Pniewski Filip, Sylwestrzak Zuzanna
Institute of Oceanography, University of Gdańsk, Al. Piłsudskiego 46, 81-378 Gdynia, Poland.
Biologia (Bratisl). 2018;73(11):1067-1072. doi: 10.2478/s11756-018-0122-6. Epub 2018 Sep 13.
Periphyton plays a vital ecological role in shallow, well-lit ecosystems which are vulnerable to rapidly changing environmental conditions, including raising temperature due to global warming. Nevertheless, little is known on the effect of increased temperatures on the taxonomic structure and functioning of periphytic communities. In this study, the influence of short-term temperature increase on the species composition and photosynthetic activity of the Baltic periphytic communities was investigated. The collected communities were exposed to increased temperature of 23 °C (ca. 4 °C above the summer average) for 72 h. After this time, species composition of the communities was studied under light microscope and their photosynthetic performance was evaluated using PAM fluorometry. Results showed that the biomass of cyanobacteria slightly increased. There were significant changes in the abundance of diatom species, among which and , were negatively affected by the elevated temperature and their cell number significantly decreased, whereas, and were stimulated by the increased temperature. Additionally, a shift towards higher abundance of smaller taxa was also observed. The higher quantum yield of photosystem II (PSII) (higher PSII) accompanied by the lower value of non-photochemical quenching (NPQ) observed in communities kept at 23 °C showed more efficient photosynthesis. This was further confirmed by the changes in rapid light curves (higher photosynthetic capacity, rETR, and photoacclimation index, E). The obtained data constitute evidence that short periods of increased temperature significantly affect the structure and functioning of the Baltic periphyton.
附生植物群落（周丛生物）在浅水、光照充足的生态系统中发挥着至关重要的生态作用，这类生态系统易受快速变化的环境条件影响，包括全球变暖导致的气温上升。然而，关于温度升高对附生植物群落的分类结构和功能的影响，我们知之甚少。在本研究中，调查了短期温度升高对波罗的海附生植物群落的物种组成和光合活性的影响。将采集的群落暴露在23℃的升高温度下（比夏季平均温度高约4℃）72小时。在此之后，在光学显微镜下研究群落的物种组成，并使用脉冲幅度调制荧光法（PAM荧光测定法）评估其光合性能。结果表明，蓝藻生物量略有增加。硅藻物种的丰度发生了显著变化，其中[具体物种1]和[具体物种2]受到温度升高的负面影响，其细胞数量显著减少，而[具体物种3]和[具体物种4]受到温度升高的刺激。此外，还观察到向较小分类单元更高丰度的转变。在23℃下保存的群落中观察到的光系统II（PSII）较高的量子产率（较高的PSII）伴随着较低的非光化学猝灭值（NPQ），表明光合作用更有效。快速光曲线的变化（更高的光合能力、相对电子传递速率rETR和光适应指数E）进一步证实了这一点。获得的数据证明，短期温度升高会显著影响波罗的海附生植物群落的结构和功能。
