wk2 2b

• Definitions of regions


  • Habitats
  • Ecosystems
  • Biomes
• Influence of space and abiotic factors

  • On habitats, ecosystems, and biomes
• Wallace and biogeography
• Biosphere


  All organic aspects of the world – all plants, animals, bacteria etc. and their remains
• A key question of ecology is what drives or controls the distribution of organisms across the planet
• Deserts have few species, the Antarctic has many compared to the Arctic, we can predict which species may live where
• Biomes


  Basic patterns of distributions of plants related to climate / latitude, based on form rather than species
• At high latitudes and altitudes, plants tend to be small and / or evergreens
• In very high temperature / low rainfall the environments tend to be deserts

  
• In middle latitudes, grasses and deciduous woodland dominate, and at low latitudes with high rainfall, tropical forests dominate
• Definitions of biomes are not universal, you will see different maps or names in different sources
• Key factors in plant distribution

  • Mean annual temperature
  • Extremes of temperature
  • Amount of sunlight
  • Rainfall
  • Soil depth and quality
• Vertical zonation


  Separation along a physical gradient as part of an ecosystem / habitat
• Primary productivity


  The productivity of plant life, which varies greatly across the Earth
• About 50% of the primary production on Earth is in the seas and oceans
• About 80% of this (40% of the total) is in the open ocean (c. 65% of the Earth's surface)
• About 20% in coastal areas (c. 5% of the Earth's surface)
• Coastal zones are much more productive than the oceans on an area basis