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1.
光照对绿豆扦插苗不定根生长硼需求的影响   总被引:1,自引:1,他引:0  
研究了光照状况对绿豆扦插苗不定根生长硼需求的影响.结果表明,当绿豆幼苗在光照强度(PAR)为50或100 μmol·m-2·s-1条件下连续生长10 d,外源供硼时扦插苗才能生长不定根,在该光照条件下连续生长6 d再遮黑4 d,无需外源供硼即可生长不定根;在PAR为180 μmol·m-2·s-1下连续生长6 d再遮黑4 d,需外源供硼才能保证不定根生长;在PAR为100 μmol·m-2·s-1条件下连续生长10 d时,每个下胚轴中自由态的硼总量仅为在此光照条件下连续生长6 d再遮黑4 d时的一半,这可能是在PAR为100 μmol·m-2·s-1时连续生长10 d需要外源供硼满足不定根生长的原因.  相似文献   

2.
为了研究流速对不同浮游藻类生长的影响, 于 2015 年 3 月采集东江流域广东惠州河段原水, 在环形有机玻璃水槽中分别培养铜绿微囊藻、斜生栅藻和小环藻, 通过调整水体流速, 研究不同流速对不同藻类的细胞密度、叶绿素 a 浓度、最大比增长率和叶绿素荧光参数 Fv/Fm 的影响。结果表明, 在不同流速条件下, 不同浮游藻类的生理生化特征有所差异; 铜绿微囊藻表现为在不同流速条件下生长状况都较弱; 斜生栅藻和小环藻在低流速(<0.075 m·s–1)条件下繁殖速度较快, 且随着水体流速的增加, 对藻类生长有促进作用, 而在较高流速(>0.075 m·s–1)条件下随着流速的增加, 藻类的生长受到抑制。可见, 不同持续的流动条件是影响浮游藻类数量和生理指标变化的重要原因。该研究为东江水源的流速流量调节控制富营养化和水华防治提供技术支撑。  相似文献   

3.
张家界大鲵生境特征   总被引:3,自引:0,他引:3  
罗庆华 《应用生态学报》2009,20(7):1723-1730
2006—2008年的7—8月,对湖南张家界大鲵国家级自然保护区境内大鲵栖息河段及其洞穴特征、水质和饵料生物资源进行了实地观测和取样分析,研究了该保护区野生大鲵的生境特征.结果表明:研究区大鲵栖息河段海拔适中,在(373±97) m,河宽与河深均较小,分别为(6.39±2.13) m和(1.07±0.53) m;河段底质均为石质性结构,多为卵石或礁石,河床多为不规则型,河岸多为石壁;两岸植被类型多为灌木丛,植被覆盖度(>50% )与坡度[(58±17)°]均较大;研究河段的水流速较大,在(0.33±0.08) m·s-1,且人为干扰较弱.研究区大鲵栖息地的洞穴数量较多,达(4±2)个·100 m-1,洞穴中水的流速较小,在(0.22±0.10) m·s-1.大鲵栖息处水质溶解氧较高,为(7.23±0.85) mg·L-1,化学耗氧量与总氮含量均较低,分别为(4.00±2.51)和(0.11±0.15) mg·L-1,总硬度适中,为(137.16±67.69) mg·L-1,大肠菌群较少,为(3419±3407) ind·L-1.对研究区大鲵种群数量影响最大的饵料生物是蟹,其次为虾.  相似文献   

4.
罗庆华 《生态学杂志》2009,20(7):1723-1730
2006—2008年的7—8月,对湖南张家界大鲵国家级自然保护区境内大鲵栖息河段及其洞穴特征、水质和饵料生物资源进行了实地观测和取样分析,研究了该保护区野生大鲵的生境特征.结果表明:研究区大鲵栖息河段海拔适中,在(373±97) m,河宽与河深均较小,分别为(6.39±2.13) m和(1.07±0.53) m;河段底质均为石质性结构,多为卵石或礁石,河床多为不规则型,河岸多为石壁;两岸植被类型多为灌木丛,植被覆盖度(>50% )与坡度[(58±17)°]均较大;研究河段的水流速较大,在(0.33±0.08) m·s-1,且人为干扰较弱.研究区大鲵栖息地的洞穴数量较多,达(4±2)个·100 m-1,洞穴中水的流速较小,在(0.22±0.10) m·s-1.大鲵栖息处水质溶解氧较高,为(7.23±0.85) mg·L-1,化学耗氧量与总氮含量均较低,分别为(4.00±2.51)和(0.11±0.15) mg·L-1,总硬度适中,为(137.16±67.69) mg·L-1,大肠菌群较少,为(3419±3407) ind·L-1.对研究区大鲵种群数量影响最大的饵料生物是蟹,其次为虾.  相似文献   

