主养青鱼高产池塘的初级生产力及其能量转化为鲢、鳙产量的效率

本文论述了主养青鱼高产池塘浮游植物初级生产力的测定结果,揭示了其垂直、季节变化及其与主要生态因子、鱼产量水平、鲢、鳙鱼产量的关系,分析了D/B、P_G/R_W、N/P的作用。研究查明:1米以上水柱的光合产氧量占水柱总产氧量的90％以上。水柱日毛产氧量变动在5.00—17.04克氧/平方米·日之间,水柱年产氧量达2063—2814克氧/平方米·年。初级生产量全年只有一个高峰,常出现在7—8月。主养青鱼型年净产鱼量7500、11250、15000公斤/公顷级池塘的浮游植物鲜重净产量分别为100 674.4、118 560、128 197.6公斤/公顷·年,青鱼、草鱼并重型年净产鱼量15000公斤/公顷级池塘的浮游植物鲜重净产量为137 323.2公斤/公顷·年。 4—11月,毛初级生产力对太阳辐射能的利用率为0.81—1.11％;鲢、鳙产量对浮游植物净产量的直接利用率为3.49—5.13％;太阳能转移为鱼产量的生态学效率为0.028—0.055％。     

盐碱池塘浮游植物初级生产力的研究

根据黑白瓶测氧法测定 ,山东省高青县赵店渔场盐碱池塘鱼类生长期内 (4— 9月 )浮游植物初级生产力为9 42± 4 2 1gO2 (m2 ·d) ,日P/B系数平均 0 2 4± 0 18,浮游植物对太阳有效辐射的利用率平均 1 5 3%。无鱼对照池浮游植物初级生产力显著低于养鱼池。回归分析表明 ,浮游植物现存量、透明度、水温、盐度是决定盐碱池塘浮游植物初级生产力的主要生态因子。营养盐中磷比氮的限制作用大。文中探讨了养鱼池初级生产力在能量转化中的生态学效率。     

滩涂池塘生态系统的光合能量利用及其影响因子

研究了江苏沿海滩涂不同养殖模式下初级生产力特征、能量利用率及其影响因子.结果表明,滩涂养殖水体浮游植物的初级生产力存在垂直分布、日变化和季节的动态变化,这种变化与太阳辐射强度有直接的关系.滩涂养殖水体净初级生产量平均值为(7.58±2.52) gO2/(m2 · d),只占毛产量的55.41%,太阳能转化为鲢、鳙鱼产量的生态效率为0.020%～0.029%,这些指标低于我国高产养殖塘,鱼塘生态系统结构有待进一步优化.浮游植物生物量、透明度、N/P值、Mg2+浓度等因素显著影响水体初级生产力的大小,多元逐步回归表明浮游植物叶绿素含量和到达水体表面的太阳辐射强度是初级生产力的最主要因子,其回归方程为:Pg =0.0785Cha+0.0577 Iλ0+1.346;n=22, FCha>F Iλ0>F0.1,而盐度、Na+、Cl-浓度影响不显著.     

刺参养殖池塘初级生产力及其粒级结构周年变化

研究了刺参(Apostichopus japonicus Selenka)养殖池塘浮游植物初级生产力及粒级结构的周年变化规律,旨在明确刺参养殖池塘的基础生态学特征,为刺参养殖生产和管理提供科学支持。结果表明:刺参养殖池塘初级生产力年平均值为(5.16±3.04)gO2m-2d-1,全年呈现明显的季节变化,初级生产量分别在初春、夏季和初冬形成高峰。初级生产力群落净产量占毛产量的50.2%。P/R值与日P/B系数的年平均值分别为2.20±1.25和0.39±0.35。按初级生产力水平和P/R值划分的水体营养类型,调查刺参养殖池塘属富营养型水体;初级生产量随深度的增加而递减,最高生产层约在透明度的0.5倍处,且0.5倍透明度(约50 cm)以上水层初级生产量占水柱总产量的56.3%;不同粒级浮游植物生产量占总生产量的百分比具有明显的季节变化。除夏季外,以小型浮游植物(micro-,20—200μm)对初级生产力的贡献最大(43.5%),夏季为微型浮游植物(nano-,2—20μm)对初级生产力贡献最大(35.3%)。以年平均值计算,不同粒级浮游植物初级生产量占总生产量百分比的大小顺序为:小型(40.1%)微型(28.2%)中大型(16.1%)超微型(15.7%)。回归分析表明:试验池塘初级生产力水平与水温、营养盐中的氨氮和亚硝酸氮均呈显著的相关关系(P0.05)。结果提示,刺参养殖池塘初级生产力的季节变化显著,垂直分布并不均匀,小型浮游植物是其生态系统中的主要生产者。     

