Ecology Flashcards
Define population
A group of organism of the same specie , living and breeding together in a habitat
Define community
All the population of all the different specie of organism living in. A habitat at any one time
Define habitat
A place where on organism lives
Define Niche
The role of an organism within a habitat
Define ecosystem
An environment including all the living organism interacting within it
The cycling of nutrients and the physical and chemical environment in which the organism are living
What is biomass
Remaining in an organism can be measured in tems of mass of carbon or dry mass of tissue per given area
How do to maximise the rate of photosynthesis
Plenty of water
Light
Warmth
Green
Define GPP ( gross primary productivity)
Is a chemical energy store in plant biomass in a given area or volume. It is the total energy resulting from photosynthesis
Rate at which chemical energy converted into carbohydrates during photosynthesis (total energy result ing from photosynthesis)
Define NPP net primary production
Is the chemical energy store in plant biomass taking into account the energy that will be lost due to respiration
NPP= GPP- R
NPP equation
NPP = GPP - R
What is NPP used for
NPP is the energy left over that is available to the plant to create new biomass and therefore available to the next trophies level in a food web
Explain how water affects NPP
Lack of water for photolysis -less electron available to replace electron from PS11 less NADPH IS produced so limiting the rate of LIP so less GALP and glucose produced
Less electron moving down the ETC means less protons pumped from stroma to thylakoids space so less of a gradient so less proton moving through ATP synthase so less ATP (so less GALP and glucose)
How does less plant affect the NPP
Less plant = less leaves= less chlorophyll so less photosynthesis so less organic materials ( GALP and glucose) being made
How does temperature affect NPP
Low temperature means less kinetic energy for enzyme/substrate so less successful enzyme-substrate collisions so lower rate of reaction . Too high temperature enzyme denatured so reaction stop
How does ions affect the NPP calcium
Producing cell wall/middle lamella during cell division
How does ions affect the NPP magnesium
For chlorophyll for light absorption (less NADPH and ATP. So less LIR so less GALP)
How does ions affect the NPP phosphate
For ATP and NADPH / nucleic acid
What happens to the R when tree increases
R would increases as the tree is larger it has more metabolic demands so needs to respire more glucose to produce ATP for active transport, protein synthesis etc
How does the GPP affect if the tree size increase
GPP would also increase as the tree has more leaves and therefore chlorophyll it can absorb more sunlight to produce more ATP and NADPH in the LDR. This increases production of organic molecule such as GALP in the light independent reaction and glucose which can increase the rate of production of biomass
Suggest why the tropical evergreen forest has one of the highest average NPP
Condition are ideal for plant growth
-temperature and water availability are high
Lots of plants and trees= lots leaves and therefore chlorophyll for absorbing light for the LDR = lots of ATP & NADPH produced for LIR = lots of GALP= lots or organic compounds for new plant tissue = high NPP
Explain why the open ocean has the highest percentage of earths NPP but the lowest average NPP
Open ocean covers very large area. NPP per gram per m^2 per year is Low but such a very large area is covered by ocean that overall the NPP is highest
What is biomass measured
Mass of carbon per unit area (kg/m^2)
G/m^2/year
gC/m^2/year
Units of energy ( KJ/m2/year)
Measuring biomass
1) dry sample in oven at Low temperature
I. High temperature burns the sample removing carbon
2) weigh sample at regular
3) once mass becomes constant, all water has evaporated
Note amount of water varies so it’s it’s better to measure dry mass
Primary productivity is expressed
Mass/energy area-1 time -1 eg kJ m-2 year-1
Energy transfer formula
Energy transfer = energy transferred to next level / energy available in plant source x 100
Efficiency limitation
1) all abundant specie have to be identified
2) number of organism, average body size and how much energy it represent has to be known
3) how much biomass is transferred between levels needs to be known
What is pyramid of biomass
Shows the amount of dry biomass at each trophic level in a food chain
A model of feeding relationship that represent the biomass of the organism at each tropic level in a food chain
Disadvantages of pyramid of biomass
1) calculating dry biomass is time consuming as you have to take the sample and get rid of the water content in the ample
2)biomass pyramid only show data at one point in time in one sample eg sample of pond water
Def pyramid of energy
Represent the total energy store of the organism at each tropic level in a food chain
Losses of energy along a food chain
1) animals cannot breakdown everything they eat ; some energy is lost in faces and un digested food
2)energy is lost in respiration, Anne other if reaction to produce ATP which heats the surrounding and cells
3) plants materials is lost as waste ie urea
Light a biotic factors on a population
Amount of light affects a habitat directly in an area
Light affect the photosynthesis of plant which is the producer in the food chain- affect to other organism as well
Direct effect of light to animals physiology and behavior
Adaptation of plant for low light level
- extra chlorophyll
-different ratio of photosynthetic pigments (that sensitive to lower light level)
-very large leaves to absorb light —> large SA
Temperature abiotic factors
Animals have a range of temperature which they can reproduce
Temperature affect the enzyme controlled reactions especially in aquatic animals that can’t control their body temperature
Temperature affects the rate of enzyme - controlled reaction to and ectothermic organism eg reptile
Temperature can affect growth and reproduction of the some organisms
Wind and water current affecting a population
Wind cools off the body and causes a lot of water loss and affect specie richness and diversity as many organism cannot handle the wind
Wind current affect the specie lives in the water can damage the ecosystem
Water availability affecting population
Low supply of water can cause a many organism out of the habitat unless they have a special adaptation
If the a,Lunt of Reese’s then biodiversity will suddenly increase as well as conditions ar enow suitable
Oxygen availability
In the aquatic habitat if the water is cold and flows the oxygen dissolves and a lot of aquatic life would be present
If the water is still then oxygen would not dissolve
Low oxygen
-high temp/still water
-waterlogged soil
-still air
-high altitude
Soil is aerated is has many holes for the oxygen to diffuses however waterlogged soil these holes are filled with water that still so O2 doesn’t dissolve
Edaphic factors that affects population
1) sand is dry and is easily drained out and so minerals is leeched as water washes them out.
