Ecosystem Flashcards
An ECOSYSTEM can be visualized as a ____ of nature , where living organisms interact among ____ and also with the _____ .
Functional unit
Themselves
Surrounding physical environment
Many ecologists regard the _____ as a composite of all the local ecosystems on Earth .
Entire biosphere
_,___and____are some examples of terrestrial ecosystems .
Forest
Grassland
Desert
Some examples of aquatic ecosystems -
Pond Lake Wetland River Estuary
Man made ecosystems -
Crop field
Aquarium
The structure of ecosystem consists of - INPUT=____, transfer of energy =____ and OUTPUT =______ .
Productivity
Food chain /web , nutrient cycling
Degradation , energy loss
Interaction of __and ___ result in a physical structure that is characteristic for each type of ECOSYSTEM .
Biotic
Abiotic components
Identification and ENUMERATION of plant and animal species of an ecosystem gives its ____ .
Species composition
___ of diff species occupying diff levels is called STRATIFICATION .
Vertical distribution
Trees occupy the top vertical strata of forest , __ the second and ____ and ___ , the bottom layer .
Shrubs
Herbs
Grasses
The structural components of ecosystem of -
Species composition
Stratification
The ASPECTS which make the ecosystem function as a unit are -
( functional aspects of ecosystem )
1) productivity
2) decomposition
3) energy flow
4) nutrient cycling
Give an example of a fairly self-sustainable ecosystem unit and rather a type that explain even the complex interactions that exist in an aquatic ecosystem .
Pond
A pond is a shallow water body in which all the ___ components of an ecosystem are well exhibited .
4 basic
The abiotic component of a pond ecosystem is __with all the ___ and ___at the bottom of the pond .
Water
Dissolved inorganic and organic substances
Rich soil deposit
The ___, ____ ____ and ____ regulate the rate of function of the entire pond .
Solar input
Cycle of temp
Day -length
Other climatic conditions
The __component of pond include PHYTOPLANKTON .
AUTOTROPHIC
The CONSUMERS are represented by _____ in a pond .
Zooplankton
The decomposers in a pond are ___ ,____and ____ especially abundant in the _____ .
Fungi
Bacteria
Flagellates
Bottom of the pond
There is a ____ movement of entry towards ____ and its dissipation and loss as heat to the environment .
Unidirectional
Higher trophies levels
Autotrophs convert __to __material with the help of radiant energy .
Inorganic
Organic
A CONSTANT ____ is the basic req for ANY ecosystem .to function and sustain .
Solar energy
_____ is defined as the at of BIOMASS do organic matter produced per unit area over a time period by plants during photosynthesis .
Prim PRODUCTION
Primary production is expressed in terms of WEIGHT as ____ or energy as _____ .
gm _2
Kcal m_2
The rate of biomass production is called ___ .
Productivity
Productivity is expressed in terms of -
gm_2 yr_1
kcal m_2 yr_1
_____ of an ecosystem is the rate of production of ORGANIC MATTER during photosynthesis .
Gross prim productivity ( GPP )
A considerable amt of _____ is utilised by plants in respiration .
GPP
NPP =_____ -_____ .
GPP - RL
NPP is the available biomass for the consumption to ____ .
Heterotrophs ( herbivores / decomposers )
Sec productivity is defined as the rate of formation of ___ by CONSUMERS .
New ORGANIC MATTER
Prim productivity depends on the ____ .
Plant species inhabiting a PARTICULAR AREA
Prim productivity also depends on a ____, ___ and _____ of plants .
Variety of environmental factors
Availability of nutrients
Photosynthetic capacity of plants
__ varies in diff types of ecosystems .
Prim productivity
The annual NET PRIM PRODUCTIVITYof the whole BIOSPHERE is approx _____ .
170 billion tons ( dry wt ) of organic matter
Oceans occupy _____% of the surface , but their productivity is only _____ TONS .
70%
55 billion tons
(P of rest of biosphere = 170-55 =115 BILLION TONS )
Productivity of land =
115 billion tons
Decomposers break __into ____ .
Complex organic matter
Inorganic substances like CO2 , H2O , nutrients
_____is the raw material for decomposition .
Detritus
What constitutes detritus ?
