In an ecosystem if the Net Primary Productivity (NPP) of first trophic level is $$100 x\left(\mathrm{kcal} \mathrm{~m}^{-2}\right) \mathrm{yr}^{-1}$$, what would be the GPP (Gross Primary Productivity) of the third trophic level of the same ecosystem?

Match List - I with List - II

Choose the correct answer from the options given below :

The amount of nutrients such as carbon, nitrogen, potassium and calcium present in the soil at any given time is referred to as :

The species of plants that plays a vital role in controlling the relative abundance of other species in a community is called _________.