我国陆地生态系统的植物太阳能利用率

本文计算分析了我国陆生植物在各种情况下的净初级生产力及其太阳能利用率。 计算表明,每年进入我国960万平方公里国土上的太阳总辐射Q和光合有效辐射PAR分别为13×10~(18)千卡和6.4×10~(18)千卡,其所含能量约合标准煤20,000亿吨和10,000亿吨。在充分利用我国光、温、水气候资源,而其他条件都处于最适状况时每年净初级气候潜力Y_(ptw)的全国总量为250亿吨(植物质干重,下同)。由植被产量的实际资料与气候因子的经验关系估算的自然植被产量Y_n的全国总量为每年70亿吨。 就全国加权平均单产而言,净初级光能潜力Y_p=87吨/公顷·年;净初级光温潜力Y_(pt)=50吨/公顷·年;净初级气候潜力Y_(ptw)=30吨/公顷·年;自然植被生产力Y_(?)=8吨/公顷·年;现阶段主要农作物的净初级实际生产力Y_α=8.7吨/公顷·年。各省区情况见表1。 太阳能利用率:就全国加权平均而言,如果把总辐射Q计为100％,则光合有效辐射PAR约占49％;具有最佳叶冠层的高产植物在生长盛期对Q的利用率上限为7％;相应于Y_p、Y_(pt),Y_(ptw)和Y_n的太阳能利用率R_p、R_(pt)、R_(ptw)和R_n分别为2.5％,1.4％、0.82％和0.22％,我国当前主要农作物的净初级产量对我国农田上Q的利用率R_α为0.28％。各省区情况见表2。     

淀山湖基于初级生产力的鲢鳙富营养化控制

于2008年10月—2009年9月,采用黑白瓶测溶氧法对淀山湖湖南区和围隔区初级生产力进行逐月测定,依据测定的湖南区初级生产力估算鲢、鳙渔产潜力及合理放养量,讨论温度、透明度、营养盐、叶绿素a等理化因子与初级生产力的相关性,分析鲢、鳙放养对淀山湖水体营养物质的定量去除效果。结果表明:1)湖南区平均水柱日毛产量(PG)为4.02gO2.m-2,8月最高、1月最低,净产量(PN)为1.99gO2.m-2,年PN/PG=52%;2)0～0.5m水层对水柱初级生产力贡献最大,湖南区占32.3%、围隔区占32.2%;3)初级生产力与透明度、水温呈明显正相关,与其他理化因子相关性不明显;4)淀山湖浮游植物年生产量为28.18×104t,按鲢鳙3:1比例放养,鲢渔产潜力为1621.58t,鳙为1216.18t,鲢合理放养量为16.94t.km-2,鳙合理放养量为6.35t.km-2;5)以淀山湖每年渔产2837.76t计算,可以固定氮、磷分别为85.50t、7.63t,由此可使淀山湖水体中氮、磷含量分别降低0.67和0.06mg.L-1。     

