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 LocationBetween temperate forests and deserts. TemperatureBetween -20°C to 30°C RainfallAbout 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. ClimateHot, 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. ClimateHot summers and cold winters. RainfallLittle 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 C Rainfall around 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 atmosphere. The secretion of grass can kill the bacteria,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 CO 2, release O 2 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

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