Chapter 5 Flashcards
What is natural vegetation?
Natural vegetation refers to plant life which covers particular parts of the world’s land areas and develops without human interference.
What is the Tropical Climate and climate?
Climate refers to the average weather conditions of a place over a long period of time, usually more than 30 years. The tropical climate is the climate experienced by many areas within the tropics, the part of the world located in between the tropic of cancer and the Tropic of Capricorn. The typical climate is also characterised by having a high annual rainfall of about 2000 mm on average, going up as high as 4500 mm, with rainfall throughout the year, and no months in which rainfall is low or absent. In addition, temperatures are high throughout the year.
What are tropical rainforests and where are they found?
The tropical rainforest is the main type of natural vegetation found in parts of the world which experience the tropical climate. They are found in central and South America, west and central Africa as well as south and south-east Asia, mostly located very close to the equator.
What are the characteristics of tropical rainforests?
The vast majority of tropical rainforest plants are evergreen. Tropical rainforests also contain a very large variety of plant species, more than any other type of ecosystem in the world.
What is the emergent layer in the tropical rainforest?
The emergent layer has the tallest trees called the emergents (up to 50 m), who grow very tall to absorb more sunlight.
What is the canopy layer in the tropical rainforest?
In the canopy layer, most tropical rainforest trees grow through about 20 to 30 metres in height. The trees grow very close to one another, and their crowns interlock to form a thick and near continuous mass of branches and leaves, preventing most of the sunlight that the top of the tropical rainforest receives from passing through to reach the forest floor.
What is the undergrowth layer in the tropical rainforest?
The undergrowth layer is found beneath the canopy layer where very little sunlight is able to reach. It is dark and cool due to lack of sunlight, hence plant growth is sparse. Only smaller plants that are able to grow in the shade and the seedlings of taller trees can grow here. There is also a layer of leaf litter due to warm and wet environment as well as rapid decomposition.
How have plants in the tropical rainforests adapted to their environment?
Individual tropical rainforest plants have developed special features or adaptations in order to cope with the intense competition for sunlight and rainfall, including broad leaves, wax leaves, drip tips and buttress roots.
What are broad leaves?
The leaves of most tropical rainforest plants are broad, which means that they have a large surface area, enabling the plant to absorb as much sunlight as possible in order to make food for its own survival and growth.
What are waxy leaves?
The leaves of tropical rainforest plants are usually waxy, which gives their surfaces a glossy appearance, helping the plant to reduce the amount of water vapour lost to the atmosphere through transpiration as a result of high temperatures in the tropical rainforests.
What are drip tips?
Some tropical rainforest plants have leaves with small narrow tips that points downwards. These drip tips together with the leaves’ waxy texture allow rainwater that falls onto them to flow off easily and the leaf to dry quickly, preventing the growth of fungi or bacteria on them. This is because there is frequent heavy rainfall in tropical rainforests.
What are buttress roots?
Tropical rainforest trees that grow to great heights in order to reach for as much sunlight as possible, usually have buttress roots to keep them upright and prevent them from toppling over.
What are mangrove forests and where are they found?
Mangrove Forests are a type of natural vegetation that is often found along, or very close to the coast. They are made out of a plant species known as mangroves which are able to grow in water that has a highest salinity compared to freshwater.
What are mangroves ideal living conditions?
Mangrove plants grow better in areas where water salinity is higher due to the lack of competition from other types of plants, which are unable to grow in such conditions. Mangrove forest are located in areas that experience the tropical climate as mangrove plants are unable to withstand freezing conditions and grow best where the average air and water temperatures do not fall below 20°C. Mangrove plants also require calm water conditions so that their seedlings are able to take route and grow without getting washed away by the strong waves. Calm water conditions also encourage the accumulations of fine sediments containing nutrients which mangrove plants require to sustain their growth, which is why mangrove forest are usually found only in sheltered environments along are very close to the coast.
