Doctoral Dissertation Research: Intensive Phenological Monitoring of Wisconsin's Northern Mixed Forest, Integrating In-situ and Remote Sensing Observations

春季植物物候（生长开始）是生物圈对全球气候变化响应的重要指标。它还为进一步了解低层大气边界层动力学和生物圈-大气能量/物质交换开辟了可能性。在过去十年中，随着卫星观测数据和生物气候模型的可用性越来越高，物候学与大规模生态系统监测的关系更加密切。然而，由于缺乏密集的地面测量，无法在象素水平上对卫星数据进行精确验证，因此来自遥感器的信息的精度仍然低于期望。为了充分发挥物候监测的作用，需要有计划地对整个景观的地表物候进行观察和表征。本研究在景观尺度上对春季植物物候特征进行了表征，并建立了包括空间分布的野外观测在内的方法基础，以期对植被动态进行更可靠和综合的物候监测。这些原位数据以及相应的卫星数据、土壤调查数据、dem等，将采用统计学、空间分析、地统计学和数字图像处理技术进行分析。这笔拨款将支持第二年的春季实地活动和研究设备的维护/改进。该项目将是第一个在高时间和空间分辨率下整合大量地面物候的项目，以在景观水平上表征植物物候和生物圈-大气相互作用。这些数据的性质将允许通过将两种观测尺度纳入相同的分辨率来合理地验证卫星衍生的物候指数。因此，本研究也是一项开创性的工作，旨在探索有效的方法来监测区域到全球尺度的生物圈对全球变化的响应，通过空间尺度的桥接和原位和遥感物候数据的协同整合。学生研究员将使用该项目来支持其完成博士论文。收集的数据和测试的方法将对其他研究生和感兴趣的研究人员进行后续研究和相关研究有用（物候观察结果将通过互联网门户共享）。从广义上讲，更好地了解景观物候和生物圈对全球气候变化的响应，对于增强地球系统的科学知识、支持社会适应和可持续发展工作具有重要意义。

Springtime plant phenology (onset of growth) is a critical indicator of biospheric response to global climate change. It also opens up possibilities to further understand lower atmospheric boundary layer dynamics and biosphere-atmosphere energy/matter exchange. With data from satellite observations and bioclimatic modeling becoming more available over the past decade, phenology is even more relevant for large scale ecosystem monitoring. However, due to the lack of intensive ground measurements which would allow precise validation of satellite data at the pixel level, the precision of information from remote sensors is still less than desired. To fully release the power of phenological monitoring, surface phenology across a landscape needs to be observed and characterized in a well-planned manner. This study is characterizing spring plant phenology at the landscape scale, and preparing a methodological base that includes spatially distributed field observations, in order to facilitate more reliable and integrated phenological monitoring of vegetation dynamics. These in-situ data, as well as corresponding satellite data, soil survey data, DEMs, etc. will be analyzed with statistics, spatial analysis, geostatistics, and digital image processing techniques. This grant will support a second year spring field campaign and research equipment maintenance/improvement. This project will be among the first to incorporate substantial ground-level phenology at high temporal and spatial resolution to characterize plant phenology and biosphere-atmosphere interactions at the landscape level. The nature of these data will allow reasonable validation of satellite-derived phenological indices by bringing two scales of observation to the same resolution. This proposed study is thus also a pioneering work designed for exploring effective approaches to monitor regional to global scale biospheric responses to global change, through the bridging of spatial scales and synergistic integration of in-situ and remotely sensed phenological data.The student investigator will use this project to support completion of his doctoral dissertation. The data collected and methods tested will be useful for other graduate students and interested researchers to conduct follow-up and related studies (phenological observations will be shared through an Internet portal). Broadly, a better understanding of landscape phenology and biospheric responses to global climate change is important for enhancing scientific knowledge of earth systems in support of societal adaptation and sustainable development efforts.