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草业学报 ›› 2023, Vol. 32 ›› Issue (6): 45-57.DOI: 10.11686/cyxb2022356

• 研究论文 • 上一篇    下一篇

藏沙蒿与多年生禾草混播对西藏沙化草地植被及土壤真菌群落特征的影响

刘欢1(), 董凯1, 仁增旺堆2, 王敬龙2, 刘云飞2, 赵桂琴1   

  1. 1.甘肃农业大学草业学院,草业生态系统教育部重点实验室,甘肃 兰州 730070
    2.西藏自治区农牧科学院草业科学研究所,西藏 拉萨 850000
  • 收稿日期:2022-09-01 修回日期:2022-10-19 出版日期:2023-06-20 发布日期:2023-04-21
  • 通讯作者: 刘欢
  • 作者简介:刘欢(1982-),女,山东招远人,副教授,博士。E-mail: liuhuan@gsau.edu.cn
  • 基金资助:
    西藏自治区重点研发及转化计划-西藏藏沙蒿和大籽蒿资源评价与应用技术研究(XZ201902NB01);西藏自治区科技计划项目(XZ202201ZY0014N);甘肃省自然科学基金(21JR7RA824);草业生态系统教育部重点实验室开放课题(KLGE-2022-16)

Effects of co-sowing of Artemisia wellbyi and perennial grasses on the characteristics of vegetation and soil fungal communities in desertified grasslands in Tibet

Huan LIU1(), Kai DONG1, Zeng-wangdui REN2, Jing-long WANG2, Yun-fei LIU2, Gui-qin ZHAO1   

  1. 1.Pratacultural College,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem,Ministry of Education,Lanzhou 730070,China
    2.Institute of Pratacultural Science,Tibet Academy of Agriculture and Animal Husbandry Sciences,Lhasa 850000,China
  • Received:2022-09-01 Revised:2022-10-19 Online:2023-06-20 Published:2023-04-21
  • Contact: Huan LIU

摘要:

为了明确青藏高原沙化草地的最佳混播修复草种比例及修复过程中的植被-土壤生态环境效应,本研究在西藏沙化草地构建人工修复试验小区,设置了西藏原生种质藏沙蒿及多年生垂穗披碱草和细茎冰草不同比例混播处理,分别为AG1(4︰1︰2),AG2(4︰2︰1),AG3(5︰1︰1),以未修复沙化裸地为对照(CK),同时以原位条件下天然草地(NG)做比较。种植试验开展3年后,测定植被生物量、土壤理化性质指标,同时采用ITS测序技术和FUNGuild功能预测的方法,研究土壤真菌的群落结构及功能的变化规律。结果表明: 1)与未修复沙化土地相比,混播修复3年的各处理可使地上生物量(AGB)和地下生物量(BGB)提高3倍以上,并显著增加土壤含水量(WC)、有机质(OM)、碱解氮(AN)、有效磷(AP)和速效钾(AK)含量 (P<0.05)。2)AG3处理下土壤真菌多样性最高,真菌群落结构与天然草地最相似。3)各沙化修复处理与NG间土壤中的担子菌门和被孢霉门存在显著差异(P<0.05)。冗余分析结果显示,BGB、AN、AP和pH是影响土壤真菌门水平群落结构的主要环境因子,担子菌门的相对丰度与BGB和pH呈正相关,被孢霉门的相对丰度与BGB、AN和AP呈正相关。4)基于FUNGuild功能预测,所有土壤样品中检测出腐生、病理和共生3类营养型和5类交叉营养型功能菌群,其中病理型、腐生型、病理-腐生型、病理-腐生-共生型和共生型为主要的营养型。由此可见,藏沙蒿与多年生禾草垂穗披碱草和细茎冰草混播有提高沙化草地植物生物量的作用,三者按5︰1︰1混播的修复土壤效果最优,可以有效改善土壤养分和真菌丰富度,从而改变土壤真菌群落结构和功能。

关键词: 生态修复, 土壤养分, 土壤真菌群落, 高通量测序

Abstract:

The aim of this study was to determine the optimal proportion of plant species when using mixed-sowing for restoration of desertified grasslands on the Tibetan plateau and for improving the ecological effects of vegetation and soil during restoration. Artificial restoration experimental plots were established in the sandy grasslands of Tibet for this study. Seeds of the native Tibetan species Artemisia wellbyi and the perennial grass species Elymus nutans and Agropyron trachycaulhum were mixed at different proportions [AG1 (4∶1∶2), AG2 (4∶2∶1) and AG3 (5∶1∶1)] and sown at the experimental plots. The controls were unrestored sandy bare ground as the desertified control (CK) and natural grassland (NG) under in situ conditions. Three years after establishing these plots, the vegetation biomass and soil physical and chemical indexes were determined, and ITS sequencing technology and FUNGuild function prediction methods were used to characterize the community structure and functions of soil fungi. The main findings can be summarized as follows: 1) Compared with the control (unrestored sandy land), the restoration treatments increased the above-ground plant biomass (AGB) and below-ground biomass (BGB) by more than three times, and significantly increased soil water content (WC), and the contents of organic matter (OM), alkali-hydrolyzale nitrogen (AN), available phosphorus (AP), and available potassium (AK) in soil (P<0.05). 2) The soil fungal community structure and diversity varied among the three replanting treatments. The AG3 treatment had the highest soil fungal diversity and its fungal community structure was most similar to that of natural grassland. 3) There were significant differences in the abundance of Basidiomycota and Mortierellomycota in soil between the restoration treatments and natural grassland (P<0.05). The results of a redundancy analysis showed that BGB, AN, AP and pH were the main environmental factors affecting the horizontal community structure of the soil fungal phyla. The relative abundance of Basidiomycota was positively correlated with BGB and pH, and the relative abundance of Mortierellomycota was positively correlated with BGB, AN, and AP. 4) Based on FUNGuild functional predictions, three trophic functional groups (saprophytic, pathogenic, and symbiotic fungi) and five cross-trophic functional groups were detected in all soil samples. Pathogenic, saprophytic, pathogenic-saprophytic, pathogenic-saprophytic, and symbiotic trophic types were dominant. These results show that replanting with A. wellbyi and the perennial grasses E. nutans and A. trachycaulhum can increase plant biomass and restore desertified soil. Under these conditions, the restoration treatment with the best effect on soil nutrients and fungal abundance was sowing with a 5∶1∶1 mixture of A. wellbyi, E. nutans, and A. trachycaulhum seeds.

Key words: ecological restoration, soil nutrients, soil fungal communities, high-throughput sequencing