Shift in Plant Species Composition Reveals Environmental Changes During the Last Decades: A Long-Term Study in Beech (Fagus sylvatica) Forests in Bavaria, Germany
Shift in Plant Species Composition Reveals Environmental Changes During the Last Decades: A Long-Term Study in Beech (Fagus sylvatica) Forests in Bavaria, Germany
复制标题
植物物种组成的变化揭示了过去几十年的环境变化：对德国巴伐利亚山毛榉（Fagus sylvatica）森林的长期研究
作者：
Matthias C. Jantsch;A. Fischer;H. Fischer;S. Winter
在过去的几十年里，欧洲的一些地区已经报道了由于气温升高而导致的植被组成的变化。已有研究表明，单一物种要么向北迁移，要么向高海拔迁移。我们预计林分的物种组成也应该发生变化，即嗜热物种的增加。另一个几十年来发生变化的场地因素是氮素的有效性；因此，我们也预计亲氮物种的数量会增加，这是以前长期研究的主要结果之一。研究了德国南部(巴伐利亚州)山毛榉林的物种组成，比较了老林(1949-1985年)和幼林(2010年)的植物社会学释放。采用代表植物特有环境因子的Ellenberg指标值与气候数据相结合的部分典型对应分析(PCCA)进行植被比较。从物种频度、Ellenberg指标值的分布、非原生植物和乔木、灌木和草本物种所占比例等方面分析了植物种类组成的变化。与我们的预期相反，在过去的几十年里，巴伐利亚的全球变暖只导致了物种组成中5%的合理分散。在物种水平上，一些研究区的耐热核桃树苗(Juglans Regia)总体增长明显。然而，在整个研究区域内，亲亚硝化物种的出现频率普遍增加。在整个巴伐利亚州，最显着的变化是幼树物种的显着增加，草本物种的减少。到目前为止，与过去几十年的全球变暖相比，森林氮素输入的增加对物种组成变化的影响更大。此外，森林管理的一般变化也对森林物种产生影响。因此，反映中欧山毛榉森林温度因素的群落重组似乎才刚刚开始。
Changes in vegetation composition due to the increasing temperatures in the past few decades have already been reported from several parts of Europe. It has been shown that single species move either northwards or to higher elevations. We expected that the species composition of forest stands should also have changed, i.e., an increase of thermophilous species. Another site factor changing for decades is nitrogen availability; we therefore also expected an increase of nitrophilous species, which was one main result in former long-term studies. We studied the species composition of beech (Fagus sylvatica) forests in southern Germany (Bavaria), comparing old (from 1949 to 1985) and young (2010) phytosociological relevés. Ellenberg indicator values representing plant species specific environmental factors combined with climatic data were used in a partial canonical correspondence analysis (pCCA) for vegetation comparisons. Changes in plant species composition were analyzed considering species frequency, distribution of Ellenberg indicator values, shares of i) non-native plants and ii) tree, shrub and herbaceous species. Contrary to our expectations, global warming in Bavaria during the past decades resulted only in an explained dispersion of 5 % in the species composition. On the species level, an overall increase of thermophilous walnut tree saplings (Juglans regia) was conspicuous in some study areas. Nitrophilous species, however, generally increased in frequency throughout the study areas. Throughout Bavaria the most significant change was a striking increase of juvenile tree species and a decrease of herbaceous species. Up to now the increased nitrogen input into forests had a stronger provable influence on species composition shift than the global warming of the last decades. Additionally general changes in forest management also had effects on forest species. Therefore community reorganization mirroring temperature factors in beech forests in central Europe seems to be only at its very beginning.