Campos Mariana Batista, Litkey Paula, Wang Yunsheng, Chen Yuwei, Hyyti Heikki, Hyyppä Juha, Puttonen Eetu
Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute (FGI), National Land Survey of Finland, Masala, Finland.
Front Plant Sci. 2021 Jan 7;11:606752. doi: 10.3389/fpls.2020.606752. eCollection 2020.
The terrestrial laser scanner (TLS) has become standard technology for vegetation dynamics monitoring. TLS time series have significant underlying application in investigating structural development and dynamics on a daily and seasonal scale. However, the high potential of TLS for the monitoring of long-term temporal phenomena in fully grown trees with high spatial and temporal resolution has not yet been fully explored. Automated TLS platforms for long-term data collection and monitoring of forest dynamics are rare; and long-term TLS time series data is not yet readily available to potential end-user, such as forestry researchers and plant biologists. This work presents an automated and permanent TLS measurement station that collects high frequency and high spatial resolution TLS time series, aiming to monitor short- and long-term phenological changes at a boreal forestry field station (0.006° angular resolution, one scan per hour). The measurement station is the first of its kind considering the scope, accuracy, and length of the time series it produces. The TLS measurement station provides a unique dataset to monitor the 3D physical structure of a boreal forest, enabling new insights into forest dynamics. For instance, the information collected by the TLS station can be used to accurately detect structural changes in tree crowns surrounding the station. These changes and their timing can be linked with the phenological state of plants, such as the start of leaf-out during spring growing season. As the first results of this novel station, we present time series data products collected with the station and what detailed information it provides about the phenological changes in the test site during the leaf sprout in spring.
地面激光扫描仪（TLS）已成为植被动态监测的标准技术。TLS时间序列在调查每日和季节性尺度上的结构发展和动态方面具有重要的潜在应用。然而，TLS在以高空间和时间分辨率监测成熟树木长期时间现象方面的巨大潜力尚未得到充分探索。用于长期数据收集和森林动态监测的自动化TLS平台很少见；并且长期TLS时间序列数据尚未能方便地提供给潜在的最终用户，如林业研究人员和植物生物学家。这项工作展示了一个自动化的永久性TLS测量站，该测量站收集高频和高空间分辨率的TLS时间序列，旨在监测北方林业野外站的短期和长期物候变化（角分辨率为0.006°，每小时扫描一次）。考虑到其产生的时间序列的范围、准确性和长度，该测量站是同类中的首个。TLS测量站提供了一个独特的数据集来监测北方森林的三维物理结构，从而能够对森林动态有新的见解。例如，TLS站收集的信息可用于准确检测该站周围树冠的结构变化。这些变化及其时间可以与植物的物候状态相关联，比如春季生长季节的展叶开始时间。作为这个新站的首批成果，我们展示了用该站收集的时间序列数据产品，以及它在春季叶芽期为测试地点的物候变化提供的详细信息。
