| 摘要: |
| 【目的】探讨青海大通河流域5种类型青杄林土壤理化性质和生态化学计量特征的变化规律，为该林区不同青杄林分质量评价、养分管理和混交树种的选择提供理论依据。【方法】选择以中龄（平均林龄57 a）为主的青杄纯林、青杄×山杨林、青杄×白桦林、青杄×红桦林和青杄×油松林，在不同类型林地内各设置3块20 m×20 m的样地，每块样地以“S”形选取5个采样点，采集0～20和20～40 cm土层土壤样品，测定土壤含水率、体积质量、pH及有机碳、全氮、全磷含量，计算土壤C/N、C/P和N/P，比较不同林型间土壤理化性质及其生态化学计量特征的差异，并分析其相关性。【结果】① 青杄针阔混交林（青杄×山杨林、青杄×白桦林、青杄×红桦林）的土壤含水率、有机碳、全氮和全磷含量均高于青杄纯林和青杄针叶混交林（青杄×油松林），其中土壤有机碳和全氮含量差异达显著水平(P<0.05)；土壤体积质量表现为青杄纯林和青杄针叶混交林高于青杄针阔混交林；5种类型青杄林土壤pH值介于7.88～8.41，青杄×红桦林和青杄×白桦林的土壤pH值显著小于其他类型青杄林（P＜0.05）；5种类型青杄林0～20 cm土层土壤含水率及有机碳、全氮和全磷含量均高于20～40 cm土层，但20～40 cm土层土壤体积质量高于0~20 cm土层土壤。② 青杄针阔混交林的C/N、C/P和N/P均显著高于青杄纯林；2个土层均以青杄纯林土壤C/N和C/P最小，青杄×油松林的土壤N/P最小。③ 相关性分析结果表明，土壤pH与全氮和全磷含量呈极显著负相关，与有机碳含量呈显著负相关；土壤含水率与有机碳含量呈极显著正相关，与全氮和全磷含量呈显著正相关；土壤体积质量与有机碳含量呈显著负相关；土壤有机碳、全氮和全磷含量之间均极显著正相关。土壤全氮含量与C/P、有机碳含量与N/P均呈极显著正相关。【结论】在青海大通河流域，与青杄纯林和青杄针叶混交林相比，青杄针阔混交林明显提高了林分土壤养分含量，其中对表层（0~20 cm）土壤养分含量的增加效果更加显著，有助于改善土壤质量。 |
| 关键词: 青杄林；林分类型；土壤养分；生态化学计量 大通河流域 |
| DOI：DOI:10.13207/j.cnki.jnwafu.2024.10.009 |
| 分类号: |
| 基金项目:2021年青海省财政林业改革发展资金新技术推广项目“青海大通河流域青杄林群落研究”（K4050422134） |
|
| Ecological stoichiometric characteristics of different types of Picea wilsonii forests in Datong River Basin of Qinghai |
|
QI Haiyu1, FU Zhenjie1, ZHAO Changhong2, ZHANG Yuhai2, LIU Guiying3, WANG Dexiang1
|
|
1.College of Forestry,Northwest A&F University,Yangling,Shaanxi 712100,China;2.Beishan Forest Farm of Huzhu Tu Autonomous County in Qinghai Province,Haidong,Qinghai 810599,China;3.Research Institute of Forestry Science of Xining,Xining,Qinghai 810010,China
|
| Abstract: |
| 【Objective】The changes of soil physicochemical properties and stoichiometric characteristics in five Picea wilsonii forests were explored in Datong River Basin of Qinghai to provide scientific basis for quality evaluation, nutrient management and mixed tree species selection.【Method】Three sample plots (20 m×20 m) were set up in each stand of middle-aged (57 years in average) pure P. wilsonii forest,P. wilsonii×Populus davidiana mixed forest,P. wilsonii×Betula platyphylla mixed forest,P. wilsonii×Betula albosinensis mixed forest and P. wilsonii×Pinus tabuliformis mixed forest.Five sampling points in an ‘S’ shape were selected for each sample plot to collect soil samples from layers of 0-20 cm and 20-40 cm.Soil moisture content (SMC),bulk density (SBD),soil pH and contents of soil organic carbon (SOC),total nitrogen (TN) and total phosphorus (TP) were measured,and soil C/N,C/P and N/P were calculated.The differences in soil physico chemical properties and their ecological stoichiometric characteristics among different forest types were compared,and the correlations between soil physicochemical properties were analyzed.【Result】① SMC,SOC,TN and TP contents of P. wilsonii coniferous broad-leaved mixed forests (P. wilsonii×P. davidiana mixed forest,P. wilsonii×B. platyphylla mixed forest and P. wilsonii×B. albosinensis mixed forest) were higher than those of pure P. wilsonii forest and P. wilsonii coniferous mixed forest (P. wilsonii×P. tabuliformis mixed forest),and SOC and TN contents of P. wilsonii coniferous broad-leaved mixed forests were signifi-cantly higher than those of pure P. wilsonii forest and P. wilsonii coniferous mixed forest. SBD contents of pure P. wilsonii forest and P. wilsonii coniferous mixed forest were higher than those of P. wilsonii coniferous broad-leaved mixed forests.Soil pH values of the five types of P. wilsonii forests ranged from 7.88 to 8.41,and soil pH values of P. wilsonii×B. albosinensis mixed forest and P. wilsonii×B. platyphylla mixed forest were significantly lower than those of other types.SMC,SOC,TN and TP contents of the 0-20 cm soil layer were higher than those of the 20-40 cm soil layer,while SBD contents of the 20-40 cm soil layer were higher than those of the surface layer.② C/N,C/P and N/P ratios of P. wilsonii coniferous broad-leaved mixed forests were significantly higher than those of pure P. wilsonii forest.Both soil layers showed that the pure P. wilsonii forest had the lowest C/N and C/P values,while the P. wilsonii×Pinus tabuliformis mixed forest had the lowest N/P value.③ Soil pH had highly significant negative correlations with TN and TP contents and a significant negative correlation with SOC content.There was a highly significant positive correlation between SMC and SOC and a significant positive correlation with TN and TP.There was a significant negative correlation be-tween SBD and SOC.There were highly significant positive correlations among SOC,TN and TP contents.There were highly significant positive correlations between TN and C/P and between SOC and N/P.【Conclusion】In Datong River Basin of Qinghai,compared to pure P. wilsonii forest and P. wilsonii coniferous mixed forest,P. wilsonii coniferous broad-leaved mixed forests significantly increased soil nutrient contents with larger effect on surface soil layer (0-20 cm) and improved soil quality. |
| Key words: Picea wilsonii forest stand type soil nutrient ecological stoichiometry Datong River Basin |
