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• Biodiversity


  The variety of living organisms and the ecosystems and ecological processes of which they are a part
• Categories of biodiversity


  • Genetic diversity
  • Species diversity
  • Ecosystem diversity
• It is estimated that there are between five (5) million and thirty (30) million species, but only 1.7 - 2 million species have been formally identified
• The greatest species diversity is exhibited by microbes, insects and small sea organisms
• The areas richest in biodiversity are the tropical moist forests of Southeast Asia, Central Africa and West Central Africa and Tropical Latin America
• Mangroves


  A plant community which lies between the sea and the land in areas which are inundated by tides
• Mangroves


  • Protect the coastline from erosion and reduce damage from hurricanes
  • Protect the quality of coastal water by diluting, filtering and settling out sediments, excess nutrients and pollutants
  • Promote sediment deposition by slowing the movement of storm water
  • Provide habitat, nursery, breeding and fishing grounds for many species of fish, invertebrates and plants
• Threats to mangroves


  • Excessive siltation and sedimentation
  • Major oil spills
  • Reduction in fresh water inflows and alteration in flushing patterns
  • Clear felling of trees
  • Dumping and filling of mangroves to build hotels and housing schemes
• Seagrasses


  Submerged marine plants occupying shallow coastal waters
• Seagrasses


  • Provide habitat and nursery grounds for species
  • Stabilize the sediment and prevent turbidity which would otherwise affect the health of coral reefs usually found adjacent to seagrass beds
  • Absorb some of the nitrates and phosphates in the water from land run-off, which reduces the amount reaching adjacent coral reefs
• Threats to seagrass beds

  • Release of excess nutrients (nitrates and phosphates) into coastal waters
  • Removal of seagrass beds by dredging for construction
  • Propeller damage caused by boating activities
  • Anchoring
  • Deployment of moorings
  • Fishing and recreational sports
• Coral reefs


  Collections of biological communities which represent some of the most diverse in the world
• Coral reefs


  • Provide habitat for marine creatures
  • Are a source of food
  • Have commercial value such as being a resource for tourism
  • Control carbon dioxide levels in the ocean
  • Protect coastlines from wave action
  • Have medicinal value
  • Provide sediments for white sand beaches
  • Are a nursery and breeding ground for many aquatic species
• Threats to coral reefs

  • Disease
  • Tropical storm damage
  • Wave action
  • Warmer ocean temperatures
  • Overfishing
  • Destructive fishing methods
  • Pollution
  • Oil spills
  • Increased sedimentation
  • Mangrove removal
• Weather


  The conditions in the atmosphere at a given place and time
• Climate


  The average weather conditions that occur in a place over a period of years
• The two most important factors that help to determine an area's climate are temperature and precipitation
• Precipitation refers to any form of water such as rain, snow, sleet or hail that falls to the Earth from the atmosphere
• Living organisms have adapted to different climatic conditions (temperature, light, moisture) forming communities of plants, animals and soil organisms in particular areas
• Biome


  A large, relatively distinct terrestrial region characterised by similar climate, soil, plants, and animals regardless of where it occurs in the world
• Major biomes


  • Tundra
  • Taiga
  • Temperate rain forest
  • Temperate deciduous forest
  • Temperate grassland
  • Chaparral
  • Desert
  • Savannah
  • Tropical rainforest
• Deforestation is a major problem in tropical rain forests, with 40% of tropical deforestation occurring in South America
• The three major agents of deforestation are subsistence agriculture, commercial logging and cattle ranching
• Agricultural importance of biodiversity

  • Human beings and other animals depend on plants to provide them with food, but the number of different kinds of food we eat is limited when compared with the total number of edible species
  • At least 1650 known tropical forest plants have potential as vegetable crops
  • Virtually 100% of the protein from domesticated animals consumed by people comes from eight species: cattle, pigs, sheep, goats, chickens, ducks, geese and turkeys
  • Maintaining a broad genetic base for organisms that are economically important is important to prevent increased susceptibility to pests and diseases
• Agricultural importance of biodiversity