南黄海表层沉积物中氮的潜在生态学功能

首次探讨了南黄海表层沉积物中不同形态可转化氮与该海域浮游植物、浮游动物的丰度、生物量以及初级生产力的关系 ,研究了沉积物中可转化氮在海洋生物生长、繁衍中的潜在生态学功能。结果表明 ,不同粒度的沉积物中各形态氮的生态学功能有较大差异 ,一般细粒度沉积物中可转化各形态氮与浮游植物、底栖生物有较密切的关系 ,而中、粗颗粒沉积物中的可转化氮主要与浮游动物有关 ;在南黄海不同粒度的表层沉积物的 4项可转化氮中 ,强氧化剂可浸取态氮 (SOEF- N )、强碱可浸取态氮(SAEF- N)与浮游植物的生长繁殖、提升海域的生产力有密切关系 ;两种无机形式的氮 (NH4 - N和 NO3- N)和叶绿素 a、浮游植物细胞总量以及初级生产力具有正相关关系 ,说明表层沉积物中的可转化态 NH4 - N和 NO3- N对于促进浮游植物的生长以及提高初级生产力具有非常重要的作用 ,是浮游植物可以直接吸收利用的氮的两种主要形式 ,其中 NO3- N的作用要稍大一些 ,且粒度越细 ,影响越大 ;NH4 - N和 NO3- N对于促进浮游动物以及底栖动物生长繁殖的作用则不明显 ,因其不能直接被它们吸收利用 ,而与通过食物链的传输等一系列中间环节有关 ;且在南黄海表层沉积物中 ,氮无论以什么形态存在 ,只有转化为无机形式的 NH 4后 ,其生态学功能才易被显     

主养青鱼池塘生态系统能量转换率的研究

1985—1987年对苏州市郊区主养青鱼池塘生态系统的能量转换率进行了分析。结果表明,主养青鱼净产7.5、11.25、15t/ha 3个产量级型池塘青鲤团头鲂产出能占养鱼总产出能的比例分别为82.49、78.03、79.34％;总投入能(太阳辐射能+辅助能)转移到鱼的总产出能转换率分别为0.19、0.24、0.31％;太阳辐射能转移到毛和净初级生产力的能量转换率分别为0.76、0.90、0.96％和0.61、0.72、0.77％;净初级生产力转移到滤食性鱼净产量的能量转换率分别为4.02、4.63、5.27％;辅助能转移到鱼净产量的能量转换率分别为12.20、11.33。11.74％。在3个产量级型池塘中,以15t/ha产量级的能量转换率为最佳型。     

池塘浮游植物的初级生产力及其与若干生态因子间的关系

本文应用黑白瓶法测定了浮游植物的初级生产力,分析了初级生产力与主要生态因子间的关系。晴天,水柱的最高生产层常出现在水下0.5倍透明度左右的水层,此处光强约为20000Lx,补偿深度常随天气变化。#br#浮游植物的生产量与生物量和镁之间常表现出正相关。生长季节内单位水面下浮游植物的P/B系数为177.7,日平均1.4。浮游植物对总辐射能的利用率为0.31%。氮是三江平原池塘浮游植物初级生产力的主要限制因子。     

海洋浮游生物和水域生产力

水域生产力已成为水生生态学(Aquatic Ecology)的一个蓬勃发展的生长点。它的重要性日益受到各国生态学家的注意。这是可以理解的,因为水域生产力不但是生态学的一个中心问题,并且,更重要的是,和渔产量密切相关——生产力愈大,渔产量愈高。解放后,我国水产品的产量虽有大幅度的增长,但还远远不能满足人民日益增长的需要。为了提高渔产量,水域生产力研究有大力开展的必要。水域生产力的大小主要决定于水生植物的产量,尤其是它的生产率。在水生植物中,浮游植物占着首要地位;其他两类水生植物——底栖植物和自养细菌,由于数量较少,分布较狭(和浮游植物比较起来),屈居次位。所以,浮游植物是水域有机物(有机碳)的原初或主要生产者,也是水域能量的主要供给者。一般生态学家称它为原初或初级生产力(primary productivity)。依浮游植物为生的浮游动物和其他水生动物称为次级生产力,这是初级生产力和终级生产力之间的能量转换者。依浮游生物或其他动物为生的鱼类则称     

