香港海域2004年浮游植物群落结构特征

根据2004年冬、春、夏和秋季对香港海域(东部、中部、西部和南部水域共取7个站位)的浮游植物进行采样调查,分析了香港海域浮游植物的种类组成、丰度、优势种、群落组成、多样性和均匀度等群落特征。2004年香港海域的浮游植物共鉴定了73属196种(含变种和变型),其中潜在赤潮种88种,丰度范围在9.17×103cells/L～8.56×106cells/L之间,平均值为9.51×105cells/L。丰度的周年变化曲线呈单峰型,夏季高,秋冬季节低。香港海域的浮游植物种类多样性较高,以暖水性和广分布性种类为主;浮游植物群落与上世纪70年代相比,仍以硅藻为主导,但甲藻和微型隐藻的优势有所增加。由于海洋环境特点的不同,香港不同海域的群落组成差异显著

Fine root distribution, seasonal pattern and production in a native forest and monoculture plantations in subtropical China

作者简介: 杨玉盛(1964～ ) , 男, 福建仙游人, 博士, 教授, 主要从事亚热带常绿阔叶林C、N 循环研究。E2mail: [email protected] tt. fj. cn 致谢: 福建农林大学蔡丽平、林瑞余、谢锦升, 陈爱玲、陈清山、邹双全、李春林, 硕士研究生郭剑芬、刘艳丽、岳永杰、于占源、江淼华、卢豪良等, 及莘口教学林场郑燕明、刘春华、王巧珍、陈辉等参加了项目研究[中文文摘] 通过对福建三明格氏栲天然林及在其采伐迹地上营造的33年生格氏栲人工林和杉木人工林细根分布、季节动态与净生产力进行的为期3a(1999～2001)的研究,结果表明,格氏栲天然林、格氏栲和杉木人工林活细根生物量分别为4.944t/hm2、3.198t/hm2和1.485t/hm2,死细根生物量分别为3.563t/hm2、2.749t/hm2和1.287t/hm2;死细根生物量占总细根生物量的比例分别为41.9%、46.2%和46.4%;0.05);活细根生物量最大值均出现在3月份,最小值一般出现在5～7月份或11～翌年1月份间。0～10cm表土层格氏栲天然林活细根生物量高达295.65g/m2,分别是格氏栲人工林和杉木人工林的2.4倍和8.1倍;该层格氏栲天然林活细根生物量占全部活细根生物量的59.8%,均高于格氏栲人工林(39.07%)和杉木人工林(24.51%)。格氏栲天然林、格氏栲人工林和杉木人工林细根分解1a后的干重损失率分别为68.34%～80.13%、63.51%～77.95%和47.69%～60.78%;年均分解量分别为8.747、5.143和2.503t/hm2;死亡量分别为8.632、5.148和2.492t/hm2;年均净生产量分别为8.797、5.425和2.513t/hm2,年周转速率分别为1.78、[英文文摘]In the last decades, large scale native forests have been converted to fast growing and high yield commercial forest plantations to meet the demands for timber, fuel material, and other forest products. Some silvicultural measures, such as planting pure stands, clear cutting and slash burning, have been widely applied during this conversion. Yield decline and land deterioration in such disturbed ecosystem has become serious. In this context, the ecological comparisons between native forests and monoculture plantations are necessary in providing the implications for sustainable management. Few studies on fine roots dynamics have been conducted within these ecosystems though the importance of fine roots in carbon and nutrient cycling has been increasingly emphasized due to their rapid turnover rates. Two 33 year old plantations, Chinese fir (Cunninghamia lanceolata, CF) and Castanopsis kawakamii (CK), were chosen to examine fine root (005). An early spring flush of root biomass (March) was found in these three forests, and the minimum value mainly occurred during May July or November January. For the NF, 598% of root biomass was found in the top soil of 0～10 cm, a layer that maximum depth distribution difference among these forests occurred, where root biomass of the NF was 237 times and 812 times as much as that of the CK and the CF, respectively. Percentages of original mass lost during the first year of decomposition ranged from 4379%～5631% for the FH to 6834%～8013% for the NF Mean annual root decomposition, mortality and production ranged from 847 t/(hm 2·a), 8632 t/(hm 2·a) and 95 t/(hm 2·a) in the NF to 2503 t/(hm 2·a), 2492 t/(hm 2·a) and 2513 t/(hm 2·a) in the CF. The mean root turnover rate ranged from 178 times/a in the NF to 169 times/a in the CF.国家自然科学基金资助项目(30170770);福建省自然科学基金资助项目(B0110025);高等学校优秀青年教师教学科研奖励计划资助项目;福建省基础研究重大资助项目(2000-F-004

