be able to reproduce in order to ensure that their species survives. Explore how trees have adapted to live in some really challenging conditions.

Sunlight In tropical rainforest more than 95% of the light from the sun is absorbed by the tree canopy making the forest floor dark. How do you think a tree could be adapted to live in this darker environment?

Adaptation to low light Plants such as fan palms have evolved to survive in these gloomy conditions by having big leaves to catch as much sunlight as possible.

Nutrients Tropical rainforests can also have shallow soils that are nutrient poor. How do you think trees might be adapted to live in areas where the nutrients in the soil are poor?

In areas where the soil doesn’t have lots of nutrients most trees have roots near the surface. But having shallow roots can mean the trees are unstable so some taller species like bay fig trees have developed buttress roots to keep them upright and stable.

Water The baobab tree which grows in African grasslands, or Savannah, has developed a huge trunk so that it can store water in the long hot dry season. Some areas in the World can have long periods without any rain. How do you think trees could be adapted to live in areas that might not have any water for months?

The Baobab tree which grows in African grasslands (called Savannah) has developed a huge trunk so that it can store water in the long hot dry season.

Some trees have leaves with a waxy coating to conserve water, such as holly. In the UK some of our own tree species have adapted to cope with drier conditions by having smaller leaves, such as hawthorn.

Cold Trees even grow in really cold places. Siberia has one of the densest woodlands, yet temperatures can be as low as -25’C. How do you think trees are adapted to survive these cold conditions?

Certain trees are great at coping with really cold conditions. These generally are the conifers which have needles instead of leaves. Needles lose less water and have a thick waxy layer to protect against cold like our native Scots Pine.

Pollution Trees that live in cities have to survive air pollution from traffic and industry. In the UK when coal fires were common, the air in the cities was often thick with smoke and soot. Only certain species of tree can cope in these conditions.

Some trees are excellent for trapping pollution due to their hairy leaves. This can help clean the air. Good trees for this include silver birch and lime. An example is London plane, which is also common in Bristol. This tree regularly sheds its bark which prevented the soot from harming the tree.

Heat Certain trees have adapted to survive very high temperatures that happen during forest fires.

An example is the giant redwood, (or Sequoia) that grow in California. These amazing trees have unusually thick and spongy bark, which in some cases, can be more than a metre thick. In Europe the cork oak has a similar thick and spongy bark. This thick bark is fire resistant and acts like an insulation blanket to protect the tree from heat. The oldest Sequoia tree is 3,500 years old and has different scars from forest fire burns over the years.