............. of an ecosystem is the rate of production of organic matter during photosynthesis.
Gross primary productivity $(GPP)$
Net primary productivity $(NPP)$
Secondary productivity
Tertiary productivity
The flora and fauna in lakes or ponds are
At which latitude, heat gain through insolation approximately equals heat loss through terrestrial radiation?
Out of the following biogeochemical cycles which one is gaseous?
$I.$ sulphur $II.$ Phosphorus
$III.$ nitrogen $IV.$ Carbon
Choose the correct option
Mention type of nutrient cycling explaining it.
Which one of the following statements is correct for secondary succession?