Independent Site Visits 9th Grade:

Independent Site Visits 9^th Grade:

Bronx Zoo

Topic: The Earth's Diverse Ecosystem: Life on land

Grade Level: 9^th

Objectives:

1. Students will be able to learn about tropical forests, savanna grasslands, desert, taiga and tundra.

2. Students will understand why Earth can support life.

3. Students will learn about how water and temperature affect living styles of animals.

Background information:

Terrestrial organisms are restricted in their distribution largely by the availability of water and appropriate temperature.

Tropical Forests

Large areas of South America and Africa lie along the equator. Temperature averages between 25 to 30 degrees Celsius with little variation, and rainfall ranges from 250 to 400 cm (100-160 in.) yearly. Although rain forests cover only 6% of the Earth’s total land area, they are believed to be home to at least 5 million species, representing ½ to 2/3 of the world’s total.

Several layers of vegetation exist – towering trees to plants that just cover the ground. Due to the relative edible plant material close to the ground, much of the animal lie in tropical rain forest is arboreal (living in the trees), including numerous birds, monkeys and insects.

Savanna grasslands

Grasses are the dominant vegetation, with only scattered trees and thorny scrub forests widely spread. Savanna grasslands have a rainy season. Virtually all of the year’s precipitation falls during this time of the year. When the dry season comes, no rain may fall for months.

African savanna has diverse array of large mammals, including numerous herbivores such as antelope, wildebeest, buffalo, elephants and giraffes and carnivores such as the lion, leopard, hyena and wild dog.

Deserts

Deserts are very dry areas. The lower water content of the atmosphere leads to daily temperature extremes. Deserts vary greatly depending upon the amount of precipitation they receive, which is generally less than 25 cm (10 in.) per year. A few deserts are so dry that virtually no plant life occurs in them. As a result, desert soil is low in organic material but often has a high mineral content.

Plant cover is sparse in deserts, and much of the soil is exposed. Both perennials and annuals (after a rain) grow there. Many desert plants are provided with defensive spines, thorns, or toxins to resist the heavy grazing pressure they experience in this food-and water-deficient environment.

Desert animals tend to be small. During the heat of the day they remain under cover or return to shelter periodically. At night they come out to forage or hunt. In addition to desert-adapted insects, there are many specialized desert reptiles-lizards, tortoises and snakes. Mammals include such rodents as the American Kangaroo rat, which does not need to drink water but can subsist solely on the water content of its food plus metabolically generated water.

Taiga

· Harsh climate – long and cold winter; growing season is short

· Because of its harsh climate, the diversity of life in the taiga is much lower than in many other biomes. Wood bison, grizzly bear, moose, wolverine, foxes and deer live in taiga.

Tundra

· A vast treeless region

· Winter temperature –40 degrees Celsius or below; winds howl at 50-100 km per hour; precipitation averages 25 cm or less per year.

· Tundra supports various life forms. The ground is carpeted with small perennial flowers and dwarf willows no more than a few inches tall. Some water pools are superb mosquito habitats. Some insects and lemmings are found in this area.

Materials needed:

Pen, paper, student’s individual knowledge on animals habitats

Video tapes of animals in wild (if applicable)

Procedure:

*Students will be asked to do the following questions.

1. What important factors are required to support life?

A: Oxygen, water and appropriate temperature

2. What is habitat?

3. What factors make the tropical forests to support so many different life forms?

A: temperature (25-30 Celsius) and abundance of water

4. What animals can be found in

Tropical forest - numerous birds, monkeys and insects

Savanna grassland – herbivores: antelope, wildebeest, buffalo, elephants and giraffes;

- carnivores: lion, leopard, hyena and wild dog

Desert - Many desert plants are provided with defensive spines, thorns, or toxins to

resist the heavy grazing pressure they experience in this food-and water-

deficient environment.

- desert-adapted insects, specialized desert reptiles-lizards, tortoises and

snakes, and rodents as the American Kangaroo rat

Taiga - Wood bison, grizzly bear, moose, wolverine, foxes and deer

Tundra - small perennial flowers and dwarf willows no more than a few inches tall

- some mosquitoes

- some insects and lemmings

5. Where do penguins live?

A: There are about 17 different species. Usually they like to live where the

temperature is not to cold. Only two are found in cold regions. Penguins are not

found in North Pole (never with polar bears). Most of them live in Antarctica.

6. Can animals from desert able to live in tundra? Why/Why not?

7. Water is very important in desert. How did plants and animals adapt to live in such environment?

· American Kangaroo rat does not need to drink water but can subsist solely on the water content of its food plus metabolically generated water.

· Many desert plants are provided with defensive spines, thorns, or toxins to resist the heavy grazing pressure they experience in this food-and water-deficient environment.

Closure:

Organisms are uniformly distributed throughout the Earth. What governs their distribution? Basically, living things are restricted to areas whose available habitats and potential lifestyles fit their adaptation. The greater the differences among habitats, the differences among the organisms that inhabit them.

*note to teachers: This lesson plan can be followed by 'life in ocean' and 'environmental destruction caused by human' and many more!

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