Recycling materials in the ecosystem Flashcards
name the two types of decomposer
bacteria and fungi
what is this form of nutrition (fungi feeding)
saprotrophic
why does decomposition result in carbon dioxide being released
due to the bacteria and fungi respiring, thus resulting in the release of carbon dioxide
why is nitrogen so important
DNA and proteins
what is nitrogen fixation
Atmospheric nitrogen gas is converted into nitrogen-containing compounds
This biological nitrogen fixation is carried out by nitrogen-fixing bacteria such as Rhizobium
The bacteria convert nitrogen into ammonia, which forms ammonium ions (in solution) that can then be used by plants
These nitrogen-fixing bacteria are found inside the root nodules (small growths on the roots) of leguminous plants such as peas, beans and clover
The bacteria have a symbiotic (mutually beneficial) relationship with these plants - the bacteria provide the plants with nitrogen-containing compounds and the plants provide the bacteria with organic compounds such as carbohydrates
what is ammonification
Nitrogen compounds in waste products (e.g. urine and faeces) and dead organisms are converted into ammonia by saprobionts (a type of decomposer including some fungi and bacteria)
This ammonia forms ammonium ions in the soil
what is nitrification
The ammonium ions in the soil are converted by nitrifying bacteria into nitrogen compounds that can be used by plants, known as nitrates
Initially, nitrifying bacteria such as Nitrosomonas convert ammonium ions into nitrites
Different nitrifying bacteria such as Nitrobacter then convert these nitrites into nitrates
what is denitrification
Denitrifying bacteria use nitrates in the soil during respiration
This process produces nitrogen gas, which returns to the atmosphere
This process occurs in anaerobic conditions (when there is little or no oxygen available, such as in waterlogged soil)
what is the purpose of leghaemoglobin
to absorb oxygen
what does nitrogen reductase do
reduces nitrogen, by adding hydrogen and producing ammonia
what are the bacteria involved in nitrogen fixation
- Azotobacter
- Rhizobium.
what are the bacteria involved in nitrification
- Nitrosomonas
- nitorbacter
what are the bacteria involved in denitrification
- anaerobic denitrifying bacteria
state 3 differences between the carbon and nitrogen cycle
- different bacterial species
- lightening lightening versus combustion
- photosynthesis only involved in combustion
state 3 similarities between the carbon and nitrogen cycle.
- decomposition (decomposers)
- plants and animals involved
- eating and egestion/ excretion involved
- mixture of biological and non - biological involvement
- how nutrients are recycled around ecosystems
- respiration
name a compound that can be classified as organic nitrogen
amino acids
name a compound that can be classified as organic nitrogen
amino acids
name one of the types of bacteria, involved in the process of turning organic nitrogen to inorganic nitrogen
nitrifying bacteria
name one of the types of bacteria, associated with turning nitrates, into nitrogen gas
denitrifying bacteria
what is succession
succession, is a directional change in the composition of species in a community, that occupy a given area throughout time.
what causes succession ( state 2 things)
- changes, in the community, cause changes in the physical environment
- this, causes another community, to become established and replace the former
what is the pioneer community
the first organism to colonise an area.
what is the climax community
the final stable community after succession
what is secondary succession
the recolonization, of an area, after an earlier community has been removed or destroyed
what is primary succession
ecological community develops in the absence of soil (i.e. from bare rock)
what is deflected succession
occurs, when a community remains stable, due to human activity, preventing further succession for example regular mowing or grazing of livestock
what plagioclimax
climax community, after deflected succession
what is the goal of the first colonizers
to make soil
what do we call the organism that first colonize
pioneer species
what is the main way that we can tell if an area is in a later stage of succession
if it has a high diversity
why is a later stage able to have greater diversity
due to being made of thousands of organism communities.
can we always predict the route succession is going to take?
no it’s random
outline the process of succession occurring on Surtsey island
- (1)after new rock has formed, lichens are established as the pioneer community
- (2)these organism, cause erosion of rock and provide dead material, which when decomposed, helps form soil
- (3)larger plants, like moss can then grow, and these types of species, replace the pioneer community
- (4)these plants, add further nutrients, moisture etc, to the soil and create shelter, This causes other species, to now occupy the area (shrubs etc) these outcompete the moss.
- (5) this process, continues, until a climax community is reached (often woodland in temperate areas)
outline the process of succession occurring on sand dunes
- beach - pioneer species, can be found here.
- mini dunes - as wind blows, sand builds up around the base of pioneer plants, inin dunes from. As dune increase in size, stabilising plants, like couch grass, helping to establish the dunes.
- young yellow dunes - increased stability, and more nutrients, allows marram grass, to grow. This collects sand well increasing dunes further in size.
- old grey dunes - more mature dunes, allow leguminous plants, to grow. these have resident bacteria, to convert nitrogen gas to nitrates, further increasing the nutrients in the dune, allowing other plants to grow.
why do sand dunes, get darker as you go away from the sea
more soil and nutrients in the sand, the further inland that you come.
why is a later stage of succession able to greater diversity
due to being made of thousands of organisms and communities.
what level of disturbance, results in the greatest developmental change?
intermediate
why do people, burn forest regularly
to avoid extremely catastrophic events, that would completely wipe out the diversity of an area.
