作　　者： (许译天）; (何梦婷）; (杨敬一）; (黎冰芷）; (王宇坤）; (赵念席）; (高玉葆）;

机构地区： 南开大学生命科学学院,天津300071

出　　处： 《生态学杂志》 2017年第9期2489-2493,共5页

摘　　要： 物种内基因型多样性是否具有类似物种多样性的生态功能是恢复生态学与保护生态学研究的热点问题。在一些群落建群种的研究中,基因型多样性被证明确实具有与物种多样性类似的生态功能,然而群落伴生种是否也具有类似的生态功能并没有实验证据。本研究以中国北方草原群落伴生种溚草为研究对象,采用单因素实验设计,构建溚草基因型单种和4基因型混种2种处理,通过2次收获分别得到溚草地上部绿叶干重、地上部枯叶干重、地上部干重(绿叶+枯叶)、地下部干重以及分蘖数5个指标对基因型数目的响应。结果表明:(1)尽管所得结果均表明4基因型组合种群的表现优于基因型单种,但仅第一次收获时地下部干重这一指标在两种处理之间差异显著(P<0.05);(2)仅第一次收获时地下部干重的基因型多样性净效应为显著正效应(P<0.05);(3)将所得多样性净效应分解为互补效应和选择效应,发现9/10的互补效应值为正值但与0之间差异不显著(P>0.05),而7/10的选择效应为负值,且第二次收获时地上部枯叶干重的选择效应显著小于0(P<0.05)。这些结果表明,群落伴生种溚草混种时选择效应不对基因型多样性正效应起正面作用,而基因型间并不能发挥类似物种多样性间的功能互补,因此仅在1/10指标中得到基因型多样性效应的正效应,显著低于已有的关于物种多样性以及建群种基因型多样性所得结果,这些结果为合理评价退化草原的生态功能提供了新的视角。 Whether genotypic diversity has similar ecological function to species diversity is a hot topic in the field of restoration ecology and conservation biology. Many studies about dominant species have proved that genotypic diversity exhibits similar ecological function to species diversity, but experimental tests about companion species are still lacking. In the present study, we selected Koeleria cristata, a common companion species in the grassland community of northern China, as study object, and examined the effects of genotypic diversity on the performance of above and belowground dry weight, number of tillers at two harvest times. Although all results showed that the combination of 4 genotypes had a better performance than a single genotype, only the belowground dry weight at the first harvest showed a significant difference （P〈0.05） between treatments. The net effect of genotypic diversity was significantly higher than zero for only one variable, the belowground dry weight （P〈0.05）. Partitioning the net effect of diversity by Loreau ＆ Hector method, the results showed that 9/10 of complementary effect values were positive but not significantly higher than zero （P〉0.05）, and that 7/10 of selection effect values were negative with the value of aboveground wilted leaf dry weight at the second harvest being significantly lower than zero （P〈0.05）. As for K. cristata the selection effect of genotypes did not have any positive effect, and the functional complementarity between genotypes of this species was not as important as that between different species. Therefore, only 1/10 of net effect of diversity was positive, and the proportion was lower than that obtained from species diversity or genotypic diversity of dominant species. Such information would provide a new perspective for evaluating the ecological function of degraded grassland.

关 键 词： 溚草 多样性净效应 选择效应 互补效应