Trees are an essential part of the natural world's ecosystem. They are present on all continents except Antarctica and have evolved into numerous different forms. Different species of trees have different average life spans. Some trees are among the oldest living things on the planet, while others live for just a decade or two.
Fruit trees do not have a particularly large life span compared to other types of trees. A standard apple tree has a life span of between 35 and 45 years, while the dwarf apple variety rarely lives beyond 20 years. Pear trees also average between 35 and 45 years, while both plum and cherry trees have average life spans of between 15 and 20 years. Peach trees have one of the shortest life spans of fruit trees, averaging between 10 and 15 years.
Coniferous trees retain their foliage throughout the year and tend to have decent longevity. The Blue Spruce averages 150 years and can reach 350, while the White Pine has an average life span of 200 years but is capable of living up to 450 years. Douglas Firs, however, outlive almost every other coniferous tree, with an average life span of 750 years and a maximum of 1,200.
Deciduous trees are those that shed their leaves each autumn and sprout new ones each spring. They also have a variety of life spans. The Chestnut Oak, for example, lives for 300 years on average and may exist for up to 400. White Ash trees average 260 years but can reach 300, and the American Beech averages 300 years with a maximum of 400.
There are some species of trees that have much longer life spans than most others. These include the Giant Redwood, which averages 1,250 years and can reach 2,200. The Giant Sequoia has an average life span of 2,000 years and a maximum of 3,000, while the Alaska Yellow Cedar has an average span of 1,000 years but is capable of living for 3,500.
It is rare that a tree will get to live out its full, natural life span. Just like in humans, diseases can kill a tree, with fungal infections rotting away the wood. Insect infestation can also weaken a tree, causing its death either because it no longer has enough foliage to photosynthesize or it is downed by a storm or winter ice because it's been weakened. A few trees die after being struck by lightening. Many trees are, of course, cut down by humans before they can live out their days.