越冬池冰下生物增氧的一个氧气平衡模式

本文根据实测数据回归得到的经验关系式,结合一定的假设及理论关系式,推导得到一个可供鱼呼吸耗用的氧气量(Rf)与浮游植物现存生物量(B)及有效水深(L)的关系式Rf=f(B,L),并利用此式作了进一步的探讨,求出了越冬池生物增氧的最适水深、最适浮游植物现存生物量及最大越冬鱼密度。提出了一个典型的越冬池生物增氧的模式。       

一株富含碳水化合物微藻的筛选和分子鉴定

微藻生长快,单位体积碳水化合物产率高,是发酵生产生物乙醇的理想原料。本研究采用通气培养系统,对初筛得到的10株微藻进行分批培养,以单位体积碳水化合物产率为主要指标,筛选富含碳水化合物的优良藻种。研究结果显示：10株微藻的生物质干重、可溶性糖含量、碳水化合物含量和碳水化合物产率变化范围分别在0.922~1.965 g/L、4.42%~19.23%、26.8%~60.9% 和36.17~149.67 mg·L-1·d-1之间,其中藻株GZ-57的碳水化合物产率和可溶糖含量最高,分别为149.67 mg·L-1·d-1 和19.23%,表明藻株GZ-57是一株具有培养潜力的高产碳水化合物微藻。进一步对其进行形态特征及基于18S rDNA、ITS序列的分子系统学分析,发现藻株GZ-57与栅藻科（Scenedesmaceae）链带藻属（Desmodesmus）的极大链带藻（Desmodesmus maximus）亲缘关系较近,因此将其鉴定为极大链带藻（Desmodesmus maximus）。     

Planktonic primary production in a tidally influenced mangrove forest on the Pacific coast of Costa Rica

The seasonal variation of planktonic primary productivity was measured during one year in the main channel in the interior part of the mangrove forest of the Estero de Morales (Estero de Punta Morales), a mangrove system located in the Golfo de Nicoya at the Pacific coast of Costa Rica. Samples were incubated at the surface, 0.5 m and 1.0 m depth and the "light and dark bottle technique" was employed. The annual gross primary productivity (PPg) was 457 and the net primary productivity (PPn) was 278 g C m(-2) a(-1). Daily PPg ranged from 0.29 to 3.88 and PPn from 0.12 to 2.76 g C m(-2) d(-1). The highest rates observed in May and September were due to red tide blooms. The seasonal variation of primary productivity inside the mangrove forest depends closely on the PP in the adjacent area of the upper Golfo de Nicoya. Obviously the PP was light-limited since the compensation depth in the ebb current was found at only 1 m depth. In the flood current it was somewhat deeper. The planktonic primary productivity inside the mangrove forest was completely restricted to the open channels. A simultaneous measurement demonstrated that PPn of the phytoplankton could not take place under the canopy of the mangroves. Additional studies on the time course of the oxygen concentration in the mouth of the main channel over 24 hrs demonstrated a relation between the O2 and the tidal curves. The ebb current had always lower O2 concentrations than the flood current, regardless of the time of the day. The difference to the foregoing high tide, however, was much smaller when the low tide occurred during the day. This indicates that under the canopy the net primary production and hence O2 liberation of the attached macro- and microalgae, together with the high PPn of the phytoplankton in the channels, helped the oxygen concentration not to decrease as far as during the night. Nevertheless it shows that the consumtion of organic material in the submersed part of the mangrove forest exceeds always its production.     

The role of compound III in reversible and irreversible inactivation of lactoperoxidase

In the presence of iodide (I-, 10 mM) and hydrogen peroxide in a large excess (H2O2, 0.1-10 mM) catalytic amounts of lactoperoxidase (2 nM) are very rapidly irreversibly inactivated without forming compound III (cpd III). In contrast, in the absence of I- cpd III is formed and inactivation proceeds very slowly. Increasing the enzyme concentration up to the micromolar range significantly accelerates the rate of inactivation. The present data reveal that irreversible inactivation of the enzyme involves cleavage of the prosthetic group and liberation of heme iron. The rate of enzyme destruction is well correlated with the production of molecular oxygen (O2), which originates from the oxidation of excess H2O2. Since H2O2 and O2 per se do not affect the heme moiety of the peroxidase, we suggest that the damaging species may be a primary intermediate of the H2O2 oxidation, such as oxygen in its excited singlet state (1 delta gO2), superoxide radicals (O-.2), or consequently formed hydroxyl radicals (OH.).     

