Biogeochemical implications of mangrove plant polyphenols and their antioxidant activities

植物多酚由于其特殊多样的生物化学活性，逐渐成为化学生态学、生物地球化学、药理学和食品化学等交叉学科的研究热点。红树植物多酚具有多样性含量分布和结构组成是红树林与环境长期协同进化的结果。有关红树植物多酚生物地球化学及结构-活性的研究在国际上处于起步阶段。本研究联合多种分析技术，包括13C-NMR、MALDI-TOF质谱、正相/反相HPLC-ESI-MS，凝胶色谱柱法，化学降解法，比色法等，研究了植物多酚在红树林湿地生态系统的生物地球化学循环及结构与抗氧化活性关系，为揭示红树植物的营养保存机制奠定理论基础，对红树林生态系统管理及林产化学领域开发植物多酚具有重要的指导意义。本研究主要结果如下： （...Studies on plant polyphenols, with a diversity of biochemical functionalities, are considered as the frontiers of many interdisciplinary researches, such as chemical ecology, biogeochemistry, pharmacology and food chemistry. As an evolutionary advantage, procession of diverse plant polyphenols in mangroves is a result of coevolution with harsh environments. However, there were little research on t...学位：理学博士院系专业：生命科学学院生物学系_植物学学号：2172009015358

Enrichment of Heavy Metals by Casuarina equisetifolia of Different Stand Ages

为认识木麻黄(Casuarina equisetifolia)防护林带重金属消减效应,利用电感耦合等离子体质谱(ICP-MS)测定了福建省平潭国有防护林场林龄分别为5,15,20,30年的木麻黄小枝、细根、凋落物及林地土壤中5种重金属(Cr、Cu、Zn、Cd和Pb)的含量.结果表明:平潭木麻黄林地土壤重金属Cr、Cu、Zn、Pb、Cd含量均低于福建省土壤和福建海岸带土壤的重金属含量背景值,未发现重金属污染;木麻黄Cr、Cd和Zn的平均含量高出普通植物的正常值范围,木麻黄中重金属含量依Zn>Cr>Pb>Cu>Cd顺序降低;木麻黄细根中的重金属含量最高,且细根对重金属的富集系数也最高;木麻黄对Cr、Cu、Zn、Cd的富集系数均大于1;木麻黄细根中Zn、Cu元素含量显著正相关;小枝对Cr、Cd和Pb,细根对Zn的富集系数均与林龄极显著正相关;木麻黄现存生物量中,Cr、Cu、Zn、Cd和Pb的现存储量分别为3.06~3.46 kg/hm2,1.14~1.57kg/hm2,11.67~12.57 kg/hm2,0.05~0.09 kg/hm2和0.45~1.84 kg/hm2,且主要存在于根和树干中;随着林龄的增加,木麻黄积累大量的重金属,并达到其峰值.综上所述,木麻黄防护林在防风固沙的同时,能够吸收富集大量的重金属,对海岸带的重金属污染具有明显的消减作用.Casuarina equisetifolia is the key species in the seashore shelter belt in Fujian Province.It is necessary to assess enrichment of heavy metals by C. equisetifolia.Concentrations of heavy metals,including Cr,Cu,Zn,Cd and Pb,in branchlet,fine root,litter and soil of C.equisetifolia in 4 ages( 5,15,20,30 a) were determined.There was no heavy metal pollution in the shelter belt soil. The results showed that the content of the heavy metals in C. equisetifolia could be ranked from high to low as Zn>Cr>Pb>Cu>Cd.The heavy metal content of the fine root was significantly higher than the other parts,and the concentration coefficient of the fine root was also the highest in C. equisetifolia.There was a significant positive correlation between the content of Zn and Cu in the fine root. The concentration coefficients of Cr,Cd,Pb in branchlet,and the concentration coefficient of Zn in the fine root were significantly correlated with stand age.Existing reserves of Cr,Cu,Zn,Cd and Pb were 3. 06-3. 46 kg / hm2,1. 14-1. 57 kg/hm2,11. 67-12. 57 kg/hm2,0. 05-0. 09 kg/hm2,0. 45-1. 84 kg/hm2. Heavy metals mainly existed in the root and trunk.C. equisetifolia had the capability of accumulating heavy metals during growth,and the potential to reduce heavy metal pollution.国家自然科学基金(41176090);; 国家科技支撑计划(2009BADB2B0302

