From Nookipedia, the Animal Crossing wiki
Trees are common flora in the Animal Crossing series. Some trees bear fruit while others are just for decoration. Certain insects can be found in or on trees, depending on the season and time of day. The number of trees will affect the environment of a town and are used to determine perfect town status. With the exception of perfect fruit trees in Animal Crossing: New Leaf, fully grown trees do not die until they are chopped down by the player, leaving behind a stump.
Saplings are baby trees available for purchase at Tom Nook's stores and the Garden Center. Not all trees grow successfully, due to poor soil quality and placement. If the player plants a tree where a different tree was cut down then it will have a much higher chance of growth. If the player stands on a tree sapling at exactly 6 a.m., the tree will grow around the player and knock them out, as though they had been bitten by a Tarantula or Scorpion.
 Types of trees
 Cedar tree
Cedar trees are evergreen trees. During December, particularly around Toy Day, and during the Bright Nights in Animal Crossing: Wild World, Cedar trees are decorated with bright lights. Cedar trees will only grow in the top two acres of the village, reflecting the fact that their real-life counterparts are found more frequently in the Northern Hemisphere, being adapted to colder temperatures.
 Oak tree
Oak trees are generic trees, resembling fruit trees but bear nothing. Their appearance differs seasonally, turning golden brown in the autumn, being snow-laden in the winter, and bearing cherry blossoms during the Cherry Blossom Festival in April.
 Fruit tree
Fruit trees resemble Oak trees but bear fruit, three at a time. During the Acorn Festival they also bear acorns. There are 5 different varieties of fruit trees (13 in New Leaf), one for each type of fruit (13 types in New Leaf). The player can receive non-native fruits in letters from Mom or from other villagers, after which they can then be grown into a fruit-bearing tree.
 Palm tree
Palm trees are foreign trees that bear two types of fruit, banana and coconut, growing two at a time. These trees can only be planted near the ocean, although not on the sand itself (except in Animal Crossing: New Leaf). There are some beetles that appear only on palm trees.
In Animal Crossing, coconuts are obtained only from visiting the island using a Game Boy Advance. In order to grow a palm tree in Wild World and City Folk, the player must find a coconut washed up on the beach, usually showing up at least once a week. In New Leaf, the player can find both coconuts and bananas on Tortimer Island.
 Money tree
Money trees are a rare variety of tree that bears money as its fruit. They can be grown by burying bells in the ground with a golden shovel. In Animal Crossing, the player can grow a money tree by burying bells in the daily glowing spot instead. To maximize potential return and minimize expected loss, the ideal amount to bury is 30,000 bells.
 Golden tree
 Dead tree
These appear only in Animal Crossing: New Leaf. When a perfect fruit tree is shaken 4 to 7 times, it dies and becomes a dead tree, which serves no use to the player and should be cut down. When a perfect fruit tree dies, it produces a rotten fruit in addition to two perfect fruit.
 Shaking trees
While all trees may be shaken by the player, only cedar and non fruit-bearing trees have a chance of containing hidden items. Each day a certain amount of 100 bell bags, beehives, and furniture leaves will be scattered among the town's trees. This number varies according to the total number of trees in the town as well as the iteration of Animal Crossing being played. The table below lists the item maximums according to game title.
 Tree stumpsAnimal Crossing series allow the player to chop down trees, producing a stump. These stumps do not count as trees (or weeds) when determining perfect town status. Animal Crossing: New Leaf introduced a few new features: two new insect species that are found only on stumps, the ability for players to use stumps as chairs, and special tree stump designs next to which mushrooms may appear.
 Special stump designs
There are twelve stump designs in New Leaf. Six of these are exclusive to pine trees, while the remainder are exclusive to fruit, bell and oak trees. Special stump designs are created by delivering the final blow to a tree with either a silver or gold axe. A silver axe guarantees a special design while a gold axe produces one only occasionally. Because only the final blow (of three) is the one that determines whether the stump will feature a special design, the first two swings can be made using a regular or gold axe to reduce wear on a silver one.