增水对伊犁绢蒿荒漠草地土壤种子库种子萌发特征的影响  

Effect of increasing precipitation on seed germination characteristics in the soil seed banks of Seriphidium transiliense desert grassland

作　　者：巴德木其其格 孙宗玖[1,2] 李培英 田梦[1] 吴咏梅 Bademuqiqige;SUN Zong-jiu;LI Pei-ying;TIAN Meng;WU Yong-mei(College of Grassland and Environment Sciences,Xinjiang Agricultural University,Urumqi 830052,China;Key Laboratory of Grassland Resources and Ecology of Xinjiang,Urumqi 830052,China)

机构地区：[1]新疆农业大学草业与环境科学学院,新疆乌鲁木齐830052 [2]新疆草地资源与生态重点实验室,新疆乌鲁木齐830052

出　　处：《草业学报》2018年第10期136-146,共11页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(31760694);新疆农业大学研究生科研创新项目"增雨对新疆蒿类荒漠土壤种子库萌发影响(XJAUGRI2017014)"资助

摘　　要：为探明土壤种子库种子萌发对未来降水变化的适应机制,研究不同降水量[对照(CK)、增加5%(W_5)、增加10%(W_(10))、增加15%(W_(15))、增加20%(W_(20))、增加25%(W_(25))]对伊犁绢蒿荒漠0~5cm、5~10cm土层土壤种子库种子萌发物种组成、萌发动态及密度的影响,并对土壤种子萌发库与地上植被的相似性进行分析。结果表明:随降水量的增加,伊犁绢蒿荒漠0~5cm土层土壤种子库萌发的物种数及其萌发总密度呈增加趋势,与对照(3种,146.5粒·m^(-2))相比,增水20%及25%处理土壤种子库萌发的物种数依次显著增加3.7、4.3倍,萌发的总密度显著增加65.2%、195.6%,且土壤种子库平均萌发总量仅占种子储存量(7.2×10~3粒·m^(-2))的2.8%,而5~10cm土层也呈现相同的变化趋势,萌发数仅占土壤种子库种子储存量(1.2×10~3粒·m^(-2))的6.2%。从萌发物种看,增水显著促进串珠老鹳草、木地肤、荒漠蒲公英的萌发。随降水量的增加,伊犁绢蒿土壤种子库萌发物种与地上植被相似性呈逐渐增加趋势,相似性系数最高达0.81,且各增水处理间相似性系数也逐渐升高。总之,增水促进了伊犁绢蒿荒漠土壤种子库种子的萌发数量,提高了萌发物种数,增加其与地上植被的相似性,利于退化草地的演替与恢复。This study explored the adaptation mechanisms for seed germination of Seriphidium transiliense desert soil seed banks under six different precipitation treatments-CK,increased 5%(W 5),increased 10%(W 10),increased 15%(W 15),increased 20%(W 20)and increased 25%(W 25).The response of species composition,seed germination dynamics and density were measured at 0-5 cm and 5-10 cm layers,and the Sorensen similarity coefficient between the soil seed banks and aboveground vegetation was also analyzed.The results showed that species number and total germination density in the 0-5 cm layer increased with rising precipitation levels.Compared with CK(3 species,146.5 grain·m-2),the number of germination species in the 0-5 cm layer increased by 3.7 times in W 20 and 4.3 times in W 25,while total seed germination density increased by 65.2%and 195.6%respectively and on average total germination quantities occupied 2.8%of the soil seed bank(7.2×10 3 grain·m-2).Seed germination in the 5-10 cm layer changed at the same rate as the 0-5 cm layer,with total germination seed quantities occupying 6.2%of the storage bank(1.2×10 3 grain·m-2).Increased precipitation improved the germination density of Geranium transversale,Kochia prostrate and Taraxacum monochlamydeum.Sorensen similarity between the soil seed bank and aboveground vegetation also increased with rising precipitation,with the highest coefficient being 0.81.In summary,increased precipitation stimulated germination density in the S.transiliense desert soil seed bank,increased the number of germination species and the similarity coefficient between the soil seed bank and aboveground vegetation,all of which benefit the succession and restoration of degraded grassland.

关 键 词：增水 伊犁绢蒿荒漠 土壤种子库 萌发密度 群落相似性 

分 类 号：S812.2[农业科学—草业科学]