Unexpected international crises reports between television and online media: Case study of the Japan nuclear radiation accident reports

随着互联网技术的不断发展,网络媒体越来越多地在国际突发危机事件中扮演重要角色,而电视媒体和网络媒体在报道国际突发危机事件中具有一定的议程互动,也表现出了各自的特点。针对日本核辐射事件这一典型的国际突发危机事件,电视媒体和网络媒体中具有代表性的央视新闻频道、新华网和新浪微博都进行了报道,而不同媒体在该事件中所充当的角色,发挥的作用及其议程互动关系都呈现出较大差异。With the continuous increasing development of the Internet technology, online media progressively play an essential position in the unexpected international crises.However, TV and online media have a certainly interactive agenda in reporting unexpected international crises, which shows their own characteristics.According to Japan's nuclear radiation events, that the typical unexpected international crises, has been reported on CCTV News Channel, XinHua Net and Sina Weibo, which are the representative samples of TV media and online media.Nevertheless, it is demonstrated that the bigger differences present in the roles and the functions of various media played in this event and its agenda interaction have been existed

Absorption and enrichment of heavy metals by Casuarina equisetifolia of different stand ages in a coastal zone

为研究不同林龄木麻黄对重金属的吸收与富集作用,用ICP-MS测定了福建东山县国有防护林场10、16、20、30年生木麻黄小枝、细根、凋落物及林地土壤中的5种重金属(Cr、Cu、zn、Cd和Pb)含量。结果表明,木麻黄对不同重金属的吸收能力不同,从高到低为zn>Cr>Pb>Cu>Cd;木麻黄细根中Cr和Cu、Pb,fE和Cu,zn和Cd具有明显的协同作用;各林龄木麻黄对重金属均具有一定的耐性,对Cu、zn、Cd、Pb有很好的富集作用;20年生木麻黄的重金属年积累量最高;说明木麻黄对重金属的净化作用具有极大的潜力,20年生木麻黄作用最为明显。To assess the absorption and enrichment of heavy metals by Casuarina equisetifolia,the concentrations of heavy metals including Cr,Cu,Zn,Cd and Pb in branchlet,fine root,litter and soil of C.equisetifolia forests at four ages( 10,16,20,30) were determined.The results showed that the enrichment degree of the heavy metals in C.equisetifolia ranked as Zn > Cr> Pb > Cu > Cd.Correlation analysis showed that Cr and Cu,Pb,Fe and Cu,Zn and Cd had significant synergies in the fine roots of C.equisetifolia.C.equisetifolia had a higher capability of absorbing and accumulating heavy metals.Annual accumulation of heavy metals was highest in20 years old C.equisetifolia.Our results indicate that C.equisetifolia has a great potential for reducing the pollution of heavy metals,especially for the 20 years old forest.国家自然科学基金项目(41176090); 国家科技支撑项目(2009BADB2B0302)资

滨海沙地主要造林树种纯林与混交林叶片热值特征

对福建东南沿海防护林4种主要树种纯林及混交林共8个林分类型成熟和衰老叶片的热值进行了研究。结果表明,在4种纯林中,厚荚相思叶片中热值最高,湿地松次之,都高于木麻黄和桉树;木麻黄纯林、木麻黄-厚荚相思混交林、木麻黄-湿地松混交林中木麻黄小枝热值差别不显著,都高于与桉树混交的木麻黄小枝;厚荚相思纯林和混交林成熟叶及衰老叶热值都高于湿地松和桉树;在所有的林分类型中,衰老叶中的热值都高于成熟叶或差别不显著。国家“十一五”科技支撑计划项目(2006BAD03A14-01);; 福建省重大科技专项(2006NZ0001-2);; 福建省森林培育与林产品加工利用重点实验室资助项

木麻黄低效林不同发育阶段小枝单宁含量

为了探讨环境条件对单宁生产的影响,该文选择木麻黄低效林三个不同发育阶段的小枝进行单宁含量的测定。结果表明:在不同的发育阶段,总酚含量表现为幼嫩>成熟>衰老小枝,缩合单宁中除纤维素结合缩合单宁外,均表现为随小枝成熟而下降,随小枝衰老而升高;在低效林中的各单宁组分均高于对照。对环境条件比较敏感的幼嫩小枝和受环境胁迫较重的低效林比对照小枝中单宁含量高,表明不良的环境条件促进了单宁的形成。国家“十一五”科技支撑计划项目(2006BAD03A14-01);; 福建省重大科技专项(2006NZ0001-2);; 福建省森林培育与林产品加工利用重点实验室资助项

