PiTS-1: Carbon Partitioning in Loblolly Pine after 13C Labeling and Shade Treatments

The Partitioning in Trees and Soil (PiTS) task was established with the objective of improving the C partitioning routines in existing ecosystem models by exploring mechanistic model representations of partitioning tested against field observations. We used short-term field manipulations of C flow, through 13CO2 labeling, canopy shading and stem girdling, to dramatically alter C partitioning, and resultant data are being used to test model representation of C partitioning processes in the Community Land Model (CLM4 or CLM4.5). The research was conducted on individual trees within a small existing stand of planted Pinus taeda L.(loblolly pine) on the University of Tennessee Forest Resources Research and Education Center in Oak Ridge, Tennessee.

树木与土壤碳分配（Partitioning in Trees and Soil, PiTS）任务的设立目标是，通过探索经野外观测验证的碳分配机制模型表征，改进现有生态系统模型中的碳分配程序。我们通过¹³CO₂标记、冠层遮荫和树干环剥等短期野外碳流操控手段，显著改变碳分配格局；所得数据正用于测试社区陆地模型（Community Land Model, CLM4或CLM4.5）中碳分配过程的模型表征。本研究在田纳西州橡树岭市的田纳西大学森林资源研究与教育中心内，对一片现存的小型人工火炬松（Pinus taeda L.，loblolly pine）林分中的单株树木开展。