IB BIO: C.2 Communities and ecosystems
formula for energy conversions
NP=GP-R -NP= net production: the amount of organic matter remaining after respiration -GP=gross production: -the total amount of organic matter produced in an ecosystem -Respiration: -stored energy used in the cellular production of ATP
Explain how the flow of energy in the food web differs from the movement of nutrients.
Nutrients are recycled in a food webs and energy enters and leaves/is not recycled Nutrients are recycled by saprotrophs While energy enters as light and is dispersed as heat
nutrient cycling vs energy flow
energy flows in one direction, and nutrients recycle.
tropical rainforest
-biomass is the main store (soil is nutrient poor= smallest store (circle)) -fast rate of nutrient transfer between stores
what do the diameter of hte sniks and thickness of the arrow indicate
-diameter of sinks= proportion to the mass of nutrients stored in the sink -thickness of the arrows= proportional to the rate of nutrient flow
closed ecosystems
-exchange energy (entry of light and loss of heat) but not matter (it reamins in the system) -water and nutrietns are cycled within the ecosystem
KNO W HOW TO ANALYZE A CLIMOGRAPH
!!!
what are sinks for nutrient storage
- biomass (flora and fauna) -litter -soil
how can biomass be useful to different people
- farmers can use it as a method of assessing growth strategies -environmental or town protection agencies may use biomass data to assess the usefullness (or potential risk in a wildfire) of an are of vegetation
why are biomass and numbers small at higher trophic levels
- less food is available to organisms further along the food chain because so much energy is lost between trophic levels
when asked to compare the percentage of energy lost in respiration between autotrophs and heterotrophs, how would you go about that?
- respiration (heat)/ gross production x100
example of unicellular organism occupying more than one trophic level
-Euglena -ingest other organisms by phagocytosis -yet it also contains chloroplasts for photosynthesis
formula for a food conversion ratio
-FCR= mass of food eaten (g)/ (increase in) desired output (g)
examples of places where primary sucession could be occurring
-abandoned settlemetns/fields -fields recovering after fire damage -fire breaks in Woodland
biomes in regions with a dashed line in a climograph are strongly influenced by what?
-factors other than precipitation and temperature ex: seasonality of drought, fire, animal grazing
gross production increases in primary sucession
-first colonizers are lichens on rock surfaces -soil builds up, following death of smaller lichens -larger plants take root as soil deepens -productivity plateaus as soil's carrying capacity is reached
what does measuring the biomass of an ecosystem tell us about that ecosystem
-how productive it is -might be used as a measure of the "health" of an ecosystem- a significant decline in producitivey would be a cause for concern
is net productivity of different ecosystems the same or does it vary?
-it varies greatly
tagia (temperate forest)
-litter (pine needles) is the main store -slow rate of nutrient transfer between stores
how do the flows between the sinks work
-littering -decomposition of the litter into inorganic nutrients, which are then stored in the soil -nutrient uptake by plants
is it better ot have a high FCR or low FCR
-lower because it means that the animals are more efficient users of feed and sustainable
what are some reasons as to why heterotrophs consume much more energy for respiration than autotrophs
-maintaining body temp -movement -energy expended in reproduction
a good (low ) FCR is obtained by doing what?
-minizing the losses of energy by respiration , for example: -restricting animal movement -slaughtering the animal at young age (older animals have higher FCR's as they grow more slowly) -optimizing feed so it is efficiently digested
primary succession: species diversity increases
-more soil allows for burrowers, worms, and detritivores -more plants take root and provide new niches -more death leads to more soil and nutrient recycling
open ecosystems
-most natural ecosystems are open -they exchange energy and matter iwth adjacent ecosystems/ environments -examples of matter: -migration of animals -harvesting of crops -the flow of water or gases
why is 90% of energy lost between trophic levels (as you move up the pyramid)
-not ingested (eaten) -not digested or assimilated -excreted (Expel as waste) -lost as heat from respiration -Carbon is lost in the form of CO2 and is also lost through respiration and unavailable for conversion to organic matter
where do organisms exist (food chain/web)
-organisms exist within a food web -food webs consists of many interlinked food chains -therefore organisms exist in multiple food chains often at different trophic levels
how do human practices affect the phosphate mined and nitrate fertilizer
-phosphate is mined and converted to fertilizer -human practice: phosphates added to the agricultural ecosystem nitrate fertilizer produced from atmospheric nitrogen -human practice: phosphates added to the agricultural ecosystem
wht is the order of the pyramids of energy
-producers -primary consumers -secondary consumers -tertiary consumers
why are climographs useful
-provide a quick view of the climate of a region -can be used to identify the seasonal pattern
when stating an organisms trophic level, how must it be done and why?