Dead plant remains - leaves ,bark , flowers
Dead remains of animals including fecal matter .
Earthworms break ____into smaller particles , therefore they are called _____ .
Detritus
Detrivores
The process by which earthworms ( detrivores ) break down detritus into smaller particles is called -
Fragmentation
By the process of leaching , ____ go down into the soil horizon and get PRECIPITATED AS _____ .
Soluble inorganic nutrients
Unavailable salts
______degrade detritus into simpler inorganic substances .
Bacterial and fungal ENZYMES
The process by which bacterial and fungal enzymes degrade. Detritus into simpler inorganic substances is called -
Catabolism
Diff btw fragmentation and catabolism ?
Frag - by earthworm ; breakdown into smaller particles ( physical process )
Cata - by bacterial and fungal enzymes ; breakdown into simpler inorganic substances ( chemical process )
It is imp to note that ____ steps in decomposition operate simultaneously on detritus .
3
Frag
Leach
Cata
____and ____ occur during decomposition in the soil .
Humification
Mineralization
____leads to accumulation of a dark coloured amorphous substance called HUMUS .
Humification
Humus is ____ to MICROBIAL ACTION and undergoes decomposition at a _____ RATE .
Highly resistant
Extremely slow rate
Being ____ in nature , humus serves as a reservoir of nutrients .
Colloidal
Humus is further degraded by ____ and release of ____ occurs by the process known as ____ .
Some microbes
Inorganic nutrients
Mineralization
Decomposition is largely an ___ process .
Oxygen req .
The rate of decomposition is controlled by the ___ and _____ .
Chemical. Composition of detritus
Climatic factors
Decomposition rate is slower if detritus is rich in _____ and quicker , if detritus is rich I n ____ .
Lignin Chitin
nitrogen , water soluble subs like sugar
___and ____are most imp CLIMATIC FACTORS that regulate decomposition through their effects on the activities of ___ .
Temp
Soil moisture
Soil microbes
__and ___ favour decomposition whereas ___ and _____ inhibit decomposition .
Warm and moist environment
Low temp and anaerobiosis
Low temp and anaerobiosis result in ____ .
Build up of organic materials
Except for the ___ , sun is the only source of energy for all ecosystems on earth .
Deep -sea hydrothermal vents
Of the INCIDENT SOLAR RADIATION , ____ of it is PAR ( photosynthetically active radiation )
Less than 50%
Plants capture only _____ % of ___ and this small amt of energy sustains the entire living world.
2-10%
PAR
Which law of thermodynamics is stated by the fact that FLOW OF ENRGY IS UNIDIRECTIONAL .
1st law
How do ecosystems follow the 2nd law of thermodynamics?
They need a constant supply of energy to synthesise the molecules they req , to counteract the universal tendency towards increasing disorderliness .
In a terrestrial ecosystem , major producers are __and ___ .
Herbaceous plants
Woody plants
Producers in an aquatic ecosystem -
Phytoplankton
Algae higher plants
The chain or web is formed becoz of _____.
Interdependency
Energy that is trapped into an organism remains in it for ever .T/F
F
___ is the beginning of the detritus foo chain / web .
Death of organism
Who are prim consumers ?
Herbivores
Common herbivores in aquatic ecosystem -
Molluscs
Prim carnivores are _____ consumers .
Sec.
The DFC begins with _____ .
Dead organic matter
DFC is composed of ____ which are heterotrophic organisms , mainly ____and ____ .
Decomposers
Fungi
Bacteria
Decomposers secrete _____ that breakdown dead and waste materials into simple , inorganic materials , which are subsequently absorbed by them .
Digestive enzymes
In aquatic ecosystem , ___is the major conduit for energy flow .
GFC
In a ___ ecosystem , a much larger fraction of energy flows through the detritus food chain than through ____ .
Terrestrial
GFC
Some of the organisms of __Are prey to __animals .
DFC
GFC
Based on _____ ,organisms occupy a specific place in the food chain that is known as their trophies level .
The source of their nutrition or food
Carnivores belong to the __trophic level .
3rd
Each organism has a certain mass of LIVING MATERIAL at a particular time called as _____ .
