In recent years, three large populations of Cyperus flavescens were found in Poland, the richest occurrence of this species in over 30 years. The goal of this research is to determine the habitat factors lead to the mass occurrence of C. flavescens and the present situation of that species and its habitat in Central Europe. Soil conditions of the three populations were studied. To determine the correlation between the occurrence and abundance of species and the chemical parameters of the soil, the DCA and CCA methods were used. The DCA of environmental Ellenberg values was made for all relevés known from Poland. The occurrence of C. flavescens in plant communities in Central Europe was studied. The maximum entropy method was used for potential distribution analysis of C. flavescens. All analyzed traits are important for this species and none has an advantage over another, so the environmental factor affecting the occurrence of C. flavescens is different from the tested. Analysis on Ellenberg values indicate that the longest gradients are temperature, moisture and nutrients. The analysis of vegetation data involving Cyperus flavescens available from Central Europe indicates that this species occurs mainly in the company of Juncus bufonius and Plantago intermedia, whereas other species of the Isoëto-Nanojuncetea class appear rarely. In MaxEnt analysis based on bioclimatic variables, the most important variable is BIO1 (Annual Mean Temperature). The results of our observation indicate that anthropogenic factors such as grazing livestock have a positive effect on the occurrence of the species. It is also very likely that the species is promoted by very warm summers with only short periods of heavy rains. A map of the potential distribution of C. flavescens in Central Europe created according historical and future data show an extension of the range of potential habitats to the north and east.

中文翻译：

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在欧洲分布区的东北边缘重新发现苦参（Cyperaceae）

近年来，在波兰发现了三个大型苦香香附群，这是该物种 30 多年来数量最多的一次。本研究的目的是确定导致苦参大量出现的栖息地因素以及该物种及其在中欧的栖息地现状。研究了三个种群的土壤条件。为了确定物种的出现和丰度与土壤化学参数之间的相关性，使用了 DCA 和 CCA 方法。环境 Ellenberg 价值观的 DCA 是针对波兰已知的所有相关因素制定的。研究了 C. flavescens 在中欧植物群落中的发生情况。最大熵法用于苦参的电位分布分析。所有分析的性状对这个物种都很重要，没有一个比另一个有优势，所以影响 C. flavescens 发生的环境因素与测试不同。对 Ellenberg 值的分析表明，最长的梯度是温度、水分和养分。对来自中欧的苦参植被数据的分析表明，该物种主要出现在 Juncus bufonius 和 Plantago intermedia 中，而 Isoëto-Nanojuncetea 类的其他物种很少出现。在基于生物气候变量的 MaxEnt 分析中，最重要的变量是 BIO1（年平均温度）。我们的观察结果表明，放牧牲畜等人为因素对该物种的发生具有积极影响。非常温暖的夏季也很可能促进了该物种的发展，并且只有短时间的大雨。根据历史和未来数据创建的苦参在中欧的潜在分布图显示潜在栖息地范围向北部和东部扩展。