-relative to a particular food chain
desert
-soil is the main store -slow rate of nutrient transfer between stores (Except for the transfer from biomass to litter)
what are the ways of measuring the affect of succession
-species diversity -stem/seedling density -biomass -canopy overage/light intensity at the surface -depth/ volume of leaf litter -soil nutrient levels
how is temperature and rainfall influential to biomes
-temperature affects the rate of metabolism-the phases in the life cycle of many organisms are temperature dependent -the availability of fresh water (both in soil and in rivers and lakes) is critical to the growth and nutrition of organisms
example of how FCR is used with diary cows? pigs?
-the output is milk -used to see how efficient the cow is in converting feed mass into milk pigs: -output is the mass gained by the animal -used to see how efficient the pig is in converting feed mass into mass (for meat)
how do human practices impact the flow of matter into and out of ecosystems?
-they accelerate the flow of matter in and out of ecosystems -this alters the nutrient cycling in ecosystems
example of how fungi occupy more than one trophic level
-they' re classified as detritovres or saprotrophs, -yet, they also feed on organisms that are still alive
what are the 6 major types of biomes
-tropical rainforest -temperate forest -coniferous forest (taiga) -tundra -shrub land - grassland (savannah) -desert
what is the food conversion ratio (FCR) and why is it used?
-used in commercial (animal) food production -farmers use it -it is a measure of an animal's efficiency in converting feed mass into the desired output
what is included in littering
-withering -defoliation? -excretion (Expelling waste) -unconsumed parts left over -dead bodies of animals
deciduous forest fire example of secondary succession caused by disturbance to ecosystems
1) a stable deciduous forest community 2) a disturbance, such as a wild fire, destroys the forest 3) the fire burns the forest to the ground 4) the fire leaves behind empty, but not destroyed, soil 5) grasses and other herbaceous plants grow back first 6) Small bushes and trees begin to colonize the area 7) gast growing evergreen trees develop to their fullest, while shade-tolerant trees develop in the understory 8) the short-lived and shade intolerant evergren trees die as the larger deciduous trees overtop them. -the ecosystem is now back to a similar state to where it began
why is high net productivity important in an ecosystem
1) high primary productivity ( by producers) means more energy is available to the ecosystem 2) the higher the efficiency of energy transfer between trophic levels the higher the net productivity. Energy transfer is typically 10% 3) -this can support longer food chains, which will lead to more trophic levels increasing net productivity -ecosystems rarely have more than 4 of 5 trophic levels
island of surtesy example of primary sucession
1962- island of surtesy was formed off the coast of iceland -there was a huge volcano and it formed the iland of surtesy
What are the units of a pyramid of energy A. kJ m-2 yr-1 B. kJ m-1 yr-1 C. J m-3 s-1 D. J m2 s-1
A
Climax community
A community composed of species that represents the final stage of colonization of a habitat.
food chains vs food webs
Food chain: only follows just one path as organisms find food ex: a hawk eats a snake, which has eaten a frog, which has eaten a grasshopper, which has eaten grass Food web: consists of many interlinked food chains`
6. Outline the changes in species diversity and production during primary succession.
In primary succession there are no species to start out with, except for pioneer species like algae so the diversity is very low, along with rocks or abiotic materials. Then as the rocks get weathered down it can become soil and then biotic factors can start to grow in this soil allowing a community to build. Then species start coming in and diversity of the different creatures is made. As the biotic factors grow and become inhabitable then species come to live here and they start to produce offspring and soon populations start living in the community.
difficulties of classifying trophic lelels
It is difficult due to the fact that some organisms can be secondary, tertiary, and may be quaternary consumers at the same time, such as humans
what is organic matter and what does it become?