—> only some plants can grow
2)Clay -> heavy, longer to warmed, easily waterlogged
3)loam—> wide range of particles size ideal, less drained , less waterlogged
Biotic factors predation affect population
Prey population will increase at first causing more food to be available for the predators so after a while they increase in numbers too
Eventually there will be more predators than prey so food resources are limited so predators leave and the cycle repeats
Biotic factors finding a mate affects a population
Reproduction patterns determines which organism are found in each habitat. Increased the biodiversity
Reproduce sexually found in an area is greatly affected by the availability of mates
Biotic factor territory affect population
Involved in making sure that breeding pair has sufficient recourse to raise the offspring
Depends on many factors
Biotic factors parasitism and disease
Parasite will feed off of the living body of the host and will weaken it
Especially in areas of high population density the disease will spread more effectively
-weak
-unsuccessful reproduction
-less likely to find food
-more impact in high population density
In areas of Low biodiversity the effect will be even greater compared to high biodiversity
Define density independent factors
Ones with the same effect regardless of the population size in a specific area
Eg . Temperature
Define density dependant factors
Ones which depends on the population size in a specific area
Eg parasitism and disease because the closer the organism are to each other the easier the disease spreads
Effects of intraspecific competition
Biotic factor
Members of the same species compete for resources +mate
Usually result a part of the population not receiving resources so they may
not reproduce or survive thus population is slowed down
More well adapted individuals will be able to perform a more impressive courtship display or may have better features in better condition so will be more likely to attract a mate+ reproduce
Interspecific competition
Biotic factor
Members of different species compete for the same resources that in limited supply
Competition will reduce the population growth of both species but one specie will win as it has advantage over the other
Primary succession
1) colonization
Where a pioneer species will take over the area such as mosses or algae
2)they will break down the rock surface causing the soil to become deeper
3) eventually a large variety of plant can be supported and so climax community
—> which is one that is constant and has relatively constant biodiversity and specie richness
Define niche
The role of the organism in the habitat
What will happen when two specie fill the same niche within a habitat
Two specie will be in a direct competition with each other for resources and one of the two specie will out compete the other causing one of the them to die
Not always specie occupying the same niche
Sometimes seem as though two specie may occupy the same niche, but there will still be subtle differences in their role
Ie
- they might feed at different times of the day
-Different good sources
How does the niche determine the abundance within the habitat
If two specie occupy similar niche within a habitat they will be competing with each other so their population will be smaller and their abundance will therefore be lower
How does niche affect its distribution
Specie can only survive in habitat to which they are well adapted if they are not well suited to a habitat biotic and abiotic factors then move to a more suitable habitat and their distribution will change
Process of primary succession step 1
Pioneer specie (mosses and lichens) germinate easily and withstand harsh conditions such as Low water availability and nutrients
As pioneer specie die and decompose the dead organic matter forms soil
—> the plants at this stage of succession are adapted to survive in shallow , nutrients poor soil
The roots of these small plants form a network that helps hold the soil in place and prevent being washed away
Process of primary succession step 2
Larger shrubs and plants and small tree being in to grow it also requires more water and stored in deeper soil
Over time the soil becomes sufficient ply deep contain enough nutrients and hold enough water to support growth of large trees this increases specie diversity
Process of primary succession step 3
The final specie to colonise the new land becomes the dominant specie of the now complex ecosystem
Climax community - contain all different plant and animals that have now colonise the land
How does pioneer specie help with
Pioneer specie such as lichen help to slowly break apart the top surface of the bare rock when the lichen dies and are broken down forms basic soil
