Doctoral Dissertation Research: Evolution of Food Networks: Foodscale Connectivity, Egocentric Networks, and Social Contagion in Community-Supported Agriculture

在北美发展了各种以订阅为基础的农业组织。它们统称为社区支持农业（CSA）。CSA种植者承诺在生长季节开始时向个人消费者用户支付CSA会员费用，以提供产品。采用csa风格的战略往往是合理的，因为它有能力以互利的方式重组生产者-消费者关系。例如，CSA组织可能会在小农场的经济地位方面培养更大的生存能力，促进可持续的农业实践，并改善获得新鲜食物的途径。然而，这些食物网络出现、演变和塑造现有食物网络的方式尚未被表征。此外，关于获取新鲜食品的公平性的问题已经出现，这表明csa可能倾向于塑造与其流行形象相矛盾的结果。更好地了解CSA网络的动态和功效，有可能改善粮食安全和粮食可及性。在佛罗里达州立大学地理系教授Jon Stallins的指导下，博士生Michael Nesius正在研究佛罗里达州塔拉哈西市区的食物网络。本研究的目的是探索与CSA形成相关的食品网络的变化，包括与提供本地种植产品的接入点的连接、与以客户为导向的消费网络的连接，以及对检测到的变化负责的具体机制。采用混合方法将定量分析与定性情境化结合起来，并用基本描述来平衡假设检验。将采用基于gis的图形理论分析来表征塔拉哈西当地食物景观的网络连通性，并检查其对食物沙漠存在的影响。多维尺度将验证自我中心食物网络的结构变化假设伴随CSA的形成。使用一个新出现的CSA的案例研究，社会传染在网络进化中的作用将被评估。这项研究的优点源于它的中心任务，揭示动态表现在食物网络的进化。网络映射将量化食物网络的变化，而这些变化以前只以定性的方式被捕获。这项研究将有助于理解食物网络在实现理想的社会结果中所起的作用。将目前的集中式粮食系统重组为一个由多层可持续和不相关的粮食网络组成的系统，可以减少网络对中断的脆弱性。拥有与大规模供应链共存的可行的地方食品网络，可以减轻与整个食品系统中食源性疾病传播相关的风险，并有助于实现国家安全目标。

A variety of subscription-based agricultural organizations have developed in North America. They are collectively referred to as Community Supported Agriculture (CSA). CSA growers make a promise to provide produce to individual consumer subscribers who pay fees for CSA membership at the start of the growing season. The adoption of CSA-style strategies is often rationalized by its reported ability to restructure the producer-consumer relationships in mutually beneficial ways. For example, CSA organizations may be fostering greater viability with regards to the economic status of small farms, facilitating sustainable farming practices, and improving access to fresh food. However, the ways in which these food networks emerge, evolve, and shape existing food networks have not been characterized. Moreover, questions about the equitability of access to fresh food have arisen, suggesting that CSAs may have the propensity to shape outcomes that are in contradiction with their popular image. A better understanding of the dynamics and efficacy of CSA networks holds potential to improve food security and accessibility to food. Doctoral student Michael Nesius under the guidance of Professor Jon Stallins in the Department of Geography at Florida State University is studying the food networks in the Tallahassee, Florida metropolitan area. The objectives of this study are to explore changes in food networks associated with CSA formation in terms of connectivity to access points offering locally grown produce, to customer-oriented consumption networks, and to the specific mechanisms responsible for the detected changes. A mixed-methods approach is used to synthesize quantitative analysis with qualitative contextualization and to counterpoise hypothesis testing with fundamental description. A GIS-based, graph theoretical analysis will be employed to characterize the network connectivity of Tallahassee's local foodscape and to examine its influence on the existence of food deserts. Multidimensional scaling will validate the structural changes of egocentric food networks hypothesized to accompany CSA formation. Using a case study of a newly emerging CSA, the role of social contagion in network evolution will be assessed.The merit of this research stems from its central task of uncovering the dynamics manifest in the evolution of food networks. Network mapping will quantify the changes of food networks that have previously only been captured in a qualitative manner. This research will facilitate understanding of the role that food networks play in the achievement of desirable social outcomes. Restructuring the current centralized food system into one that comprises multiple tiers of sustainable and uncorrelated food networks could reduce network vulnerability to disruption. Having viable local food networks that coexist with large-scale supply chains can mitigate the risk associated with the propagation of food-borne disease throughout the food system and help achieve national security goals.