Sustaining ecosystems

• Ecosystem


  A system in which organisms interact with each other and with their environment
• Ecosystem's Components


  • Abiotic (non-living, such as air, water, heat, rock)
  • Biotic (living, such as plants, insects, and animals)
• Flora


  Plant life occurring in a particular region or time
• Fauna


  Animal life of any particular region or time
• Food Chains


  Show only one species at a particular level from where energy is transferred up to the next
• Biome


  A large geographical area of distinctive plant and animal groups, which are adapted to that particular environment
• Biomes


  • Coniferous forest
  • Deciduous forest
  • Tropical rainforests
  • Tundra
  • Temperate grasslands
  • Tropical grasslands
  • Hot deserts
• The most productive biomes – which have the greatest biomass- grow in climates that are hot and wet
• Biome's climate and plants

  • Tropical rainforest (Centred along the Equator, Hot all year, Very high rainfall, Tall trees forming a canopy, Greatest range of different animal species)
  • Tropical grasslands (Between latitudes 5°- 30° north & south of Equator, Warm all year, Wet + dry season, Grasslands with widely spaced trees, Large hoofed herbivores and carnivores dominate)
  • Hot desert (Found along the tropics of Cancer and Capricorn, Hot by day, Cold by night, Very low rainfall, Lack of plants and few species, Many animals are small and nocturnal)
  • Temperate forest (Between latitudes 40°- 60° north of Equator, Warm summers + mild winters, Variable rainfall, Mainly deciduous trees, Animals adapt to colder and warmer climates)
  • Tundra (Far Latitudes of 65° north and south of Equator, Cold winter + cool summers, Low rainfall, Small plants grow close to the ground and only in summer, Low number of species)
  • Coral Reefs (Found within 30° north – south of Equator in tropical waters, Warm water all year round, Wet + dry seasons, Small range of plant life, Dominated by polyps and a diverse range of fish species)
• Nutrient cycle


  Plants take in nutrients which are built into new organic matter, then taken up by animals and returned to the soil when animals die and decompose
• Litter


  The surface layer of vegetation, which over time breaks down to become humus
• Biomass


  The total mass of living organisms per unit area
• Tropical rainforests are centred along the Equator between the Tropic of Cancer and Capricorn, and can be found in South America, central Africa and South-East Asia

  
• Climate of Tropical Rainforests

  • Evening temperatures rarely fall below 22°C
  • Due to the presence of clouds, temperatures rarely rise above 32°C
  • Most afternoons have heavy showers
  • At night with no clouds insulating, temperature drops
• Rainforest nutrient cycle


  The hot, damp conditions on the forest floor allow for the rapid decomposition of dead plant material, providing plentiful nutrients that are easily absorbed by plant roots, but do not remain in the soil for long

  
• Convectional rainfall


  1. Roots of plants take up water from the ground

  2. Water evaporates into the atmosphere as the rainforest heats up

  3. Water condenses and forms clouds to make the next day's rain

  
• Layers of the Rainforest

  • Emergent (Highest layer with tree reaching 50 metres)
  • Canopy (Most life is found here as It receives 70% of the sunlight and 80% of the light)
  • U-Canopy (Consists of trees that reach 20 metres high)
  • Shrub Layer (Lowest layer with small trees that have adapted to living in the shade)

  
• Rainforest soil profile


  • Leaf Litter (Thin litter layer rapidly decomposes in heat)
  • Top Soil (Shallow topsoil is a mixture of decomposed organic matter and minerals)
  • Sub Soil (The sub-soil is deep due to weathering of rocks below)
  • Rock (Underlying rock weathers quickly at high temperatures to form sub-soil)
• Interdependence in the rainforest

  The plants and animals depend on each other for survival
• Effects of Human Activity on the Rainforest

  • Logging (Most widely reported cause of destructions to biodiversity, Timber is harvested to create commercial items)
  • Agriculture (Large scale 'slash and burn' of land for ranches and palm oil, Increases carbon emission, River saltation and soil erosion increasing, Increase in palm oil is making the soil infertile)
  • Mineral Extraction (Precious metals are found in the rainforest, Areas mined can experience soil and water contamination, Indigenous people are becoming displaced from their land due to roads being built)
  • Tourism (Mass tourism is resulting in the building of hotels in extremely vulnerable areas, Has caused negative relationships between the government and tribes, Tourism has affected wildlife by exposing them to human diseases)
• Adaptations to the rainforest

