太湖蓝藻水华暴发机制与控制对策   总被引：2，自引：0，他引：2  

杨柳燕  杨欣妍  任丽曼  钱新  肖琳 《湖泊科学》2019,31(1):18-27

湖泊蓝藻水华暴发由于引发水生态系统的灾害和饮用水安全风险而成为国内外研究的热点之一.太湖蓝藻水华暴发原因多样，其中蓝藻自身的特性是水华暴发的内因，太湖的地理、水文和气象特征为蓝藻水华暴发提供了合适的温度和水动力条件，是蓝藻水华暴发的外因，湖泊草-藻型生态系统的转变以及氮、磷营养盐的高负荷输入更利于蓝藻生长，湖泊氮、磷营养盐四重循环是蓝藻水华不断暴发的维持机制，蓝藻水华暴发与氮、磷营养盐浓度之间存在交互作用关系.太湖蓝藻水华的控制应以陆源控源截污为基础，增加湖泊营养盐输出为重点，实现疏堵有机结合，其中恢复水生植被，重建草-藻结合型水生态系统是太湖湖泊生态修复的关键所在.  相似文献   

Water quality modeling and sensitivity analysis using Water Quality Analysis Simulation Program (WASP) in the Shenandoah River watershed     

Mbongowo J. Mbuh  Richard Mbih  Comfort Wendi 《自然地理学》2019,40(2):127-148

This study used the Water Quality Analysis Simulation Program (WASP) to simulate nutrients, dissolved oxygen (DO), and chlorophyll-a dynamics in the Shenandoah River basin and performed an uncertainty analysis to examine the complexity of these variables in water quality estimation and their influence on the Shenandoah River. Significant progress has been made; however, nutrient loads emitted into the Shenandoah River from nonpoint sources remain high. Modeling of three points on the Shenandoah River in Virginia and West Virginia provides an ideal case study since the river is classified by the Virginia Department of Environmental Quality as being impaired. The results of a sensitivity test show that model error decreases with increasing model complexity and sensitivity. The model predicted DO values that tended to be close to the measured data, while total nitrogen and phosphorus tended to be overemphasized. Our results examine the importance of temperature, stream flow, and velocity in influencing water quality between seasons and levels on the different sections of the watershed.  相似文献   

广东雷州半岛土壤氮、磷、钾元素地球化学特征及其土壤肥力评价          下载免费PDF全文

汪实  朱鑫  黎旭荣  罗思亮 《中国地质》2021,48(4):1177-1187

广东雷州半岛位于中国大陆最南端,是中国菠萝、香蕉、甘蔗等农产品重要产地。土壤氮、磷、钾等养分是作物生长需要最多的营养元素,对农业发展至关重要。文章通过对雷州半岛土壤取样,首次对该地区土壤氮磷钾的背景特征进行了分析,研究了不同成土母质、不同土地利用类型氮磷钾的含量水平,探讨了氮磷钾人为影响因素和时空演化规律,并进行了土壤肥力评价。研究发现,雷州半岛土壤中氮、磷、钾分布受地质背景制约,并受人为活动干扰强烈,氮、磷受人类活动影响显著,钾受人为扰动程度较轻。与20世纪90年代相比,表层土壤磷元素含量增幅较大,钾元素含量与前期相当。土壤肥力评价结果表明,雷州半岛土壤富磷,缺钾,局部缺氮。  相似文献   

元古宙真核藻类演化及环境控制因素     

张凤廉  王华建  张水昌  邓胜徽  叶云涛  邓焱  王晓梅  吕丹  卢远征  吕怡潼 《地质学报》2021,95(5):1334-1355

宜居地球、地外生命探索以及资源勘查等的需求使真核生物的早期溯源和演化趋势研究成为国际热点.根据已发现实体化石、分子化石和分子钟证据,将元古宙真核藻类演化划分为环境准备(2.45～1.70 Ga)、缓慢发展(1.70～0.80 Ga)、剧烈波动(0.80～0.64 Ga)、快速辐射(0.64～0.54 Ga)四个阶段.元古宙真核生物的出现、演化和辐射进程与地球氧化和极端气候事件(如冰期)的发生具耦合性,表现出早期生命与地球表层环境的协同演化.真核藻类在1.70～0.80 Ga期间的缓慢演化可能与长期较低的大气氧含量(约为现今水平的1％～10％PAL)有关.低的大气-海洋氧化程度不仅限制了真核藻类生存空间,也通过对氮、磷等营养元素的供应约束,限制了真核藻类初级生产力水平.因此,地球表层氧化可能是地球宜居演化,并孕育出真核生物等各种复杂生命的主要原因.从地球系统形成与演变的角度探索生物圈演化或能对生命的过去和未来给出更为可靠的答案.  相似文献   

三峡库区消落区表层沉积物磷吸附特征   总被引：2，自引：0，他引：2       下载免费PDF全文

曹琳  吉芳英  林茂  黎司  王图锦 《水科学进展》2011,22(1):89-96

以三峡库区消落区表层沉积物为研究对象,通过对干湿交替沉积物中磷的赋存形式、吸附等温曲线的分析,揭示了干湿交替过程中沉积物磷的分布规律、吸附特征以及磷的源汇变化。结果表明:上覆水总磷变化呈现11月总磷<5月总磷<8月总磷。消落区覆水到出露沉积物最大磷吸附量、土壤最大缓冲能力在增加,磷零吸持平衡浓度、易解吸磷在降低,表明沉积物在夏季出露落干的过程中,固磷能力增强,释磷能力减弱;消落区土壤首次覆水过程中土壤磷呈现出由源到汇的转变。成库初期,覆水时沉积物主要表现为磷的积累,次年水库开闸放水排沙时,消落区表层富磷沉积物被冲刷排出。  相似文献   

