Effects of land use and its changes on productivity and carbon balance are very important issues for Clean Development Mechanism (CDM), particularly under the tropics. A tropical plantation of coconut tree with a grass under-storey (total LAI of around 6 for the two layers) and placed in close-to-optimum growing conditions (high level of fertility, no seasonal drought, evergreen, continuous growth) displayed productivity characteristics close to tropical evergreen humid forests, i.e. amongst the highest levels encountered in global forest biomes. This is an appealing result, notably for other tropical perennial crops grown in fertile conditions and in absence of drought, such as e.g. oil palm, coffee, rubber tree. It would deserve further investigations, together with other annual tropical crops.