Grassland

草地

What is a Grassland?

A open, continuous and fairly flat areas of grass and other herbs

cover 40 percent of the earth's surface

Location Between temperate forests and deserts.

Temperature

Between -20°C to 30°C

Rainfall About 500 to 900 mm of rain per year

Deep-rooted grasses and oats are commonly seen in grasslands

very few trees and shrubs in a grassland

Types of grasslands

1. Tropical grassland

A continuous cover of perennial grasses are found

Location close to the equator, often bordering a rainforest. Africa, South America, etc.

Climate Hot, dry and wet seasons

Types of grasslands

2. Temperate grasslands

Prairie is an example of Temperate Grassland

Location Farther from the equator e.g. the interior of North America.

Climate Hot summers and cold winters.

Rainfall Little rain fall

Grasslands in Hong Kong

On hillside grass and shrubs under

0.3 meters in height Small amount Mainly found in the

New Territories Varied ( mixture of

herbs and small shrubs)

Reasons for the lack of grassland

1. Soil Grasslands in..... Higher slopes are subjected to wind

exposure, poor soil condition and rapid runoff.

Lower slopes with poor soil conditions are mainly formed after abandon of farmland

Soil erosion

Reasons for the lack of grassland

2. Climate & Temperature

Moderate climate

High annual rainfall would forms a forest or woodland.

Temperature

around 12-30 C

Rainfall around 2214.24 mm per year

Reasons for the lack of grassland

3. Latitude Not enough land Not near the equator At subtropical latitudes Not lying on the region of grasslands

Ways to form grasslands

Fire is the factor to balance from forest to grasslands.

Fires set by lightning and by humans Perennial grasses and herbs are not harmed

by fires that destroy most shrubs and trees.

Use of Grassland

大氣過濾器 Grass absorb the toxic gases in the a

tmosphere. The secretion of grass can kill the ba

cteria ,reduce the concentration of bacteria in the atmosphere.

Absorb and adsorb the dust.

Use of Grassland

城市之肺 ,房屋之窗 Grass carry out photosynthesis Absorb CO2, release O2 1.5g per meter square in 1hour

Use of Grassland

Grasslands are highly productive when converted into agricultural uses

Since the soil is full of nutrients. The organic material (i.e. decomposers) makes the soil so productive

Conclusion

Grassland in HK is a poor habitat for vertebrates and most invertebrates

Since it provide neither food nor protection

So, we need to conserve certain species of grass or herbs

The End