People and the Biosphere + Forests under threat

Biome

Biome

A specific geographic area, home to animals and plants that have adapted to live in that specific environment. It can be made of more than one ecosystem

Biosphere

A plants and animals community covering a large surface of the Earth

Ecosystem

A community of plants and animals that interact with each other and their physical environment

Goods

Products and items sourced from the biome for survival or commercial use (things that are of value to us)

Services

Measures that the biome takes to serve the planet (eg regulating the composition of the atmosphere or maintaining the health of the soil)

Tundra

Location - 60N of the equator (Northern regions of Europe and North America Flora + Fauna - 80 mammal species (Arctic Fox and Caribou), 1700 plant species (Arctic cotton), very few birds that live there permanently Climate - Winter temps between -28C and -50C, summer temps -12C to 10C (Summer is only 50-60 days), less than 250mm rainfall per year (cold desert), winds of up to 60mph Other - No sunlight in winter but 24hr sunlight in summer, primarily permafrost soil

Tropical Rainforest

Location - Between the Tropic of Cancer and Tropic of Capricorn (23.5N and 23.5S) in South America and Africa Flora and Fauna - 427 mammal species, 1300 bird species, 40,000 plant species, home to 50% of the world's plant + animal species (Spider monkey, Brazil Nut Tree, Poison dart frog) Climate - temp ranges from 27C and 32C with no clear seasons, 2000mm rainfall per year Other - poor soil with a thin top layer of nutrients for growth, trees release most of their own rain (evapotranspiration)

Savannah

Location - between 5-15N and 5-15S of the equator in South America, Africa and Australasia Flora and Fauna - Mammals (Zebras + Meerkats), Reptiles (Snakes + crocodiles), Birds (Ostriches + Vultures), Plants (Acacia tree + lemon grass) Climate - temp 20C-30C, has wet season and dry season each ~6 months, lightning storms in the dry season Other - infertile soil with thin nutrient layer

Temperate Grasslands

Location - between 40-60N and 40-60S in Europe, North America and Australasia Flora and Fauna - Mammals (Prairie dogs, jack rabbits, bison), reptiles (snakes), plants (aster and sagebrush) Climate - Cold winters (-40C) with hot + humid summer (up to 37C), rainfall between 100-250mm) Other - thin soil therefore few trees can root, however its nutrient rich so grass and herbs grow

Desert

Location - between 15-30N and 15-30S in South America, Africa and Asia Flora and Fauna - Mammals (camel + onyx) , reptiles (horned lizard + geckos), insects (locust, scorpion, dung beetles), plants (Cacti + brittle bush) Climate - Extreme temps (50C day and 0C night), less than 250mm rainfall Other - 4 types (Subtropical, semiarid, coastal, and polar), has thin, sandy, infertile soil

Chaparral

Location - 30-40N and 30-40S in Europe and Africa Flora and Fauna - Mammals (Cougar and Jackal), Reptiles (rattle snakes and lizards), Birds (hummingbirds and owls), plants (oak tree and lavender) Climate - hot and dry, summer temps 20-40C and mild winter of 4-20C

Temperate Decidous Forest

Location - 40-60N and 40-60S in Europe, North America, Asia Flora and Fauna - Amphibians (toads and frogs), Reptiles (adders and lizards), abundnace of insects and plants (ferns and bluebells) Climate - mild and wet most of the year (winter -1C-30C, summer 27C-32C) 750-1500mm rainfall per year, has 4 seasons Other - Nutrient rich soil due to leaf litter

Taiga

Location - 50-60N of the equator in northern regions of Europe and North America Flora and Fauna - 85 mammal species (Canada lynx), very few permanent birds as they migrate Climate - humid rainy summers with temps between 7-21C, cold winters between 1 and -54C, up to 750mm precipitation per year, 4 seasons Other - primarily permafrost soil

Biosphere cleaning the atmosphere

Trees take in CO2 reducing global warming and give out oxygen

Biosphere cleaning water

Forest roots trap silt from reaching the rivers

Biosphere protecting bidodiversity

Provides habitats, forest protect soil from erosion to help prevent floods, reefs and mangroves provide coastal protection from storms, forest provide leaf litter to make soil more fertile

Biosphere providing recreation and leasure

Reefs and rainforests provide attractive scenery for tourism

Biotic Factors

Living factors in the ecosystem (eg plants, decomposers)

Abiotic Factors

Non-living factors in the ecosystem (eg rainfall, nutrient cycle)

Boserup Theory

Population growth has a positive impact on people as it forces them to invent a way out of problems when resources start to run out (eg GM crops)

Malthus Theory

Population Increases faster than food supply so there will be a time when the world cannot cope

Malthus negative response

Choosing methods to reduce fertility (eg China's one child policy)

Malthus positive response

Anything that increases mortality (eg low living standards or disease)

How the Biosphere helps us

• regulates gases that make up the atmosphere (plants absorb CO2 and emit Oxygen to breathe)

• regulates water cycle (plants slow the flow of water to rivers and filters to make it clean)

• keeps soil healthy for plants to grow (new nutrients are provided by rotting plant material)

Threats to forests

Deforestation, Global warming, pollution