Evidence of morphometric differentiation among Antarctic moss populations as a response to local microenvironment

ABSTRACTStudies on phenotypic variation among populations growing in different microenvironments may provide information about plasticity related to environmental pressures, and thus help to elucidate the potential evolutionary forces contributing to the origin and maintenance of diversity in any region. In this study we investigate morphometric variation on a small geographic scale for three species of Antarctic mosses. All species revealed significant differentiation among populations for all evaluated traits. The comparison of morphometric measures of populations of Polytrichum juniperinumfrom Nelson Island and from southern Brazil suggests that the effects of a small geographic scale in Antarctica are the same as a large geographic scale in environments where the climate is more homogeneous and microhabitats have minor influence on vegetation. However, further investigations over a larger area, evaluating more species, and using controlled garden experiments are recommended in order to evaluate the capacity for plasticity of moss species in different climatic conditions and on different geographic scales.

摘要：对生长于不同微环境的种群间表型变异开展研究，可揭示与环境压力相关的表型可塑性，进而有助于阐明驱动任一区域物种多样性起源与维持的潜在进化力量。本研究针对三种南极苔藓，在小地理尺度下开展形态计量学变异分析。所有供试物种的全部观测性状均在种群间呈现出显著分化。对纳尔逊岛与巴西南部的桧叶金发藓（Polytrichum juniperinum）种群形态计量指标的对比分析显示，南极地区小地理尺度下的环境效应，与气候更均质、微生境对植被影响较弱的区域中大地理尺度下的效应一致。不过，未来仍需在更大范围区域内开展研究，纳入更多物种，并采用受控栽培实验，以评估不同气候条件与不同地理尺度下苔藓物种的表型可塑性能力。