基于根系发育分级的砂壤土下成熟林木根系构型分析

以30多年生的两个毛白杨(Populus tomentosa)和一个刺槐(Robinia pseudoacacia)的根系系统为研究对象，以Rose提出的发育分级标准作为根系分级标准,分析了不同等级根系形态特征以及根系间的拓扑关系。结果表明 1)3个根系系统均呈现叉状分支;2)3个根系系统能够分支到7-8级根;一级根基径和长度显著高于后几级根，一级根基径是后几级根的5.79-36.92倍，一级根长度是后几级根的1.45-9.11倍;根系数量随着根系等级增加先增后减，在三级根上达到最大值。3)在前三级根中,各级根上的连结长度从根基到根尖变化不大,说明子级根在母级根上分布均匀，能够充分高效地吸收土壤资源。4)母级根对子级根的基径拟合线性方程斜率，一级根最小，二级根和三级根的斜率相差不大，说明一级根优先发育自身直径,达到锚固和支撑的作用，二、三级根则会优先发育子级根,通过不断增强子级根以达到高效占领土壤空间的目的。5)基径对长度的拟合线性方程斜率随着根系等级增加而增加，说明高级别根系会倾向于发展根系长度来达到探索资源、拓展空间的目的。

Taking the root systems of two 30-plus-year-old *Populus tomentosa* and one *Robinia pseudoacacia* as research subjects, and adopting the developmental grading standard proposed by Rose as the root classification criterion, this study analyzed the morphological characteristics of roots at different grades and the topological relationships between roots. The results showed that: 1) All three root systems exhibited dichotomous branching; 2) All three root systems could branch up to 7–8 root grades. The basal diameter and length of first-grade roots were significantly higher than those of subsequent grades: the basal diameter of first-grade roots was 5.79–36.92 times that of subsequent grades, and their length was 1.45–9.11 times that of subsequent grades. The number of roots first increased and then decreased with increasing root grade, reaching the maximum at the third-grade roots. 3) In the first three root grades, the connected length of each grade changed slightly from the basal root to the root tip, indicating that secondary roots were evenly distributed on the mother roots, enabling sufficient and efficient absorption of soil resources. 4) Regarding the slope of the linear fitting equation for the basal diameter of mother roots versus their secondary roots, first-grade roots had the smallest slope, while the slopes of second- and third-grade roots were relatively similar. This suggests that first-grade roots prioritize developing their own diameter to achieve anchorage and support, whereas second- and third-grade roots prioritize developing their secondary roots, continuously enhancing the latter to efficiently occupy soil space. 5) The slope of the linear fitting equation of basal diameter versus root length increased with increasing root grade, indicating that higher-grade roots tend to develop greater root length to explore resources and expand their spatial distribution.

搜集汇总

背景与挑战

背景概述

该数据集聚焦于砂壤土环境下成熟林木的根系构型，以毛白杨和刺槐为研究对象，采用根系发育分级标准，系统分析了不同等级根系的形态特征与拓扑关系。研究揭示了根系分支结构、等级间尺寸差异及资源吸收策略等关键规律。