T7 People And The Biosphere Flashcards
Climate
The long-term average weather conditions of an area. Affect the type of biome.
Biome
A large-scale global ecosystem with distinctive vegetation.
Ecosystem
Abiotic and biotic factors within an area and their interactions.
Describe the distribution of the worlds biomes
Tropical rainforests are located either side of the equator in Alinia. They are generally found 15° north and south of the equator. key locations could be South America West Africa and Southeast Asia. Despite this, there are no tropical rainforest in Africa even though it’s on the equator.
Tropical rainforest ecosystem climate and characteristics
Climate:
Hot (due to equatorial sunshine)(25-28°C) and humid w high precipitation (2000mm) all year round > no seasons.
Day length same all year round.
characteristics:
Evergreen trees growing quickly and adapted to receiving most light.
Dense vegetation provides much food for wide food web.
Nutrient rich shallow soil due to fast decomposition and leaching.
Temperate forest climate and characteristics
4 distinct seasons w warm summers/cold winters.
High rainfall.
Shorter winter days and longer summer days.
Supports fewer plant species than tropical but more than boreal. Broad leafed, deciduous woodland
Thick, nutrient rich soil
Taiga climate and characteristics
Short summers and long cold winters below -20°C, low precipitation, clear skies.
Evergreen plants w coniferous trees like pine or fir. Low biodiversity and productivity, thin, nutrient poor, acidic soil.
Tropical grassland climate and characteristics
Low rainfall, wet and dry seasons. (Ranges between 35°C and 15°C) found around equator.
Grass, scrub and small plants. Thin, nutrient rich soil (leaching occurs in wet seasons)
Temperate grasslands climate and characteristics
Hot summers and cold winters (between 40°C and -40°C) low precipitation. Far from equator so sunlight varies.
Dominated by grass and small plants w fewer species than tropical. Thick and nutrient rich soil.
Desert climate and characteristics
V hot temperatures in day (45°C) and cold at night (0°C). Low precipitation (<250mm annually). Area of high atmospheric pressure w clear skies for maximal sunshine.
Sparse plant growth and little animal species due to harsh conditions and lack of precipitation.
Little leaf litter, dry conditions mean little decomposition and so thin and nutrient poor soil.
Tundra climate and conditions
Located at higher altitudes low temperatures and little rainfall. Continuous daylight in summer and little in winter.
Coldness and lack of sunlight mean few plant species and so animal species who eat vegetation.
Little leaf litter, low precipitation, temperature and permafrost layer produces thin and nutrient poor soil.
Local factors affecting biome type
Altitude Rock type Soil type Drainage Sea distance Latitude Prevailing winds
How does altitude affect biomes
Higher altitude= lower temp (100m up =-1°C)
Exposure to wind and relief rainfall
Steeper slopes= thinner soil
Hardier species as reach higher altitudes
Temps accommodate different species, allowing for gradient in biotic factors
Relief rainfall
When warm, moist air forming clouds condenses at mountains before warming, descending to form a rain shadow.
Rock type effect on biome
Permeability links to drainage factors
Erosion rates affect plant growth
Soil type
How does soil type affect biomes
Nutrient cycle
Facilitation of animals/plants
Fertility and so frequency of plant types
How does drainage affect biomes
Impermeability leads to waterlogged land, preventing plant growth and leading to swamp/ bog ecosystems w specialist vegetation
How does latitude affect biomes
Distance from equator affects atmospheric pressure and so temperature/climate of each biome.
How does sea distance affect biome
Smallest range of temperatures closest to the sea as ocean changes temp slowly
Landlocked countries have greater temp ranges
How does prevailing winds affect biome
Land prevailing wind provides warmer summers and colder winters
Ocean prevailing winds provide warmer winters and cooler summers
Biotic
Living components of an ecosystem
Abiotic
Non-living components of an ecosystem
Biodiversity
Variety of biotic components in an ecosystem
Goods provided by the biosphere
Food (natural vegetation used by indigenous people, sustainable harvesting of berries, nuts and fruits, fish/meat)
Medicine (medicinal properties of plants like Madagascan periwinkle cure illness)
Building materials (timber exploitation, straw for roofing/insulation)
Fuel (wood from trees/shrubs, dried dung burnt, biofuels, indigenous use animal fat)
Services provided by the biosphere
Global atmospheric circulation (trees/animals exchange gases so organisms can breathe, preventing global warming, lowering pH of oceans, controlling earth temp) Hydrological cycle (plant uptake decreases flooding and soil erosion, slowly releasing water into atmosphere) Nutrient cycle (provided by rotting material, maintaining soil structure/fertility, allowing plant growth, interception prevents leaching)
Characteristics of the rainforest
Climate is the same all year round with no definite seasons, hot (20-28°C and wet (2000mm rainfall annually) equatorial climates, high level of plant adaptations and biodiversity, dense and lush vegetation, evergreen trees, constant supply of nutrients in the soil which is cycled quickly
Convectional rainfall
Rising, warm pockets of air that cool and condense to form clouds that produce heavy rainfall and thunderstorms.
Layers of rainforest
Forest floor (bottom) Shrub layer Understory layer Canopy layer Emergent layer
Emergent layer
Hardwood, evergreen trees that have broken through dense canopy layer below to reach sunlight.
Monkey/bird habitat
Canopy layer
Dense layer, habitat to tree snakes, birds, tree frogs… as there’s much food available.
Understory layer
Young trees with large leaves capture sunlight and are habitat to many insects
Shrub layer
Dark area/ habitat to shade-loving plants and animals.
Adaptation
Change/development to suit/ survive the environment
Lianas
Woody vines w roots in ground, climb up trees to reach sunlight, growing in canopy.
Trunks
Tall and thin to allow trees to reach sunlight. Smooth bark allows water to flow down to roots much faster.
Drip tips
Waxy, smooth cuticles and pointed tips maximise water shedding so as to prevent water accumulation which leads to water-borne bacteria transmission and rotting.
Buttress roots
Large roots with ridges create a large surface area to support large trees.
Epiphytes
Plants that live on branches of trees high in the canopy, receiving nutrients from air and water.
(Symbiotic relationship)
Sloth adaptations
Large claws allow grip to hang upside down
Fur grows away from feet to shed water
Green algae allows camouflage from predators
Slow movement is difficult to spot from predators
Primate adaptations
Tail allows balance for climbing
Long strong limbs aid in climbing through forest.
Nutrient cycle
How nutrients are transferred around an ecosystem.
Rainforest nutrient cycle
Rapid as hot/damp conditions speed up rate of decomposition of dead plant material, providing plentiful nutrients easily absorbed by plant roots.
Are cycled quickly due to high demand for nutrients and plant leaching.
Food chain
Succession of organisms that eat another organism, supported by the main producer.
Trophic level
The position an organism occupies in the food chain
Tropical rainforest food webs
Complex as there is a high biodiversity and therefore a multitude of animals within/between trophic levels. Wide range of biotic factors enable symbiosis and interactions.
Reasons for deforestation
Transmigration HEP mining Timber Crop growth Cattle farming
How is deforestation identified in TRF
GIS
Geographical information systems
How does poverty lead to deforestation
developing countries use TRF for agriculture and sustenance farming
How does debt lead to deforestation
Countries profit from TRF exports to relieve national debt
