The savannah. Image credit

The savannah. Image credit

ZIMSEC O Level Combined Science Notes: Managing Ecosystems

  • The ecosystem needs to looked after to ensure it is in balance
  • Humans can have good or bad effects on the ecosystem
  • Soil is an especially important component of the Zimbabwean ecosystem because the country’s economy is still agro-based
  • There are several types of soil in Zimbabwe:
  • Savannah soils are most prevalent and these can be divided into
  • Granite soils and
  • Red soils

Savannah soils

  • Higher temperatures- soils heat up easily
  • Rapid denitrification-nitrates easily decompose releasing nitrogen back into the atmosphere
  • Few earthworms-indicator of fwe micro-organisms
  • Low fertility- the soils have low nutrient content

Effects of ground coverĀ in ecosystems

  • Surface runoff-ground cover reduces surface runoff as more water can penetrate the soil
  • Erosion-is reduced resulting in top soil being preserved
  • Evaporation-is reduced as ground cover provides mulching

Effects of human activity on the ecosystem

  • Acid rain
  • Eutrophication
  • Pollution
  • Reduced biodiversity
  • Global warming
  • Greenhouse effect
  • Reduced soil fertility
  • Increased erosion
  • Overgrazing

To access more topics go to the Combined Science Notes page.


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