Standing CROP
The standing crop is measured as the ____ or _______ .
Mass of living organisms( BIOMASS )
Number on UNIT AREA
The BIOMASS is measured in terms of _____ weight .
Fresh or dry (both )
Measurement of biomass in terms of _____ is more ACCURATE .
Dry weight
The number of tragic levels in a GFC is restricted as _____ .
Transfer of energy follows 10%LAW
How trophic levels are possible in a GFC ?
4 -5 Producer Herbivore Prim carnivore Sec carnivore
The top (apex )of ecological pyramids represents -
Tertiary / top level consumer
An calculation of energy content , biomass and numbers has to include ____ at that trophic level .
All organisms
No generalizations regarding pyramids will be true if we take ______ into account .
Only a few indivisuals at any trophic level
The trophic level in any ecological pyramid represents a _____ , not a ____as such .
Functional level
Species
Give an example when a given species occupies more than one trophic level at the same time .
Sparrow - prim consumer - eats seeds , fruits , peas
Sec consumer -eats insects 🐞, worms 🐛
In most ecosystems , pyramids of ____are upright .
All the pyramids , energy , biomass nd number
The pyramid of _____ in SEA is generally INVERTED .
Biomass
becoz biomass of fishes exceeds that of phytoplankton
Ecological pyramids do not accommodate a ___ .
Food web
____are not given any place in ecological pyramids , even though they play a vital role in the ecosystem .
Saprophytes
Ecological pyramid does not take not account ___.
Same species belonging to 2 or more trophic levels
In a sea , small STANDING CROP of ____ supports a large standing crop of _____ .
Phytoplankton
Zooplankton
Pyramid of number ina grassland ecosystem is -
Upright
Pyramid of number of tree is -
Spindle shaped
Big tree - small insects - small birds-large birds
Type of pyramid of number is : tree —> herbivorous birds —> parasites .
Inverted
Pyramid of number in a pond ecosystem .
Upright
Pyramid of biomass in a terrestrial ecosystem -
Upright
An imp aspect of all communities is that their __and ____ constantly change in response to the changing environmental conditions .
Composition
Structure
The composition and structure change of communities is ____and ____ , parallel with the changes in the physical environments .
Orderly
Sequential
The changes lead finally to a community that is in near equilibrium with the environment and is called ___.
Climax community
The GRADUAL and FAIRLY PREDICTABLE change in the species composition of a given area is called ____ .
Ecological succession
Ecological succession is the gradual and fairly predictable change in the ____ of a given area .
Species composition
What all happens during succession ?
Some species colonise an area while others decline and disappear
The entire sequence of communities that successive change in a given area are called ____
Seres
Succession and __would have parallel processes million of yrs ago .
Evolution
Succession starts in an area where no living organisms are there . T/F
T
Succession where no living organism ever existed would occur where ?
Bare rock
A succession occurring in an area which somehow lost all the living organism that existed there is called ___.
Sec succession
Examples where prim succession occurs -
Newly cooled lava
Bare rock
Newly created pond /reservoir
Before a biotic community can be established , there must be ____ .
Soil
__succession is slow .
Prim
Sec succession occurs where ?
Abandoned farm land
Burned or cut forests
Lands that have been flooded
( al these places have some soil )
Description of ecological succession usually focuses on changes in ______.
Vegetation
As succession proceeds , the ___and ____ also change .
Number and types of animals
Decomposers
Hydrarch succession takes place in ____ and xerarch succession takes place in ___ .
Wet areas
Dry areas
Both hydrarch and xerarch lead to ____ conditions .
Medium water ( mesic )
The species that invade a bare area are called __ .
Pioneer species
In prim succession on rocks , __are the pioneer species and are able to _____ , help in wealthier and soil formation .
Lichens
Secrete acids to dissolve rocks
Lichens pave way to very smooth plants like ____ which are able to take hold in small amt of sol .
Bryophytes
The climax community remains stable as long as ______ .
Environment remains unchanged
In sec succession , the species that invade depend on the ___ , ____ , ____and _____ .
