黄土高原蓝藻和藓类生物结皮对草本植物多样性及生物量的影响  

Effects of cyanobacteria and moss-dominated biocrusts on the diversity and biomass of herbaceous plants in the Loess Plateau

作　　者：王彦峰 肖波[2] 汪万福 余星兴 张雪 WANG Yanfeng;XIAO Bo;WANG Wanfu;YU Xingxing;ZHANG Xue(Key Laboratory of Desert and Desertification,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,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,沙漠与沙漠化重点实验室,兰州730000 [2]中国科学院水利部水土保持研究所,黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100 [3]中国科学院大学,北京100049

出　　处：《生态学报》2023年第16期6570-6580,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金面上项目(42077010);中国科学院“西部之光”人才培养引进计划(2019)。

摘　　要：生物结皮在干旱和半干旱气候区占据了广阔的生态位,深刻影响草本植物的空间格局,但其影响程度和作用途径目前仍存有争议。分别以黄土高原风沙土和黄绵土上的蓝藻结皮和藓结皮为对象,以无结皮为对照,通过样方法调查并测定了生物结皮与无结皮样地中草本植物的多样性和生物量,继而结合灰色关联分析和结构方程模型,对比分析了两类生物结皮对草本植物多样性和生物量的影响程度及作用途径。结果表明:(1)风沙土上,无结皮样地的优势科为禾本科和菊科,蓝藻结皮样地的优势科为藜科,藓结皮样地的优势科为禾本科,而黄绵土上无结皮样地的优势科为菊科、禾本科和豆科,蓝藻结皮样地的优势科与无结皮相似,藓结皮样地的优势科为禾本科和菊科;(2)与无结皮相比,风沙土上蓝藻结皮和藓结皮样地中多年生草本的株数分别增加了30%和16%,而黄绵土上两类生物结皮样地中多年生草本株数则分别增加了44%和减少了46%;(3)与无结皮相比,风沙土上蓝藻结皮和藓结皮样地中草本植物的Patrick和Shannon指数分别降低了1.0、0.2和3.4、0.5;而黄绵土上蓝藻结皮和藓结皮样地中两种多样性指数分别降低了4.8、0.2和4.2、0.4;(4)风沙土上蓝藻结皮和藓结皮样地的草本植物生物量比无结皮减少了111.5 g/m^(2)和145.0 g/m^(2),而在黄绵土上则分别减少了127.8 g/m^(2)和172.2 g/m^(2);⑤灰色关联分析显示,土壤穿透阻力对草本植物的多样性影响最大(关联系数分别为0.960和0.996),而NH_(4)^(+)-N和NO_(3)^(-)-N含量对草本植物的生物量影响最大(两种土壤上关联系数分别为0.727和0.752)。综上,黄土高原生物结皮显著降低了草本植物的多样性和生物量,其途径为通过增加土壤穿透阻力以降低草本植物的种子萌发几率并限制幼苗根系伸展,同时通过土壤氮竞争限制了草本植物生长。Biocrusts occupy wide and diverse ecological niches in arid and semi-arid climate regions,and thus they would dramatically affect the distribution pattern of herbaceous plants.However,the extent and pathways of their influences on the diversity and biomass of herbaceous plants are still in controversial.In a semiarid climate area on the Chinese Loess Plateau,we selected representative plots of uncrusted soil and cyanobacteria-and moss-dominated biocrusts,both on aeolian sand and loess soil,respectively.Then,the diversity of herbaceous plant community in each plot was investigated,and the total biomass was harvested and measured in laboratory.Based on the differences between the biocrusts and bare soil plots,the effects of biocrusts on herbaceous plant diversity and biomass were assessed,and the pathways of these influences were also analyzed using the gray relation analysis and structural equation model.Our results showed that(1)on aeolian sand,Gramineae and Compositae are the dominant herbaceous families in uncrusted plots,Chenopodiaceae is the dominant herbaceous family in cyanobacteria-dominated biocrusts plots,and Gramineae and Compositae are the dominant herbaceous families in moss-dominated biocrusts plots.Correspondingly,on the loess soil,uncrusted plots are dominanted by Compositae,Gramineae,and Leguminosae,which is the same as cyanobacteria-dominated biocrusts plots,and moss-dominated biocrusts plots are dominanted by Gramineae and Compositae.(2)As compared with the uncrusted soil,the cyanobacteria and moss-dominated biocrusts on aeolian sand increased the number of annual herbaceous species by 30%and 16%,respectively,and the number of perennial herbaceous species was increased by 44%by the cyanobacteria biocrusts but decreased by 46%by the moss biocrusts on the loess soil.(3)In comparison to the uncrusted soil,the cyanobacteria biocrusts on aeolian sand reduced the Patrick and Shannon diversity indices of herbaceous plants by 1.0 and 0.2,respectively,while the moss biocrusts on aeolian sand reduced thes

关 键 词：黄土高原 生物结皮 草本植物多样性 植物群落结构 生物量 

分 类 号：Q948.1[生物学—植物学]