摘要
土壤节肢动物作为土壤生态系统的重要组成部分,对于周围环境的变化十分敏感,可作为环境变化的"指示剂"。放牧作为青藏高原地区高寒草地的主要利用方式,不仅影响土壤理化性质,同时会对生物多样性产生影响,进而影响到以土壤为主要生存场所的土壤节肢动物。为了明确不同放牧家畜及其混合比例对青藏高原高寒草地土壤节肢动物群落结构及多样性的影响,于2020年7月在青海省海北州海晏县西海镇"高寒草地-家畜系统适应性管理技术平台",设置中等放牧强度下牦牛单牧(YG)、藏羊单牧(SG)、牦牛藏羊1∶2混合放牧(MG1∶2)、牦牛藏羊1∶4混合放牧(MG1∶4)和牦牛藏羊1∶6混合放牧(MG1∶6)5个放牧样地,以无放牧(CK)为对照样地,采集0~5 cm、5~10cm、10~15 cm的土样,利用干漏斗法(Tullgren法)分离土壤节肢动物,并进行鉴定统计。结果表明:1)试验样地分离得到的土壤节肢动物优势类群为螨总科(Acaroidae)和甲螨总科(Oiibatida),分别占土壤节肢动物总捕获量的36.67%和41.14%,且在0~5 cm土层数量最多,具有表聚性;2)不同放牧方式对土壤节肢动物的组成、群落结构、密度及多样性存在不同的影响。与对照相比,放牧降低了土壤节肢动物优势类群螨总科的组成比例,而增加了甲螨总科的组成比例;无放牧样地与其他放牧方式样地土壤节肢动物群落结构存在明显差异;土壤节肢动物丰富度指数、多样性指数、类群数均表现为藏羊单牧放牧样地较高,而均匀度指数与之相反;3)土壤节肢动物均匀度指数与土壤全氮、全碳、速效钾呈显著负相关(P<0.05或P<0.01),而与有机质、pH呈显著正相关(P<0.05或P<0.01);土壤节肢动物丰富度指数与土壤pH呈显著负相关,而与土壤全氮、速效氮、有机质呈显著正相关;土壤节肢动物多样性指数与土壤pH呈显著负相关,而与土壤全氮、速效氮、速效磷、有机质呈显著正相关;土壤节肢动物平均密度、总类群数与土壤pH呈显著负相关,而与土壤全氮、速效氮、速效钾、有机质呈显著正相关;4)土壤全氮、全磷、全碳、速效氮、速效磷在藏羊单牧放牧样地较高;速效钾、有机质在无放牧样地最高;pH、土壤含水量在牦牛藏羊1∶6混合放牧样地最高。综上所述,在青藏高原高寒草地生态系统,藏羊单牧对于土壤节肢动物密度、群落组成以及群落多样性的提高具有正向作用。
Soil arthropods are an important component of the soil ecosystem and have been used as“indicators”of environmental change,because of their sensitivity to changes in the surrounding environment.Grazing is the main use of alpine grassland in the Qinghai-Tibet Plateau.Grazing affects both the physical and chemical properties of the soil,and also the biodiversity,including soil arthropods.This research investigated changes in the soil arthropod community structure and diversity associated with grazing by different animal species.Soil arthropods were sampled in July 2020 from a grazing experiment in an alpine meadow on the Qinghai-Tibetan Plateau.The grazing experiment included two single-species grazing treatments(yak only and Tibetan sheep only;YG,SG),three mixed-grazing(MG)treatments(yak:Tibetan sheep ratios of 1∶2,1∶4 and 1∶6)and an ungrazed control treatment(CK).Soil samples were collected from 0-5 cm,5-10 cm,and 10-15 cm soil depths,and the soil arthropods were separated by the dry funnel(Tullgren)method,identified,and the data statistically analysed.It was found that:1)Of the total sampled soil arthropod population,36.67%belonged to the taxonomic family Acaroidae and41.14%belonged to the family Oiibatida.The highest densities of arthropods were found in the 0-5 cm soil layer.2)The composition,community structure,density and diversity of the soil arthropod communities differed between the animal species grazing treatments.Compared with the control,grazing decreased the proportion of Acaroidae,but increased the proportion of Oiibatida in the soil arthropod population.There were significant differences in soil arthropod community structure between CK plots and grazed plots.The species richness index,diversity index and the number of soil arthropods were highest,and the evenness index was lowest in the Tibetan sheep grazing treatment.3)Soil arthropod evenness index was negatively correlated with soil total nitrogen,total carbon and available potassium(P<0.05 or P<0.01),but positively correlated with soil organic matter and pH(P<0.05 or P<0.01);soil arthropod richness index was negatively correlated with soil pH,but positively correlated with soil total nitrogen,available nitrogen and organic matter contents.Soil arthropod diversity index was negatively correlated with soil pH,but positively correlated with soil total nitrogen,available nitrogen,available phosphorus and organic matter contents.The mean density and the number of groups of soil arthropods were negatively correlated with soil pH,but positively correlated with soil total nitrogen,available nitrogen,available potassium and organic matter.4)Soil total nitrogen,total phosphorus,total carbon,available nitrogen and available phosphorus levels were higher in the SG treatment.Available phosphorus and organic matter were highest in the CK plots.Soil water content and pH were highest in the MG1:6 treatment.In summary,only Tibetan sheep grazing had a positive effect in increasing soil arthropod density,community composition and community diversity in the alpine grassland ecosystem of the Qinghai-Tibetan Plateau.
作者
孙彩彩
董全民
刘文亭
冯斌
时光
刘玉祯
俞旸
张春平
张小芳
李彩弟
杨增增
杨晓霞
SUN Cai-cai;DONG Quan-min;LIU Wen-ting;FENG Bin;SHI Guang;LIU Yu-zhen;YU Yang;ZHANG Chun-ping;ZHANG Xiao-fang;LI Cai-di;YANG Zeng-zeng;YANG Xiao-xia(Academy of Animal Science and Veterinary Medicine,Qinghai University,Qinghai Provincial Key Laboratory of Adaptive Management on Alpine Grassland,Xining 810016,China)
出处
《草业学报》
CSCD
北大核心
2022年第2期62-75,共14页
Acta Prataculturae Sinica
基金
青海省科技厅创新团队项目(2021-ZJ-901)
青海省科技厅创新平台建设专项(2020-ZJ-T07)
国家自然基金联合基金项目(U20A2007)
国家自然基金地区科学基金项目(32160343)资助。