Land Environments

A Spruce and Fir Biome

Moving further south, we find scattered clumps of trees. Go further south and entering great forests of spruce and fir trees that seems endless in all directions; that are dense with little light.

Very little plant life under this dense foliage. There are needle-like leaves on these trees that fall and makes a deep layer on the ground. Only a few bushes appear here and there and on occasion when the forest breaks wild grasses grow.

Animals that live in these forests are seed-eating- birds, moose, bobcats (lynxes), ground squirrels, wolverines, and other rodents.

A Temperate Hardwood Forest Biome

South in the United States, but still in the great fir and spruce forests and west of the Great Lakes a noticable change occurs. Evergreen forests now are sprinkled more and more with hardwood trees like oak and hickory. Further south below Lake Michigan many hardwood forests. Now there are still patches of woodlands. Going east, the regions are much warmer than arctic and even warmer than fir and spruce biomes.

(Now time for a check for understanding of subject. Review the terms so far and have the students define them. biome, tundra, hibernate, lichen. Ask the students to describe climates of the areas including plants and animals of each area studied so far.)

The United States areas (regions) are much warmer then the arctic and the fir and spruce biomes. Summers are quite hot and the winters are well below freezing for many days. In Springtime the hardwood trees grow a new crop of leaves along with a wide variety of bushes and grasses (write these on the blackboard as a list of what grows in the region.)

What types of plants grow in these areas? What do you suppose is very important to the area for the various types of plants to grow? Rainfall (write on blackboard). In the Midwest with the dry weather trees are mainly oaks and hickories (write on blackboard) (heading-Trees in Midwest) Going further east and north the weather is cooler and wetter and for the types of trees (write on blackboard-maples and beeches).

(Write on the blackboard-the many animals. (Headings- Plant-eaters and Meat-eaters)

Plant-eaters: birds, mice, ground squirrels, muskrats, squirrels, rabbits, deer, and other rodents.

Meat-eaters: foxes, skunks(also eats fruits/berries), shrews, snakes, owls and hawks.

Food chains in the hardwood forests are complex and interdependent and these are spread over the biome and known as food webs.

A Tropical Rain forest

New Orleans around the Gulf of Mexico and the Caribbean Sea to South America. Our travels now take us over the equator to Brazil.

A Description of an Amazon Rain forest (Put on blackboard)

As mentioned in the textbook- Jumping from an airplane you will not be able to land on the ground for you will land in a great tree and will probably have long vines stretching through the branches and you will cut your way out of the parachute and swing down to the forest floor.

On the blackboard write Amazon rain forest is made up of layers from top to bottom.

Layers of the Rain Forest

Top- Giant towering trees- one layer

2nd- now several layers of trees (30 meters tall)

3rd- these trees about half as high

4th- reaching only 4 meters tall

The environments differ at each level (layer) of the tropical rain forest.

Top trees- get full sunlight

Each layer gets a little less light than the top layer.

(Dr. W.C. Allee studied of the amount of light filtered through the layers of trees and vines in a rain forest in Panama. He found that the jungle floor received only 1/500 of the light that hit the highest trees.)

All or most of the plants on the ground level are able to live in dense shade.

There will also be temperature differences because of the differing amounts of sunlight at the various levels, as well as differing temperatures within one level.

(Example- Highest trees- very hot in day and cools down at night; Lower trees/ground level- same temperature day and night

There are many kinds of plants- (Ask students if they know any plants/flowers that grow in extreme temperatures. (Answer- orchids, aerial plants because they are supported by the trees and vines- the roots in the air.

Other bromeliads collect and hold rain in specially formed leaves. (A question you could ask-'How do the roots help these plants to grow?' The roots may grow into cracks and furrows in the trunk of the trees or vines that supports them. They also catch dust, leaves that fall and other materials, and these collected materials act like a sponge to hold water that provides a source of minerals that the roots can absorb.

What kind of plants/trees and animal life are found in the tropical rain forest? List on board: Tapir-two-toed sloth; Birds-toucan; Insects-leopard moth; other animals anteaters, monkeys, pigs, small/giant snakes, lizards, frogs, salamanders, deer, jaguars, parrots.

The rain forest has a very complicated food webs (chains). The year-round warmth - sunlight and the tremendous amount of rain make conditions ideal for green plants to grow and make food.

This allows for many animals to feed in the tropical rain forest.

Adaptation is important fact for the various plants and animals in whatever environments they live.

Life from High to Low

Wind trajectories (Write the term and define - trajectory. There are prevailing winds blowing in from the west called the 'prevailing westerlies' moving in off the Pacific Ocean going inland at Caliafornia. This air has picked up a large amount of moisture from its' trip over the ocean. When air arrived at the western base of the Sierra-Nevada range in Caliafornia the wind is forced to climb the mountain side. More air is pushing in behind it forces it up. As the air is pushed up the mountain side it expands and it cools.

A Mountain and A Desert

(Write the term 'condensation' on the blackboard and then describe the term to give meaning.) Air is not visible and water vapor in the air is usually not visible except when water vapor condenses from the gaseous to the liguid state.

Air goes higher and higher up the western side and it becomes cool enough for water vapor to condense and form clouds, and thus when the droplets collect and then fall on the western side it is rain, and if cold enough the droplets will fall as snow or even as a snowstorm.

The combined effect of condensation and expansion is a gradual cooling of the air as it rises to the top of the mountain.

Now follow the eastern slope/ the air sinks down and it becomes compressed; the molecules are pressed closer together then the air heats up since hot air can hold more water vapor than cold air, and no more condensation of water vapor. In other words what starts out as moist on one side will usually end up dried for losing its' moisture after being warmed.

A question- Can you now see why deserts lie to the east of high mountain ranges on the continent? Because the air is drier on the eastern slopes of the mountain and due to the compression of the air/heat-becomes hot/dry and forms deserts. ( This is a question the teacher can pose to the students.) (A mini-lesson unit on weather may follow this lesson or chapter. )

(End of Part Two)

(Reference: Life A Biological Science (1975) Chapter 3 Land Environments)