Part 1

• Biogeography


  Study of distribution of organisms and their existing and changing relationships
• Biosphere


  Parts of atmosphere, hydrosphere and lithosphere that supports life
• Ecosystem


  Community of organisms (biotic) functioning together through interdependent relationships with the non-living environment (abiotic) that they occupy
• Ecotone


  Transition zone of varied natural vegetation occupying the boundary between two adjacent and different plant communities
• Biome


  Major types of terrestrial ecosystems associated with specific range of temperature, precipitation, soil, plant and animal types
• Habitat


  A place or type of place where an organism or population lives
• Niche


  The "job" or "role" that a species performs within nature
• Biodiversity


  The variety of life found in a place on Earth or, the total variety of life on Earth

  
• South Africa is host to a range of biomes, which encapsulate the huge biological diversity of the country

  
• These biomes can be attributed to the presence of strong environmental gradients in rainfall, temperature, geology, and soils, as well as the strong effect of fire and herbivory on vegetation
• Desert Biome


  • Harsh environmental conditions (rainfall >100mm/year)
  • High levels of summer aridity/evaporation
• Desert Biome Rainfall


  • 10–80 mm per annum
  • Highly variable (unpredictable)
• Desert Biome Plant and Animal Adaptations

  • Drought escape
  • Morphological adaptations
  • Physiological adaptations
  • Behavioural adaptations
• Forest Biome


  • Occupies <0.25% of SA land surface
  • Patchy distribution
  • Might have been larger in Pleistocene
• Forest Biome Characteristics


  • Distributed from sea level to >2000 m a.s.l.
  • Frost-free areas with high rainfall
  • Largest forests are in the southern Cape (e.g. Tsitsikamma)
  • Others are small and highly fragmented (e.g. KZN)
• Forest Biome Types


  • Afromontane
  • Mistbelt
  • Scarp
  • Coastal
  • Sand
  • Riverine
  • Swamp
  • Mangrove
• Forests are moist and do not tolerate fire (but embedded often in fire-prone vegetation)
• Typical animals in the Forest Biome include bushpig, bushbuck, monkeys, louries, pigeons and eagles but even elephants (>Knysna elephants)
• The Cape Parrot (Poicephalus robustus) is endemic to SA and critically endangered (1000 to 1500 remaining in the wild), dependent on the three yellowwood species for sustenance and nesting opportunities
• Forest is less susceptible to fire than Fynbos (& savanna, grasslands)
• Plants in Afromontane Forest

  • Podocarpus (yellowwood), Ocotea, Celtis, climbers, epiphytes, mosses, ferns
• Typical animals in Afromontane Forest

  • Bushpig, bushbuck, monkeys, louries, pigeons, eagles, elephants (Knysna elephants)
• Cape Parrot (Poicephalus robustus) is endemic to South Africa
• Cape Parrot is critically endangered with 1000 to 1500 remaining in the wild
• Cape Parrot


  Dependent on the three yellowwood species for sustenance and nesting opportunities
• Fynbos (grey slope in midground) burned completely


  Indigenous Afromontane forest only patchily burned (green is unburned, brown is scorched)
• Forest is less susceptible to fire than Fynbos (and savanna, grasslands)
• Indian Ocean Coastal Belt Forest

  • Sub-tropical climate, warm/wet/humid, soils deep and leached, higher species diversity than Afromontane, very dense cover, complex stratal structure
• Indian Ocean Coastal Belt Forest types

  • Dune, swamp, sand, riverine, coast lowland, coastal scarp
• Indian Ocean Coastal Belt Forest

  • High tree diversity, many tropical trees and epiphytes
• Indian Ocean Coastal Belt Forest tree species

  • Mimusops (milkwood), Sideroxylon, Ficus (fig trees)
• Ongoye Forest in Zululand has exceptionally high floral and faunal diversity
• Ongoye Forest hosts the only population of Woodward's (Green) Barbet in southern Africa
• Mangrove Forests


  • On eastern coast south to East London, rely on daily tidal fluctuations, warm surface water, have stilt roots and aerial roots (pneumatophores), can cope with brackish water
• Mangrove tree species


  • Bruguiera, Rhizophora, Avicennia
• About 40% of South Africa's forests were lost between 1800-2000
• Trees were harvested for timber (yellowwood, e.g. Knysna) and coastal forests were destroyed to plant sugarcane
• Harvesting of indigenous forest trees is now strictly controlled
• Knysna forests had an Elephant population, now only 1 female remaining in 2022
• Many forests (and grasslands) were replaced by plantations of alien timber tree species like Pinus and Eucalyptus