The tree is a life form of woody plants with a usually single, distinctly expressed, perennial, lignified structure. It is branched (except palm trees) and their main axis called the trunk.
The total number of trees on planet Earth in 2018 was estimated at 3.04 trillion; the estimated number of trees in Russia reached 642 billion (the first place in the world), for Canada the number is 318 billion and for Brazil it is 300. Furthermore, the number of trees on the planet declines by about 15 billion. The main reasons are both deforestation and global warming.
Trees by leaf shape are divided into two. These are coniferous and deciduous.
If we want to classify the leaf shapes, the trees are divided according to the life of the leaves and they can be either deciduous or evergreen.
Moreover, the tallest trees in the world are the redwood species which stays in the Redwood National Park and their height reaches about 115.55 m.
If we compare thickness, the thickest tree in the world is the baobab which has 15.9 m in diameter. In addition, the oldest tree in the world is a spruce growing in the mountains in the west of Sweden since the ice age and its’ age is older than 9550 years.