Ecology 5 (F) Flashcards
How are nutrients lost from agricultural land – give an example
Phosphate ions – leaching, soil erosion, removed by the harvesting of agricultural crops
Movement of energy and inorganic nutrients in an ecosystem:
1) Producers obtain inorganic nutrients from the abiotic environment (sunlight, redox reactions)
2) Light/chemical energy is converted to useful chemical energy through photosynthesis/chemosynthesis which converts carbon dioxide and water into carbon compounds
3) Carbon compounds are a source of usable energy and are transferred along food chains when eaten by consumers
4) Respiration returns carbon to the environment together with chemical energy as heat
5) Energy is lost, nutrients are recycled – decomposers recycle minerals/inorganic nutrients
How does the biomass of autotrophs change with temperature increase
Biomass of autotrophs decreases as T rises – greater heterotroph population (zooplankton), also each individual feeds more
How does temperature and nitrate concentration impact biomass
increased T raises biomass, increased nitrate raises biomass even more
Abiotic factors that may affect the growth of plants:
Temperature
nutrient supply
water availability
sunlight intensity
salinity of soil
pH
chemical pollution/allelopathy
Keystone species
Disproportionately large effect on their ecosystem (relative to their size) – preventing overpopulation/monopoly), their disappearance would start a domino effect (other species in the habitat would also disappear and thus decrease in biodiversity)
Eutrophic lake characteristics
shallow, low water visibility, rich in nutrients (phosphates, potassium), low oxygen concentration, algal bloom (high primary productivity), low biodiversity
Reasons for the slowing down of population growth
depleted nutrients, overcrowding (competition for resources), carrying capacity reached
Problems caused by plastics in ecosystems
Entanglement in plastics – birds unable to fly, swim for food, escape predators, they can drown/suffocate
Ingested plastics fill up their stomachs so they feel full and starve to death, damage their digestive system (internal bleeding), cause choking, decomposition of toxic chemicals (poisoning)
How does deforestation (of a rainforest) cause frequent forest fires?
Example of positive feedback mechanism
evaporation of water from leaves (transpiration) has a cooling effect – water vapor that has transpired from leaves condenses in the atmosphere above the forest, lowering air pressure and causing wind as well as rainfall, so it can be absorbed by trees and transpired again
Deforestation => less transpiration => higher T, lower rainfall, less wind => climate change, drier biomass, frequenter fires => area of forest converted to grassland => less transpiration …
Autotrophs, consumers and detritivores E loss by CR
50 – 60 – 90%
Peat
Limestone
type of soil made as a result of partial decomposition of vegetation in bogs & swamps (acidic, anaerobic env.); used as fossil fuel, if fossilized it turns into coal
sedimentary rock made of CaCO3 created from the pieces of the calcareous shells produced by marine animals including clams, snails…(fosilization of calcareous marine animals) – limestone gets broken down by acidified ocean water to form CO2
partial decomposition of dead consumers to form shale
