🦎Climate and Vegetation

• Factors influencing climate

  • Latitude
  • Altitude
  • Continentality
  • Ocean currents
  • Aspect
  • Prevailing winds
  • Pressure systems
• Equatorial climate

  Low latitudes, within the Tropics 23.5° north and south of the equator
• Equatorial climate characteristics

  • Annual precipitation over 2000mm
  • Temperature range 26−28°C
  • Constant high temperatures
  • No seasons - hot and wet all year round
  • High humidity, usually over 75−80%

  
• Trade winds

  Winds blowing into the equatorial region from high pressure areas to the north and south
• Factors influencing the equatorial climate include the midday sun being almost directly overhead all year, low pressure all year, dense vegetation cover, and warm air storing large amounts of water vapour
• Hot desert climate

  15 - 30° north and south of the equator (tropical and sub-tropical)
• Hot desert climate characteristics


  • Annual precipitation below 250mm
  • Daytime temperatures can reach 50°C but average around 25°C
  • Night-time temperatures below 0°C
  • Large diurnal range up to 45°C
  • Annual range around 15°C
  • Summer and winter seasons
  • Low humidity often between 10−30%
• Hot deserts form between 15 - 30° north and south of the equator as a result of the atmospheric pressure systems
• Influence of pressure systems

  1. Air rises at the equator, moves north and south, cools and starts to sink

  2. This creates a zone of high pressure at about 30° north and south of the equator

  3. Due to the sinking air, warm air cannot rise, condense and form clouds, resulting in high aridity
• Tropical rainforest (TRF) biome is mainly found in a band between 15° north and 15° south of the equator within the equatorial climate zone
• Main areas of tropical rainforest ecosystem

  • Amazon
  • Central America
  • Central Africa
  • Indo-Malaysia
• Tropical rainforest biodiversity

  • Contains the highest biodiversity of plants and animals on Earth
  • Estimates range from over 50% to 80% of the world's plant and animal species
  • One 10km area can contain up to 1,500 flowering plants, 750 species of trees, 400 species of birds and 150 species of butterflies
• Tropical rainforest nutrient cycle

  Continual growing season with high rainfall and temperatures all year round<|>Rapid decomposition and recycling of nutrients<|>Plants grow quickly which leads to a rapid uptake of nutrients from the soil
• Tropical rainforest structure

  • Ground layer (0m)
  • Shrub layer (3−4m)
  • Under canopy (15m)
  • Canopy (30m)
  • Emergents (45−55m)
• Tropical rainforest plant adaptations

  • Waxy leaves with drip tips
  • Buttress roots
  • Lianas
  • Epiphytes
  • Straight, smooth trunks
• Tropical rainforest animal adaptations

  • Sloth
  • Toucan
  • Primates
  • Geckos
  • Stick Insects
• Tropical rainforest food web includes producers, primary consumers, secondary consumers, and tertiary consumers
• Hot desert biomes are mostly found in a band around the Tropic of Cancer and Tropic of Capricorn
• Hot desert biodiversity

  • One of the lowest biodiversity of plants and animals on Earth
  • Supports approximately 5000−6000 plant species, many invertebrates and up to 20 species of bird
• Hot desert nutrient cycle

  Growth of plants is limited due to extremes of temperature and lack of water<|>Nutrient cycle is very slow<|>Most nutrients are stored in the soil
• Hot desert plant adaptations

  • Low growing
  • Thick stems
  • Shallow roots
  • Long roots
  • Small leaves or needles
• Hot desert animal adaptations

  • Camels
  • Fennec Fox
  • Burrowing
  • Waterproof skin
  • Nocturnal
• Hot desert food web includes producers, primary consumers, secondary consumers, and tertiary consumers
• Deforestation is the felling and clearance of trees
• Countries experiencing high levels of deforestation


  • Malaysia
  • Brazil
  • India
  • Indonesia
• Human causes of deforestation


  • Subsistence agriculture
  • Commercial agriculture
  • Logging
  • Road construction
  • Mining
  • Urban expansion
• Wildfires are a natural cause of deforestation, and the frequency and severity of wildfires have increased due to human-induced climate change
• Deforestation has many environmental impacts, including loss of biodiversity, soil erosion, disruption of the water cycle, and increased greenhouse gas emissions
• Wildfires


  A natural cause of deforestation
• The frequency and severity of wildfires have increased


  This is linked to human induced climate change
• Deforestation is often the result of a combination of factors which are linked together rather than any one cause
• Environmental impacts of deforestation

  • Reduced biodiversity
  • Decreased interception and infiltration leading to reduced evapotranspiration and precipitation
  • Increased overland flow leading to soil erosion and sedimentation
  • Sediment buildup in rivers increasing flood risk
  • Increased leaching of nutrients
  • Increased CO2 in the atmosphere contributing to enhanced greenhouse effect
• The majority of nutrients in the tropical rainforest are held in the biomass, and when trees and vegetation are cleared by deforestation the main store of nutrients is removed
• Social impacts of deforestation

  • Indigenous communities have less land to sustain their traditional way of life
  • Loss of culture and traditions
  • Increased risk of landslides
  • Loss of potential medicines
  • Increased risk of flooding settlements
• Economic impacts of deforestation

  • More jobs available in mining, forestry, agriculture and hydroelectric power
  • Increased income for the country through the export of goods from the forest
  • Almost a quarter of Brazil's GDP comes from activities in the deforested areas of the Amazon
• Large amounts of deforestation have occurred in tropical rainforests due to economic development, earning money, difficulty in monitoring large areas, corruption, logging, firewood/charcoal, cattle grazing, cash crop farming, settlement/urban growth, road building, and mining
• Malaysia is located in Southeast Asia and almost 70% of the land is covered by tropical rainforest
• The Malaysian rainforest has high biodiversity with over 15,000 plant species, 750 bird species, 250 mammal species, 350 reptile species, 190 amphibian species, 350 fish species, and 1000 butterfly species
• Plant adaptations in the Malaysian rainforest

  • Pitcher plants
  • Orchids
  • Lianas
  • Kapur tree
• Animal adaptations in the Malaysian rainforest

  • Hornbill
  • Orangutans
  • Malayan Tapir
  • Mulu Flying Frog