三种典型山地河岸林土壤氮含量时空格局对高地氮输入的响应  

Spatial-Temporal Responses of Soil Nitrogen in Three Typical Mountain Riparian Forests to Upland Nitrogen Input

作　　者：杨三红[1,2] 张芸香 郭晋平[1,2] YANG Sanhong;ZHANG Yunxiang;GUO Jinping(Forestry College,Shanxi Agricultural University,Taigu 030801,Shanxi,China;Shanxi Key Laboratory of Functional Oil Tree Cultivation and Research,Taigu 030801,Shanxi,China)

机构地区：[1]山西农业大学林学院,山西太谷030801 [2]功能油料树种培育与利用山西省重点实验室,山西太谷030801

出　　处：《山地学报》2022年第5期648-660,共13页Mountain Research

基　　金：国家自然科学基金(30970480)。

摘　　要：河岸林土壤和植被对高地养分的滤除功能是河岸带生态保护与恢复的基础。揭示特定河岸林土壤氮含量的时空格局对高地氮输入的响应,有助于加深对河岸林氮滤除过程和机制的认识。目前对高地氮输入下山地河岸林土壤对氮的削减作用及林型差异、距离梯度格局及其变化的规律尚不确切。本文以文峪河上游云杉、华北落叶松和杨桦三种典型山地河岸林土壤为研究对象,采用原位土壤实验槽并模拟高地氮输入的方法,分析土壤全氮、硝态氮和铵态氮含量在土层深度、距离上的梯度格局及其随时间的变化,分析不同林型和输入量之间的差异。结果表明:(1)三种山地河岸林土壤在不同氮输入下,土壤全氮和铵态氮含量随时间升高而硝态氮降低,华北落叶松林土壤对氮的转化最明显;(2)河岸林土壤中全氮含量变化率阈值在5 m附近,而铵态氮和硝态氮含量变化率阈值分别在9 m和10 m附近;(3)土层深度对土壤全氮和硝态氮含量起决定作用,而氮输入量大小显著影响了土壤铵态氮含量。研究结果可为流域污染防控中的山地河岸林类型选择和河岸带宽度设计提供依据。The intercepting and stabilizing of upland nutrient by soil and vegetation in riparian forests is pivotal to ecological protection and restoration of riparian zones.Unfortunately,it was not quite clear about the interception behavior of soil and vegetation in riparian forests on upland nitrogen input in the varied forms,and their differences in filtration capacity due to distinct forest types or distance gradient of nutrient migration.In this paper,soils in three typical riparian forest(Larix gmelinii var.principis-rupprechtii,Picea meyeri-Picea willsonii and Populus davidiana-Betula platyphylla)located in the upper reaches of the Wenyu River were investigated.The gradient pattern of soil total nitrogen,nitrate nitrogen and ammonium nitrogen contents at soil depths and distances and their changes with time were analyzed by using an in-situ soil experiment tank and simulating the nitrogen input in the upland.The differences among different forest types and inputs were also analyzed.Here are results:(1)The conversion rate of soil nitrogen was the highest in Larix gmelinii var.principis-rupprechtii forest at different nitrogen input levels.Soil total nitrogen contents and ammonium nitrogen contents increased with time,while soil nitrate nitrogen contents decreased with time in three riparian forest types.(2)There were temporal and spatial variations of soil nitrogen conversion rate in three riparian forests with a clear turning point:The turning points of conversion rate of soil total nitrogen,ammonium nitrogen and nitrate nitrogen were nearly at 5 m,9 m and 10 m respectively.(3)The soil depth had decisive effect on soil total nitrogen and nitrate nitrogen contents,and the different levels of nitrogen input significantly influenced soil ammonium nitrogen contents.By this study,it reveals the spatial and temporal patterns of soil N content in specific riparian forests in response to upland N input,which deepens the understanding of the process and mechanism of nitrogen filtration in riparian forests,and it can provid

关 键 词：高地氮输入 土壤氮含量 时空响应 山地河岸林 文峪河流域 

分 类 号：S714.5[农业科学—林学]