Will Heidrun, Maussner Stefanie, Tackenberg Oliver
Institute of Botany, University of Regensburg, 93040 Regensburg, Germany.
Oecologia. 2007 Aug;153(2):331-9. doi: 10.1007/s00442-007-0731-1. Epub 2007 May 22.
The transport of diaspores on animal hairs depends on the ability of a diaspore to attach to the hair and to be retained in it over longer periods of time. Whereas several studies of diaspore retention on animal hairs have been conducted recently, the process of diaspore attachment to the hair has not yet been studied systematically. We describe a new method to quantify the attachment potential (AtP) of plant diaspores. Attachment potential was measured as the proportion of diaspores of a given species that attached to pieces of an animal coat in a standardised experiment. The experiment was conducted for 58 plant species (herbs and grasses) and three different coat types: sheep wool, cattle and roe deer hair. Attachment potentials differed widely between the three coat types, but also between plant species. We found diaspore surface structure (a quantitative measure of diaspore morphology) and diaspore exposition (describing the morphology of the infructescence) to be the most important plant traits regulating AtP. An influence of seed mass on attachment potential could not be detected. For sheep wool, a general linear model (with diaspore exposure as a factor and diaspore surface structure as covariate) explained 77% of the variation in AtPs. To validate this model, we predicted AtPs for 27 additional species and compared these to the measured Atps; the predicted and measured AtPscorrelated significantly with r(s) = 0.68. A comparison of attachment and retention potentials to sheep wool for 127 randomly selected plant species showed that attachment and retention are only very weakly correlated, indicating that both processes act rather independently of each other. Since many diaspores seem to perform well in only one of these processes, attachment can be considered to be as equally as decisive as retention in terms of epizoochorous dispersal.
植物传播体在动物毛发上的传播取决于传播体附着在毛发上并在较长时间内保留在其中的能力。尽管最近已经对植物传播体在动物毛发上的保留情况进行了多项研究，但传播体附着在毛发上的过程尚未得到系统研究。我们描述了一种量化植物传播体附着潜力（AtP）的新方法。附着潜力通过在标准化实验中附着在动物皮毛碎片上的给定物种传播体的比例来衡量。该实验针对58种植物物种（草本植物和禾本科植物）以及三种不同的皮毛类型进行：羊毛、牛皮和狍子毛。三种皮毛类型之间的附着潜力差异很大，植物物种之间也是如此。我们发现传播体表面结构（传播体形态的定量指标）和传播体暴露情况（描述果实形态）是调节AtP的最重要植物特征。未检测到种子质量对附着潜力的影响。对于羊毛，一个通用线性模型（以传播体暴露为因素，传播体表面结构为协变量）解释了AtP变化的77%。为了验证该模型，我们预测了另外27个物种的AtP，并将其与测量的AtP进行比较；预测值和测量值的AtP显著相关，r(s)=0.68。对127种随机选择的植物物种在羊毛上的附着和保留潜力进行比较表明，附着和保留之间的相关性非常弱，这表明这两个过程的作用相当独立。由于许多传播体似乎仅在其中一个过程中表现良好，就动物传播扩散而言，附着可以被认为与保留同样具有决定性作用。
