Question

A man-made micro ecosystem is
A. Plants grown in a pond
B. Crop field
C. Tank formed naturally in your courtyard
D. Lake in a forest

Answer 1

Hint: An ecosystem is composed of biotic and abiotic things. Natural (macro) and artificial (micro) ecosystems are the two types of ecosystem. Micro ecosystems as the name indicates exist in small or tiny places.

Complete answer:
Option (A) is incorrect. Plants grown in a pond are not a man-made micro ecosystem because, in a pond, plants grow by themselves through natural means. There is no involvement of man in the growth of plants in a pond.
Option (B) is correct. Crop field is a man-made micro ecosystem because in this field the plants are not grown naturally. They have aided with artificial means such as the application of irrigation facilities (to fulfill the water requirement of plants), fertilizers (to provide nutrients for the growth of the plants), and pesticides (to protect the plants from pests). These artificial means through the involvement of man helps in the growth of the plant in the fields. These fields thus possess both biotic and abiotic components of an ecosystem. Also, crop fields comprise food chains, food webs, the flow of energy, etc. making it an ecosystem that is artificially driven through man-made activities.

Image depicting the fertilization of crop fields.
Option (C) is incorrect. Tank formed naturally in your courtyard cannot be a man-made micro ecosystem because the tank is formed naturally without the involvement of man-made activities.
Option (D) is incorrect. Lake in a forest is a natural ecosystem because it is formed naturally through the melting of glaciers and the water then fills the depressions on the earth’s surface. Hence, it is a natural ecosystem.

Hence, the correct option is (B).

Note: Micro ecosystems are defined by critical environmental factors such as pH, nutrient supply, presence of symbionts, abiotic factors, etc. Since the crop field consists of all the biotic and abiotic factors and is produced artificially by providing all the critical environmental factors to these fields therefore, it is a man-made micro ecosystem.