土壤学报2017，Vol.54Issue(3)：682-692,11.DOI:10.11766/trxb201608170269
典型自然带土壤氮磷化学计量空间分异特征及其驱动因素研究
Study on Spatial Variability and Driving Factors of Stoichiometry of Nitrogen and Phosphorus in Soils of Typical Natural Zones of China
摘要
Abstract
[Objective]Nitrogen(N)and phosphorus(P)are two important nutrients and play important role in sustaining plant growth in natural ecosystems,and changes in structure and function of an ecosystem may reflect in stoichiometric characteristics of the elements in the soil. Natural zone,life form and elevation are major factors affecting soil nutrients in all climatic zones. Therefore,the study on stoichiometric characteristics on large spatial scales may help explore distribution characteristics of soil nutrients and driving factors of the evolution of soil nutrients,and provide important reference to studies to understand in depth global biogeochemical recycling of the soil nutrients and simulate regional responses to global change.[Method]From the literature available regarding soil stoichiometry in the subtropical evergreen broad-leaved forest zone(SEB),warm temperate deciduous broad-leaved forest zone(WTD),temperate steppe zone(TSZ),temperate desert zone(TDZ)and Qinghai-Tibet Plateau Alpine vegetation zones(QST), a total of 594 data of N and P contents in natural soils,0-20 cm in depth of various regions of the country and their stoichiometric analyses,covering a time span of 15 years were acquired using the aid of electronic search engines. Statistic analysis of the collected data were performed using methods of one-way analysis of variance(ANOVA),least significant difference(LSD),Spearman correlation coefficient analysis,and multivariate linear and non-linear autoregressive modeling(MAR),to explore distribution and variability of soil total nitrogen(TN)and total phosphorus(TP)and their stoichiometry in soil in relation to elevation, temperature and precipitationin the SEB,WTD,TSZ,TDZ and QST.[Result]Results show that soil TN and N/P varied significantly from natural zone to natural zone,but soil TP did not as much. The average TN content was 2.35 mg g-1,1.13 mg g-1,1.07 mg g-1,3.59 mg g-1,and 5.66 mg g-1;the average TP content 0.80 mg g-1,0.82 mg g-1,0.75 mg g-1,0.47 mg g-1,and 0.75 mg g-1;and the average N/P 4.04,2.26, 2.49,6.71,and 7.73 in the SEB,WTD,TSZ,TDZ and QST,respectively. In all the five zones,TN, TP and N/P varied with elevation,displaying a non-linear secondary relationship,and a single peak pattern. However,in the SEB and TSZ soil TN was mainly affected by temperature and elevation,and the impact of elevation was more significant in the TSZ. In the TDZ soil TN was influenced by elevation and precipitation. However,in the WTD and QST,soil TN was not so much affected by the three factors. In the SEB,soil TP was jointly affected by the three natural factors,which,however,followed a declining order of precipitation> temperature > elevation in extent,and in the WTD and TDZ and QST soil TP was mainly affected by elevation,while in the TSZ,precipitation was the dominant factor that affects soil TP. Furthermore,in the SEB,soil N/Pwas more affected by by precipitation than by elevation,and in the TSZ,TDZ and QST it was affected jointly by all the three factors,temperature,precipitation and elevation,while in the TDZ, elevation was the key factor affecting soil N/P and in the TSZ,temperature and precipitation were,but differed in degree of the effect. [Conclusion]In different natural zones,the relationships of TN,TP and N/P in the soil with elevation,temperature and precipitation differ from natural zone to natural zone or from plant life form to plant life forms,which the impacts of elevation,temperature and precipitation on soil N, P and N/P vary with the natural zone or plant life form. Therefore,natural zone and plant life form are the important factors affecting spatial variability of soil nutrients,and elevation,temperature and precipitation are the driving factors of the variation of soil N and P. In the future,global warming may have significant effects on soil nutrients and the effects vary with elevation gradients. In areas low in elevation,increment of soil N/P may turn P into a major factor limiting growth of the plants,while in areas high in elevation,N may be the factor.关键词
自然带/植物生活型/海拔梯度/气候因子/主控因素Key words
Natural zone/Plant life form/Elevation gradient/Climatic factors/Dominant control factors分类
天文与地球科学引用本文复制引用
卢同平,张文翔,牛洁,林永静,武梦娟..典型自然带土壤氮磷化学计量空间分异特征及其驱动因素研究[J].土壤学报,2017,54(3):682-692,11.基金项目
国家自然科学基金项目(41461015)、云南省中青年学术技术带头人后备人才项目(2015HB029)和云南省水利厅项目(2014003)联合资助 Supported by the National Natural Science Fundation of China(No. 41461015),the Reserve Talents of Young and Middle-aged Academic Technology Leaders of Yunnan Province of China(No. 2015HB029),the Department of Water Resources of Yunnan Province of China(No. 2014003) （41461015）
