Cycles Part 4 Flashcards
ecosystem services
With respect to the global nitrogen cycle, what services do ecosystems provide to society?
Ecosystems provide the intermediate service of biological fixation, which in turn serves society with food production and soil formation services.
What are ecosystem disservices?
ecosystem disservices (negative impacts on society) of climate change, food scarcity and soil erosion, among others.
What can damage of the nitrogen scosystem structure lead to?
nitrogen cycle, damage to ecosystem structure can lead to leaching of nitrogen from the system. This, in turn, can cause food scarcity and soil erosion, and potentially climate change if changes to ecosystem structure lead to losses of N2O to the atmosphere.
What are Provisioning services i.e.
products obtained
from ecosystems, give some examples?
Food e.g. crops, fruit, fish
• Fibre and fuel e.g. timber, wool
• Biochemicals, natural medicines and pharmaceuticals
• Genetic resources: genes and genetic information used for animal/plant breeding
and biotechnology
• Ornamental resources e.g. shells, flowers
What are Regulating services i.e.
benefits obtained from the
regulation of
ecosystem processes, give some examples?
Air-quality maintenance: ecosystems contribute chemicals to and extract chemicals from
the atmosphere
• Climate regulation e.g. land cover can affect local temperature and precipitation; globally
ecosystems affect greenhouse gas sequestration and emissions
• Water regulation: ecosystems affect e.g. the timing and magnitude of runoff, flooding etc.
• Erosion control: vegetative cover plays an important role in soil retention/prevention of
land/asset erosion
• Water purification/detoxification: ecosystems can be a source of water impurities but can also
help to filter out/decompose organic waste
• Natural hazard protection e.g. storms, floods, landslides
• Bioremediation of waste i.e. removal of pollutants through storage, dilution, transformation
and burial
What are Cultural services i.e. nonmaterial benefits that people obtain through spiritual enrichment, cognitive development, recreation etc, give some examples?
• Spiritual and religious value: many religions attach spiritual and religious values to ecosystems
• Inspiration for art, folklore, architecture etc
• Social relations: ecosystems affect the types of social relations that are established
e.g. fishing societies
• Aesthetic values: many people find beauty in various aspects of ecosystems
• Cultural heritage values: many societies place high value on the maintenance of important
landscapes or species
• Recreation and ecotourism
What are Supporting services,
necessary for the
production of all other
ecosystem services, give some examples?
Soil formation and retention • Nutrient cycling • Primary production • Water cycling • Production of atmospheric oxygen • Provision of habitat
What is eutrophication caused by?
concentrations of nutrients in the water, The collective term ‘nutrients’ is used for the elements that are essential for primary production by plants or other photosynthetic organisms.
name the nine macronutrients that are essential for plant growth?
Macronutrients are those required in relatively high amounts. Carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, sulfur, calcium and magnesium are all macronutrients.
What elements most often causes eutrophication?
Eutrophication is most often caused by increases in the availability of nitrogen and phosphorus. These elements are common in soil and water in the form of nitrate and phosphate, respectively. However, alterations in the concentration of any plant nutrient may have a recognisable biological effect.
What is another example of the adjective trophic being used in a scientific context?
Trophic levels, as applied to a food-chain.
What are the series of stages to describe the trophic state?
A series of stages were used to describe the trophic state:
oligotrophic – mesotrophic – eutrophic – hypertrophic
where oligotrophic means ‘low in nutrients’, mesotrophic ‘with intermediate nutrient concentration’, eutrophic ‘high in nutrients’ and hypertrophic ‘very high in nutrients’.
What is phytoplankton a collective term for?
‘Phytoplankton’ is a collective term for the free-floating photosynthetic organisms within the water column. It encompasses both algae and photosynthetic bacteria. Therefore:
an oligotrophic lake has clear water with little phytoplankton
an eutrophic lake is more turbid and green from dense phytoplankton growth
a mesotrophic lake is intermediate between the tw
What are dystrophic waters caused by?
A further term – dystrophic – describes ‘brown-water lakes’. These have heavily stained water caused by large amounts of organic matter, usually leached from peat soils.
What will primary production be like in an oligotrophic and eutrophic lake?
Characteristic Oligotrophic Eutrophic
primary production low high
What will the diversity of primary producers be like in an oligotrophic and eutrophic lake?
oligotrophic -high species diversity, low population densities
Eutrophic - low species diversity, high population densities
What will the diversity of light penetration into water column be like in an oligotrophic and eutrophic lake?
oligotrophic - high
eutrophic - low
What will toxic blooms be like in an oligotrophic and eutrophic lake?
oligotrophic - rare
eutrophic - frequent
What will plant nutrient availability be like in an oligotrophic and eutrophic lake?
oligotrophic - low
eutrophic - high
What will animal production be like in an oligotrophic and eutrophic lake?
oligotrophic - low
eutrophic - high
What will oxygen status of surface water be like in an oligotrophic and eutrophic lake?
oligotrophic - high
eutrophic - low
What will dominant fish be like in an oligotrophic and eutrophic lake?
oligotrophic - salmonid fish (e.g. trout, char)
eutrophic - coarse fish (e.g. perch, roach, carp)
Why is light penetration poor in eutrophic lakes?
The high density of phytoplankton absorbs the light for photosynthesis and prevents it penetrating deeper into the water.
Why are cyanobacteria so productive in eutrophic water bodies (Figure 5.5.3b) compared with oligotrophic ones?
The ready availability of nutrients allows rapid growth. In oligotrophic water, the rate of growth is limited by the nutrient supply. In eutrophic water, often only the availability of light regulates primary production.