Justify the following statement in terms of ecosystem dynamics. “Nature tends to increase the gross primary productivity, while man tends to increase the net primary productivity”.
In the conditions of dynamics of ecosystem, the flow of energy moves from one trophic level to the another. $50 \%$ events of sunlight on the earth, are in photosynthetically active radiation. Plants capture $2$ to $10$ per cent of the $PAR$ to form $GPP.$
Maximum gross primary productivity during respiration and other biotic processes is of $90 \%$. Gross net primary productivity is used in respiration by plants. Subtracting respiration loses plants use GPP for respiration which is used in second trophic level $C$ herbivores and decomposers.
Gross primary productivity of an ecosystem is the rate of production of organic matter during photosynthesis.
Therefore to increase gross primary productivity in natural ecosystem, large amount of trees help in ecological system.
Net primary productivity is the available biomass for consumption to heterotrophs (herbivores and decomposers).
Human beings try to produce net primary productivity by producing other crops to fulfill their requirements, develop food.
$NPP$ (Formula to find net Primary productivity)
$\mathrm{NPP}-\mathrm{GPP}-\mathrm{R}$
What is maximum in a pond-ecosystem
In a terrestial ecosystem such as forest, maximum energy is in which trophic level
Which of the following in an ecosystem exhibits one-way flow rather than cyclic flow
Justify the pitcher plant as a producer.
Consider the following statements concerning food chains.
$I$. Removal of $80\; \%$ tigers from an area resulted in greatly increased growth of vegetation.
$II.$ Removal of most of the carnivores resulted in an increased population of deers.
$III.$ The length of food chains is generally limited to $3$ to $4$ trophic levels due to energy loss.
$IV.$ The length of food chains may vary from $2$ to $8$ trophic levels.
Which two of the above statements are correct?