Organic matter: starch (stored energy), proteins, and structural molecules -a lot of stored energy and nutrients are used by each individual -it becomes biomass: -the total dry mass of organic matter in organisms or ecosystems
during sucession, how do living organisms change the abiotic environment?
Soil: -produced by detritivores (worms) following death of other plants and animal -detritivores and bacteria fix nitrogen and other inorganic nutrients into the soil -decay accumulates minerals around roots - aerated (introduce air) by burrowing animals: more respiration and drainage Plant roots: -bind the soil, preventing erosion -support large plants - uptake, filter and recycle massive amounts of water, preventing flood and drought Microclimates are generated -small niches of differing temperature, light levels and humidity -provide opportunities for more species,
explain the energy flow
Sun- energy- producer -heat given off (respiration-energy passed to-consumers
Discuss reasons why the levels of a pyramid of energy differ in size.
The shape of the pyramid shows energy lost from base to the top of pyramid (90% lost at each level) because energy is used/released through cell respiration not all tissues are eaten, such as bone, hair, cellulose undigested/die
what is a food web
a diagram that shows how food chains are linked together into more complex feeding relationship within a community
what is a climograph? who developed it?
a diagram which shows the ecosystems/ biomes that arise as a result of the relative combo of temperature and precipitation in an area -first developed by Robert Whittaker
what is a biome
a geographical area that has a particular climate and sustains a specific community of plants and animals (i.e. a type of ecosystem) -
how do human practices alter the flow of matter from agriculture to harvesting crops? agriculture to waterways?
agriculture to harvesting crops: -human practice: biomass (including phosphates and nitrates) are removed from the agricultural ecosystem -harvesting of crops agriculture to waterways: -human pratice: phosphates and nitrates removed from the agricultural ecosystem and added to adjacent aquatic ecosystems -water run-off (leaching) from agricultural fields results in build up of phosphates and nitrates in watwerways and leads to eutrophication
Gersmhel diagrams -who developed them and what is the function
first developed in 1976 by P.F. Gerhmel - show the differences in nutrient flow and storage between different ecosystems
pioneer organisms
first to come into an area after there is a disturbance and make the conditions better for larger species to move back
how are nutrients input into the ecosystem? how are nutrients output (lost) from the ecosystem
input into the ecosystem: -nutrients dissolved in raindrops -nutrients from weathered rock nutrient outputs (losses) from the ecosystem: -nutrients lost through leaching -nutrients lost through surface runoff
the transfer of energy is never what? and why?
it is never 100% efficient because around 90% of energy is lost between trophic levels
lupine and lodge pole pines examle of pioneer organisms
lupine= a flower that's actually a legume -has bacteria that lives on its root and can actually take nitrogen in the air and return it to the soil Lodge pole pines= skinny, long coniferous -filled with wax and only open in a fire when their seeds come back
why can consumers occupy multiple trophic levels?
many animals (including chimps and humans) feed on both producers and consumers- putting them in the levels of primary and secondary consumer
pyramid of biomass
shows the total mass of the organisms that each trophic level occupies in an ecosystem
what are the main factors affecting the distribution of biomes ?
temperature and rainfall -these factors will vary according to latitude and longitude, elevation and proximity to the sea -rainfall and water temps. are more common near the equator and less common at the poles
what does a pyramid of energy show? what is it measured in?
the flow of energy between trophic levels -measured in units of energy per unit area per unit time
what is ecological sucession what is primary sucession what is secondary sucession
the predictable and orderly changes in the composition of an ecosystem over time primary: the emergence of an entirely new ecosystem ex: a new volcanic island forms in Tonga -volcano erupts and leads to the formation of rock, results in a new island -climate change causes glaciers to retreat- retreating glaciers /rock under glacier had life on it secondary: the replacement of one ecosystem by another following environmental change ex: a woodland can grow from an area of clear grassland
Productivity in an ecosystem has to do with
the rate of biomass production
what is biomass
the total dry mass of organic matter in organisms or ecosystems
biosphere
the total of all areas where living things are found (i.e. the totality of biomes)
