升温对超富营养型浅水湖泊沉积物营养盐动态迁移影响的初步研究

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 升温对超富营养型浅水湖泊沉积物营养盐动态迁移的影响 DOI: 10.5846/stxb201309102244 作者: 作者单位: 华中农业大学水产学院 湖北武汉,华中农业大学水产学院 湖北武汉,华中农业大学水产学院 湖北武汉,华中农业大学水产学院 湖北武汉,华中农业大学水产学院 湖北武汉,中国科学院水生生物研究所 湖北武汉 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目(31200359); 国家水体污染控制与治理科技重大专项课题子课题(2012ZX07501001-06); 公益性行业(农业)科研专项(201203083) A preliminary study of effects of warming on the nutrients dynamic in sediment of hypereutrophic shallow lake Author: Affiliation: College of fisheries,Huazhong Agricultural University,College of fisheries,Huazhong Agricultural University,College of fisheries,Huazhong Agricultural University,College of fisheries,Huazhong Agricultural University,College of fisheries,Huazhong Agricultural University, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在实验室控制条件下,以超富营养型浅水湖泊——武汉南湖表层沉积物和表层水为研究对象,设置18 ℃和22.5 ℃两个温度处理组,模拟武汉地区预测的21世纪末春季变暖的情景,研究升温对沉积物营养盐释放的影响。实验结果表明:整个实验过程中,22.5 ℃处理组水体中正磷酸盐(o-P)和总磷(TP)含量显著高于18 ℃处理组,说明气温升高可以显著促进富营养化浅水湖泊沉积物磷的释放,促进水体中磷含量的显著升高;此外,在实验的初始阶段,升温能够加速水体中氨氮(NH4+-N)向硝态氮(NO3--N)转化的过程,同时水体与沉积物中氮含量的下降可能是水体与沉积物中的氮通过反硝化作用从系统中溢出以及被系统中的底栖生物利用所致,没有观察到气温升高对沉积物中总氮的释放产生显著影响。 Abstract:It is now accepted that human-induced climate change is unavoidable. On average, global surface temperatures have increased by about 0.74 ℃ over the past 100 years with the majority of the increase (0.55 ℃) occurring over the past 30 years. Marked changes may be expected to occur in the global climate during this century. Temperature increase, although only one of several related climate changes, is the key variable of change and one that pervades almost all biological processes. All ecosystems will therefore be affected to some extent by global warming and predicting potential effects on the ecosystems is of great importance for ecology and management. Lake ecosystems are vital resources for aquatic wildlife and human needs, and any alteration of their environmental quality and water renewal rates has wide-ranging ecological and societal implications. However, lakes have always been subject to the impacts of climate change, and natural climate variations in the past have been one of the main reasons that lakes are ephemeral features of the landscape. The sediment in lakes typically has high concentrations of nutrients and organic matter, and hosts a biologically active autotrophic-heterotrophic community. Thus, knowledge of the warming effects on nutrients dynamic in sediment is in urgent need. In the present study, an indoor microcosm system was set up to explore the effects of warming on the nutrients dynamic in sediment of a hypereutrophic shallow lake, Lake Nanhu. Sieved sediment cores were incubated under laboratory conditions, the experimental temperature regimes consisted of decadal spring average of Wuhan city (18 ℃) and an elevated regime with 4.5 ℃ difference from that at baseline (22.5 ℃). The contents of orthophosphate and total phosphorus in the water under the ambient temperature of 22.5 ℃ was significantly higher than those of 18 ℃ during the middle stage of the experiment, which indicated that warming accelerated the release of phosphorus from the sediment into water and the increase of the phosphorus content in the water would further increase the eutrophication. The concentration of the nitrate nitrogen in water raise rapidly accompany with the ammonia nitrogen concentration decreasing fast in the beginning of the experiment. Nevertheless, the contents of total nitrogen in water under two different temperature conditions were not significantly different from each other. The concentrations of total nitrogen in water and sediment were continuously declining at both conditions in all the experimental phases, which may indicate the denitrification and the benthic biological absorption in this experiment system. The total phosphorus content in sediment, loss on ignition of sediment, an indicator for loss of organic matter, and the chlorophyll a in the sediments were not significantly affected by the elevated temperature in this experiment system. In conclusion, warming may profoundly affect the phosphorus dynamics, but no obvious impact on the nitrogen dynamics in sediment. 参考文献 相似文献 引证文献