Division of Limnology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
Sci Rep. 2023 Aug 19;13(1):13503. doi: 10.1038/s41598-023-40596-6.
Lakes located in the boreal region are generally supersaturated with carbon dioxide (CO), which emerges from inflowing inorganic carbon from the surrounding watershed and from mineralization of allochthonous organic carbon. While these CO sources gained a lot of attention, processes that reduce the amount of CO have been less studied. We therefore examined the CO reduction capacity during times of phytoplankton blooms. We investigated partial pressure of CO (pCO) in two lakes at times of blooms dominated by the cyanobacterium Gloeotrichia echinulata (Erken, Sweden) or by the nuisance alga Gonyostomum semen (Erssjön, Sweden) during two years. Our results showed that pCO and phytoplankton densities remained unrelated in the two lakes even during blooms. We suggest that physical factors, such as wind-induced water column mixing and import of inorganic carbon via inflowing waters suppressed the phytoplankton signal on pCO. These results advance our understanding of carbon cycling in lakes and highlight the importance of detailed lake studies for more precise estimates of local, regional and global carbon budgets.
位于北方地区的湖泊通常过饱和二氧化碳（CO），这些 CO 来源于周围流域的无机碳流入和异源有机碳的矿化作用。虽然这些 CO 来源引起了广泛关注，但减少 CO 数量的过程却研究较少。因此，我们在浮游植物大量繁殖期间研究了 CO 的还原能力。我们在两年内调查了两个湖泊在蓝藻 Gloeotrichia echinulata（Erken，瑞典）或有害藻类 Gonyostomum semen（Erssjön，瑞典）大量繁殖期间的 CO 分压（pCO）。我们的结果表明，即使在浮游植物大量繁殖期间，两个湖泊的 pCO 和浮游植物密度仍然没有相关性。我们认为，物理因素，如风引起的水柱混合和通过流入水输入的无机碳，抑制了 pCO 上的浮游植物信号。这些结果增进了我们对湖泊碳循环的理解，并强调了详细的湖泊研究对于更准确估计当地、区域和全球碳预算的重要性。
