ecosystem processes (7-13) Flashcards
what happens to water once it undergoes infiltration into subsurface soil and rock?
- some will remain in the shallower soil layer where it gradually moves vertically and horizontally through soils and subsurface material
- eventually it might enter a stream by seeping into stream banks
- much of the water moves vertically downwards and ends up as groundwater
how much do flood damage costs in England each year?
£1.1bn
what are the main water pollutants?
- inorganic soil particles
- organic sediments or particulate matter
- plant nutrients
- pesticides
what areas are salination associated with?
they are often associated with irrigated areas where low rainfall, high evapotranspiration rates, or soil texture characteristics impede washing out of salts which subsequently build up in soil surface layers
what can lead to local salination?
de-icing of roads with salt
what are the aims of the EU water framework?
it aims to:
- protect or enhance all waters
- achieve ‘good status for all waters’ by December 2015
- manage water bodies based on river basins or catchments
- involve the public
how can flooding be regulated?
- provide vegetative cover
- manage drainage
- maintain rivers by increasing channel flow and restoring meanders
- install infiltration devices
- dry basins to promote infiltration
- implement ponds
what is artificial recharge?
the practise of increasing water entering aquifers by artificial means
what does the nitrate directive require states to do?
they have to:
- designate nitrate vulnerable zones
- establish a voluntary code of good agricultural practices
- establish a mandatory action programme of measures for purposes of lacking nitrate loss from agriculture
what are wetlands?
areas of marsh, fen, peatland, or water whether natural or artificial, permanent of temporary, with water that is static or flowing, fresh, brackish, or salty, including areas of marine water - the depth at which low tide does not exceed 6m
what weather patterns are impacted by temperature trends?
- precipitation trends
- increased occurrence of extreme weather events
what environmental changes are linked to temperature trends?
- retreat of land ice and loss of sea ice
- thawing of permafrost, chemical cycling
what ecological changes are impacted by temperature trends?
- shifting habitat ranges
- phenological shifts
when is radiative equilibrium achieved?
when solar energy input = radiation output
what is radiative forcing?
the change in average net radiation at the top of the troposphere which occurs because the concentration of a greenhouse gas or another change in the overall climate system
what are climate feedback loops?
processes that can either amplify or diminish the effects of radiative forcing
what are some examples of climate feedback loops?
- precipitation
- clouds
- greening of forests
- desertification
- ice albedo
what are climate tipping points?
conditions beyond which changes in a part of the climate system become self-perpetuating
what are milankovitch cycles?
the periodic motions in Earth’s orbit contribute a predictable amount of variation to the Earth’s climate over time frames of tens of thousands to hundreds of thousands of years
what are sunspots?
explosions on the sun’s surface which cause warmer periods
are volcanoes associated with a rise or fall in global temperature?
a fall
what are the 2 fractions that contribute to anthropogenic emissions?
1 - CO2 from fossil fuel burning and cement production
2 - CO2 from deforestation and agricultural development
what did early microbial metabolism probably include?
- methanogenesis in early Archaea
- autogenesis in early bacteria
- sulfur based metabolism
- anoxygenic photosynthesis
what are stromatolites?
they are living fossils thought to contain ancestors or cyanobacteria present in archaeal oceans 3.5bn years ago
