The challenges - and some solutions - to process-based modelling of grazed agricultural systems

摘要: Pastoral systems are characterised by a number of features that absent in arable cropping systems. These include: (i) pastures biologically diverse so interactions between plant species must be considered; (ii) economic return requires the inclusion animal as an additional trophic level; (iii) interaction grazing and pasture is complex, influenced environment, behaviour this creates feedbacks can result vicious cycles; (iv) animals spatially transfer substantial amounts nutrients both randomly systematically or exacerbates soil variability; (v) whole farm management more complex important to system function grazed compared it harder capture simulation models. challenges complicate process-based modelling pastoral present significant obstacles model developers users.Here we discuss these challenges, describe range solutions used different models strengths weaknesses solutions. We have placed particular emphasis on analysis possible with point view diversity within provide flexibility needed for future uses.We find most there incorporated into potential diversity, if needed, from other note apparent lack development extreme events such very high temperatures, systematic animal-mediated nutrient transfers, pests, weeds gene-environment suggest subject areas should receive attention. review major simulating farming systems.Simple burden conceptualisation developer user.The probably not suitable routine use.Modelling effects transfers attention.Modelling diseases