An Introduction to Ecology and The Biosphere

Landscape ecology- interactions among ecosystems.                                     An ecosystem consists of all abiotic factors plus all organisms that exist in a certain area à Ecosystem ecology.   Landscape ecology- interactions among ecosystems. The biosphere is the global ecosystem.  Global climate research is an example of ecology at the biosphere scale.

Major Determinants of Global Climate 1. Shape of the Earth – differential heating and cooling results in rising and sinking air masses: Hadley cells

2. Revolution of the Earth around the Sun on a tilted axis – results in seasons as Hadley cells move latitudinally, tracking changes in the position of the solar equator with a slight time lag

Major Determinants of Global Climate 1. Shape of the Earth 2. Revolution of the Earth around the Sun on a tilted axis

Major Determinants of Global Climate 1. Shape of the Earth 2. Revolution of the Earth around the Sun on a tilted axis

Fig. 50.13 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Local effects on climate… Bodies of water and topographic features such as mountain ranges can affect local climates. Ocean currents can influence climate in coastal areas. Mountains affect rainfall greatly. Fig. 50.14 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Terrestrial biomes • Tropical forest • Savanna • Desert • Chaparral               • Temperate grassland               • Temperate deciduous forest               • Coniferous forest               • Tundra                          

Tropical Forest: Vertical stratification with trees in canopy blocking light to bottom strata. Many trees covered by epiphytes (plants that grow on other plants).

Example of Tropical, Dry Forest

Desert: Sparse rainfall (< 30 cm per year), plants and animals adapted for water storage and conservation. Can be either very, very hot, or very cold (e.g. Antarctica)

Chaparral: Dense, spiny, evergreen shrubs, mild rainy winters; long, hot, dry summers. Periodic fires, some plants require fire for seeds to germinate.

Temperate Grassland: Marked by seasonal drought and fires, and grazing by large animals. Rich habitat for agriculture, very little prairie exists in US today.

Temperate Deciduous Forest: Mid-latitudes with moderate amounts of moisture, distinct vertical strata: trees, understory shrubs, herbaceous sub-stratum. Loss of leaves in cold, many animals hibernate or migrate then. Original forests lost from North America by logging and clearing.

Coniferous forest: Largest terrestial biome on earth, old growth forests rapidly disappearing, usually receives lots of moisture as rain or snow.

Taiga or Boreal Forest

Tundra: Permafrost (Permanent frozen ground), bitter cold, high winds and thus no trees. Has 20% of land surface on earth.