Background
Considering the valuable work that trees do for this planet, every one of them should get a medal. Aside from providing shelter and food for all sorts of wildlife, from fungus and beetles to mice and moose, trees contribute to a clean, healthy environment. They keep our air fresh by absorbing carbon dioxide, and supply the oxygen we need to breathe.
The bigger the tree, the more carbon dioxide it removes. Believe it or not, in one year a single tree can absorb the amount of carbon dioxide produced by a car driven 41,600 kilometres. Trees also lower air temperature by evaporating water into their leaves. They act as sound barriers against noise pollution, stabilize soil to prevent erosion, and reduce our heating and cooling costs with their shelter and shade.
The world needs a lot more trees; the very survival of humans and wildlife is impossible without them! Did you know that every year, 400,000 hectares of forest are gobbled up by expanding cities, and that only one in four trees removed are replaced?
You might say that trees are like "biodiversity hotels" for wildlife. Even dead and decaying trees, or snags, are used by an amazing array of species, and the bigger the tree the better. Hawks, owls, and other predators use snags as lookout spots. Some species, such as woodpeckers, drill out nesting spaces. Once vacated, these holes are often used by creatures like flying squirrels, owls, bluebirds, chickadees, nuthatches, and raccoons. Bats roost beneath loosened bark or inside hollow trunks. Larger animals need trees too. Caribou eat lichens that grow on decaying trees, and large hollow trees are sometimes used by bears for hibernating. Salamanders, skinks, toads, moles, shrews, fungi, and insects all have their turn as well when a tree becomes a rotten, spongy stump.
You can see what an enormously good deed you do by planting trees! In spring and summer, they offer sheltering branches for nesting creatures. In fall and winter, they provide edible treats such as nuts, seeds, and berries. In fact, trees are on duty year-round for the benefit of more wild creatures than you can shake a branch at!
Procedure
Plant a tree in your backyard. See "How to Plant Trees and Shrubs for Wildlife" for guidelines on planting seedlings and saplings. As your tree grows, discover the amazing ways in which it benefits wildlife. Here's a list of what to watch for:
• Once you've planted a tree, a host of wildlife species will take up residence. Birds and squirrels will nest in the branches in spring. Insects will hatch underneath the bark and soon become meals for hungry woodpeckers and nuthatches. Eventually, the tree will blossom, providing a feast of nectar for butterflies and hummingbirds. Bees will make honey, which may become a meal for some bear or skunk, although not necessarily in your backyard!
• Later in spring, the leaves of your tree will be munched on by colourful caterpillars, which will become dinner for birds like yellow warblers and red-eyed vireos.
• A tree is a great lookout spot for predators. You may be lucky enough to see an owl in the lower branches, waiting to pounce on some unwary mouse. Cooper's hawks perch patiently in trees for hours, watching for unsuspecting chickadees and other birds to come fluttering by.
• As the months pass, your tree will become a first-class eating establishment for wildlife. Berries, seeds, nuts, or cones will provide birds with protein and energy for the long migration south. This same food will help birds survive frigid Canadian winters when your tree becomes a regular drop-in centre for residents like cedar waxwings, evening grosbeaks, and squirrels.
• Coniferous trees will provide welcome shelter for grouse, songbirds, and white-tailed deer in winter.
• Note that different species will use different levels of a tree - almost like an apartment building. Hawks, owls, and larger birds use the uppermost branches for perching. Squirrels, songbirds, and some snake species, such as the black rat snake, use the branches of the tree for travelling, nesting, and feeding. Loose bark on the trunk provides bats with roosting spots, while nuthatches and woodpeckers tap on the trunk looking for insects. Fungus and moss grow on the lower levels, ants and termites help break down the rotting stump, and moles and insects burrow amongst the roots.