What does the base tier of the ecological pyramid represent?
The base tier of the ecological pyramids represent the producers or first trophic level in case of three ecological pyramids
(i) Pyramid of number
(ii) Pyramid of biomass
(iii) Pyramid of energy
Under what conditions would a particular stage in the process of succession revert back to an earlier stage?
Natural disturbances like fire, flood or any other natural disaster and anthropogen activities can revert back to an earlier stage of succession.
Arrange the following as observed in vertical stratification of a forest; Grass, Shrubby plants, Teak, Amaranths.
Vertical stratification (dispersion) of species in a forest ecosystem is arranged as grass (floor of forest) $\rightarrow$ Amaranthus $\rightarrow$ Shrubby plants $\rightarrow$ Teak (tree).
Name an omnivore which occurs in both grazing food chain and the decomposer food chain.
Cockroaches and crow are two omnivore, that are present in both grazing or predator and detritus food chain.
Justify the pitcher plant as a producer.
Pitcher plant (Napenthes) is an insectivores plant, which is chlorophyllus and capable of trapping solar radiations for chemical energy for photosynthesis. It is infectivorous plant which are produced in the soil lacking nitrogen thus to make up their nitrogen deficiency they trap insects.