Nitrogen and phosphorus concentrations,N∶P ratio and resorption efficiency of leaves in different forest types

以福建东山沿海防护林中木麻黄、厚荚相思、刚果桉和湿地松4种主要树种为研究对象,探讨了纯林和混交林成熟叶与衰老叶中的养分状况、氮磷比、养分内吸收率以及它们之间的关系。结果表明:叶片中的养分浓度和内吸收率一般表现为纯林高于混交林、固氮树种高于非固氮树种。这是由于混交林和固氮树种改善了立地条件,林木能够从土壤中吸收较多的养分,从而降低了二者叶片中的养分内吸收率。各林分类型成熟叶片中的氮磷比都大于14,表明这些立地条件都存在不同程度的磷限制,导致大部分林分叶片磷内吸收率(rEP)大于氮内吸收率(rEn),因而衰老叶中的氮磷比大于成熟叶,但成熟叶和衰老叶氮磷比之间依然存在显著的正相关关系。不同林分类型成熟叶和衰老叶养分浓度、内吸收率和氮磷比在固氮树种和非固氮树种中存在互补性,表明固氮树种和非固氮树种在养分利用方面存在差异。不同树种的营养利用策略不同,在选择造林树种时,应优先考虑叶片养分含量低而内吸收率高的“营养保存型“树种。Nitrogen and phosphorus concentrations,N∶P ratio,nutrient resorption efficiency and their relationship in mature and senescent leaves in pure and mixed protection forest of Casuarina equisetifolia,Acacia crassicarpa,Eucalyptus ABL 12 W5 and Pinus elliottii were discussed in this paper.The results showed that nutrient concentration and resorption efficiency of leaves were higher in pure forest and N fixing species than in mixed forest and non-N-fixing species,respectively.This indicated that soil nutrient availability increased in mixed forest and N-fixing species,so the trees could absorb more nutrients from soil and depended less on nutrient resorption from senescent leaves.The N∶P ratios of mature leaves were all above 14,nitrogen was less limiting than phosphorus,and accordingly phosphorus resorption efficiency(RE_P)was higher than nitrogen resorption efficiency(RE_N).N∶P ratio was increased with leaf senescence.There was significant positive relationship between N∶P ratio in mature and in senescent leaves.Inter-and intraspecific correlations among nutrient concentrations,nutrient resorption and N∶P ratio of mature and senescent leaves in various forest types were different in N-fixing and non-N-fixing species.Due to the difference of nutrient use strategy for various life-forms,there was a significant correlation in N-fixing species,but no correlation in non-N-fixing species,and vice versa."Nutrient conservation" species,such as P.elliottii,with low leaf nutrient and high nutrient resorption efficiency should be prior selected for afforestation.“十一五”国家科技支撑计划项目(2006BAD03A14-01);福建省科技重大项目(2006NZ0001-2);国家林业局南方山地用材林培育重点实验室项

Characterization of Condensed Tannins from Litchi Seed by Reflectron Modes and Linear Modes of MALDI-TOF MS

E-mail: [email protected][中文文摘]利用不同模式的基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)分析荔枝果核缩合单宁.在反射模式(Reflectron modes)下,加速电压20.0 kV,反射电压23.0 kV,延时取出电压16.32 kV,聚焦电压9.45 kV,获得缩合单宁的准确结构单元组成和连接方式信息,其为三聚体至十八聚体组成的A型原花青定多聚物.在线性模式(Linear modes)下,加速电压20.0 kV,延时取出电压16.25 kV,聚焦电压10.0 kV,检测到十九聚体至二十七聚体的缩合单宁信号,其更全面获取缩合单宁聚合度的分布信息.综合两种模式,荔枝果核缩合单宁是由三聚体至二十七聚体分布的A型原花青定多聚物.探讨了一种联合反射模式与线性模式对植物单宁结构准确分析的基质辅助激光解吸电离飞行时间质谱方法.[英文文摘]Condensed tannins from litchi seed were analyzed using reflectron modes and linear modes of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS).The reflectron modes(accelerating voltage,20.0 kV;reflectron voltage,23.0 kV;delayed extraction voltage,16.32 kV;lens voltage,9.45 kV) spectra obtained clear information on basic unit,interflavan linkage and polymerization degree extended from 3-mers to 18-mers.The linear modes(accelerating voltage,20.0 kV;delayed extraction voltage, 16.25 kV; lens voltage, 10.0 kV) spectra further expanded the detectable polymers up to 27-mers. Litchi seed condensed tannins were A-type procyanidins polymer with as high as 27-mers. In the present study, reflectron modes coupled with linear modes was discussed as a potential method of MALDI-TOF MS in characterization of condensed tannins.教育部新世纪优秀人才支持计划(No.NCET-07-0725); 国家自然科学基金(No.31070522)资助项