5.
在设施基质栽培条件下,研究了营养液中120、240及360 mg·L-1 3个钾素水平对网纹甜瓜‘甜甜1号’叶片光合特性及叶绿体亚显微结构的影响.结果表明,营养液中钾素水平过低(120 mg·L-1)或过高(360 mg·L-1)均导致网纹甜瓜叶片净光合速率下降,使叶绿体片层结构混乱、变形和片层数减少,但对CO2补偿点(70 μl·L-1)、饱和CO2(600 μl·L-1)、光补偿点(50 μmol·m-2·s-1)无显著影响.适宜的钾素水平能显著提高叶片的饱和光强、羧化效率和表观量子效率,3个指标分别为1 200 μmol·m-2·s-1、0.1364和0.0237.在试验条件下,提高温室内基质栽培网纹甜瓜叶片光合效率的最适钾素水平为240 mg·L-1.  相似文献   

6.
热带季节雨林冠层树种绒毛番龙眼的光合生理生态特性   总被引:15,自引:0,他引:15  
采用Li-6400便携式光合作用测定仪,对西双版纳热带季节雨林冠层树种绒毛番龙眼成树树冠上、中、下3层叶片进行了测定,分析西双版纳热带季节雨林冠层树木的光合作用.结果表明,绒毛番龙眼成树具有喜光的光合特性,光饱和点较高(1 000~1 500 μmol·m-2·s-1),而光补偿点较低(7.7~15.3 μmol·m-2·s-1),对光环境有较强的适应和调节能力,光合有效辐射是影响绒毛番龙眼光合日进程的关键因子;12月,叶片处于成熟期,生长良好,光合能力较强,树冠上层净光合速率(Pn)日变化为单峰型,最大净光合速率(Amax)约为8.9 μmol CO2·m-2·s-1;4月处于新老树叶更替期,光合能力下降,树冠上层Pn日变化为双峰型,中午出现“午休”现象,树冠上层Amax约为4.3 μmol CO2·m-2·s-1;7月上、中层叶片Pn为单峰型,下层出现“午休”.如人为使CO2浓度在短期内迅速升高,则绒毛番龙眼的Pn会增加,而气孔导度和蒸腾速率降低;CO2浓度从400 μmol·mol-1升高到800 μmol·mol-1时,干季水分利用效率(WUE)提高约50%~100%,雨季WUE较低.  相似文献   

7.
镇江内江湿地不同演替阶段植物群落小气候日动态   总被引:9,自引:0,他引:9  
2005年5月,选择镇江内江湿地具有代表性的裸地、虉草群落和芦苇群落,分别代表植被群落的不同演替阶段,测定不同群落、不同层次的光照强度、气温、土温和空气相对湿度,研究其植物群落小气候的日动态.结果表明,随演替由裸地到虉草群落到芦苇群落进行,群落内光照强度、气温和土壤温度均明显降低,日变幅减小.其中,日均光照强度由1 204.7 μmol·m-2·s-1降至141.28 μmol·m-2·s-1,日均变幅由1 126μmol·m-2·s-1降至265 μmol·m-2·s-1;日均气温由32.2 ℃降至24.9 ℃,日均变幅由12.75 ℃降至4.8 ℃;日均土温由21.83 ℃降至19.47 ℃,日均变幅由4.5 ℃降至2.1 ℃.群落内空气相对湿度明显升高(由58.95%增至87.3%),变幅减小(由29.75%降至5.15%).生境具有早期的开放性和后期的封闭性,小气候环境朝着更为阴、凉、湿的环境变化,且波动性减弱,稳定性增强.各群落内的光强、气温、湿度及土温之间均存在一定相关,但不同演替阶段各因子间相关程度各异.  相似文献   

8.
正三峡水库成库以来,支流回水区频繁出现水华现象,成为近10年来我国水库生态学领域研究热点~([1])。水流条件是水华形成的主要诱导因素之一~([2]),合适的流速条件能给藻类生长营造有利的外部环境~([3])。温度、光照和营养盐是影响藻类生长的重要环境因子,在自然水体中随着深度的变化而变化~([4])。普遍认为,紊流扰动通过改变藻类在水体中的相对位置和分布,从而改变藻类生长的  相似文献   

