2 Place the pan on a gentle heat until it is simmering, then take the pan away from the heat and place your leaves in the solution.
3 Leave them submerged for a good 30 minutes, making sure all of the leaves are under the surface. Then gently wash the leaves with fresh water by placing the pan under a slowly running cold tap, letting the water flush out the soda mixture and soft debris.
4 You should now be left with beautiful transparent leaves. To remove the soft material surrounding the veins, place the leaves on a saucer and gently brush with an artist’s paintbrush. Leave to dry on some kitchen towel.
Another distinguishing feature of a tree, and one that remains even in the winter when most leaves would have dropped, is the texture of the bark. The quickest and easiest way to record this is to make a rubbing – see Nick’s trick, below. The other way of recording your tree requires a little more effort, but it produces a really smart, three-dimensional model of a section of tree trunk – and that is by making a cast of it (see opposite).
Hold the crayon or pastel on its side for the most effective technique. This really helps to bring out the textures underneath.
Nick’s trick
* Carefully tape a piece of paper to the trunk of the tree and then colour over it with a crayon or pencil (dark looks best on white paper, but white chalk on black paper is pretty stylish, too).
* In this way you record all those textures and patterns and soon you will start to recognize a combination of these features and the colours. I have a friend who is a blind naturalist and he can tell most species of tree by these very textures you will be recording with your rubbings.
YOU WILL NEED
> modelling clay
> strong cardboard box
> plaster of Paris
> water
> poster paints
> paintbrush
1 First find the tree you wish to make an impression of. Then knead and pummel your modelling clay so it is soft and free of air bubbles. This makes it much easier to work with and gives you a better impression at the end.
2 Firmly press the clay into the tree’s surface. Try to keep the clay at least 1.5cm thick and aim to keep the edges from tapering. If you are going to make many such casts for a collection, use standard dimensions at this point as it makes the casts easier to store and/or mount.
3 Peel away the clay and you will notice all the bark textures on it. You now have to get this home without damaging the mould, so this is where a stout box to transport the clay comes in handy.
4 Once back at base, place the mould with the textured surface uppermost. Then use more modelling clay to make a ridge at least 2.5cm higher than the mould. You can choose at this point whether to make a curved cast, like the profile of the tree, or a flat section.
5 Following the packet’s instructions, mix some plaster of Paris with water. Pour the plaster into the mould and leave to set for a few hours. Then carefully lift and peel away the modelling clay to leave your bark cast, ready for display.
6 If you like, you can paint your bark impression with poster paints so that it looks even more lifelike.
The most accurate way to tell the age of a tree is to look at a slice through its trunk and count the growth rings. The cells under the tree’s skin (the bark) produce new wood as the tree grows and each summer, more new cells are made when conditions are best for growth. Growth rings show each year’s new growth – one for each year of the tree’s life. In years of good growth, the rings will be wider.
Obviously getting to see these growth rings in a healthy tree is impossible without cutting it down and destroying the thing you are studying! But if you come across stumps that have been sawn through and the cut is a smooth one, you should be able to see how old it was when the tree was felled. This will give you an estimated age of any tree of the same species in the same area.
Some trees grow very slowly indeed, but others have many a growth spurt, such as the commercially grown pines, various cedars, spruce and fir, poplars, cricket-bat willow and other non-natives such as eucalyptus. Slower-growing trees include pine, yew, chestnut, lime and most smaller-growing trees.
Fab facts
* Trees grow from the outside in! The growth cells are all in the surface of the wood, under the bark. They lay down new wood as the tree trunk expands. The wood in the middle of an old tree is usually dead and when a branch falls off, it is this that sometimes gets hollowed out by fungus and birds.
YOU WILL NEED
> a tape measure
> pencil
> paper
> calculator
1 Another way to estimate a tree’s age is by measuring the girth of the trunk about 1m up. Because large trees tend to grow at a predictable rate, their trunk gets thicker as they grow and on average, trees put on about 2.5cm a year.
2 So measure your tree’s girth in centimetres and divide it by 2.5. You will then have an approximate age for your tree. This is a very rough guess and growth rate does vary from species to species and from place to place.
Take it further
* Try to find a tree stump that shows the tree is, say, at least 100 years old and take a photograph of it.
* Either have the photograph enlarged or I enlarge a photocopy. If you have a digital camera, print