红砂灌丛根系构型特征对沙堆土壤养分的响应机制  

Response of root configuration characteristics of Reaumuria songarica to soil nutrients

作　　者：贾相岳 朱丽[2] 侯红蕊 左轶璆[2] JIA Xiangyue;ZHU Li;HOU Hongrui;ZUO Yiqiu(College of Food and Environment,Jinzhong College of Information,Jinzhong,Shanxi 030800,China;Department of Resource and Environment,Baotou Teachers’College,Baotou,Inner Mongolia 014030,China)

机构地区：[1]晋中信息学院食品与环境学院,山西晋中030800 [2]包头师范学院资源与环境学院,内蒙古包头014030

出　　处：《西北农林科技大学学报（自然科学版）》2024年第11期113-120,共8页Journal of Northwest A&F University(Natural Science Edition)

基　　金：山东省自然科学基金项目“用于预测污染土壤中铬人体生物有效性的模型构建与应用”(ZR2018BB073)。

摘　　要：【目的】探究胁迫环境下红沙灌丛根系构型特征以及其与土壤养分的耦合关系,以期明晰植物为适应环境而进行的根系动态生长策略。【方法】以白音恩格尔自然保护区的红纱(Reaumuria songarica)灌丛为研究对象,测量其根径、分支率并计算拓扑指数,采集土壤测定其养分含量并计算相对作用强度(RII),采用冗余分析(RDA)揭示根系构型特征对沙堆土壤养分的响应机制。【结果】(1)白音恩格尔自然保护区的红砂灌丛根系生长平均深度可达68.63 cm,水平分布范围均值可达99.97 cm,根系以水平分布根为主。研究区的红砂灌丛根系分支一般分为4级,根系次级分支较多,分支结构复杂,更接近叉状分支结构。(2)红砂灌丛覆盖地表改变了区域土壤养分空间分布状况,灌丛沙堆内部养分含量高于无植被覆盖的丘间空地,形成“肥岛效应”,其中0~20 cm土层土壤有机碳(SOC)和全磷(TP)的含量高于20~30 cm土层,但未表现出显著差异(P>0.05);全氮(TN)与土层深度呈正相关,并随土层深度增加而显著提高(P<0.05)。(3)土壤养分化学计量比(C/N、C/P、N/P)与根系构型拓扑参数(TI、q_(b)、q_(a))表现为正相关,其中C/P、N/P与拓扑参数的线段夹角最小,说明相关性更强。总分支率(R_(b))、TN、TP与以上参数呈负相关,其中R_(b)与TN相关性较强。【结论】红砂灌丛形成了“肥岛效应”,沙堆土壤中的C/P、N/P对根系构型有较强影响。【Objective】 The characteristics of root architecture and the coupling relationship with soil nutrients under stress environment were investigated to clarify the dynamic root growth strategies of plants to adapt to the environment.【Method】 Reaumuria songarica in the Baiyin Engel Nature Reserve was selected to measure root diameter and branching rate,and calculate the topological index.Soil samples were also collected to measure nutrients and calculate RII parameters.Then,RDA analysis was used to reveal the response mechanism of root configuration characteristics to soil nutrients in sand piles.【Result】(1) The average depth of root growth in Reaumuria songarica in the Baiyin Engel Nature Reserve reached 68.63 cm,and average horizontal distribution range was 99.97 cm.The root system was mainly horizontally distributed.Reaumuria songarica had 4 levels of roots,with many secondary branches and a complex branch structure that was closer to a forked branch structure.(2) The coverage of Reaumuria songarica on the surface changed the spatial distribution of soil nutrients in the region,and the nutrients inside were higher than those in vacant land between hills,forming “fertilizer island effects”.Contents of SOC and TP in the 0-20 cm soil layer were higher than those in the 20-30 cm soil layer without significant difference(P>0.05).TN was positively correlated with soil depth and it increased significantly with the increase of soil depth(P<0.05).(3) C/N,C/P,q_(b),N/P,q_(a),and TI showed positive correlations,and C/P and N/P had the smallest angle with topological parameters,indicating stronger correlations.R_b,TN and TP had negative correlations with above parameters,with a strong correlation between R_(b) and TN.【Conclusion】 The Reaumuria songarica formed “fertilizer island effects” and soil C/P and N/P had strong impacts on root system configuration.

关 键 词：红砂灌丛 根系构型 土壤养分 白音恩格尔 

分 类 号：Q948.1[生物学—植物学]