陕西北部蝗虫群落多样性及生境片断化对其的影响研究

【作者】 刘缠民；

【导师】 廉振民；

【作者基本信息】 陕西师范大学 ， 动物学， 2000， 硕士

【摘要】 陕北位于陕西省北部，气候干旱，黄土沟壑纵横地形复杂，草地较多，蝗虫灾害是影响该地区农牧业发展的主要因素，因此，研究蝗虫群落，弄清其群落组成，分布格局及群落多样性，对于进一步有效控制蝗灾危害，合理开发利用昆虫资源，有着重要的现实意义。 论文从陕北蝗虫物种调查，区域分布，生物学特性和防治等几方面综述了陕北蝗虫研究概况。提出了存在的问题，明确了研究的方向，介绍了生物群落和保护生物学的概念，特点及生物多样性的测定方法。 根据陕北的地形、地貌和植被特征，可把陕北划分为7个不同生境类型，荒漠草原地带，荒漠地带，典型草原，草甸草原，滩湿地草甸，农田地带，河谷阶地草甸，通过在不同生境地带大面积调查，研究了陕北蝗虫的群落结构组成，生态分布，分析了不同生境中蝗虫种类的相似性，探讨了蝗虫在不同生境中的存在情况，结果表明，在所调查地区，采得蝗虫分属蚌科（Tetrigdae）、蝗科（Prpomorphidae）、癞蝗科（pamphagidae）、斑腿蝗科（catanlopidae）、斑翅蝗科（Oedipodidae）、网翅蝗科（Arcyptridae）、剑角蝗科（Acrididae）共7科，21属、37种、不同生境中蝗虫的种类组成及其丰富度也不同，荒漠地带 21种，荒漠草原 31种，典型草原 26种，草甸草原26种，滩湿地草地24种，农田地带13种，河谷阶地草甸20种，通过比较不同生境蝗虫群落的相似性，并经聚类和PCA分析，可将不同生境划分为三种大的类型，水源充足类型包括农田地带，滩湿地草地，河谷阶地草甸；较湿润植被较好类型包括典型草原和草甸草原；极干旱植被较差类型包括荒漠地带和荒漠草原地带。 蝗虫群落格局特性研究。两年中调查了陕北的榆林、延安、铜川三个地区，取样面积10000多平方米，采得蝗虫4800多头，在抽样调查的基础上建立了陕北蝗虫群落物种—面积关系模型：S_q＝2.9571q^0.2983[r=0.9534 r_8,0.01=0.632]并建立了物种一多度模型：N（R）=10exp[-0.097（r-5）²](X²=20.43 X²_9,0.0121.63) 蝗虫群落多样性的研究。在两年调查的基础之上，运用Shannon──wiener多样性指数（H’），pielou均匀度指数（E），simpson的优势度指数（D），对陕北不同生境的蝗虫群落多样性进行了分析，并探讨了多样性与均匀度和丰富度的关系，结果表明，不同生境蝗虫多样性指数由高到低依次为荒漠草原〉典型草原〉草甸草原〉典型荒漠〉滩地湿地草地〉农田草地〉河谷阶地草地，多样性指数是丰富度和均匀度的函数，其效用不可等同。 对于沙漠绿洲蝗虫群落研究发现，沙漠绿洲蝗虫种类数明显少于榆林对比地，绿洲蝗虫种类数与土壤湿度、气候、干燥度、植被状况等生境因子明显相关，而与绿洲面积大小。距种源对比地的距离，不存在明显的关系。 森林片断化对蝗虫影响、林缘草地间蝗虫种类和数量不存在明显差异，林中草地在面积适中，树木砍坏不严重时，变化不大，而在面积小，树木砍伐严重时，种类和数量明显增加，PCA及多元逐步回归分析显示。草地植物结构复杂性是影响蝗虫种类和数量变化的最主要因素。 生境片断化后，片断生境的物理、化学、生物学因素都发生一系列变化，片断生境能量平衡明显不同，辐射增加，温度日较差变大，营养循环，水分循环，能量流动受到干扰而改变，种群迁入率和灭绝率增加。由于生境抗环境随机因素抵抗力下降、生境专性化、种群减小、物种年龄结构、大小结构、性别比、饱和密度、空间分布动态、内禀基因杂合性、竞争力、繁殖率，增长率及种群内个体之间，某一斑块内和斑块之间种群增长率的变异都可导致物种的灭绝。在隔离比较大情况下更是如此，对于蝗虫，这中以草地生存为主的昆虫。在沙漠入侵，草地明显片断化时，种类明显减少，而对于林中草地，毁林砍伐，一方面使密林变疏，打破了森林的隔离与封闭性，造成林中草地与林外草地隔离减少，林地相对面积增大，温度少照增加，蝗虫种类增加，密度增大，危害加重。更多还原

【Abstract】 Shaanei lied in North Shaanxi, with arid weather complicated terrain and more grass.The plague of locusts is one of the most serious factor the hinder the development ofagriculture and enimal husbandry. The paper mainly studied the composition、Structure、diversity of grass-hopper community.According to character of geography and vegetaion, Shaanbei was divided into 7different habitat regions: desert prairie region、 desert region typical steppe、 meadowprairie、bottomland meadow、 farmland region、 river marshland region. The compositionof grasshoppers community and the distribution laws were studied, Which based on the largearea investigation in different habitat region. The grasshoppers species, which had beencollected from this region, were examied inculde 7 families, 2l genera and 37species. Theybelong to Tetrigidae, Pyrgomorphidae, Pamphagidae, Catantopidae, Arcypteridae,Oedipodidae and Acrididae. The grasshopper species composition and abundance aredifferent in different habitat regions. By comparing the resemblance of grasshoperscommunity in different habitat regions and dendorgram and PCA analysis, the differenthabitat region can be divided into 3 types; the Water abundance type include farmlandregion, bottomland river marshland, the damp and better vegetation type include typicalsteppe and meadow praise. The arid and worse vegetation type include desert prairie regionand desert region.Based on the sampling investigation, the patterns of species-area relationship modelwas ehablished S_q=2.957lq^0.2983[r=0.9534 r_8,0.01=0.632]and the species-abundancerelationship model was established N（R）=l0exp[-0.097（r-5）²] [X²=20.43 X²_0.01=2l.63]According to the data obtained from the investigation in different habitat region, thediversity index of shannon-wiener （H’）, pielou’s evenness（E）, simpson’s dominance （D）were computed the relationship of diversity and evenness. Abundance was disussed too.The results as fO1lows; the diversity index of different habitat region from high to low wastdesert Prairie region>yPical stCPPe>meadow prairie>desert region> Bottomland meadoW>driland region>river marshland region, By the analyses, the community diversity was thefimction of evenness and abundance but not equal in value.Stuopng the graSshOPPer coInInunity in oases, the SPecies in oases are fewer thanYulin. It is obviously related with the grasshopper SPecies’ in oases and soil hUmidityweatheT, vegeaion and other factors, but it is not obviously related with the oasis area anddiStance to the contrast land.EffeCt of fragmented forest on grasshoppers is not different in forest edge grass. Thechange of interior forest grass is sligh. Whn the forest area is not small and the tree wasnOt badiy cul,bu grasshoPPer species and number in foreSt imerior grass don’t riseviolenty When the forest area is small, and was cut badly, the grasshopper sPecies andWer in forest interior rise obviously It showed by PCA and stePwise regression analsis,the comPlicated comPosition of grass in fOrest is the mainly faCtor on affecting thegrasshoPPer sPecies and ntnnber更多还原