REU: Belowground Processes and Nitrogen Availability Across a Dynamic, Nutrient Poor, Barrier Island Landscape

过去的研究表明，营养素>。可怜的网站 更大的养分固定在凋落物中， 地下生物量的分配，和较慢的衰减;所有 导致更保守的营养循环。 大多数这些 研究侧重于森林生态系统， 地下动力学 新的主要目标 研究项目是（1）量化之间的关系 C和N的有效性和地下动态 营养贫乏、动态、屏障型岛屿景观;（2） 量化微地形、演替年龄 和微环境界面（由波动 地下水位）对地下过程的影响;（3） 改进和扩大新技术的应用， 地下研究这项研究将沿着一条 65、35、25和5年生样带群落 在美国国家科学基金会弗吉尼亚海岸的猪岛的生长端， 长期生态研究（LTER）。 氮 修改和未修改的地块将用于测试效果 氮的可利用性在地下过程中。 根 产量，根系分解，氮固定率 在根凋落物、矿化率、根和土壤中 在处理和对照中测定氮含量 情节相互垃圾袋移植将测试程度 外源氮控制根系分解的研究 对比垃圾质量。 所有过程将在 与微环境条件和演替年龄的关系 沿着样带和垂直土壤剖面内。 微电子技术在屏障岛生态系统中的应用 也将受到考验。 该项目的成果对以下方面至关重要： 养分治理的基本生态对策 养分贫乏区的植物群落组成 生态系统 此外，这项工作应该产生见解， 协助更好地管理堰洲， 海滨，保护利益的地区， 娱乐和商业发展经常发生冲突。 主要研究者资质良好， 机构设施足以完成这项任务。一体化 这个新项目与正在进行的研究计划的结合 弗吉尼亚海岸保护区LTER项目将导致生产力 加强这两方面的努力。

Past studies have suggested that nutrient>.>poor sites have greater nutrient immobilization in the litter, greater belowground allocation of biomass, and slower decay; all resulting in more conservative nutrient cycles. Most of these studies focused on forested ecosystems with minimal emphasis on belowground dynamics. The primary objectives of this new research project are (1) to quantify the relationships between C and N availability and belowground dynamics across a nutrient-poor, dynamic, barrier island landscape; (2) to quantify the influences of microtopography, successional age and microenvironmental interfaces (caused by fluctuating groundwater levels) on belowground processes; and (3) to refine and extend the application of newer techniques for belowground research. The research will be conducted along an established transect incommunities 65, 35, 25 and 5 years old on the accreting end of Hog Island on NSF's Virginia Coast Reserve Long-Term Ecological Research (LTER) site. Nitrogen amended and unamended plots will be used to test the effects of nitrogen availability on belowground processes. Root production, root decomposition, nitrogen immobilization rates in root litter, mineralization rates, and root and soil nitrogen content will be measured in the treatment and control plots. Reciprocal litter bag transplants will test the degree of control of root decomposition by external nitrogen supply versus litter quality. All processes will be evaluated in relation to microenvironmental conditions and successional age along the transect and vertically within the soil profile. The application of minirhizotrons in barrier island ecosystems will also be tested. Results from the project will be of fundamental importance to the basic ecological resolution of the governance of nutrient dynamics and plant community composition in nutrient-poor ecosystems. Additionally, the work should produce insights to assist in better management of barrier islands and beachfronts, areas where the interests of conservation, recreation and commercial development often collide. The principal investigator is well qualified, and institutional facilities are adequate to the task. Integration of this new project with the ongoing research program of the Virginia Coast Reserve LTER project will result in productive augmentation of both efforts.