Describe three reasons for the relatively high net primary productivity and high trophic efficiencies of natural grasslands

The natural grassland ecosystem is known for its relatively high net primary productivity and high trophic efficiencies compare to other types of ecosystem, many reasons are responsible for this and three of them are listed below: 
1. Natural grassland are regionally adapted to survive environmental fluctuations and grazing pressure.
2. The diverse producer base of the natural grassland ecosystem results in a large number of trophic connections. This enhances energy transfer and reduces energy losses. 
3. Nutrient cycling in the natural grassland ecosystem is very efficient and this contributes to the overall efficiency of the ecosystem. The recyclers in the ecosystem decompose dead organic matters and release the energy trapped inside them.