9.
低温小麦种质叶片结构及某些生理特性   总被引:9,自引:0,他引:9  
通过对小麦冠层温度的长期观测,发现自然界存在冠层温度持续偏低的低温种质和冠层温度持续偏高的高温种质.在扬花结实期,低温种质冠层温度比高温种质低1~4 ℃.低温种质功能叶片叶肉细胞小,排列紧密,层数较多,通常比高温种质多1~2层叶肉细胞.低温种质陕229、901和小偃6号3片功能叶的平均厚度分别为166、192和165 μm,平均比高温种质薄26 μm;3片功能叶叶脉的平均间距分别为257、231和245 μm,平均比高温种质小31 μm;3片功能叶大叶脉平均横截面积分别为5 961、6 580和5 603 μm2,平均比高温种质大837 μm2;小叶脉平均横截面积分别为1 624、1 521和1 472 μm2,平均比高温种质大246 μm2.在扬花结实期,低温种质陕229、901和小偃6号3片功能叶平均叶绿素含量分别为2.8749、2.8162和2.4129 g·100 g-1 FW;净光合速率分别为10.8640、10.8003和10.1939 μmol·m-2·s-1;蒸腾速率分别为0.0076、0.0074和0.0067 mol·m-2·s-1,均明显高于高温种质.结果表明,植物的冠层温度与植物本身的器官结构和生理功能联系密切.  相似文献   

10.
不同土壤水分条件下紫藤叶片生理参数的光响应   总被引:21,自引:3,他引:21  
测定了不同土壤湿度下2年生紫藤叶片光合速率(Pn)、蒸腾速率(Tr)及水分利用效率(WUE)等生理参数的光响应过程,探讨了紫藤正常生长发育所需的土壤水分和光照条件.结果表明:紫藤叶片的Pn、Tr及WUE对土壤湿度和光照强度的变化具有明显的阈值响应.维持紫藤正常生长(同时具有较高Pn和WUE)的土壤湿度范围为:体积含水量(Wv)15.3%~26.5%、相对含水量(Wr)46.4%~80.3%,最佳土壤湿度约为Wv 23.3%、Wr 70.6%.紫藤叶片对光照环境的适应性较强,在光合有效辐射强度(PAR)为600~1 600 μmol·m-2·s-1时,Pn和WUE具有较高水平,饱和光强在PAR为800~1 000 μmol·m-2·s-1.紫藤叶片光合作用非气孔限制的发生与土壤湿度与光照强度密切相关,Wv为18.4%~26.5%、Wr为55.8%~80.3%时,光合作用主要受气孔限制,光照强度的影响较小;超出此范围后,其受光照强度的影响较大,出现由气孔限制转变为非气孔限制的PAR临界值.紫藤正常生长允许的最低土壤湿度约为Wv 11.9%、Wr 36.1%,允许最高PAR约为1 000 μmol·m-2·s-1,是紫藤叶片光合机构受到破坏的临界点.  相似文献   

11.
水动力条件下藻类动态模拟   总被引:17,自引:0,他引:17  
丁玲  逄勇  李凌  高光 《生态学报》2005,25(8):1863-1868
藻类动态变化是其内部生理特征和外部驱动因素综合作用的结果。除了藻类自身生理因素及光、温度、营养盐等因素,水动力作用使底泥发生再悬浮所造成的营养盐的内源释放对藻类的影响也非常重要。1999年5月8日~6月24日在太湖湖泊生态系统研究站大型生态实验槽中进行了模拟水动力条件下的太湖藻类动态实验,并应用国外先进的PHREEQC软件从生物化学和生态动力学角度建立了藻类生态动力学模型。模型不仅考虑了氮循环及磷循环,还考虑了水动力条件引起的内源释放问题,根据2003年4月26~4月30日在河海大学环形水槽所做的底泥释放实验结果建立了水流和各形态氮磷营养盐释放的定量化关系。由于目前太湖的野外监测资料存在较明显的时空不一致性,模型参数率定的精度受到了较大影响。从室内模拟实验出发,通过对生态槽实验结果的模拟,确定和验证了模型的各参数值,计算结果显示模拟值能较好地拟合实验测量值,表明所建藻类生态动力学模型能较好地描述藻类及各种营养盐的动态变化,这对揭示藻类“水华”暴发机理有一定的意义。  相似文献   

