Multi-Scale Evaluation of Dominant Factors (MSDF) on Forage: An Ecosystemic Method to Understand the Function of Forage

Grassland agroecosystem plays a key role on resource cycling and sustainability of global ecosystem. Forage is the basic factor and core of the grassland agroecosystem. At a single scale, the most of forage evaluation remain in a state of qualitative or quantitative evaluation, and lack a series of quantitative evaluation at multi spatial scales and influence of society, environment and economy. This study collected dominant indicators at micro, plot, farm, ecoregional and macro scales to compile a systemic evaluation of forage in agroecosystems. A case study is presented for forage evaluation by using plot, farm, and regional data from an arid region of Gansu, China. Multi-scale evaluation of dominant factors (MSDF) was used to aggregate forage evaluation indicators. Results showed that the scale of evaluation had significant effects on the results of the evaluation. The evaluation results of the single index for the same forage species among plot, farm and ecoregional scales were different. Results implied that forage MSDF are needed to guide the evaluation of forage and then production of forage and herbivore in the future. An appropriate scale of evaluation could be selected in term of the forage production objectives and moreover, MSDF evaluation of forage should be used to improve the environmental, social and productive evaluation of forage in a grassland agroecosystems.