CBSE Class 10 Science 2022 · Paper 31/3/1 · Question 8

Human-made (artificial) ecosystems are ecosystems that are created and maintained by human beings, as distinct from natural ecosystems such as forests, ponds and lakes. Example: a crop field (gardens, parks and aquaria are others). Yes, a human-made ecosystem can become self-sustaining, provided it contains producers, consumers and decomposers in balance. For example, when a few aquatic plants and animals are added to an aquarium, the plants make food and oxygen by photosynthesis using sunlight, the animals feed on them and release carbon dioxide that the plants use, and decomposers break down the wastes and dead remains into minerals that the plants take up again. Materials such as carbon (in food and carbon dioxide), oxygen and minerals are then recycled within the tank, so it can keep going without being fed or cleaned, with sunlight as its source of energy. Without that balance, as in a crop field that has to be sown, watered, fertilised and weeded, or a tank holding only fish, the ecosystem depends on people and is not self-sustaining.