Ecosystem Flashcards
An ecosystem can be visualised as a — of nature, where living organisms —- and also with the —- .
functional unit
interact among themselves
surrounding physical environment
Ecosystem varies greatly in — from a —- to a large forest or a sea.
size
small pond
Many ecologists regard the entire biosphere as a —-, as a composite of all
—- on Earth.
global ecosystem
local ecosystems
Since this system is too much — and —- to be studied at one time, it is convenient to divide it into two basic categories, namely the —- and —-.
big and complex
terrestrial and the aquatic
Forest, — and — are some examples of terrestrial ecosystems; pond, lake, —- , — and —are some examples of aquatic ecosystems.
grassland, desert
WETLAND, river and estuary
—- and —- may also be
considered as man-made ecosystems.
Crop fields and an aquarium
We will first look at the structure of the ecosystem, in order to appreciate the input (— ), —- (food chain/web, —–) and the output (— and —-).
productivity
transfer of energy
nutrient cycling
degradation and energy loss
We will also look at the
relationships – —, — and — – that are created as a result of these — within the system and their inter- relationship
cycles, chains, webs
energy flows
Various components of the environment- — and —.
abiotic and biotic
Individual biotic and abiotic factors affected — and —.
each other and their surrounding
Interaction of biotic and abiotic components result in a —-
physical structure
—- is characteristic for each type of ecosystem.
Physical structure (produced by interaction of biotic and abiotic factors)
— and —- of PLANT and ANIMAL species of an ecosystem gives its
—–.
Identification and enumeration
species composition
— distribution of different species occupying different levels is called —.
Vertical
stratification
For example, trees occupy —- or layer of a —,
— the second and —-
occupy the bottom layers.
top vertical strata, forest
shrubs
herbs and grasses
The components of the ecosystem are seen to function as a — when
you consider the following aspects: —- (4)
unit
(i) Productivity;
(ii) Decomposition;
(iii) Energy flow; and
(iv) Nutrient cycling.
To understand the — of an — ecosystem let us take a small pond as an example.
This is fairly a — and rather — example that explain even the — interactions that exist in an aquatic ecosystem.
ethos, aquatic
self-sustainable unit
simple
complex
A pond is a —- body in which all the above mentioned — basic components of an ecosystem are well exhibited
shallow water
four
The abiotic component in a small pond is the — with all the —- and —-substances and the —- at the bottom of the pond.
water
dissolved inorganic and organic
rich soil deposit
The —-, the cycle of —, — and other — conditions regulate the —- of the entire pond
solar input
temperature
day-length
climatic
rate of function
The — components of small pond include the —, some — and the —, — and —plants found at the edges.
autotrophic
phytoplankton, algae
floating, submerged and marginal
The consumers of small pond are represented by the —, the — and —- forms.
zooplankton
free swimming and bottom dwelling
The decomposers of small pond are the —, — and —- especially abundant in the — of the pond.
fungi, bacteria and flagellates
bottom
This pond system performs all the functions of any — and of the — as a whole, i.e., conversion of — material with the help of the —- of the sun by the autotrophs; — by heterotrophs; decomposition and — of the dead matter to release them back
for —-, these event are repeated over and over again.
ecosystem, biosphere
inorganic into organic
radiant energy
consumption of the autotrophs
mineralisation
reuse by the autotrophs
There is — movement of energy towards the — trophic levels and its —- and —- to the environment.
unidirectional
higher
dissipation and loss as heat
A — input of — is the basic requirement for any ecosystem to — and —.
constant
solar energy
function and sustain
— production is defined as the amount of — and –produced per unit — over a time period by PLANTS during —
Primary
biomass or organic matter
area
photosynthesis
Primary production is expressed in terms of —or —-.
weight (g/m^2) or
energy (kcal/m^2).
The —- is called productivity.
rate of biomass production
Productivity is expressed in terms of —- or —- to compare the productivity of different ecosystems.
g/ (m^2 year)
kcal/ (m^2 year)
Productivity can be divided into — and —-
gross primary productivity (GPP) and net primary productivity (NPP).
Gross primary productivity of an ecosystem is the rate of production of —- during — .
organic matter
photosynthesis
A considerable amount of GPP is utilised by plants
in — .
respiration
Gross primary productivity minus respiration losses (R), is the —–
net primary productivity (NPP).
GPP – ? = NPP
GPP – R = NPP
Net primary productivity is the —- for the consumption to heterotrophs (—)
available biomass
(herbiviores and decomposers)
Secondary productivity
is defined as the rate of formation of —–
new organic matter by consumers.
Primary productivity depends on the —- a
particular area. It also depends on a variety of —factors, availability of —and — of plants.
plant species inhabiting
environmental
nutrients
photosynthetic capacity
Therefore, —– varies in different types of ecosystems
1’ productivity
The — NET primary
productivity of the whole biosphere is approximately —- (—-) of organic matter.
annual
170 BILLION tons (dry weight)
Of the 170 billion tons of NPP, despite occupying about —- of the surface, the productivity of the oceans are only —
Rest of course, is on land.
70 percent
55 billion tons.
You may have heard of the earthworm being referred to as the —-. This is so because they help in the —- as well as in —
farmer’s ‘friend’
breakdown of complex organic matter
loosening of the soil.
Similarly, decomposers break down —- into inorganic substances like —-, — and —- and the process is called decomposition.
complex organic matter
carbon dioxide, water and nutrients
—– such as leaves, bark, flowers and dead remains of animals, including —, constitute —-
Dead plant remains
fecal matter
detritus
—– is the raw material for decomposition.
Detritus
The important steps in the process of
decomposition are —- (5)
fragmentation, leaching, catabolism, humification
mineralisation
Detritivores (Ex:—-) break down detritus into —.
This process is called —.
e.g., earthworm
smaller particles
fragmentation
By the process of —, —-nutrients go down into the —- and get precipitated as —-
leaching
water soluble inorganic
soil horizon
unavailable salts.
—– enzymes degrade detritus into simpler —-. This process is called as –.
Bacterial and fungal
inorganic substances
catabolism
It is important to note that all the above steps (frag, leach, cata) in decomposition —- on the detritus
operate simultaneously
Humification and
mineralisation occur during decomposition in the — .
soil
Humification leads to accumulation of a —- substance called —
dark coloured amorphous
humus
Humus is HIGHLY resistant to—- and undergoes decomposition
at —- rate.
highly resistant to microbial action
an extremely slow
Humus being — in nature it serves as a reservoir
of —.
colloidal
nutrients
The humus is further degraded by —- and release of — nutrients occur by the process known as —.
some microbes
inorganic
mineralisation