  • Sloths (Camouflaged to forest environment)
  • Buttress Roots (Support tall trees & absorb nutrients)
  • Drip Tips (Allows heavy rain to run off leaves easily)
  • Lianas & Vines (Climbs trees to reach sunlight at canopy)
• Many tribes have developed sustainable ways of survival, such as shifting cultivation, and the forest provides them with food, natural medicines, and materials for homes and boats
• Benefits of the rainforest

  • Raw Materials (Commonly used materials such as timber and rubber are found here)
  • Water (Controls the flow of water to prevent floods/droughts regions)
  • Food (Important foods such as bananas, pineapples and coffee are grown there)
  • Health (25% of modern medicines are sourced from rainforest ingredients)
  • Energy (Large dams generate 2/3 of Brazil's energy needs)
  • Climate (Acts as carbon sinks by storing 15% of carbon emissions)
• Costa Rica is a small country in Central America that is home to 6% of the world's biodiversity and attracts 6 million tourists a year
• Threats to the Costa Rican Rainforest


  • Cattle Ranching and agricultural development by clearing land through slash & burn methods
  • Gold and other metal mining meant large scale soil and rock removing, deforesting and chemicals entering water systems
  • By 1990, 32,000 hectors of forest were cut down each year – devastating the fragile ecosystem
• Ecotourism


  Tourism that is directed towards the natural environments & conservation
• Rainforest Management in Costa Rica

  • Government created 28 National Parks with 24% of the country's land protect
  • Laws and enforcement meant that deforestation had fallen from 1.8 to almost zero by 2005
  • Agroforestry encourages growing trees and crops together to create better farming conditions
  • Afforestation has led to the replanting of trees to replace original forest that have been lost
  • Local people employed
  • Sustainable principles e.g. afforested wood, collected rainwater, on stilts, natural light
• There are still some disruption of the rainforest and risk of mass tourism in Costa Rica despite the rainforest management efforts
• The Arctic is the region north of latitude 60°N around the North Pole, and the Antarctic is the continent south of latitude 60°S around the South Pole

  
• Climate of Polar Regions

  • Polar areas are very cold with temperatures rarely reaching above 0 °C, with winters averaging below -40 °C and summers a maximum of only 10 °C, and low rainfall throughout the year
• Land & Sea Features of Polar Regions

  • Arctic (Large areas are permafrost, At sea, most of the region is frozen over)
  • Antarctic (Large and thick ice sheets, A mountain range crosses the continent)

  
• Flora and Fauna of Polar Regions

  • Flora (Very few plants - some lichens, mosses and grasses along the coastal areas)
  • Fauna (Relatively few species of animals - Polar Bears, Penguins and marine mammals like whales, seals and walrus)
• Scientific reports outline the effect global warming is having on polar regions, with ice sheets and glaciers melting at an alarming rate, thawing of permafrost increasing methane emissions, and the decline of Arctic ice creating waves capable of causing coastal erosion
• Arctic soil profile


  • Active Layer (Thaws in the summer, Becomes deeper towards pole)
  • Permafrost (Permanently frozen all year, Layer Increases further north)
  • Bed Rock (Low temperatures weathers rock slowly = less nutrients)
• Effects of Human Activity in Polar Regions

  • Oil & Gas exploration (Arctic holds a large amount of untapped oil and gas, Oil spills would threaten ecosystems as clean up operations would be slow)
  • Whaling (Hunting of whales is a major industry, This led to a rapid decline in whale populations, Many countries have banned whaling, but some still continue)
  • Fishing (Has made area possible to fish large untapped stocks, The polar areas are difficult to police due to harsh conditions, Collapse of the fish stocks might damage ecosystems)
  • Tourism (The tourism industry is steadily growing within polar regions, Travel by tourists have increase emissions further, Wildlife may become disturbed by tourists getting up close)
• Union Glacier in Antarctica has strict guidelines on how tourists should behave to respect the natural environment, uses solar panels to reduce carbon emissions, and carefully contains and removes all waste
• Basic Principles of the Antarctic Treaty

  • Bans mining and resource extraction
  • Prevents territorial disputes of the continent
  • Promotes scientific research and co-operation
  • Protects the fragile environments and its wildlife by preventing and managing waste/pollution
• The Antarctic Treaty System has stayed in place for 50 years with more countries signing up to enforce strict controls and improve its stability