Diversity loss in grasslands due to the increasing dominance of alien and native competitive herbs

作者：Marta Czarniecka‐Wiera, Zygmunt Kącki, Milan Chytrý, Salza Palpurina · 发表于：Biodiversity and Conservation · 年份：2019 · DOI：10.1007/s10531-019-01794-9 · 被引用次数：41 · 研究领域：Ecology and Vegetation Dynamics Studies、Plant and animal studies、Plant Parasitism and Resistance

The increasing dominance of competitive plant species may reduce species richness of plant communities. Yet, species richness may depend on spatial scale and the alien versus native status of the dominant species. To explore the dominance effects of alien versus native species on species richness, we sampled semi-natural grasslands in southwestern Poland. We established 100 m 2 squares at different grassland sites, and in two opposite corners we placed two series of five nested plots (0.001, 0.01, 0.1, 1 and 10 m 2 ), in which we recorded all vascular plant species. Next, we selected squares with a strongly dominant plant in one corner (high-dominance series) and with no strong dominant in the opposite corner (low-dominance series). The number of species per plot and the slopes of the species–area curves fitted to each nested-plot series were used to assess whether the alien vs. native status of the dominant species influences species-richness pattern across scales. We found a significantly lower number of species in the high-dominance series than in the low-dominance series, regardless of the alien versus native status of the dominant species. The slopes of the species–area curves indicated that the rate of species accumulation with increasing area was faster in the high-dominance series than in the low-dominance series; however, this pattern did not depend on the alien vs. native status of the dominants. Our study confirms that increasing dominance is linked to a decline in...