12.
利用场强为0.1、0.25、0.4T恒定磁场,以流速为1 m·s-1,分别对普通水进行9次处理,串联(SC)磁场处理3次的磁处理水,进而用于栽培蛹虫草,并研究了生物磁效应对蛹虫草虫草素、虫草酸、多糖含量及生物学转化效率的影响。结果表明,0.4T处理有利于蛹虫草虫草酸含量及生物学效率的提高,相比对照组分别提高了7.29%和15.37%;0.25T处理组有利于虫草素的积累,比对照组提高了11.31%;0.1T处理有利于多糖的积累,相比对照组提高了14.80%。方差分析表明,经不同场强处理的磁化水对蛹虫草子实体生长和活性物的代谢影响差异显著。但磁处理水对于不同物质含量的影响规律存在一定的差异性。  相似文献   

13.
Previous studies have shown major differences in the way biomass of stream periphyton is controlled by spatial variations in velocity. We hypothesize that these differences may be the result of different growth forms within the community. Some dense and coherent growth forms (e.g. mucilaginous diatom/cyanobacterial mats) may be resistant to diffusion and also resistant to dislodgment by shear stress. Higher velocities applied to such communities could therefore be expected to enhance biomass accrual by increasing rates of mass transfer, but without greatly increasing losses through sloughing. Conversely, other growth forms (e.g. long filamentous green algae) have an open matrix, and high rates of diffusion into the mats can potentially occur even at low velocity. However, as velocities increase, high skin friction and form drag should lead to higher rates of sloughing. The overall result of these processes should be that maximum biomass occurs at low velocities. This “subsidy-stress” hypothesis was tested twice with each of three different periphytal growth forms: a coherent, mucilaginous, diatom community; a moderately coherent, stalked/ short, filamentous diatom community; and an open-weave, long, filamentous green algal community. A monotonic increase in chl a biomass occurred as a function of near-bed velocities for the first of the two mucilaginous diatom communities investigated. No biomass-velocity relationship was found, however, with the second mucilaginous community, probably because the waters were highly enriched and mass transfer driven by molecular diffusion was probably high throughout the velocity gradient. Biomass was moderate at low velocities, peaked at near-bed velocities from 0.18 to 0.2 m·s?1 (~0.40–0.45 m·s?1 mean column velocity), and then decreased at higher velocities in both of the stalked/ short filament communities of diatoms analyzed. With the long filamentous green algal communities, a monotonic reduction in biomass occurred as a function of increases in velocity. Proliferations greater than 100 mg·m?2 chl a occurred at low near-bed velocities (i.e. <0.2 m·s?1), after which biomass declined nearly exponentially as a function of increasing velocity to less than 10 mg·m?2 chl a at velocities greater than 0.4 m·s?1. These biomass-velocity trends support our hypothesis that community growth form determines periphytal responses to spatial variations in velocity within stream reaches.  相似文献   

14.
防己抑藻效应及其化感物质的HPLC分析   总被引:3,自引:1,他引:2  
柴民伟  石福臣  马妍 《植物研究》2010,30(6):758-762
通过常温水浸提方法获得12种药用植物浸提液,并分别研究其抑藻效应。结果显示:防己水浸提物(相对浓度1 g·L-1)抑制蛋白核小球藻的效应最强,最大比生长率为-0.28 d-1。防己甲醇浸提物对蛋白核小球藻的抑藻效应显著,且持续时间长,最低有效抑藻浓度为30 mg·L-1。HPLC鉴定结果显示:防己水浸提液和甲醇浸提液中主要含有防己诺林碱、粉防己碱等生物碱类化学成分,防己对治理水华发生有较大的应用前景。  相似文献   

