The import of virtual nutrients meant the conservation of domestic nutrient resources, especially P (due to the low cost-effectiveness of recycling through natural cycling, Fig. S6). For instance, the imports to Africa in 2016 embedded 0.37 Tg of virtual P, meaning that the sending system ...
When bottom-up models are developed, by detailing the base elements of the system, these are often linked together to form larger subsystems at another scale for example, within a top-down framework. The approach to map the nutrient cycling system in “Mapping the environmental and agricultural ...
trade network; (2) analyze the natural resource depletion and environmental effects of N and P flows on different sending and receiving systems and on global nutrient cycling; and (3) discuss the policy suggestions conducive to sustainable utilization of nutrient resources and environmental protection....
indicating that cattle preference for the improved area decreases when the improved area constitutes an increasing proportion of the pasture area, whereas data showed no effect of grazer density (LSU) on electivity (Additional file