State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China.
Sci Total Environ. 2019 Jan 10;647:1398-1409. doi: 10.1016/j.scitotenv.2018.08.081. Epub 2018 Aug 7.
Studies that address the potential effects of climate and anthropogenic activities on lacustrine phytoplankton succession are scarce in the shallow lakes. In the present work, the succession of phytoplankton community inferred from sedimentary pigments has been investigated; the impacts of climate and anthropogenic activities on the succession have been evaluated by the generalized additive models (GAMs) in a shallow eutrophied lake, Lake Chaohu, located eastern China. The results show that phytoplankton succession can be divided into two periods: pre-1960s and post 1960s. The mean values of ββ‑Car and Chl a increased after the 1960s at both sites sampled, from 0.013 to 0.359, and 0.013 to 1.382 μg g, respectively (site C4), and from 0.015 to 0.530, and 0.010 to 0.921 μg g, respectively (site C14), reflecting significant increases of primary productivity since the 1960s. The percentage of diatoms and dinoflagellates preserved in sediments decreased from ~90% to ~15% since the 1960s, while cyanobacteria and green algae increased from ~5% to ~35%, respectively, reflecting the shift of the lake phytoplankton community. This succession was related to construction of the Chaohu Dam in 1963, increasing discharges of anthropogenic N and P into the Lake, and a generally warming environment as reflected by increasing average air temperatures. The results of GAMs showed aquatic total phosphorus (TP) concentration is the dominant contributor to phytoplankton community change, explaining 42.74%, 40.27%, 40.77% and 72.28% of the variance of total algae, cyanobacteria, green algae, and diatoms and dinoflagellates, respectively. The positive impacts of increasing TP concentrations on abundances of total algae, cyanobacteria, and green algae were observed during periods of relatively high TP concentrations since the mid-1970s. The positive responses of total algae, cyanobacteria, green algae and diatoms and dinoflagellates to increasing average air temperatures were observed since the mid-1990s, showing that a generally warmer environment facilitated algae proliferation.
在浅水湖泊中，研究气候和人为活动对湖泊浮游植物演替的潜在影响的研究很少。本研究通过沉积物色素推断浮游植物群落的演替，并用广义加性模型（GAMs）评估了气候和人为活动对中国东部浅水富营养化湖泊巢湖演替的影响。结果表明，浮游植物演替可分为两个时期：1960 年代前和 1960 年代后。自 20 世纪 60 年代以来，两个采样点的ββ-胡萝卜素和 Chl a 的平均值分别从 0.013 增加到 0.359 和 0.013 增加到 1.382μg/g（C4 点），和从 0.015 增加到 0.530 和 0.010 增加到 0.921μg/g（C14 点），反映了自 20 世纪 60 年代以来初级生产力的显著增加。自 20 世纪 60 年代以来，沉积物中保存的硅藻和甲藻的百分比从90%下降到15%，而蓝藻和绿藻分别从5%增加到35%，反映了湖泊浮游植物群落的转变。这种演替与 1963 年的巢湖大坝建设有关，增加了人为 N 和 P 排放到湖中，以及平均空气温度升高反映的普遍变暖环境。GAMs 的结果表明，水体总磷（TP）浓度是浮游植物群落变化的主要贡献者，分别解释了总藻类、蓝藻、绿藻和硅藻和甲藻变化的 42.74%、40.27%、40.77%和 72.28%。自 20 世纪 70 年代中期以来，相对较高的 TP 浓度期间，TP 浓度的增加对总藻类、蓝藻和绿藻的丰度产生了积极影响。自 20 世纪 90 年代中期以来，总藻类、蓝藻、绿藻和硅藻和甲藻对平均空气温度升高的积极响应表明，一般较暖的环境有利于藻类的增殖。