15.
Biomass, chemical composition, growth rates and the photosynthetic response of natural populations of sea ice algae in McMurdo Sound, Antarctica were followed over most of the spring bloom to examine temporal variability under a relatively constant incident irradiance (ca. 1500–1700 μE · m-2· s-1 at solar noon). Collection were restricted to bottom 20 cm of the ice sheet in an area with little or no snow (0–5 cm). At low temperature and irradiance these algae normally exhibited low assimilation numbers (ca. 0.1–0.4 mg C · mg Chl-1· h-1). Average growth rates (0.02–0.45 d-1), based on changes in standing stocks, were also low. Biomass, biochemical composition, growth rates, assimilation numbers and photosynthetic efficiencies (mg C · mg Chl-1· h-1 (μE · m-2· s-1)-1) displayed large fluctuations over periods of several days during the growth season. On the other hand, Ik which is an index of photoadaptation, and Im, the optimal irradiance for photosynthesis, were relatively constant with less than twofold variation throughout our study. Substantial nutrient fluxes (3.3–8.0 mmol Si or N · m-2· d-1) were necessary to satisfy the minimum nutrient demand for the observed biomass levels and population growth rates; over the 41 days of our study, integrated nutrient demand represented 69–150 mmol N or Si · m-2, Only 5–25% of this total demand could be met by all of the nutrients in the ice sheet, if they were readily available. However, adequate amounts were present in the top few meters of the water column. With small nutrient gradients in surface waters below the sea ice, vertical eddy diffusivities on the order of 3.8–9.3 cm2· s- should supply sufficient nutrients to meet algal demand.  相似文献   

16.
三峡水库神农溪2014年春季浮游藻类演替成因分析   总被引:1,自引:0,他引:1  
摘要:【目的】研究三峡水库神农溪库湾春季水华期间浮游藻类演替及其成因分析。【方法】2014年3–5月在神农溪库湾布置了6个断面(SN01–SN06),在神农溪汇入长江干流河口附近水域设置1个断面CJBD,对浮游藻类、相关环境因子及水动力因子进行了同步监测,据此分析了水体层化结构及水动力特性。【结果】神农溪在监测时段内共检测到浮游藻类6门38种(属);库湾浮游藻类生物量时间上差异显著(ANOVA,P<0.05)。春季浮游藻类群落结构具有明显的演替规律,3月份暴发大面积的硅藻水华(藻密度>100×105 cells/L),小环藻(Cyclotella spp.)为优势藻种;4月在SN02–SN06暴发以小球藻(Chlorella spp.)为主要优势种、衣藻(Chlamydomonas spp.)为次优势种的绿藻水华(藻密度>100×105 cells/L),5月份受水位大幅消落影响,浮游藻类生物量降低且无明显优势藻种。【结论】在具备充足的营养盐的水体中,水体层化结构与水动力特性对浮游藻类演替影响重大。三峡水库水位处于快速消落阶段时,流速成为抑制神农溪库湾藻类生长的主要因素。  相似文献   

17.
We developed models to predict the effect of water velocity on prey capture rates and on optimal foraging velocities of two sympatric juvenile salmonids, coho salmon and steelhead. Mean fish size was ~80 mm, the size of age I+ coho and steelhead during their second summer in Southeast Alaska streams, when size overlap suggests that competition might be strongest. We used experimentally determined prey capture probabilities to estimate the effect of water velocity on gross energy intake rates, and we modeled prey capture costs using experimental data for search and handling times and published models of swimming costs. We used the difference between gross energy intake and prey capture costs to predict velocities at which each species maximized net energy intake rate. Predicted prey capture rates for both species declined from ~75 to 30–40 prey/h with a velocity increase from 0.30 to 0.60 m·s−1. We found little difference between coho and steelhead in predicted optimum foraging velocities (0.29 m·s−1 for coho and 0.30 m·s−1 for steelhead). Although prey capture ability appears to be more important than are prey capture costs in determining optimum foraging velocities, capture costs may be important for models that predict fish growth. Because coho are assumed to pay a greater swimming cost due to a less hydrodynamic body form, we also modeled 10 and 25% increases in hydrodynamic drag to assess the effect of increased prey capture costs. This reduced optimum velocity by 0 and 0.01 m∙s−1, respectively. Habitat segregation among equal-sized coho and steelhead does not appear to be related to the effects of water velocity on their respective foraging abilities.  相似文献   

