半干旱沙区3种优势固沙灌木生物量分配及其生态学意义  

Biomass allocation and its ecological significance of three dominant sand-fixing shrubs in the semi-arid desert area

作　　者：詹瑾 李玉霖 韩丹 杨红玲 Zhan Jin;Li Yulin;Han Dan;Yang Hongling(Naiman Desertification Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西北生态环境资源研究院奈曼沙漠化研究站,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《中国沙漠》2020年第5期149-157,共9页Journal of Desert Research

基　　金：内蒙古自治区科技计划项目(201601052);国家重点研发计划项目(2016YFC0500907)。

摘　　要：为探究科尔沁沙地3种优势固沙灌木生物量的分配特征,以黄柳(Salix gordejevii)、差不嘎蒿(Artemisia halodendron)和小叶锦鸡儿(Caragana microphylla)为对象,采用全挖法在个体水平上研究了固沙灌木生物量构件及其占比、R/S(root-shoot ratio)、地上新生生物量占比、地上新生生物量与老枝生物量占比及其与冠幅的相关性和地下-地上生物量关系。结果表明:(1)科尔沁沙地3种优势固沙灌木生物量构件及其占比存在显著性的种间差异(P<0.05);黄柳的老枝生物量及其占比居于首位,NAB(new aboveground biomass,新枝生物量)/OBA(old branch biomass,老枝生物量)为43.90%;差不嘎蒿的地上生物量占比居于首位,地上新生生物量是老枝生物量的2.43倍;黄柳和差不嘎蒿地下生物量集中分布在浅土层,不存在深根系(根系长度>100 cm)。(2)小叶锦鸡儿地下生物量及其占比和R/S(root/stem)均居于首位;地下生物量在根系长度>30 cm处的生物量占比达到61.61%,深根系(根系长度>100 cm)层地上生物量占比达到22.33%。(3)黄柳和差不嘎蒿的R/S、NAB/AGB(aboveground biomass,地上生物量)和NAB/OBA均与冠幅呈负线性关系,在固沙后期该两种灌木随着冠幅的增大,地上新生部分锐减,生产力下降,植被出现衰退。(4)通过非线性回归拟合得到3种灌木地上(y)-地下(x)生物量异速生长模型为:黄柳y=2.928x1.039(R2=0.901,P<0.01),差不嘎蒿y=32.802x0.685(R2=0.469,P<0.01),小叶锦鸡儿y=1.337x0.066(R2=0.833,P<0.01)。In order to explored the biomass allocation patterns of three dominant sand-fixing shrubs in Horqin Sandy Land,we investigated the biomass components and their proportions,R/S,proportions of above-ground new biomass,aboveground new biomass and old branch biomass ratio,and their correlation with crown width and the relationship between underground and above-ground biomass of Salix gordejevii,Artemisia halodendron and Caragana microphylla on the individual level.The results showed that:(1)The biomass and proportion of three dominant sand-fixing shrubs in Horqin Sandy Land were significantly different(P<0.05),the size and pro‐portion of old branch biomass were the first and the NAB/OBA values were 43.90%about Salix gordejevii;the proportion of above-ground biomass were the largest and the new above-ground biomass was 2.43 times that of old branch biomass about A.halodendron;the Underground biomass were concentrated in shallow soil and there were no deep root system(root length>100 cm)of S.gordejevii and A.halodendron.(2)The size of underground biomass and its proportion,R/S were in the first place about C.microphylla;the underground biomass was main‐ly distributed in the root length>30 cm layer,the proportion of the amount reached 61.61%,and the layer of deep roots(root length>100 cm)accounted for 22.33%of the total biomass.(3)The R/S,NAB/AGB and NAB/OBA of S.gordejevii and A.halodendron showed a negative linear relationship with the crown width;In the late stage of sand fixation,the above-ground new part of S.gordejevii and A.halodendron would decrease with the in‐crease of crown width,productivity would decrease,and vegetations would decline.(4)The allogeneic growth models of aboveground and underground biomass of three shrubs were obtained by nonlinear regression fitting:Salix gordejevii y=2.928x1.039(R2=0.901,P<0.01)A.halodendron y=32.802x0.685(R2=0.469,P<0.01),C.micro‐phylla y=1.337x0.066(R2=0.833,P<0.01).

关 键 词：生物量分配 灌木 科尔沁沙地 

分 类 号：Q948.1[生物学—植物学]