Transcript File
Chapter 4 BIOSPHERE Ecosystems:How do they work? BIOMES • Biomes are major areas where interactions between abiotic & biotic factors occur. • They are groups of similar ecosystems characterized by: – precipitation – temperature ranges – soil properties – plant communities – animal communities. Biomes Biomes are based on climate (average precipitation and temperature) The Earth’s Major Biomes Tropical Rainforest • Canopy: dense covering of tree tops • Understory: 2nd story of shorter trees and vines under the canopy – Stratification • Fern Gully/Rio Nutrient Cycling in Rainforests • World’s poorest soils – New nutrients are not readily available here – Heavy rainfalls leaching and rapid removal of minerals • How can there be such vegetation cover? – Nutrient Supply & Material Cycling Taiga (Coniferous Forests) • Trees such as fir, pine, spruce – Produce from cones – Very uniform in appearance • North America & Eurasia Monsoon Rainforest • Deciduous trees: broad leaves that fall • Wet/Dry season • “Jungle Book” forest • • • • Tropical Savannah In the tropics Wet/dry season Less rainfall than trop. Dry forest Think “Lion King” Desert • Around 25-35o Latitude N and S • Plants and animal adaptations – Spines, waxy cuticles, scales • Think “The Mummy” and “The Sahara” Temperate Deciduous Forest • Mix of coniferous and deciduous trees • Humus (HUE-Mus) material formed from decaying leaves….very fertile!!! • Forests with leaves that change colors • Think fairy tale forest “Snow White” and “Sleeping Beauty” Tundra • Permafrost: layer of permanently frozen subsoil • “Ice Age” Trees will NOT grow because: 1. Growing season (summer) is too hot 2. Too cold in winter (frost damage) 3. Strong winds blow ALL year 4. Soils above permafrost are waterlogged Other interesting ecosystems… • • Mountain Ranges – On all continents – Abiotic and biotic factors change with ELAVATION (as u go up) • Therefore plants and animals change VERTICALLY • Grassland at base woodland/pines spruce/conifer forest tundra like open area at summit with wildflowers Polar Ice Caps – Border the Tundra – Cold year round – Characterized by ice and snow – Plants and algae are few but include Mosses and Lichens – North Pole • Sea ice and ice cap that covers Greenland • Polar bears, seals, insects and mites – South Pole • 5 km thick layer of ice • Penguins and marine mammals