Ecosystems: Need to Know • Distribution, characteristics and adaptation of three ecosystems (coniferous and rain forests and savannah grasslands) • Human activity and impact on each ecosystem.
Ecosystems: Keywords • Biodiversity • Coniferous woodland • Ecosystem • Hydrology • Savanna Grassland • Slash and burn • Soil • Tropical Rain Forest • Deforestation • Desertification • Sustainable Developemnt
What is an Ecosystem? A community of plants and animals which interact with each other and with the non-living environment.
Energy from the sun Climate Vegetation Rocks and Soil Ecosystem Links Living Creatures
Dense vegetation Twigs and leaves fall to the ground and become ‘litter’ Soil is fertile Nutrient Cycle Decomposition (breaking down) of litter by termites, fungi and bacteria Nutrients enter the soil
Reasons for distribution of Coniferous Forest • Very cold winters • Strong winds • Short warm summers • Low annual precipitation Only a few types of tree (pine, spruce) can survive the cold = no biodiversity
Coniferous Woodlands • Evergreen • One layer of trees • Only one or two types of trees • Dark with trees growing close together • Thick mat of dead needles on forest floor • Podsol soil (acidic)
Podsol Soil • Decaying Pine needles on surface • Dark, narrow humus layer • Grey layer at horizon A (minerals leached out) • Reddish brow layer forming horizon B
Podsol Soil • Needles decay slowly, adding little humus to trap minerals • Precipitation greater than evapotranspiration • Water drains down through soil • Water carries organic materials and minerals • Iron and clay are leached out of A • Re-deposited at B
Plant adaptations • Conical shape (flexible, bend in strong winds) • Downward sloping branches (snow slides off) • Needle leaves (Water loss by transpiration reduced) • Thick Bark (Protects from cold, sap contains anti freeze) • Evergreen (Must be ready for short growing seasons
Animal Adaptations • Colour change • Fur • Hibernation • Dig for food
Human Impacts • Deforestation • Tourism • Acid Rain
Tropical Rainforest Climate • Hot all year round • Wet all year • High annual rainfall • No Seasons • Vegetation needs both of these • Extensive species eg mahogany and teak (massive bio diversity) • Only restriction to growth is access to sunlight
Leads to five layers Great density of vegetation Great height Massive biodiversity Evergreen trees (constant growth) Thin Barks Adaptations to reach sunlight
Deep soil Red in colour However high rainfall creates similar conditions to podsols, thin humus, rapid leaching then deposition Minerals held in large quantity of leaf litter which is rapidly recycled Soils - Latosols
Traditional Human Impact • Traditionally impact minimal • Access difficult • Hot, humid climate with many pests • Latosol soil soon found to be infertile on removal of vegetation • Highly specialised nomadic cultures only survived well
Modern Human Impact • RESOURCES • TRANSPORT • FARMING • SETTLEMENTS
Modern Human Impact • RESOURCES • TRANSPORT • FARMING • SETTLEMENTS Leads To DEFFORESTATION
In Favour of Deforestation Hunters and collectors Shifting cultivators Rubber tappers Collectors of forest products Environmentalists Medical researchers Against Deforestation Logging companies Miners Cattle ranches Farmers from the east Some governments For/Against deforestation
What is sustainable development? • "Development that meets the needs of the present without compromising the ability of future generations to meet their own needs."- The United Nations World Commission on Environment and Development
Liana project • Founded in 1995, the Liana Project coordinates the efforts of skilled people within the forest communities of the Brazilian Government’s Extractive Reserves. • By creating locally controlled micro-enterprises that use sustainably harvested vines and natural fibers to make furniture and decorative goods, the project integrates forest conservation, local economic development, and the preservation of traditional skills.
There are six aims Improve quality of life of locals Provide secure income for locals Develop ways of increasing production without debt To conserve the environment To encourage re-use To develop technology which is appropriate to the skills, wealth and needs of locals