波浪扰动对太湖底泥磷释放影响模拟   总被引：7，自引：0，他引：7       下载免费PDF全文

丁艳青  朱广伟  秦伯强  王永平  吴挺峰  申霞  洪大林 《水科学进展》2011,22(2):273-278

为揭示波浪扰动对湖泊底泥磷释放的影响,在波浪水槽中模拟了不同波高情况下扰动对水体、水土界面、底泥间隙水的磷、溶解氧等的影响.结果显示,在大波扰动下,沉积物大量悬浮,水体总磷随之增加,溶解性磷增加却不显著;波浪扰动显著增加了水体和沉积物界面的溶解氧浓度,并增加了溶解氧在沉积物的侵蚀深度;波浪扰动降低了沉积物表层10 cm内间隙水中的磷浓度,而10 cm以下沉积物中间隙水中磷浓度基本保持不变.研究表明,波浪扰动可迅速增加水体中颗粒态的营养盐,但是对于溶解态营养盐,尤其是水体中活性磷浓度的影响,则受沉积物性质、水-沉积物间隙水磷浓度差,以及水-沉积物中氧含量等多方面因素的影响.  相似文献   

长江口跨越锋面颗粒磷季节分布变化特征及影响因素   总被引：1，自引：0，他引：1  

刘希真  李宏亮  陈建芳  金海燕  王文亮  刘际弟  王奎  庄燕培 《海洋学研究》2011,(3):88-98

根据2006年夏、冬季以及2007年春、秋季“海监49号”科学考察船的调查数据,分析了长江口跨越锋面区域(31.00°～31.78°N、121.04°～123.99°E)颗粒总磷(PP),颗粒无机磷(PIP),颗粒有机磷(POP)的季节变化和空间分布特征.结果表明,PIP是水体颗粒磷的主要存在形式;受长江径流输沙量的影...  相似文献   

Photosynthetic efficiency, cell volume, and elemental stoichiometric ratios in Thalassirosira weissflogii under phosphorus limitation     

��ʤ  ��־��  ����  ����  ��ɭ�� 《中国海洋湖沼学报》2011,29(5):1048-1056

Nutrient limitation is known to inhibit growth and metabolism and to alter elemental stoichiometric ratios in phytoplankton. In this study, physiological changes in Thalassirosira weissflogii were measured under different dissolved inorganic phosphate (DIP) regimes in semi-continuous cultures to revisit the utility of the Redfield ratio for assessing nutrient limitation. The results showed that cell size increased with decreasing DIP availability. In the P-depleted treatment (f/2-P) the cell size was 1.48 times larger than that in the P-limited (f/100) treatment and 2.67 times larger than that in the P-saturated treatment (f/2 and f/10). The fucoxanthin to chlorophyll a ratio (Fuco/chl a) was relatively stable (about 0.3) in P-saturated cultures and was 10 times higher than that in P-limited and P-depleted cultures. During the experimental period, the photosynthetic efficiency index, ?F/Fm′, was relatively stable at ~0.50 in the P-saturated cultures, but quickly declined with decreasing DIP availability. Although cellular P content showed a significant difference between the P-saturated culture (1.6 pg/cell) and the P-limited culture (0.7 pg/cell), the N/P ratio in T. weissflogii did not show a trend with DIP availability and fluctuated slightly around 25. Our results suggest that cell division in T. weissflogii is not strictly size-gated but is probably regulated by a biochemical, and hence, an elemental stoichiometric ratio threshold, and that deviation of the cellular N/P ratio from the Redfield ratio is not a reliable indicator of algal nutrient stress.  相似文献   

Harmful algal blooms and eutrophication: ��strategies�� for nutrient uptake and growth outside the Redfield comfort zone     

Patricia M. GLIBERT  JoAnn M. BURKHOLDER 《中国海洋湖沼学报》2011,29(4):724-738

While many harmful algal blooms have been associated with increasing eutrophication, not all species respond similarly and the increasing challenge, especially for resource managers, is to determine which blooms are related to eutrophication and to understand why particular species proliferate under specific nutrient conditions. The overall goal of this brief review is to describe why nutrient loads are not changing in stoichiometric proportion to the "Redfield ratio", and why this has important consequences for algal growth. Many types of harmful algae appear to be able to thrive, and/or increase their production of toxins, when nutrient loads are not in proportion classically identified as Redfield ratios. Here we also describe some of the physiological mechanisms of different species to take up nutrients and to thrive under conditions of nutrient imbalance.  相似文献   

Effect of nitrogen to phosphorus ratios on cell proliferation in marine micro algae     

张青田  胡桂坤 《中国海洋湖沼学报》2011,(4)

The ratio of nitrogen/phosphorus (N/P) is known to affect cell proliferation of some marine micro algae. We evaluated the effect of N/P ratios on the proliferation and succession of phytoplankton using five marine micro algae species. We used two sources of nitrogen, NH4Cl (N1) and urea (N2), and a single source of phosphorous, NaH2PO4(P). The optimal N/P ratio that differed among the five species was affected by the source of nitrogen, being as follows (N1/P, N2/P in order): Thalassiosira sp. (30/1, 20/1),...  相似文献