Abstract

Some species intrinsically have a high invasiveness capacity, shown by high phenotypic plasticity and rapid growth, enabling a wide distribution across their native habitats and successful invasion in the introduced range. For such species, information from native habitats is critically important. An example is Glechoma hederacea, native to Eurasia but introduced and widespread in the USA. Our main objective was to investigate variation in traits of native G. hederacea populations across contrasting habitats: open, forest edge and understory. Vegetation was sampled and the ecophysiological and morphological traits were measured with accompanying environmental parameters. Results showed that in native habitats environmental conditions cover wide gradients of light and soil moisture. Plants had the highest cover in nutrient-rich, shaded habitats, representing the optimal habitat, indicating shade tolerance of G. hederacea. Plants from forest understory exhibited strong similarities in investigated traits to plants from the forest edge, even though this was a drier, sunnier habitat. Plants from open, sunny habitats experienced stress as indicated by the quantum efficiency of PSII and significantly higher sexual reproduction. Results show that G. hederacea is moderately tolerant simultaneously to shade and drought, a characteristic that has been reported for numerous invasive species, while at the same time it shares some characteristics with weedy plants.

摘要

一些物种本质上具有高入侵能力，表现为高表型可塑性和快速生长，从而使其能够广泛分布于其原生栖息地并在引入范围内成功入侵。对于此类物种，来自本地栖息地的信息至关重要。一个例子是Glechoma hederacea，原产于欧亚大陆，但在美国传入并广泛传播。我们的主要目标是调查本地G. hederacea的性状变异不同栖息地之间的种群数量：开放，森林边缘和林下。对植被进行采样，并随环境参数测量其生态生理和形态特征。结果表明，在原始栖息地中，环境条件覆盖了光和土壤水分的宽梯度。在营养丰富，阴暗的生境中，植物具有最高的覆盖率，代表了最佳的生境，这表明黑麦草的耐荫性。尽管这是一个干燥，阳光充足的栖息地，但林下的植物在研究的性状上与森林边缘的植物表现出强烈的相似性。PSII的量子效率和显着更高的有性生殖表明，来自开放，阳光充足的栖息地的植物会承受压力。结果表明，G。hederacea 同时具有一定的耐荫和耐旱性，许多入侵物种都报道了这一特征，同时与杂草植物也具有某些特征。