sustaning ecosystem

• Tundra ecosystems are found at high latitudes above 60 degrees north of the equator in northern Europe, Canada, and Alaska
• Winters in tundra ecosystems are very cold, summers are brief, and there is little rainfall all year
• Tundra ecosystems have hardly any trees but contain moss, grass, and low shrubs
• There is a layer of permafrost on the ground all year in tundra ecosystems
• Taiga ecosystems are found at mid-high latitudes between 50 and 60 degrees north
• Winters in taiga ecosystems are cold and dry, while summers are mild and moist
• Trees in taiga ecosystems are coniferous, meaning they are evergreen and have needles to conserve energy
• Tropical rainforests are found at the equator between the tropics of Cancer and Capricorn
• It is hot and wet all year round in tropical rainforests
• Tropical rainforests have lush forests with dense canopies of vegetation forming distinct layers
• Hot deserts are found between 15 and 35 degrees north and south of the equator
• Hot deserts experience little rainfall and extreme temperature changes, with temperatures reaching 45 degrees Celsius during the day and dropping to zero degrees Celsius at night
• There is hardly any vegetation in hot deserts, but some needle-like trees are present to conserve water
• Grasslands:

  • Temperate grasslands are found at higher latitudes with more temperature variation and less rainfall, containing no trees, only grass
  • Savannah grasslands are found between the tropics, experiencing dry and wet seasons with relatively low rainfall, mostly consisting of grasses with scattered trees
• Temperate deciduous forests are mainly found at mid-latitudes, experiencing four distinct seasons with warm summers and mild winters, and rainfall throughout the year
• Deciduous trees in temperate deciduous forests lose their leaves in winter to cope with the cold
• Polar ecosystems are found around the north and south poles
• Polar regions are very cold and dry with limited growth, remaining dark for several months each year, resulting in a very short growing season of only two months
• Characteristics of tropical rainforests:

  • Animals: contain more animal species than any other ecosystem
  • Indigenous people adapt to live in the rainforest by hunting, farming, and fishing
  • Plants and soil: most trees are evergreen to take advantage of the continual growing season
  • Trees are very tall and the vegetation cover is dense
  • Epiphytes grow on other living plants and take nutrients from the air
  • Soil is not very fertile due to heavy rain washing away nutrients, but there are surface nutrients from decayed leaf fall
• • Climate: same all year round, between 20 to 28 degrees Celsius, high rainfall around 2,000 millimeters per year
• How tropical rainforests are interdependent:

  • Interdependent means all parts of an ecosystem are dependent on one another
  • Examples: Sucropia trees produce energy-rich food at the base of their leaves, relied on by Azteca ants for food and shelter
  • Azteca ants fight off other insects trying to feed from the same tree, protecting the Sucropia trees
• • Flying frog: fully webbed hands and feet, loose skin flap for gliding
  • Toucan: long large bill for reaching and cutting fruit from weak branches
• Adaptations of plants and animals in rainforests:

  • Lianas: woody vines with roots in the ground that climb trees to reach sunlight
  • Tree trunks: tall and thin to reach sunlight, smooth bark to allow water flow
  • Drip tips: leaves with pointy tips for water runoff
  • Buttress roots: large roots with ridges to support large trees
  • Epiphytes: plants living high up in the canopy, getting nutrients from air and water
  • Sloth: uses camouflage and moves slowly to avoid predators
  • Spider monkey: has long strong limbs for climbing
• Desertification is the degradation of land, making it drier and less productive
• One third of the Earth is at risk of desertification
• The process of desertification:

  • Vegetation either dies or is removed
  • Exposed soil is easily removed by wind or water without roots to hold it together
  • Nutrients in the soil are lost, making it unproductive
• Two main causes of desertification:

  • Climate change affects rainfall, reducing water available for plant growth
  • Global temperatures increase, causing more water to evaporate from the land
  • Human activities, such as removal of fuel wood, overgrazing, trampling by animals, and over cultivation
• Management strategies to reduce the risk of desertification:

  • Water management: growing crops that need little water, using drip irrigation to prevent soil erosion
  • Tree planting: acting as wind breaks, stabilizing roots, and preventing deserts from encroaching on farmland
  • Soil management: letting land rest between grazing or planting, rotating crops to prevent nutrient depletion
  • Appropriate technology: using cheap, sustainable materials for building, such as sand fences
• Characteristics of polar environments:

  • Climate is very cold, below freezing
  • Winters can drop to -40 degrees and reach -90 degrees Celsius
  • Ice sheets cover polar areas, no exposed soil
  • Few plants such as lichens, mosses, rocks, and grasses at the coast
  • Animals include polar bears, penguins, whales, and seals
  • Mostly uninhabited, but some indigenous people and scientists in Antarctica
• Characteristics of tundra environments:

  • Slightly warmer, can reach up to 10 degrees Celsius
  • Thin, acidic, and not very fertile soil
  • Hardly any shrubs, grasses, or mosses
  • Lichens are common
  • Animals include lemmings, wolves, and reindeer
  • Home to indigenous people and oil/gas workers in larger towns
• Both polar and tundra environments:

  • Low precipitation
  • Well-defined seasons
  • Layer of permafrost holding trapped gases
  • Most growth occurs during the short warm period
  • Relatively few animals
• Plant adaptations in polar and tundra environments:

  • Cotton grass is an example of a plant able to survive in these conditions
  • Features that help it survive:
  • Low-lying, snow covers in winter to insulate
  • Seeds scatter in the wind
  • Narrow leaves reduce transpiration and water loss
  • Adapted to a short growing season with a short life cycle
  • Dense flower heads reduce heat loss
  • Darker leaves help absorb energy from the sun
• Animal adaptations in polar environments:

  • Polar bears have a white appearance for camouflage on snow and ice
  • Thick layer of fat and fur for insulation against the cold
  • Small surface area to volume ratio to minimize heat loss
  • Greasy coat sheds water after swimming to reduce heat loss
  • Large feet help distribute load and increase grip on ice