Ecosystems of the World

Climax Vegetation - the natural vegetation in the last possible stage of vegetation development. Climax vegetation is in balance with the climatic conditions. It should change very little if left undisturbed.

Climax vegetation in boreal (coniferous) forest: * Evergreen trees * Needle like leaves * Thick bark * Conical shape * Drooping branches * needle leaves reduce surface area meaning less water loss. * thick bark reduces water loss. * drooping branches and conical shape allow heavy snow to fall off relieving the pressure. Climate is temperate cold winter – these trees are hardy enough to endure long winters with limited water.

Complete # 19 on pages 102 – 103. a.Boreal Forest & Tundra are wide spread in high latitudes. b.Tropical Rain Forests occur in low latitudes. c.Tropical Rain Forest is most predominant in South America. d.South America, Africa, Australia and Antarctica do not have tundra. e.Boreal Forest is our ecosystem.

Elevation and Latitude Affect Ecosystems The changes in ecosystems from the equator to the poles is very similar to the changes in ecosystems from the base of a tropical mountain to the summit.

Complete # 23 on page 105. A = Temperate Deciduous Forest B = Tropical Rain Forest C = Grasslands D = Savanna E = Tundra F = Coniferous Forest G = Desert

Complete # 24 on pages 105 – 106. Ecosystem A = Savanna Ecosystem B = Boreal Forest Ecosystem C = Temperate Forest Ecosystem D = Temperate Grassland Ecosystem E = Tropical Rainforest Ecosystem F = Tundra Ecosystem G = Desert

Complete # 25 on page 107. Tropical Rain Forest Answer

Ecosystems and Climatic Regions Ecosystems of the world are largely defined by their climax vegetation. Example: tropical rain forest, grasslands, boreal forests, cacti, etc. Climax vegetation is determined by climate. Therefore, ecosystems parallel climate zones.

Arid gives Desert Semi-Arid gives Grassland Tropical Wet gives Tropical Rain Forest Temperate cold winter gives Boreal Forest Temp. mild winter gives Temp. deciduous Forest Ecosystems and Climatic Regions

ECOSYSTEMCLIMATIC CONDITIONSCLIMAX VEGETATION Tundra Polar to subarctic climate - short summers - temperature always below 10 0 C - very cold long winters - light precipitation Grasses and shrubs with shallow roots that reproduce quickly Boreal Forest Temperate cold winter climate - warm summers - moderate precipitation Evergreen trees with needle leaves & thick bark that reduce moisture loss Temperate Forest Temperate mild winter climate - mild winters - quite warm to hot summers - moderate to heavy precipitation Deciduous trees like oak & birch that lose their leaves in fall to reduce moisture loss Temperate Grassland Steppe to semi-arid climate OR Temperate cold winter (in some cases) - light precipitation usually in summer - warm to hot summer temperatures - cold winters Grass with shallow roots that require little water

ECOSYSTEMCLIMATIC CONDITIONSCLIMAX VEGETATION Savanna Tropical wet/dry to semi-arid climate - high temperatures most of year - light to moderate precipitation usually during one season Grass with shallow roots that require little water DesertArid climate - high temperatures all year - very light precipitation Plants that are thick, have needles, long roots, and can store water. Tropical Rain Forest Tropical wet climate - high temperatures all year - heavy precipitation most of year Tall evergreen broadleaf trees that have broad roots in thin soil to support height Mountain Varied climate but usually cold due to high elevations - Conditions depend on where mountains are - Quite similar to tundra ecosystem at highest elevations Vegetation varies with elevation and temperature