Dissertation Research: The effect of human management and soil properties on heavy metal content of Los Angeles Community Garden soils

社区花园是人与环境互动的热点。人们对这些人造生态系统中的生物地球化学循环或金属积累知之甚少，这两者都可能影响作物和食用它们的人的健康。这些知识缺口将通过调查管理、土地使用遗产和社区对洛杉矶社区花园土壤和作物金属可用性的影响来解决。研究人员将收集12个花园的土壤，分别来自已开垦、未开垦和周边地区，并分析其pH值、营养物质、有机物和29种金属的浓度。将从每个菜园收集叶菜和根菜样品，并测试金属浓度，以确定生物利用度和人类接触风险。园艺师还将接受关于他们管理活动的采访。将使用多元回归框架来确定是否可以使用园艺实践或社区特征（例如，高速公路附近，以前的土地利用）来预测园丁，花园和区域尺度上的土壤金属浓度和生物利用度。有关管理对金属供应的影响的数据将对花园管理人员和城市规划部门有用。洛杉矶城市土壤和农作物的金属含量对人类健康具有重要影响。关于花园土壤和作物金属含量的报告，以及土壤测试的教育材料，将提交给花园管理者、参与者和支持非营利机构。这些活动将为少数民族提供获取科学资源的机会。

Community gardens are hotspots of interactions between humans and the environment. Little is known about biogeochemical cycles or metal accumulation in these constructed ecosystems, both of which can impact the health of crops and the people who consume them. These knowledge gaps will be addressed by investigating the impact of management, land use legacy, and neighborhood on soil and crop metal availability in Los Angeles community gardens. Soils will be collected in 12 gardens from cultivated, uncultivated, and surrounding locations and analyzed for pH and concentrations of nutrients, organic matter, and 29 metals. Leafy and root vegetable samples will be collected from each garden and tested for metal concentrations to determine bioavailability and human exposure risk. Gardeners will also be interviewed about their management activities. A multiple regression framework will be used to determine if gardening practices or neighborhood characteristics (e.g., freeway proximity, previous land use) can be used to predict soil metal concentrations and bioavailability at gardener, garden, and regional scales.Data pertaining to management influence on metal availability will be of use to garden managers and city planning departments. The metal content of urban soils and crops in Los Angeles has important human health implications. Reports on metal content of garden soils and crops, as well as educational materials on soil testing, will be presented to garden managers, participants, and supporting non-profit agencies. These activities will provide access to scientific resources for minority populations.