Q.A paddy field maintained by a farmer, with regular irrigation, fertiliser application and weeding, is best classified as

An ecotone is a zone of junction/transition between two distinct ecosystems, sharing features of both and often supporting extra diversity.

An ecotone is a transitional zone that occurs where two different ecosystems or biological communities meet and overlap — such as the boundary between a forest and a grassland, or a mangrove forest lying between purely marine and purely terrestrial ecosystems. Key features of an ecotone:

• It has some characteristics of each of the bordering communities, in addition to characteristics of its own.
• It can be narrow (e.g. forest-grassland boundary) or wide (e.g. the transition between a forest and a desert). …

A biome is a major, climate-defined regional ecosystem type, distinguished by its characteristic vegetation and animal life.

A Biome is a large naturally-occurring community of flora and fauna occupying a major habitat, and is primarily determined by the region's climate - mainly temperature and rainfall pattern.

• Each biome has a characteristic dominant vegetation type and associated animal community adapted to that climate.
• Examples include tropical rainforest, temperate deciduous forest, grassland (savanna), desert, and tundra biomes. …

Ecosystem stability is the ability to resist and recover from disturbance; the ocean, being the largest, most homogeneous and best-buffered ecosystem, shows the least fluctuation and is considered the most stable.

Stability of an ecosystem depends on its size, homogeneity, and buffering capacity against environmental change:

• The ocean is enormous in volume and area, has a relatively uniform (buffered) temperature and chemical composition, and is far less affected by short-term local disturbances (e.g., seasonal changes, human interference) compared with smaller, more exposed ecosystems. This large thermal and chemical "inertia" makes it highly resistant to sudden change. …