Trees & ForestsGrade 6 ScienceMrs. DeForge

Levels of the Forest

Level:

Plant:

Animal:

Level:Plant:Animal:

Level:Plant:Animal:

Level:Plant:Animal:

Different birds (owls etc) and insects (aphids, tent caterpillars)

top level of the forest formed by leaves & branches of tallest trees.

Upper Canopy

Middle Level or UnderstorySmaller trees & shrubsInsects, lichens, squirrels, woodpeckers and many other birdsHerb, Underbrush or Shubbery Layer

Ferns, wildflowers and other soft stem plants, tree seedlings.Butterflies, dragonflies, mice, weasels, deer, porcupine, skunks, rabbits

Forest FloorGround cover and soil; leaf litter, mushroom, moss, flowers.

Toads, salamanders, worms, bacteria, soil insects, spiders, millipedes centipedes.

Who Lives on Trees and Uses Them as Homes? Fungi: white and brown but never

green; most fungi feed on dead trees, a few on living trees.

Lichens: are two plants, a fungus and an alga, that live together in symbiosis (help each other); are grey, green or orange; use the tree only for support; they look like splotches of paint.

Mosses: are green, even all winter; like the cool moist bases of tree trunks, as well as fallen dead trees; use the tree just for support.

Animals: include woodpeckers, squirrels, owls; many of them use trees for their homes and for their food supplies.

How Do Trees Affect a Forest? They break the wind and with less

air movement, there is less drying. They shade the ground from the

sun thereby lowering air temperature; forests tend to be cool, humid places and the soil is moist there.

Forest soil is also very rich in nutrient because of all the leaves, branches, and stems which decompose into humus.

How do Other Living Organisms Affect the Trees in a Forest? Herbivores such as deer and

caterpillars eat leaves; large populations of tent caterpillars can have a devastating effect on popular trees in Alberta, wiping out all the leaves in stands of such trees in a short time; these trees grow secondary leaves which are fewer in number and smaller in size; the trees will not survive to successive summers of tent caterpillars.

How do Other Living Organisms Affect the Trees in a Forest? Coniferous trees are also affected by

certain insects; the spruce bud worm kills the growing shoots on spruce trees.

Birds can hurt trees; yellow-bellied sapsuckers peck rows of shallow holes around the trunk of trees to draw out the sap; often the birds will make a series of holes in one tree and drain enough sap to kill sections of the tree.

Blight, which is a kind of fungus, can get on leaves and into the wood of tree stems, gradually destroying leaves or wood and eventually killing the tree.