Using mechanistic land-use models to explore the potential of agroforestry for enhancing ecological and economic functions

农林业一直被提倡作为满足日益增长的粮食和能源需求的途径，同时加强生态系统服务的提供。过去在这一领域的研究往往只集中在地块层面，而科学家和政策制定者正在呼吁对多功能景观的研究。因此，这里提出的研究旨在开发一种多功能的机械土地使用建模方法，以确定农林业有助于减少土地使用冲突的条件。它的目的是调查在地块、农场和景观层面上，哪种多样化水平最适合将公共利益和农民的目标结合起来。为此，将进一步开发新的单目标和多目标建模方法，以优化不确定性条件下的土地利用分配。对于第一个原型模型，将为巴拿马东部森林边界的典型热带景观开发这种方法。景观一级的方法应首先回答这个问题，在景观组合中有多少农林复合系统是可取的，以实现多种生态系统服务，同时减少它们之间的权衡（多目标模型）。农场一级模型应调查如何设计农林复合经营，使其成为满足农民（最有可能的经济）需求的农场组合的有效组成部分（单目标模型）。一系列已经常见的和潜在的新的农林复合系统和布局可以在不同的条件下使用基于过程的WaNuLCAS进行模拟。其中，将根据优化方法期间确定的条件预先选择特定布局。最后，土地利用的组成和提供的生态系统服务的综合农场模型应对比景观模型，以调查是否包括有效的农林系统可以减少潜在的差异。拟议的研究是创新的，因为它比较农林业其他形式的土地使用多样化，并纳入决策过程中的不确定性。新的强大的优化技术允许减少模型的复杂性，从而包括大量的土地使用的选择。因此，拟议的研究可能会作出重要贡献，设计有弹性的多功能景观和指导未来的农林研究。

Agroforestry has been advocated as a pathway to satisfy growing food and energy demands, while enhancing the provision of ecosystem services. Past research in this field has often focused only on the plot level, while scientists and policy makers are calling for research on multifunctional landscapes. The research proposed here therefore seeks to develop a mechanistic land-use modelling approach for multifunctionality to identify the conditions under which agroforestry could contribute to reducing land-use conflicts. It aims at investigating which level of diversification will be most appropriate at the plot, farm and landscape level to bring together public interests and farmer s objectives. For this purpose, novel single and multi objective modelling approaches to optimize land use allocation under uncertainty will be further developed. For a first prototype model, the approach will be developed for a typical tropical landscape at the forest frontier in eastern Panama. A landscape level approach shall first answer the question, how much of agroforestry will be desirable in a landscape portfolio to achieve multiple ecosystem services, while reducing trade-offs between them (multi objective model). A farm level model shall investigate how agroforestry should be designed to become an efficient part of a farm portfolio that satisfies the farmer s (most likely economic) needs (single objective model). A range of already common and potentially new agroforestry systems and layouts could be simulated under different conditions using the process based WaNuLCAS. Among these, specific layouts will be pre selected according to the conditions identified during the optimization approach. Finally, the land use composition and provision of ecosystem services of the aggregated farm models shall be contrasted to the landscape model, in order to investigate whether including efficient agroforestry systems may reduce potential differences. The proposed research is innovative in that it compares agroforestry to other forms of land-use diversification and incorporates uncertainties into the decision making process. Novel robust optimization techniques allow for a reduction of model complexity and thus inclusion of a large number of land-use options. The proposed research may therefore make an important contribution to designing resilient multifunctional landscapes and directing future agroforestry research.