冬季巢湖SPOM来源、空间变化及营养盐效应

为研究枯水期巢湖水体悬浮颗粒物（SPM）营养元素组成及其潜在环境效应，分析了2020年1月巢湖18个采样点表层水体SPM含量、颗粒有机质（SPOM）含量及氮磷组成，并利用颗粒有机碳、氮同位素组成及C/N研究了冬季巢湖SPOM的来源及其空间变化. 结果表明，悬浮颗粒物总磷(PP)浓度为0.032~0.065 mg/L，平均值为0.049 mg/L；悬浮颗粒物无机磷(PIP)浓度为0.018~0.046 mg/L，平均值为0.032 mg/L，是PP的主要组分，二者浓度均呈西湖区>东湖区>中湖区的空间分布特征. 悬浮颗粒物总氮(PN)浓度为0.254~0.424 mg/L，平均值为0.342 mg/L，其中悬浮颗粒物有机氮(PON)占比较高，表明颗粒态氮以湖泊内源性有机来源为主. 巢湖表层水体SPOM的δ13C范围在?28.72‰~?26.68‰之间，δ15N为3.34‰~9.97‰，C/N为2.51±0.95，指示冬季枯水期水体SPOM主要来自内源水生生物碎屑，而陆源径流输入对湖泊颗粒物影响较小. 研究显示:冬季巢湖悬浮颗粒有机质主要来自湖泊内源，具有潜在的营养盐效应，污染控制需要相应的策略. 

Sources,Spatial Variation and the Nutrient Effects of Winter Suspended Particulate Organic Matter from a Shallow Eutrophic Lake Chaohu,China

In order to study the nutrient compositions and potential environmental effects of suspended particulate matter in Chaohu lake during low water period, sources and spatial variation of suspended particulate organic matter (SPOM) in January, 2020 were analyzed by measuring the mass of suspended particulate matter, nitrogen and phosphorus content, carbon and nitrogen isotope compositions of SPOM in this study. The results showed that the content of total particulate phosphorus (PP) and inorganic particulate phosphorus (PIP) were 0.032 - 0.065 and 0.018 - 0.046 mg/L, respectively. PIP was the main fraction of PP; they showed similar spatial distributions with highest in western lake, moderate in eastern and lowest in central. The content of total particulate nitrogen (PN) in suspended particulate matter ranged from 0.254 to 0.424 mg/L, with a large variation in spatial distributions. The δ13C and δ15N of suspended particulate matter ranged from ?28.72‰ to ?26.68‰ and 3.34‰ to 9.97‰, respectively, with the mean C/N ratio of 2.51±0.95. The stable carbon and nitrogen isotope compositions and C/N ratios indicated dominant autochthonous sources of algae and other aquatic organisms for suspended particulate organic matter in January, 2020, likely due to less water flow and runoff into the lake in winter time. This study indicated that the autochthonous organic matter was the main source for winter SPOM in Chaohu lake, and the SPOM contributed potentially to lake nutrients, and a corresponding strategy for pollution control should be considered.