Question

Primary succession is the development of communities on
A. Newly exposed habitat
B. Cleared forest area
C. Freshly harvested crop field
D. Pond filled after a dry season

Answer 1

Hint: The change in the species composition of a given area which is gradual and fairly predictable is called ecological succession or simply succession. It can occur in any habitat.

Step by step answer:Due to changing environmental conditions in a given area or in a given habitat, the composition, and structure of all communities constantly change in response to the surrounding changes. This change occurs in parallel with the changes in the physical environment and these changes are always orderly and sequential. It is said that succession and evolution are the parallel processes occurring since the first life formed. These changes in communities finally lead to a community that comes to the equilibrium with the environment and that stable community is called a climax community. Since changes occur in a habitat, some of the species colonies in any area and their numbers increase greatly in size but some of the communities decline and then may even disappear from that area. The entire sequence of communities that successively change in a given area is called sere(s) where the individual transitional communities are called seral communities or seral stages. In every seral stage, there is an increase in the total number of species, there is a change in the diversity of species of organisms and an increase in the total biomass of the habitat.
It is important to note that succession starts in that area where no living organisms are there. It can occur in that area where no living organism ever existed or the one where all living organisms were lost.
Depending on that there are two types of succession: primary succession and secondary succession. Primary succession occurs in that area where no living forms ever existed and secondary succession occurs where living forms existed but they all disappeared due to some natural or man-made disturbances.
Primary succession occurs on bare rock, newly cooled lava, or newly created ponds or reservoirs, whereas secondary succession occurs at a deforested site, flooded lands, or abandoned farmlands.
Secondary succession is faster than primary succession because some soil sediment is already present at the destroyed site. It is important to note that for a biotic community to get established, there must be soil. Based on the nature of the habitat there are two successions that are hydrarch succession and xerarch succession. Hydrarch succession occurs in wet areas and xerarch succession occurs in dry areas.
In hydrarch succession, the successive changes occur from hydric to mesic conditions whereas in xerarch conditions the changes occur from xeric to mesic conditions. Both the succession leads to mesic conditions that are medium water conditions.
Hence option A is correct.
Note: If during primary or secondary succession, some disturbances like natural or human-induced disturbances occur like fire or deforestation, then it can convert a particular seral stage or seral community of succession to an earlier stage.