6.3 Ecosystems Flashcards
nitrogen cycle
- plants cannot use nitrogen directly so NITROGEN FIXATION occurs. can occur during lightening strikes or through Haber process in making fertilizers. Mainly nitrogen-fixing bacteria such as Azobacter and Rhizobium are used. Rhizobium has a mutallistic relationship with the plant as it provides them with nitrogen whilst the plant provides the bacterium with carbon compounds. nitrogen becomes ammonium ions or nitrate ions
-AMMONIFICATION= nitrogen compounds from dead organisms are turned into ammonia by decomposers which turns into ammonium ions - NITRIFICATION= chemoautotrophic such as Nitrosomonas bacteria in the soil get energy by oxidising ammonium ions into nitrites and some nitrites into nitrates such as Nitrobacters
-Denitrification= denitrifying bacteria converts nitrates back to nitrogen gas. when bacteria is growing in anaerobic conditions such as waterlogged soils they use nitrates as a source of respiration and produce nitrogen gas and nitrous oxides
carbon cycle
-Carbon dioxide in the air is absorbed by plants during photosynthesis and respiration.
-carbon is passed to the primary consumers when they eat the plant. and secondary and tertiary when they eat consumers
-decomposers digest on dead organisms
-if organic matter end up in places where decomposer arent there they their carbon content can be turned into fossil fuels an relased when the fuels are burned
-rocks can also be formed by organic matter deposited on sea floors e,g, limestone and chalk which is mainily CACO (tres). this carbon can be released by the movement of tectonic plates
ecosystems
-all interacting living organisms and non-living factors within an area
Habitat
-the place where an organisms lives
community
- all the populations of different species, who live in the same place at the same time,and who can interact with each other
consumers
-an organisms that eats other organisms, e.g. animals, rocks
producer
-an organism that produces organic molecules using sunlight e.g, plants
- convert light energy to chemical energy
trophic level
- a stage in a food chain occupied by a particular group of organisms, e.g. producers are the first tropic level in a food chain
abiotic factors that affect ecosystems
-oxygen availability
-light
-temperature
-water availability
-type of soil
biotic factors
-predation
-competition= interspecific - between different species
intraspecific- within the same species
-diseases
rock pools
-Biotic factors may be seaweed which is a food source, competition can limit the number of organisms present
-Abiotic factors= tides. high tides= PH,temperature, salt conc(salinity) similar to ocean ecosystems due to the submersion
-low tides=higher salinity and temperatures which is more extreme and only a few organisms can tolerate
playing trees
- biotic=producers large amount of plants which may attract a large amount of animals which use them as food source
-abiotic=rainfull and sunlight. wet year= waterlogged soil =poor plant growth which may decrease th number of consumers
large trees
-biotic factors= insects which consume the leaves of trees. if they consume all the leaves they can slow tree growth and lead to death
-abiotic= drought conditions (continuous low rainful) can negatively impact growth of trees and lead to death
trophic level order
-producers,primary consumers,secondary consumers,tertiary consumers
why is efficiency of biomass transfer never one hundred percent
- sunlight reflected
-only ten percent of sunlight is used in photosynthesis
-some energy lost in respiration as thermal energy
-energy lost in excretion. some food is indigestible
-not all parts of food are eaten
-food parts not eaten are recycled in the ecosystem by decomposes
