The Dollshouse Q&A page has some facts about trees, but, for those interested, here are some more:---
Our largest native trees, such as oak, ash and beech are the biggest living things in Britain, can weigh around 40 tons and have ten miles of branches and twigs. Trees pump several tons of water up to 100 feet into the air, and can have half an acre of bark.
The British Isles has a richer tree heritage than the remainder of Europe which could be due to our farming inheritance methodology. For example, the French removed theirs to create larger fields. However, in some areas (such as Seine et Marne in the South East) this has been so detrimental to the soil stability that large amounts of fertilizer have had to be used, rendering the local water undrinkable. Although there is still a forest of ancients at Moulins.
An ancient tree is difficult to define precisely. However it is one that is old, fat or hollow by comparison with other trees of the same type. Some ancient trees are instantly recognisable but others can be less obvious. A tree in natural conditions may pass through three main stages in its life: growing from seedling to a mature tree, fully mature to late maturity and finally ancient. Girth size is not always a good indicator of age. Different species vary enormously in girth – just compare an ancient oak of more than 6m and a birch of about one metre.
Yunnan, in China, has an amazing diversity of botany. There are ten times more tree species in western Yunnan than the entire British Isles. However, due to logging these are all, bar one, new trees, except in the monasteries/Buddhist temples. The single remaining specimen of ancient tree is a Chinese Hemlock Spruce (Tsuga Dumosa) around 35 feet in girth, but still contains less timber than the average large beech found in British Parklands.
It is not possible to date some trees, eg the Much Marcle Yew, because the core of central rings have rotted away. However, some trees are mentioned in literature such as Shakespeare/Tennyson and it is possible to locate some of these.
Most people are aware that counting the rings in a felled tree (or a core sample) gives the age, one year per ring. However, this does not hold true for the Araucaria aracauna, a pine named after an India tribe. Known to most as the Monkey Puzzle Tree. For some reason this tree grows only two thirds of a ring a year. Thus 66 rings could be a 100 year old tree. There was a beautiful 70 foot tall Monkey Puzzle near my parents in Suffolk. Unfortunately when the roads were updated the roots were chopped too severely for it to survive although the main tree itself was untouched.
There is an Oak Tree (quercus robur) in Kent, near where I did my teacher training so many years ago, that looks whole from one view, but the opposite side shows a main trunk that is hollow and like a chimney.
It takes three coniferous trees to put back into the air the same amount oxygen as one deciduous tree. Habit and economics these days dictate that conifers are planted as they grow quickly and the wood is available sooner. However replanting solely with conifers does not keep the balance of the world's oxygen. In the last 100 years there is measurable decrease of oxygen in the air. If it drops just a further four percent it will be unable to sustain human life apart from those accustomed to living in rarified atmosphere such as the Andes who will have to move to lower ground.,