  • Wild tomato discovered in the Andes has been used to increase the sugar content in cultivated species
  • Rice grain in Asia is protected from the main rice diseases by genes brought in from a wild species from India
  • The sugar cane industry in the US was saved from collapse by disease resistant genes brought in from wild Asian species
  • A wild barley plant from Ethiopia provided a gene that protects California barley crop from lethal yellow dwarf virus
• Industrial importance of biodiversity

  • Modern industrial technology depends on a broad range of genetic material from organisms, particularly plants that are used in many products
  • Plants supply oils, lubricants, perfumes and fragrances, dyes, paper, lumber, waxes, rubber, resins, poisons, corks and fibres while animals provide wool, silk, fur, leather, lubricants, waxes and transportation
• Industrial importance of biodiversity

  • The neem tree has been found to be a source of insecticides, spermicides and agents potentially valuable in birth control
  • Daisy plants (used centuries ago as a lice remedy in the Middle East) led to the discovery of pyrethrum insecticides
• Medicinal importance of biodiversity

  • The genetic resources of organisms are vitally important to the pharmaceutical industry, which incorporates hundreds of chemicals derived from organisms into its medicines
  • About a quarter of all prescription drugs are taken directly from plants or are chemically modified versions of plant substances and more than half of them are modelled on natural compounds
• Medicinal importance of biodiversity

  • Morphine, codeine, quinine, atropine and digitalis
• Ecosystem stability


  • Plants, animals, fungi and other microorganisms are instrumental in many environmental processes without which humans could not exist
  • Forests provide watersheds, from which we obtain water, and reduce the severity and number of local floods
  • Many species of flowering plants depend on insects to transfer pollen for reproduction
  • Soil dwellers from earthworms to bacteria develop and maintain soil
• Medicinal importance


  The genetic resources of organisms are vitally important to the pharmaceutical industry, which incorporates hundreds of chemicals derived from organisms into its medicines. About a quarter of all prescription drugs are taken directly from plants or are chemically modified versions of plant substances and more than half of them are modelled on natural compounds.
• Examples of medicinal products

  morphine, codeine, quinine, atropine and digitalis
• Ecosystem stability


  Plants, animals, fungi and other microorganisms are instrumental in many environmental processes without which humans could not exist. Forests provide watersheds, from which we obtain water, and reduce the severity and number of local floods. Many species of flowering plants depend on insects to transfer pollen for reproduction. Soil dwellers from earthworms to bacteria develop and maintain soil fertility for plants. Bacteria and fungi decompose organic material, which allows nutrients to recycle in the ecosystem.
• Scientific importance


  The study of organisms may lead to breakthroughs in several different fields including medicine, industry, genetic engineering and agriculture.
• Genetic engineering


  The incorporation of genes from one organism into an entirely different species, making it possible to use the genetic resources of organisms on a much wider scale. The gene for human insulin has been engineered into a bacterium which subsequently become tiny chemical factories manufacturing, at a relatively low cost, the insulin required in large amounts by diabetics. Genetic engineering has provided us with new vaccines, more productive farm animals, agricultural products with longer shelf lives and other desirable characteristics.
• Genes cannot be made; hence engineering depends on the availability of a broad base of genetic diversity from which genes can be obtained.
• Aesthetic value


  Organisms provide recreation, inspiration and spiritual solace. The natural world is a thing of beauty because of its diversity.
• Ethical value


  The traditional view is that humans are masters of the rest of the world subduing and exploiting other forms of life for their benefit. An alternative view is that organisms have intrinsic value, in and of themselves, and that as stewards of the life forms on Earth, humans should watch over and protect their existence.
• Threatened species


  A threatened species is any species of animal, plant, fungi etc. which is vulnerable to extinction in the near future.
• Categories of threatened species

  • Vulnerable species
  • Endangered species
  • Critically endangered species