Ecosystems Flashcards
Ecosystem
A community of plants/animals interacting withn one another and the non-living environment surrounding them
Biotic and Abiotic
Biotic - living factors, e.g flora, fauna, micro-organisms, humans, soil
Abiotic - non living factors, e.g soil, rock, climate
Interdependence
The reliance of biotic and abiotic parts of ecosystems on each other in order to keep the ecosystem going, through nutrients and food webs
Where are tropical rainforests found?
- Between 15 degrees N&S of equator
- Covers only 6% of Earth’s surface
Climate of a rainforest
- Hot and wet all year round
- Mean monthly temperatures range from 26-28 degrees
- > 2000 mm rainfall per year
Nutrient cycle of the rainforest
- Precipitation and fallout from BIOMASS leads to nutrients in the litter, which transfers nutrients through decomposition to the soil and loss through run off
- Soil receives nutrients through input from weathered rock, before losing it by leaching and an uptake by plants as biomass
- Biomass gains nutrients through uptake from soil, before losing it as fallout when leaves die
Soil profile of the rainforest
- Thick leaflitter layer
- Thin humus layer as litter incorporates into soil and decomposes
- Greyish/red coloured soil which is slightly acidic
- Red clay layer due to iron and aluminium compounds
- Rapid leaching washes nutrients down and out of soil
- Clays decompose at the bottom
- Soil depth reaches 30 metres
Water cycle of the rainforest
- Produce their own rainfall, called convectional rainfall
- Heat up during the day, evaporating water into the atmosphere forming clouds, with rainfall then being made for the next day
- Water lost through leaf pores, and evaporated by heat through evapotranspiration
Much of water evaporates from canopy, which later intercepts most rainfall - Deforestation means less water in atmosphere and decrease in rainfall
Value of the rainforest to humans
Goods - e.g nuts, crops, meat, water, medicine, building materials
Services - e.g tourism, agriculture, reducing flood risk, protecting soils, gas exchange
How do humans impact the rainforest?
- Logging
- Agriculture
- Metal extraction
- Tourism
- Dam building, hydroelectricity
- Road construction
What are the main impacts from these activities?
- Deforestation leads to release of carbon, less interception, leading to more greenhouse gases and flood risk
- Need for space results in more habitats for plants/animals being destroyed
- Roots aren’t able to hold soil, interception doesn’t occur, increase in flood risk
Characteristics of the Arctic
- 66.5-90 degrees N of Equator, region within the Arctic Circle
- 10 degrees in summer,
to -40 degrees in winter - Precipitation 500mm> annually
- Surrounded by continents and large islands, with sea pack ice extending in winter, reaching 3m in places
- Mountainous regions on land, areas covered in permanent ice/snow
- Includes treeless permafrost tundra, with only the top layer of soil thawing each summer
- Flora: lichen, mosses, grasses, shrubs
- Fauna: whales, wolves, fish, polar bears, birds
Characteristics of the Antarctic
- 66.5-90 degrees S of equator
- Temperatures peaking around -28 in summer and reaching as low as -90 degrees in winter
- 50mm rainfall annual inland, 200mm rainfall at coast
- Covered in permanent ice cap, surrounded by antarctic ocean
- Mountains as high as 3794m
- Ice as thick as 4.5km in places
- Doubles in size in winter due to freezing seawater
- Flora: lichen, some moss, phytoplankton in ocean
- Fauna: penguins, seals, whales
Human impacts
- Scientific reasearch
- Indigenous people (only Arctic)
- Whaling/fishing
- Mineral extraction
- Energy
- Tourism
Examples of interdependence in the polar regions
- Arctic food web: Phytoklankton > Fish > Seals > Polar bears
- Inuits rely on wild animals as main food source, and sewing clothes of seals
- Harsh arctic conditions means that no crops are able to grow due to permafrost, whilst the ice covers do not melt, and so sea levels are stable and communities are safe