Nutrient dynamics of decomposing leaf litter in natural and monoculture plantation forests of Castanopsis kawakamii in subtropical China

通过对中亚热带格氏栲天然林 (natural forest of Castanopsis kawakamii,约 15 0 a)、格氏栲和杉木人工林 (monocultureplantations of C.kawakamii and Cunninghamia lanceolata,33年生 )凋落叶分解过程中养分动态的研究表明 ,各凋落叶分解过程中 N初始浓度均发生不同程度的增加后下降 ;除格氏栲天然林中其它树种叶和杉木叶 P浓度先增加后下降外 ,其它均随分解过程而下降 ;除杉木叶外 ,其它类型凋落叶的 Ca和 Mg浓度呈上升趋势 ;凋落叶 K浓度均随分解过程不断下降。养分残留率与分解时间之间存在着指数函数关系 xt=x0 e- kt。凋落叶分解过程中各养分释放常数分别为 :N (k N) 0 .6 78～ 4 .0 88;P (k P)0 .6 2 1～ 4 .30 8;K(k K) 1.4 0 8～ 4 .4 2 1;Ca (k Ca) 0 .799～ 3.75 6 ;Mg (k Mg) 0 .837～ 3.894。除杉木叶外 ,其它凋落叶分解过程中均呈 k K>k P>k N>k Mg>k Ca的顺序... 【英文摘要】 Nutrient dynamics of decomposing leaf litter was studied in two 33-year-old plantations, Chinese fir (Cunninghamia lanceolata, CF) and Castanopsis kawakamii (CK), and compared with that of an adjacent natural forest of Castanopsis kawakamii (NF, ~150 year old) in Sanming, Fujian, China. During the decomposition, varying degree of initial increase followed by decrease of N concentrations was observed in leaf litter, while initial increase and then decrease of P concentration was only found in leaves of other...教育部高等学校优秀青年教师奖资助项目;; 教育部高等学校骨干教师资助计划资助项目 ;; 福建省重大基础研究资助项目 (2 0 0 0 F 0 0 4)~

Subtropical red tides and their ecological significance in Hong Kong waters

published_or_final_versionBotanyDoctoralDoctor of Philosoph

Investigation of Iron Corrosion Process Beneath Coating in DiFFerent Kinds of Anion Solution Using the Technique of Array Electrode

应用阵列电极测量不同阴离子介质中有机涂层/铁电极界面电位分布图，研究腐蚀发生、发展过程.实验结果表明：腐蚀优先发生在有机涂层/铁电极界面边缘.涂层一旦破裂，在Cl-介质中腐蚀很快发生并不断发展，在nO-3介质中腐蚀也很快发生，一段时间后就逐渐受抑制，而在CO2-3介质中腐蚀不发生.与常规电极相比，阵列电极能给出更详细的腐蚀界面的电化学参数.The array electrode as a new electrochemical technique is applied to map the corrosion potential imaging and to sutdy the corrosion process at the interFace of organic coating/iron aFter being immmersed in solutions containing diFFerent kinds of anion.The experiment results indicated that the corrosion preFerentially occured on the edge of the surFace of organic coating/iron and ,when the coating was broken down ,the crrosion occured and developeed in Cl - solution, however corrosion occured First and then was suppressed in NO - 3 solution and the corrosion was prevented in CO 2- 3 solution.In comparison with the traditional methodpolarization curve, more detailed crrosion inFormation of coating/iron interFace can be obtained From the array electrode technique.国家自然科学基