Weithoff Guntram, Stefan Marley B
Institute of Biochemistry and Biology, Aquatic Ecology Group, University of Potsdam, Potsdam, Germany.
J Phycol. 2025 Apr;61(2):261-266. doi: 10.1111/jpy.13536. Epub 2024 Dec 9.
Biological invasions are a major threat for many aquatic ecosystems. In contrast to higher plants and animals, microbial invasions are less obvious and more difficult to detect. One of the most prominent microbial invaders is the cyanobacterium Raphidiopsis raciborskii. To better understand the environmental conditions favoring its invasion success, we studied invasion under three different temperature regimes (one constant and two variable) in experimental plankton communities by invader addition experiments. To account for intraspecific variation, we tested four different strains of R. raciborskii and the mixture of them. Invasion success of R. raciborskii was higher under constant temperature conditions than under fluctuations suggesting that the resident species responded faster to the environmental changes than the invaders. We observed a clear strain-specific effect, demonstrating that strain identity is an important determinant of invasion success. The interaction of temperature fluctuations and strain identity indicates that, among the tested strains, the response to the temperature regimes varied. The mixture of all four strains did not perform better than the best single strain showing no sign of a positive genetic diversity effect. In our experiment, environmental fluctuations did not widen a window of opportunity for the invasion of R. raciborskii.
生物入侵对许多水生生态系统构成重大威胁。与高等植物和动物不同，微生物入侵不太明显且更难检测。最突出的微生物入侵者之一是蓝藻拉氏尖头藻（Raphidiopsis raciborskii）。为了更好地了解有利于其入侵成功的环境条件，我们通过添加入侵者实验，在实验浮游生物群落的三种不同温度条件（一种恒温条件和两种变温条件）下研究了入侵情况。为了考虑种内变异，我们测试了拉氏尖头藻的四种不同菌株及其混合物。拉氏尖头藻在恒温条件下的入侵成功率高于温度波动条件下的成功率，这表明本地物种对环境变化的响应比入侵者更快。我们观察到了明显的菌株特异性效应，表明菌株特性是入侵成功的一个重要决定因素。温度波动与菌株特性之间的相互作用表明，在所测试的菌株中，对温度条件的响应各不相同。所有四种菌株的混合物表现并不比最佳单一菌株更好，没有显示出正遗传多样性效应的迹象。在我们的实验中，环境波动并未为拉氏尖头藻的入侵拓宽机会窗口。
