海拔、坡向对川西高山灌丛草甸土壤氮、磷分布的影响  

Effects of elevation and slope aspect on soil nitrogen and phosphorus distribution of western Sichuan Plateau shrub meadow

作　　者：车明轩 吴强 方浩 康成芳 吕宸[1] 许蔓菁 宫渊波[1] CHE Mingxuan;WU Qiang;FANG Hao;KANG Chengfang;Lü Chen;XU Manjing;GONG Yuanbo(College of Forest,Sichuan Agricultural University,Chengdu 611130,China;Water Management Station of Luzhou Water Authority,Luzhou 646000,China;Jiange Management Station of Water Conservancy Project Construction,Guangyuan 628300,China;Gansu Appraisal Center for Eco-Environment&Engineering,Lanzhou 730000,China)

机构地区：[1]四川农业大学林学院,成都611130 [2]泸州市水务局水利管理站,泸州646000 [3]剑阁县水利工程建设管理总站,广元628300 [4]甘肃省生态环境工程评估中心,兰州730000

出　　处：《应用与环境生物学报》2021年第5期1163-1169,共7页Chinese Journal of Applied and Environmental Biology

基　　金：四川省科技厅重点课题(2015FZ0022);四川省高校重点实验室建设项目资助。

摘　　要：土壤氮(N)、磷(P)是植被生长、发育过程中最重要的养分元素,对生态系统的稳定和植被资源利用的可持续发展有重要意义.为了解川西高山灌丛草甸土壤氮、磷组分的分布状况,对3个海拔梯度(3800 m、4000 m、4200 m)和两个坡向(半阴坡和半阳坡)下的土壤氮、磷组分及土壤理化性质进行研究.结果表明:研究区土壤全氮含量(2.04±0.92 g/kg)较为丰富且高于全国水平,而全磷含量(0.43±0.12 g/kg)则较为缺乏且低于全国水平.与相似植被类型和环境的高山灌丛草甸土相比,较高的氮磷比(N/P,4.85±1.97)可能说明磷是研究区内植被生产力的主要限制因子.随海拔升高,土壤含水量的增加和温度的降低有利于土壤有机质的积累,土壤全氮和全磷含量均呈现出增加的趋势.相关分析表明,土壤铵态氮(4.86±1.65 mg/kg)、硝态氮(2.19±1.78 mg/kg)和有效磷(3.18±1.75 mg/kg)与土壤含水量均呈正相关,而与土壤pH均呈负相关.高海拔的硝态氮和有效磷含量显著高于低海拔,而土壤铵态氮在海拔间差异不显著,可能与温度、pH的分布有关.坡向显著改变了土壤水分和pH的分布,半阴坡土壤含有较高的土壤水分和较低的土壤pH,也含有更高的土壤矿质氮和有效磷含量,而土壤全氮和全磷在坡向间差异不显著.本研究表明川西高山灌丛草甸土壤氮、磷组分含量大体呈现出高海拔高于低海拔,阴坡的矿质氮和有效磷高于阳坡的规律;结果对今后高山灌丛草甸氮、磷养分的循环与调控研究提供一定的科学数据与理论依据.Soil nitrogen(N)and phosphorus(P)are the most important nutrient elements for vegetation growth and development,and are also of great significance to ecosystem stability and the sustainable development of vegetation resource utilization.To understand the distribution of soil N and P in the shrub-meadow soil in western Sichuan Plateau,China,soil N and P fractions,as well as soil physiochemical properties,were investigated at three elevations(3800 m,4000 m,and 4200 m)and two slope aspects(semi-sunny and semi-shady).The results showed that in the study area,the total nitrogen(TN)content(2.04±0.92 g/kg)was relatively rich whereas the total phosphorus(TP)content(0.43±0.12 g/kg)was relatively deficient in comparison with the national level.Compared with the alpine shrub-meadow soils with similar vegetation types and environments,the higher N/P ratio(4.85±1.97)in our study indicates that P was the main limiting factor for vegetation productivity.With increasing elevation,the increase in soil water content and the decrease in temperature were conducive to soil organic carbon(SOC)accumulation.Both TN and TP tended to increase with increasing elevation.Correlation analysis showed that ammonium nitrogen(NH_(4)^(+)-N;4.86±1.65 mg/kg),nitrate nitrogen(NO_(3)^(-)-N;2.19±1.78 mg/kg),and available phosphorus(AP;3.18±1.75 mg/kg)were positively correlated with soil water content,but negatively correlated with soil pH.The content of NO3--N and AP at high elevation was significantly higher than that at low elevation,while there were no significant differences in NH_(4)^(+)-N among elevation gradients,which may be related to the distribution of temperature and pH.The slope aspect significantly affected the distribution of soil water content and pH.The soil in the NE slope aspect contained higher soil water content and lower soil pH than the SW slope aspect,and also contained higher mineral nitrogen and available phosphorus contents,while the difference between TN and TP was not significant.Our results showed that the contents o

关 键 词：灌丛草甸土 海拔 坡向 氮 磷 空间分布 

分 类 号：S812.2[农业科学—草业科学]