太湖湖岸带浮游植物初级生产力特征及影响因素

利用高频溶解氧监测,估算了太湖梅梁湾湖岸带浮游植物初级生产力的高频变化特征。结合同步气象监测及浮游植物、浮游动物和营养盐的周年逐周观测数据,分析了气象和环境条件对富营养化湖泊浮游植物初级生产力的影响。结果发现,高频溶解氧监测估算的初级生产力变化与浮游藻类生物量的变化一致,能够反映出浮游植物生产力的昼夜变化、季节变化等规律。统计分析表明,气温对太湖这一富营养化湖泊初级生产力影响很大;氮的供给与浮游动物的选择性牧食也是影响浮游植物初级生产力的重要因素。湖岸带的水华堆积过程对初级生产力影响巨大,气象、水文过程又加剧了蓝藻水华初级生产力的变化幅度,反映出富营养化湖泊初级生产力可能存在极大的时空不均一性。研究表明,溶解氧高频监测法估算初级生产力能够捕捉到湖泊初级生产力的快速变化过程,可以用于富营养化湖泊初级生产力监测、蓝藻水华灾害预警中。     

Comparison of methods to assess water column primary production in wetlands

We compared a number of techniques to measure water column autotroph production in a shallow, hypereutrophic wetland: diurnal oxygen changes; light and dark bottle incubations; chlorophyll a concentrations; daily changes in pH; and algal volume. Productivity from diurnal oxygen changes calculated at 0.25, 0.5, 1, 2, 3, and 4 h intervals give similar estimates, but not 12 h intervals (dawn-dusk-dawn). Net productivity in bottles was slightly lower than that indicated by diurnal oxygen changes, and gross productivity in bottles was much lower than diurnal changes. Changes in pH correlated well with gross and net productivity measurements, as well as algal volume. Chlorophyll a is correlated with diurnal and bottle net productivity measurements and pH changes, but not algal volume. Since daily pH flux and oxygen changes provide a better overall assessment of ecosystem processes than standing crop or bottle incubations, they could be useful measurements for ecological engineers interested in assessing the ecosystem function.     

Evaluation of water productivity and fish yield in sewage-fed vis-à-vis fertilized based carp culture

Reuse of wastewater in aquaculture provides a scope to enhance water productivity of the system. Quantification of nutrient inputs incorporated through treated domestic sewage with varying dosages viz. 79.3 x 10(5)lha(-1) and 67.7 x 10(5)lha(-1) and water productivity in a controlled carp culture system were assessed in comparison to those involved in a fertilized based one, with a view to correlate among physical, chemical and biological processes involved in fish yield under the systems. The net water productivities were measured on the basis of net return values (in Indian rupees; INR) from the carp production systems at a stocking density @ 5000 per ha with four species combination. Selected relevant water parameters such as dissolved oxygen, total alkalinity, biochemical oxygen demand (BOD5) in sewage effluent and fertilizer based systems were monitored along with certain biological parameters viz. gross primary productivity, fish production and water productivity. The nutrient inputs in terms of total ammonia-nitrogen (TAN) in effluents, total nitrogen (TN) in fertilizers and phosphorus (P2O5) in both effluents and fertilizers were found significantly correlated with biological production. The results of the experiment revealed that the sewage incorporation at 79.3 x 10(5)lha(-1) yielded similar gross fish production as recorded from fertilizer based system, whereas net water productivity using sewage as nutrient source was found 64% higher than that of a fertilizer based system.     