Condition of soil
Availability of water
Environment
Seeds and other propagules present
What are the 2 imp facts about succession -
Prim succession is a very slow process ( 1000yrs to reach climax )
All successions proceeds to a SIMILAR CLIMAX COMMUNITY -mesic
The amt of nutrients present in the soil at any given time is referred to as ____ .
Standing state
Standing state varies in _____ and also on a ___basis .
Diff kinds of ecosystems
Seasonal basis
Give some examples of NUTRIENTS that constitute the STANDING STATE -
C N P S Ca
____are never lost form the ecosystem , rather they are ___ indefinitely .
Nutrients
Recycled time and again
The movement of nutrient elements through various components of an ecosystem is called ___.
Nutrition cycling
Another name for nutrient cycling -
BIOGEOCHEMICAL cycling ( bio-living ; geo-rocks ,air ,water )
Nutrient cycles are of _____ types . Name -
2
Gaseous
Sedimentary
Stages of prim succession in hydrarch community -
Phytoplankton —> submerged rooted plants —> submerged free -floating —> reed -swamp—> marsh meadow —> scrub stage —> forest
The reservoir for gaseous type of cycle is ___ and for sedimentary cycle is _____ .
Atmosphere
Earths’s crust
Sedimentary cycles are -
P
S
Environmental factors that regulate the release of nutrients into the atm are -
Soil
Moisture
PH
Temp
The function of reservoir -
To meet the deficit which occurs due to imbalance in the rate of influx and efflux .
CARBON constitutes __% of dry wt of organisms .
49%
C as a constituent of dry wt of organs is next only to ____ .
Water
after water , C is most abundant in living organisms
____% C is found dissolved in the oceans .
71%
___regulates the amt of CO2 in the amt .
Oceanic reservoir of C
The atm contains only __% of total global C .
1%
fossil fuel represent _____ of C .
Reservoir of C
C cycling occurs through ____ , ___ and through ___ and ___ .
Atm
Ocean
Living and dead organisms
_____ kg of C is fixed in the biosphere through photosynthesis ANNUALLY .
4* 10_13 kg
A considerable amt of C returns to the atm as ___ through ____ .
CO2
Respiratory activities of the producers and consumers
______ also contribute substantially to CO2 pool by their processing of waste materials and dead organic matter of land or oceans .
Decomposers
Some amt of fixed C is lost to ____ and removed from circulation .
Sediments
Human activities have greatly influenced the ____ .
C cycle
P is the major constituents of _____ , ___ and ______ .
Biological membranes
Nucleic acids
Cellular energy transfer systems
Many animals need large quantities of ___ to make shells , bones and teeth .
P
The natural reservoir of P is _____ , which contains P in the form of ____ .
Rock
Phosphates
How do plants get P ?
When rocks are weathered , minute amt of these P dissolve in soil solution and are absorbed by the plants .
Animals obtain P from ____.
Plants
The waste products and the dead organisms are decomposed by _____ releasing P .
Phosphate -solubilising bacteria
Unlike C , there is no ____ of P .
Respiratory release of P into ATMOSPHERE .
Amt inputs of P through ____ are much smaller than C inputs .
Rainfall
Gaseous exchange of P btw organisms and environment are _____ .
Negligible
2 major diff btw C and P cycles -
Atm input of P through rainfall are ugh smaller than C
Gaseous exchange of P btw organisms and environment are NEGLIGIBLE .
The products of ecosystem processes are named as _____ .
Ecosystem services
Ecosystem services provided by healthy forests -
Ecosystem purifies air and water Mitigate droughts and floods Cycle nutrients Generate fertile soils Provide wildlife habitat Maintain biodiversity Pollinate crops Provide storage site for C. Provide aesthetic , cultural and spiritual values
__and his colleagues have recently put prize tags on nature’s life support services .
Robert Constanza
Researches have put a prize tag of ____ aYEAR on fundamental services .
US $ 33 trillion
Avg prize tag of ecosystem services is __amt of ____ which is ____ .
Twice
Global gross national product ( GNP)
US $ 18 trillion
Soil formation accounts for __ % .
50%
Contribution of nutrient cycling is __% .
Less than 10%
Contribution fo recreation is __% .
Less than 10%
Cost of climate regulation is ______ .
6%
Cost of habitat for wildlife is ____.
6%
