Climate change will modify the marine ecosystem in several ways, but the effects of changing climate on benthic diatoms, which are one of the most important photosynthesizing organism groups in benthic habitats, are poorly studied. We conducted a mesocosm experiment to investigate the effects of increasing temperature and decreasing salinity on the taxonomic and functional diversity of benthic diatoms. We showed that decreasing salinity affects the taxonomic and functional composition of communities, and the threshold salinity for community composition is ~5. This indicates that when climate change leads to decreasing salinity in brackish systems, the most pronounced changes in communities occur in areas where salinity decreases from >5 to <5. We also showed that both increasing temperature and decreasing salinity exert stress on communities and, hence, lead to the decrease of the alpha and beta diversity of communities. This indicates that climate change reduces the size of the species pool of diatoms. Our results show that, along with the changing climate, we can expect benthic diatom communities to become less diverse and less resilient.

中文翻译：

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盐度下降和温度升高降低了底栖硅藻的多样性和恢复力

气候变化将以多种方式改变海洋生态系统，但气候变化对底栖硅藻的影响却很少研究，底栖硅藻是底栖栖息地最重要的光合作用生物群之一。我们进行了中生态实验，以研究温度升高和盐度降低对底栖硅藻的分类和功能多样性的影响。我们发现盐度降低会影响群落的分类和功能组成，群落组成的阈值盐度约为 5。这表明，当气候变化导致咸水系统盐度降低时，群落最显着的变化发生在盐度从>5降低到<5的地区。我们还表明，温度升高和盐度降低都会对群落产生压力，从而导致群落的α和β多样性减少。这表明气候变化减少了硅藻物种库的规模。我们的研究结果表明，随着气候的变化，我们可以预期底栖硅藻群落的多样性和弹性会降低。