High-resolution time-series data for 1991/1992 primary production and related parameters at a Palmer LTER coastal site: implications for modeling carbon fixation in the Southern Ocean

 Our goal was to provide a high-resolution temporal data base for modeling primary production in shelf waters adjacent to Palmer Station, Antarctica. Here, the resulting 1991/1992 data base is used to: (1) determine in situ productivity over a range of seasonal to subseasonal time scales; (2) identify time scales of significant variability in marine productivity during the peak growing season; (3) identify environmental, experimental and analytical factors that can significantly impact the accuracy of daily, weekly and seasonal productivity estimates; and (4) integrate our findings with previous studies of Antarctic coastal primary pro- duction. Data were gathered every 2–3 days during a 3-month period in the austral spring/summer of 1991/1992. Photosynthesis-irradiance (P-I) relationships were determined throughout the euphotic zone and P-I parameters, combined with knowledge of the in-water light field, were used to derive instantaneous rates of in situ primary production. Additionally, weekly samples were collected from surface and chlorophyll a maxima for characterization of the patterns of diel periodicity in P-I parameters. Seven diel patterns were discerned over the season and used to time-correct instantaneous measurements and derive noontime, daily, monthly and seasonally integrated estimates of production. During the season, a large bloom was responsible for some of the highest daily produc- tivity rates reported for the Southern Ocean (0.8 g C m^-3 d^-1, 6.3 g C m^-2 d^-1). Significant variation in daily integrated rates occurred generally on time scales less than a week. Peak timing and magnitude of daytime periodicities in photosynthesis varied widely over the season, closely coupled to changes in phytoplankton community composition. Instantaneous measurements of primary production, if uncorrected or improperly corrected for daytime periodicities in carbon fixation, were unreliable predictors of production on longer time scales even if the water column was sampled every few days. High frequency sampling and consideration of diel periodicity may be requirements when attempting to discern differences between short time-scale variability and long-term trends in Antarctic primary production. Received: 9 October 1995/Accepted: 18 February 1996     

Large-scale (20 l) culture of surface-immobilized Catharanthus roseus cells.

Surface-immobilized C. roseus cell cultures were grown in a 20-l modified airlift bioreactor operated at 0.51 vvm (kLa approximately 8 h-1) under various gassing regimes [air, 2% (v/v) and 5% CO2]. Extracellular ammonium, phosphate, and nitrate ions as well as carbohydrate uptake and pH value of the medium were monitored together with on-line dissolved oxygen concentration, conductivity of the medium, and carbon dioxide production rate (CPR) of the cultures. Cultures supplemented with 2% CO2 showed higher nitrate (5.0-7.0 mM d-1) and carbohydrate (3.3 g l-1 d-1) uptake rates and biomass production (mu approximately 0.24 d-1, yield approximately 0.33 g dw g CHO-1 and 7.4 g dw L-1) as compared to air (3.6 mM d-1, 2.1 g l-1 d-1; 0.20 d-1, 0.25 g dw g CHO-1 and 5 g dw l-1) and 5% CO2 (2.0-3.6 mM d-1, 2.0 g l-1 d-1; 0.11 d-1, 0.20 g dw g CHO-1 and 5 g dw l-1) cultures and as reported previously for suspension cultures. In addition, air and 5% CO2 cultures displayed incomplete carbohydrate uptake and, more important, phosphate and ammonium ion release into the medium at the end, which was ascribed to loss of viability. This was not observed for 2% CO2 immobilized bioreactor as well as shake flask control suspension cultures, which suggests that sparged C. roseus surface-immobilized cell cultures require 2% CO2 supplementation of the gas phase for both maximum growth and retained viability. The maximum CPRs of all cultures were in the same range (2.1-2.8 mM CO2 l-1 h-1). However, the estimated maximum specific CO2 production rates of 2% CO2 and 5% CO2 immobilized cultures (0.6 mM g dw-1 h-1) were lower than those found for air-sparged immobilized cultures (1.0-1.3 mM g dw-1 h-1). These rates are significantly higher than those reported in the literature for C. roseus cell suspension cultures performed in bioreactors gassed with air (approximately 0.2-0.55 mM g dw-1 h-1).