伊犁河谷不同生境苦豆子根系生态化学计量特征及其与土壤理化因子的关系

Stoichiometric characteristics of Sophora alopecuroides roots in different habitats of Yili River Valley and their relationship with soil physicochemical factors

苦豆子(Sophora alopecuroides)为中旱生且耐盐碱,多生长于荒漠、半荒漠地带中的植物,属于新疆伊犁河谷山地草原典型毒害草之一,其强大的根系是吸收土壤养分的重要器官。本研究以伊犁河谷4种不同生境(林下、荒地、路边、农田)的苦豆子根系及其根际土壤为对象,分析苦豆子根系的化学计量学特征,结合冗余分析探讨苦豆子根系化学计量特征与土壤理化因子的关系。结果表明:伊犁河谷苦豆子根系C、N、P含量均值分别为422.99、10.06、1.16 g·kg-1,苦豆子根系C、N、P中变异系数最大的是N(0.25),变异系数最小的是P(0.17);C/N值为9.93,C/P值为10.54,N/P值为1.06;通过冗余分析得出,不同生境土壤理化因子对苦豆子化学计量特征的重要性排序为:林地生境的重要性排序为速效钾>硝态氮>全碳>速效磷>有机质>全磷>pH>全钾>全氮>铵态氮;路边生境的排序为铵态氮>pH>全磷>速效钾>全钾>有机质>全碳>速效磷>全氮>硝态氮;荒地生境的排序为有机质>pH>速效钾>硝态氮>速效磷>全磷>全碳>全钾>全氮>铵态氮;农田生境的排序为有机质>硝态氮>全氮>pH>速效钾>全碳>速效磷>全钾>铵态氮>全磷。研究结果为伊犁山地草原毒害草的防治提供了依据。

Sophora alopecuroides is a mid-xerotrophic and salt-tolerant plant species that grows mostly in deserts and semi-desert areas.It is one of the typical poisonous grasses in the mountain grasslands of the Yili River Valley in Xinjiang.Root is the important organ for absorbing soil nutrients.In this study,we collected roots and rhizosphere soil of S.alopecuroides in four different habitats(forest,wasteland,roadside,and cropland) in the Yili River Valley to analyze their stoichiometric characteristics and the relationship between stoichiometric characteristics of S.alopecuroides roots and soil physicochemical factors by redundancy analysis.The results showed that the average root C,N,and P concentrations were 422.99,10.06,and 1.16 g·kg-1,respectively.Among those three elements,the coefficient of variation of N concentration was the largest(0.25),and that of P concentration was the smallest(0.17).The C/N ratio was 9.93,C/P ratio was 10.54,and N/P ratio was 1.06.We quantified the importance of soil physical and chemical factors to the stoichiometric characteristics of S.alopecuroides roots in different habitats by redundancy analysis.The importance of all the factors ranked as available potassium > nitrate > total carbon > available phosphorus > organic matter > total phosphorus > pH > total potassium > total nitrogen > ammonium in forest habitat;as ammonium > p H > total phosphorus > available potassium > total potassium > organic matter > total carbon > available phosphorus > total nitrogen >nitrate in roadside habitat;as organic matter > p H > available potassium > nitrate > available phosphorus > total phosphorus > total carbon > total potassium > total nitrogen > ammonium in uncultivated land;as organic matter > nitrate > total nitrogen > pH > available potassium > total carbon > available phosphorus > total potassium > ammonium > total phosphorus in cropland habitat.Our results provide a theoretical basis for controlling poisonous grasses in the Yili mountain grassland.