Low productivity ecosystems are

High productivity ecosystems: Net productivity is about 2-4kg/${\mathrm{m}}^2$/yr. E.g., Coral reefs, Estuaries, Sugarcane fields, Tropical forests.

Average productivity ecosystems: Productivity is 1-2kg/${\mathrm{m}}^2$/yr. E.g., Agricultural land, Temperate forests.
Less productivity ecosystems: Productivity is 200-1000 g/${\mathrm{m}}^2$/yr.  E.g., Grassland ecosystems.
Low productivity ecosystems: Productivity is less than 200 g/${\mathrm{m}}^2$/yr. E.g., Deep sea, Arid lands or Deserts.