Question

The gradual and fairly predictable change in species composition of a given area is
A) Ecological succession
B) Climax community
C) Pioneer species
D) Stratification

Answer 1

An ecosystem composed of biotic and abiotic components. This includes the study of two basic categories; aquatic and terrestrial. The forest, desert, and grassland are terrestrial ecosystems and the pond, lakes, and other water bodies are aquatic ecosystems.

Complete answer:
To answer this question, we should know about the structure and function of an ecosystem. An ecosystem is the interaction between the biotic and the abiotic components that forms a structure. Through the identification of the different plants and animals species of an ecosystem gives its species composition. The productivity, decomposition, energy flow, and nutrient cycling is considered as the unit that functions together to understand the component of the ecosystem. To understand this better, let’s take the example of an aquatic ecosystem, in a pond the abiotic component is the water and the inorganic and organic compounds dissolved in it and the soil deposit. The autotrophic components are the phytoplankton, the floating, and some of the algae. The consumers are the zooplanktons, decomposers are the bacteria, fungi, and flagellates, therefore this system has all the functions of an ecosystem.
Now, the important characteristics of all the communities are that their structure and the composition changes constantly due to the change in environmental conditions. This change is sequential and orderly, parallel with the changes in the environment. This change leads to a formation of community that is almost equilibrium with the environment and is termed as climax community. The fairly and gradual predictable changes in the composition of a species is called ecological succession, during succession some of the species get colonies and the population gets increased while the population of the other species get decreased and even disappear.

Note: The succession of plants is based on the nature of the habitats it is also termed as xerarch and hydrach. The hydrarch succession takes place in wetter area and the progress in the succession series is from hydric to the mesic conditions. The search succession takes place in a dry area and the progress is from xeric to mesic condition.