Land Environments

This is a continuation of the lecture for Land Environments. I broke up the sections in case there are any early childhood or primary teachers who may want to use the material.

Land Environments (continued)

Mountain Peaks and Living Things

Ask the students if they know what the highest peak of the Sierra Nevada range is? The answer is: Mt. Whitney at 348.5 meters above sea level. At the top of the mountain is usually below the freezing point year round. Meaning condensation of moisture in the air results in snow. Peak is snow-capped at all times of the year (meaning also on such peaks there is little or no life.

There are places called snow packs down deeper and deeper/ year after year until its own weight changes it into a kind of ice pack that is much like the permanent ice pack covering most of Greenland.

There maybe an occasional bird or a stray animal, but a region like this as memtioned earlier will exhibit little life.

There are places just below an ice cap/ a narrow belt region in which the climate is very like that of an Arctic biome (Coast of Greenland). The animals are similar as in the snowshoe rabbit/arctic hare. There may be low growing plants such as mosses and lichens. There may be a patch of cold-resistant grasses or a gnarled shrub that sticks up out of the soil.

Temperatures- very cold- most of the year Similar environments have resulted with similar living things in similar communities. Another layer like that of Northern Canada that is a narrow band of spruce and fir biome.

Still another layer (narrow) but heavily covered with 'Douglas fir' trees that are larger than the spruce and alpine firs above them. A warmer climate at this altitude and in particular in the western slopes-a great amount of moisture.

Below all of these environments lie a band of 'Ponderosa pine' trees and still below those lie the 'Juniper' and 'Scrub' trees. On the eastern lower slopes there is very little rainfall, and with an only source of water usually from melting snow of the peaks, where even scrub trees soon cease and the landscape is that of a desert.

Desert Life

One-fifth of the world is desert (write on blackboard)

Deserts do vary and write the variations on the blackboard. Commonalities are- severe lack of rainfall and surface water. They have much less plant life than most other areas of the world.

What about animal life? Snakes, reptiles, wolves, coyotes made adaptations to survive

Air that sweeps off the American deserts east of the Sierra Nevadas is hot and dry and any moisture that may exist is sandy and rocky soil and it quickly evaporates into the air. (Ask students what does 'evaporate' mean?)

Occassional rains either evaporates as fast as they fall or quickly sinks in far below the surface of the land.

(What about plant and animal life of the desert?) Plants will adapt (ask students if they remember what 'adapt' and 'adaptation' means) to a life of little moisture.

(List on blackboard) Types of Plants of the Desert

1. Cactuses/cactus plants

2. mesquite

3. yucca

4. agaves

5. century plants (ask them what they think this means)

6. sage plants

Some/few specialized kinds of grasses and some typical plants grow on the desert landscape.

When it does rain occasionally there are a variety of short-lived plants that grow, bloom and die leaving seeds to repeat the performance when the next brief rain.

Plants live one season/one year are called annuals (write on blackboard) There seeds are able to absorb water rapidly. Allows 'germination'/'germinate' (write terms on blackboard) defining- The act and process of starting to produce a young plant swiftly.

Capable of flowering and producing seeds before the swift return of the desert dryness that robs them of all moisture in all of a total of eight months to live.

Other desert plants live for years due to special structures that have adapted to desert life conditions. (Example- on blackboard- Mariposa Lily)-stores food and moisture in an underground bulb, as other lilies. These lilies produce a beautiful flame colored blooms, then the foliage dies; leaving the bulb buried in the ground.

Other plants like the 'brittle-bush' (write on blackboard) when all the branches die during the long, dry season. It has parts that live underground and sends up new shoots when rain returns.

(On the blackboard) 'Octilla' always keeps its' branches but grows leaves only during heavy rains that thoroughly soaks the ground with water. Leaves remain only as long as the ground moisture is available.

'Because of 'specialized structures' are the reason desert plants are able to adapt and acquire and conserve moisture.'

Now the all familiar 'cactus' that have thick, waxy green stems that both store water and manufacture food. Cactus leaves have become 'modified' (ask students if they know the definition of this term.) (A very brief English language arts lesson). until they remain only as protective spines. *A huge 'saguaro' (write on blackboard) cactus grows 15 meters and weighs 11 metric tons that equals 'metric ton = 2204.6 pounds. Small variety of plant 'Teddy Bear Cholla (write on blackboard).

Some desert plants have shallow roots that spread out great distances-to (can) absorb water from sudden, short lived rains. 'How far do you think some plants have solved their water problem?' (The teacher asks the students this question.)

Some plants send their roots as far down as 30 meters (100 feet) and often run into a permanent supply of underground water.

There are sudden appearances of carpets of flowering annuals during brief and heavy rainfalls and desert plants are usually widely spaced. Many climates there is sufficient moisture for plants to grow close together. A desert plant that tried to grow close to another plant that had already sent out its shallow but extensive root system might simply die from lack of water. The established plant would absorb most of the water from its' network of roots before the young plant could secure enough water to last over the long, dry season.

(Discussion) Walking through a particular desert what do you suppose you will see? There are a variety of plants and animals like the white-footed mouse, badger, tiny kit fox, pocket mouse, kangaroo rat. To stay cool they stay in holes and burrows. Soil and sand makes good insulators.

List on blackboard- Other animals

1. Quail

2. thrashers

3. lizards

4. skunk

5. jack rabbit

6. coyote

7. squirrels

8. iguanas

9. tortoises

In the desert a green cactus is the common first link followed by the second link of mice, kangaroo rat, and other rodents. They eat plant life or at times insects and spiders who that are eaten by homed owls, hawks, badgers, coyotes, bobcats, skunks, snakes, kit foxes and list these on the blackboard and mention that this could appear on the test to name some animals that live on the desert and what all these animals have that is beneficial use for humans.

Desert animals, no less than desert plants must conserve what little water they can get.

'What adaptations do desert animals have to make for for survival?' Sleeping during the days. Rarely is there water to drink. Plant-eating animals get their water from the tissues of the desert plants they eat, and the meat-eating animals get water from the tissues of the animals they eat.

A tiny kangaroo rat eats nothing but dry seeds which is only 1/28 water. Kangaroo rats gains some water through his 'cellular respirations' (write on blackboard) a part of which is the oxidizing of food for energy.

'What are some of the ways animals lose water?' Body excrements, evaporation of water from the lungs exhaled while breathing; but the kangaroo rat loses a very small amount of moisture in those ways.

(A phrase we now learn 'the enviroment must be conserved.)

Enviroments must be conserved and to show the relationships of various animals to their own environments as teh larger animals (coyotes) to smaller animals like the (kangaroo rat).