$...A...$ is required for higher primary productivity. $...B...$ have the lowest primary productivity as the soil is deficient in moisture.

Choose the correct option for $\mathrm{A}$ and $\mathrm{B}$

In an ecosystem, the largest population is of

In food chain initial organisms are

The rate of decomposition is faster in the ecosystem due to following factors $EXCEPT$

In an ecosystem bacteria are considered as

The food chain in which microbes split energy rich compounds of the producer community is