干旱沙区土壤结皮发育对草本植物土壤种子库的影响  

Influences of soil crust development on soil seed bank of herbaceous plants in arid desert area

作　　者：陶海璇 郭春秀[1] 马俊梅[1] 王忠文[1] 赵赫然 宋达成 何芳兰[1] Haixuan Tao;Chunxiu Guo;Junmei Ma;Zhongwen Wang;Heran Zhao;Dacheng Song;Fanglan He(Gansu Hexi Corridor Forest Ecosystem National Research Station,Gansu Desert Control Research Institute,Lanzhou 730070,China;Minqin County Forestry Technology Extension Station,Minqin 733399,Gansu,China)

机构地区：[1]甘肃省治沙研究所甘肃河西走廊森林生态系统国家定位研究站,甘肃兰州730070 [2]民勤县林业技术推广站,甘肃民勤733399

出　　处：《中国沙漠》2023年第4期89-97,共9页Journal of Desert Research

基　　金：国家自然科学基金项目(31860175);中央财政林业科技推广示范项目(2019ZYTG07);甘肃省基础研究创新群体项目(20JR5RA098)。

摘　　要：为了探讨干旱沙区土壤结皮发育对草本植物土壤种子库的影响,以巴丹吉林沙漠南缘已发育土壤结皮的区域为场所,通过野外调查与土培萌发的方法,对土壤结皮不同发育阶段的地表特征及草本植物土壤种子库特性进行了研究。结果表明:(1)结皮前期向藓类结皮的演替导致地表微形态、结皮层厚度均出现明显的变化,并在不同发育阶段间呈现出一定的差异性(P<0.05)。(2)随着土壤结皮不断演替,种子库中沙生物种逐渐退出、旱生物种陆续出现,优势种演变为画眉草(Eragrostis pilosa)、雾冰藜(Bassia dasyphylla)→画眉草、雾冰藜、盐生草(Halogeton glomeratu)→画眉草、盐生草→画眉草。(3)在土壤结皮整个演替过程中,种子库密度、物种多样性指数均出现了先增大后减小的变化趋势(峰值在藻类-地衣结皮阶段),地衣-藓类结皮阶段(或更高)各指标值均显著小于结皮前期(P<0.05);同时,种子库水平分布逐渐均匀化、垂直分布趋于结皮层,种子库与地上植被物种相似性明显降低。因此认为,土壤结皮发育不仅通过增强地表稳定性、改变地表微形态影响种子库的空间分布,还通过改变土壤生境条件影响地上植被对种子库的贡献能力。Soil seed bank refers to the sum of all active seeds existing in the litter of soil surface and soil,supplying an important seed source for potential regeneration of aboveground vegetation.In order to explore the effects of soil crust development on the characteristics of herbaceous soil seed bank in arid desert area,the test sites were deployed on the southern margin of Badain Jaran Desert,where the surface morphologies of soil crusts at different development stages and characteristics of herbaceous soil seed bank were studied by field investigation and seed germination.The results showed that:(1)the succession from no crust stage to moss crust stage leaded to significant changes in the micromorphologies and thickness of soil crusts per unit area,of which obvious differences among development stages were observed(P<0.05).(2)With the continuous succession of soil crusts,some psammophytes in the seed bank withdrew gradually,while obvious increases in xerophyte species.At the same time,the successional processes of dominant species were as follows:Eragrostis pilosa and Bassia dasyphylla→E.pilosa,B.dasyphylla and Halogeton glomeratu→E.pilosa and H.glomeratu→E.pilosa.(3)In the whole succession process of soil crusts,the densities and species diversity indexes of soil seed bank showed unanimous trends of increasing first and then decreasing(the peak value was in the algae-lichen crust stage),which in lichen moss stage or higher stage were significantly lower than those in the no crust stage(P<0.05).Meanwhile,the distribution of soil seed bank in horizontal direction gradually became homogenization,and its vertical distribution tended to centralization in soil crust layer;besides,the species similarity between seed bank and aboveground vegetation decreased significantly.Therefore,the formation and progressive succession of soil crusts not only influenced the spatial distribution of soil seed bank by enhancing stability and changing micromorphology of soil surface,but also affected the contribution ability of abov

关 键 词：土壤结皮 土壤种子库 空间分布 物种多样性 演替 

分 类 号：S330.3[农业科学—作物遗传育种]