Montagnoli Antonio, Hudak Andrew T, Raumonen Pasi, Lasserre Bruno, Terzaghi Mattia, Silva Carlos A, Bright Benjamin C, Vierling Lee A, de Vasconcellos Bruna N, Chiatante Donato, Dumroese R Kasten
Department of Biotechnology and Life Science, University of Insubria, Varese, Italy.
USDA Forest Service, Rocky Mountain Research Station, Moscow, ID, USA.
Plant Methods. 2024 Jul 9;20(1):102. doi: 10.1186/s13007-024-01229-9.
Understanding how trees develop their root systems is crucial for the comprehension of how wildland and urban forest ecosystems plastically respond to disturbances such as harvest, fire, and climate change. The interplay between the endogenously determined root traits and the response to environmental stimuli results in tree adaptations to biotic and abiotic factors, influencing stability, carbon allocation, and nutrient uptake. Combining the three-dimensional structure of the root system, with root morphological trait information promotes a robust understanding of root function and adaptation plasticity. Low Magnetic Field Digitization coupled with AMAPmod (botAnique et Modelisation de l'Architecture des Plantes) software has been the best-performing method for describing root system architecture and providing reliable measurements of coarse root traits, but the pace and scale of data collection remain difficult. Instrumentation and applications related to Terrestrial Laser Scanning (TLS) have advanced appreciably, and when coupled with Quantitative Structure Models (QSM), have shown some potential toward robust measurements of tree root systems. Here we compare, we believe for the first time, these two methodologies by analyzing the root system of 32-year-old Pinus ponderosa trees.
In general, at the total root system level and by root-order class, both methods yielded comparable values for the root traits volume, length, and number. QSM for each root trait was highly sensitive to the root size (i.e., input parameter PatchDiam) and models were optimized when discrete PatchDiam ranges were specified for each trait. When examining roots in the four cardinal direction sectors, we observed differences between methodologies for length and number depending on root order but not volume.
We believe that TLS and QSM could facilitate rapid data collection, perhaps in situ, while providing quantitative accuracy, especially at the total root system level. If more detailed measures of root system architecture are desired, a TLS method would benefit from additional scans at differing perspectives, avoiding gravitational displacement to the extent possible, while subsampling roots by hand to calibrate and validate QSM models. Despite some unresolved logistical challenges, our results suggest that future use of TLS may hold promise for quantifying tree root system architecture in a rapid, replicable manner.
了解树木根系如何发育对于理解荒地和城市森林生态系统如何灵活应对诸如采伐、火灾和气候变化等干扰至关重要。内源性决定的根系特征与对环境刺激的反应之间的相互作用导致树木适应生物和非生物因素，影响稳定性、碳分配和养分吸收。将根系的三维结构与根系形态特征信息相结合，有助于深入理解根系功能和适应可塑性。低磁场数字化结合AMAPmod（植物结构的植物学与建模）软件一直是描述根系结构并提供粗根特征可靠测量的最佳方法，但数据收集的速度和规模仍然困难。与地面激光扫描（TLS）相关的仪器和应用有了显著进展，并且与定量结构模型（QSM）结合时，在稳健测量树木根系方面显示出一定潜力。在这里，我们通过分析32年生黄松的根系，首次比较了这两种方法。
总体而言，在整个根系水平和按根序类别来看，两种方法在根系特征体积、长度和数量方面得出了可比的值。每个根系特征的QSM对根大小（即输入参数PatchDiam）高度敏感，并且当为每个特征指定离散的PatchDiam范围时，模型得到了优化。在检查四个主要方向扇区的根系时，我们观察到根据根序不同，两种方法在长度和数量上存在差异，但在体积上没有差异。
我们认为TLS和QSM可以促进快速数据收集，也许可以在原地进行，同时提供定量准确性，特别是在整个根系水平。如果需要更详细的根系结构测量，TLS方法将受益于从不同角度进行额外扫描，尽可能避免重力位移，同时手动对根系进行子采样以校准和验证QSM模型。尽管存在一些未解决的后勤挑战，但我们的结果表明，未来使用TLS可能有望以快速、可复制的方式量化树木根系结构。
