Environmental Studies

• Abiotiese Komponente

  Abiotic components
• Abiotic factors can be placed into 3 groups

  • Climatic factors
  • Edaphic factors
  • Physiographic factors
• Climatic factors

  • Temperature
  • Light
  • Water
• Temperature

  • Can determine the plant life growing in an area
  • Exothermic animals become inactive in cold winter months
• Excessive water loss in plants can result from high temperature
• Transpiration

  The process responsible for the loss of water through the stomata
• Light

  • Needed by green plants for photosynthesis
  • Plants will compete for sufficient light
• Plants

  • Grow thin and tall to receive light
  • Vines climb on others to reach more light
• Epiphytes

  Grow on larger trees to get to the sunlight
• Vines

  Only use other plants for support
• Water

  • Used by plants and animals for many physiological processes
  • Plants need water for photosynthesis
  • Animals need water for digestion and transport
• Hydrophytes

  Plants that live in water or around large amounts of water
• Adaptations of hydrophytes

  • No root hairs, no conducting tissue, no supporting tissue, no cuticles
• Hydrophytes

  • Some have only roots in water, others have leaves and flowers floating on surface, some are submerged
• Terrestrial plants

  • Plants that live on land
  • Biggest problem is lack of water
• Terrestrial plants

  • Mesophytes: plants that need moderate amount of water
  • Xerophytes: plants that can live with very little water
• Adaptations of xerophytes

  • Leaves close together to reduce surface area exposed
  • Leaves reduced to thorns
  • Thick waxy cuticles
  • More stomata on lower surface
  • Sunken stomata
• Aquatic animals

  • Have gills to extract oxygen from water
  • Have fins to swim and maintain balance
  • Some can breathe with lungs
• Terrestrial animals

  • Camels can live long periods without water
  • Insects have exoskeletons that reduce water loss by evaporation
• Kangaroo rat obtains water from the food it eats
• Reptiles can reduce water loss because they are covered in dry horny scales
• Atmospheric gases

  • Oxygen required for cellular respiration
  • Plants absorb carbon dioxide for photosynthesis
  • Nitrogen required by plants to manufacture proteins
• Plants can only absorb nitrogen as nitrate, not as N2 gas
• Animals get nitrogen from plants or other animals that have eaten plants
• Edaphic factors: soil types

  • Sand: loose with poor water holding capacity
  • Loam: good water holding capacity and aeration
  • Clay: high water holding capacity but poor aeration
• pH scale

  Measures acidity or alkalinity of substances in solution
• Physiographic factors

  • Aspect: direction a slope faces
  • Slope: steepness of incline
  • Altitude: climate differences at higher vs lower altitudes
• North facing slopes in southern hemisphere are warmer and drier than south facing slopes
• Steeper slopes have thinner ground layer, faster water flow leading to erosion, and are more difficult for animals to graze
• Higher altitudes have lower temperatures, atmospheric pressure and stronger winds compared to lower altitudes
• Terminology

  • Ecosystem
  • Ecology
  • Abiotic
  • Biotic
  • Micro-organism
  • Producers
  • Consumers
  • Photosynthesis
  • Decomposers
  • Herbivores
  • Carnivores
  • Omnivores
  • Ectothermic
  • Endothermic
  • Transpiration
  • Terrestrial
  • Aquatic
  • Xerophytes
  • Mesophytes
  • Hydrophytes
  • Acidity
  • Alkalinity
  • Aspect
  • Altitude
• ž Abiotic factors can be placed into 3 groups.

  Climatic factors

  Edaphic factors

  Physiographic factors
• The temperature of an area can determine the plant life growing in that area.

  Some animals like the exothermic animals become inactive in the cold winter months because the temperatures are so low.

  Some of these animals hibernate to overcome the cold weather.
• hibernation

  Animals become dormant during very cold periods