不同水分处理对狗牙根种内相互作用的影响  

The effects of different water treatments on intraspecific interactions of Cynodon dactylon

作　　者：曾成城 王振夏[1] 陈锦平[1] 顾艳文[1] 贾中民[1] 魏虹[1] 

机构地区：[1]三峡库区生态环境教育部重点实验室,重庆市三峡库区植物生态与资源重点实验室,西南大学生命科学学院,重庆400715

出　　处：《生态学报》2016年第3期696-704,共9页Acta Ecologica Sinica

基　　金：国家林业公益性行业科研专项(201004039);重庆市自然科学基金资助(cstc2012jj A80003);重庆市基础与前沿研究计划重点项目(CSTC2013JJB00004);中央高校基本科研业务费专项资金(XDJK2013A011)

摘　　要：以狗牙根当年生扦插苗为试验材料,根据库区河岸带水分特征设置4种水分处理方式:水分对照组(CK)、水淹与干旱交替组(FD)、土壤水分饱和组(LF)和全淹组(FL),4种密度方式:对照(1株/盆)、低密度(2株/盆)、中密度(4株/盆)及高密度(12株/盆),探究狗牙根生长及形态响应,并验证胁迫梯度假说。结果表明:(1)狗牙根各生物量随水分胁迫强度的增加显著下降(P<0.001);密度处理和二者交互作用显著影响狗牙根叶干重、茎干重、根干重、地上生物量和总生物量(P<0.001)。(2)水分处理显著影响狗牙根各形态指标(P<0.001);密度和二者交互作用显著影响狗牙根分枝数、总茎长和节间长(P<0.001)。(3)CK组和LF组狗牙根生物量相对邻体效应(RNE)均为负值,表明其种内关系为竞争关系。FL组各密度组生物量RNE值均为正值,其种内关系转化为促进关系。(4)中高密度组总茎长RNE值随水分胁迫增加而增大。研究表明:(1)狗牙根对不同的水分胁迫均表现出积极响应,可考虑将狗牙根用于库区河岸带植被重建。(2)随种植密度的增大,狗牙根生长及形态均表现出一定的负面效应。(3)本试验在一定程度上支持胁迫梯度假说,但尚需更多概念模型将其改进完善。Altered water regime of reservoirs has changed the interactions among native plant species, thus leading to many serious environmental problems. To restore the riparian vegetation is of great significance. Among many plant interaction studies, the stress-gradient hypothesis has been supported by many researchers, while some research did not support it, The stress-gradient hypothesis indicates that the interactions among plants largely depend on external stresses, and the importance of facilitation is predicted to increase with the severity of environmental stress. In this research, we had two purposes ： （ 1 ） to explore the responses of the biomass and morphology of Cynodon dactylon to different water treatments and different plant densities; （2） to test whether these responses support the stress-gradient hypothesis. Four water treatments including normal water supply （ CK）, light flooding followed by light drought （ FD）, light flooding （LF） and flooding （FL） were applied to C. dactylon seedlings. For each water treatment, four densities including l, 2, 4, and 12 plants per pot were used as the planting treatment. Biomass and morphological traits were determined at final harvest. The intensity of intraspeeific competition of C. dactylon was determined by the relative neighbor effect （RNE）. The results showed that： （1） the dry biomass of plant leaf, stem, root, aboveground biomass, root：shoot ratio and total biomass of C. dactylon weresignificantly affected by water treatments （P〈0.001）. The biomass of C. dactylon was reduced with increasing water stress regime. The different densities and the interaction between soil moisture and density also significantly affected the leaf, stem and root dry mass, aboveground biomass and total biomass of C. dactylon （P〈 0. 001 ）. （2） Area per leaf, branching number, total stem length and internode length of C. dactylon were significantly affected by water treatments （P〈0.001）, and the different densities and the interac

关 键 词：河岸带 狗牙根 水分 密度 生长 形态 胁迫梯度假说 

分 类 号：Q948[生物学—植物学]