Center for Ecological Research, Northeast Forestry University/Ministry of Education Key Laboratory of Sustainable Forest Ecosystem Management, Harbin 150040, China.
Ying Yong Sheng Tai Xue Bao. 2023 Jul;34(7):1797-1805. doi: 10.13287/j.1001-9332.202307.005.
For exploring the difference of root stoichiometric characteristics among diameter classes and provenances, we examined the contents and stoichiometric ratios of carbon (C), nitrogen (N), phosphorus (P), and potassium (K) in three diameter classes of roots (0-1, 1-2 and 2-5 mm, respectively) of 39-year-old grown in a common garden. The results showed that root element contents and their stoichiometric ratios had significant difference among three diameter classes of roots. C content, C:N, C:P, C:K were the lowest, and N, P, K contents, N:P, and N:K were the highest in 0-1 mm diameter class roots. Compared with the 1-2 and 2-5 mm diameter class roots, 0-1 mm diameter class roots had different seasonal dynamics, which might be caused by the fact that 0-1 mm diameter class roots are absorptive roots and the other diameter class roots are transport roots. There was no provenance difference in C content among all diameter class roots, while significant provenance differences were found in N, K contents, C:N, and C:K in 0-1 mm diameter class roots, and great provenance differences for in P content, C:P, N:P, and N:K in 0-1 and 1-2 mm diameter class roots. N content, K content, C:P, N:P, and N:K in 0-1 mm diameter class roots had positive correlation with the aridity index of seed-source sites, while the P content, C:N and C:K had negative correlations. The stoichiometric characteristics were related with the diameter (or function) of roots, and had significant provenance differences in 0-1 mm (absorptive root) and 1-2 mm diameter class roots, which might be attributed to their genotypic adaptation to the environment of seed-source sites.
为了探究不同径级和种源间根系化学计量特征的差异，我们对 39 年生生长于同一实验林内的各 3 种径级（0-1、1-2 和 2-5mm）根系（分别代表吸收根和运输根）的碳（C）、氮（N）、磷（P）和钾（K）含量及化学计量比进行了分析。结果表明：不同径级根系的元素含量及其化学计量比均存在显著差异。0-1mm 直径级根系的 C 含量、C:N、C:P 和 C:K 最低，而 N、P、K 含量、N:P 和 N:K 最高。与 1-2 和 2-5mm 直径级根系相比，0-1mm 直径级根系具有不同的季节性动态，这可能是因为 0-1mm 直径级根系为吸收根，而其他径级根系为运输根。各径级根系的 C 含量在种源间无差异，但 0-1mm 直径级根系的 N、K 含量、C:N 和 C:K 存在显著的种源差异，0-1 和 1-2mm 直径级根系的 P 含量、C:P、N:P 和 N:K 存在较大的种源差异。0-1mm 直径级根系的 N 含量、K 含量、C:P、N:P 和 N:K 与种源地干燥指数呈正相关，而 P 含量、C:N 和 C:K 与干燥指数呈负相关。化学计量特征与根系的直径（或功能）有关，在 0-1mm（吸收根）和 1-2mm 直径级根系中存在显著的种源差异，这可能是由于它们对种源地环境的基因型适应。