18.
The effects of flowing water on net photosynthesis, dark respiration, specific growth rate, and optimum N:P ratios by Spirogyra fluviatilis Hilse were assessed. The alga was cultivated under nitrogen or phosphorus limitation in laboratory streams at three flow velocities: 3, 12, and 30 cm·s?1. The Droop equation adequately described respiration and photosynthesis (PSnet) as a function of N or P cell quota (QN or Qp). The data show that for N- or P-limited Spirogyra fluviatilis, flowing water is physiologically costly. Generally, flowing water had little effect on respiration rates; however, the proportion of gross photosynthesis devoted to dark respiration did increase with flow velocity. For photosynthesis, the minimum N and P cell quotas increased with velocity, and the theoretical PSnet maxima for N and P both appeared greatest at 12 cm·s?1. The Droop models showed that for any given QN or Qp, PSnet, was reduced by the 30-cm·s?1 treatment. Consistent with this finding, independent estimates of specific growth rates for P-limited S. fluviatilis in the laboratory streams were inversely related to flow velocity when ambient PO4?3 was undetectable. However, growth was not diminished at the fastest velocity when PO4?3 was available for uptake. Thus, the increase in cellular phosphorus demand can be offset by flow-enhanced P uptake when conditions permit; otherwise, growth will be impaired. The optimum N:P ratios for S. fluviatilis at 3, 12, and 30 cm·s?1 were 50, 58, and 52 by atoms, respectively, when calculated for PSnet= 0. The optimum ratios were inversely related to PSnet and decreased to approximately 20 when PSnet was near maximum. The potential for flowing water to mediate nutrient partitioning among lotic algae by altering growth rates and optimum nutrient ratios is discussed.  相似文献   

19.
The inorganic phosphorus (Pi) uptake kinetics of Spirogyra fluviatilis Hilse were examined as a function of phosphorus cell quota (QP) and flow velocity in a laboratory stream apparatus. Short-term uptake and the acclimation of the uptake mechanism to flow were measured by the disappearance of Pi pulses in a recirculating flow cell. Short-term Pi uptake was biphasic. When the alga was P-deficient, Phase 1 and 2 half-saturation constants and maximum uptake rates were 11.0 and 47.2 μg P·L?1 and 473 and 803 μg P·g dry wt?1 h?1, respectively. Flowing water altered short-term uptake when the alga was P-deficient, but not when it was P-replete. When QP was less than 0.21%, increases in flow velocity from 3 to 15 cm·s?1 enhanced uptake with maximum uptake for any Pi pulse at 12 and 15 cm·s?1. At 22 and 30 cm·s?1, uptake was reduced by 12% or more relative to the maxima. If, however, the alga was cultivated at 22 and 30 cm·s?1 and short-term Pi uptake was measured at 12 cm·s?1, uptake was on average 33% greater than when the alga was cultivated at the latter velocity. Apparently, the alga could adjust short-term uptake to compensate for the suboptimal conditions of the faster velocities. Long-term Pi uptake and net phosphorus efflux were estimated by a non-steady state application of the Droop equation. Long-term uptake of very low Pi concentrations was not reduced by fast flowing water. Instead, uptake increased proportionately with flow velocity. Maximum phosphorus efflux from S. fluviatilis was 3% of cellular P per hour and occurred when QP was greater than 0.2%. At lower QP, the hourly efflux rate was typically less than 1%. Flowing water did not greatly enhance efflux, although when Pi was undetectable, efflux did tend to increase slightly with velocity. The data show that the effects of flowing water on Pi uptake were varied and not always beneficial. If the effects of flowing water on nutrient acquisition by other lotic algae are similarly varied and complex, flow may be an important determinant of nutrient partitioning among benthic algae in streams.  相似文献   

20.
This study focuses on the role of wind exposure and storm events, in interaction with trophic status and temperature, on the competition between two species: Microcystis aeruginosa and a typical green alga. It is based on a water column model containing ecological and fluid mechanic features including mixing and shear stress at the bottom. This model addresses for the first time the impact of storm events (inducing sediment and nutrient resuspension) on algal dynamics. Simulations with realistic environmental forcings were performed with different sets of wind, temperature, and trophic conditions. With normal temperatures, conditions for dominance and bloom formation of M. aeruginosa in summer are restricted to hypertrophic waters with low wind exposure. Higher wind exposure (above 2 m s?1) impairs the formation blooms even in favorable trophic conditions and enhances the dominance of green algae. Hotter temperatures allow the dominance of M. aeruginosa for lower phosphorus conditions and higher wind exposure and lead to the exclusion of green algae for high phosphorus content and low wind exposure. Nevertheless, high wind exposure (above 3 m s?1) still prevents dense bloom formation and allows the coexistence of both species. Storm events bring two counterbalancing features: sediment and nutrient resuspension. The first leads to a decrease of phytoplankton density in response to high turbidity, and the second leads to an increase and better maintenance of M. aeruginosa blooms due to high phosphorus concentration released in the water. This result depends on the timing of the event and on general wind exposure as phosphorus release only benefits M. aeruginosa if exposure to wind is low.  相似文献   

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