Characterization of Condensed Tannins from Litchi Seed by Reflectron Modes and Linear Modes of MALDI-Tof MS

利用不同模式的基质辅助激光解吸电离飞行时间质谱(MAldI-TOf MS)分析荔枝果核缩合单宁.在反射模式(rEflECTrOn MOdES)下,加速电压20.0 kV,反射电压23.0 kV,延时取出电压16.32 kV,聚焦电压9.45 kV,获得缩合单宁的准确结构单元组成和连接方式信息,其为三聚体至十八聚体组成的A型原花青定多聚物.在线性模式(lInEAr MOdES)下,加速电压20.0 kV,延时取出电压16.25 kV,聚焦电压10.0 kV,检测到十九聚体至二十七聚体的缩合单宁信号,其更全面获取缩合单宁聚合度的分布信息.综合两种模式,荔枝果核缩合单宁是由三聚体至二十七聚体分布的A型原花青定多聚物.探讨了一种联合反射模式与线性模式对植物单宁结构准确分析的基质辅助激光解吸电离飞行时间质谱方法.Condensed tannins from litchi seed were analyzed using reflectron modes and linear modes of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-Tof MS).The reflectron modes(accelerating voltage,20.0 kV;reflectron voltage,23.0 kV;delayed extraction voltage,16.32 kV;lens voltage,9.45 kV) spectra obtained clear information on basic unit,interflavan linkage and polymerization degree extended from 3-mers to 18-mers.The linear modes(accelerating voltage,20.0 kV;delayed extraction voltage,16.25 kV;lens voltage,10.0 kV) spectra further expanded the detectable polymers up to 27-mers.Litchi seed condensed tannins were A-type procyanidins polymer with as high as 27-mers.In the present study,reflectron modes coupled with linear modes was discussed as a potential method of MALDI-Tof MS in characterization of condensed tannins.教育部新世纪优秀人才支持计划(No.NCET-07-0725);国家自然科学基金(No.31070522)资助项

Seasonal dynamics of nitrogen and phosphorus concentrations,and nutrient resorption efficiencies of Casuarina equisetifolia branchlets in Dongshan County,Fujian

对福建东山赤山林场短枝木麻黄纯林小枝中的n和P含量、n∶P比、养分再吸收率的季节动态进行研究。结果表明,随着小枝的成熟和衰老,各季节n和P的含量依次降低,其中衰老小枝中n和P含量分别为(3.97±0.21)~(8.64±0.58)Mg·g-1和(0.04±0.03)~(0.10±0.03)Mg·g-1,基本上表现为n和P的完全再吸收。成熟小枝n∶P比的季节动态介于(18.67±3.24)~(37.98±1.32)之间,均高于16,表明木麻黄的生长受到不同程度的P限制。n、P再吸收率的季节变化分别为(51.02±4.66)%~(63.00±8.61)%和(81.24±5.08)%~(91.78±5.84)%,P再吸收率显著高于n。n和P的再吸收率之间以及成熟叶中n、P含量与二者再吸收率之间没有显著相关性,但在衰老叶中存在显著负相关,表明养分再吸收程度越高,其再吸收率就越高。因此,木麻黄通过小枝衰老过程中的养分再吸收,减少养分的损失,从而适应贫瘠的立地条件。Seasonal dynamics of nitrogen and phosphorus concentrations,N∶P ratios and nutrient resorption efficiency of Casuarina equisetifolia branchlets was studied at Chishan Forestry Center of Dongshan County,Fujian Province,China.The results showed that N and P concentrations were highest in young branchlets and decreased with maturity and senescence.N and P concentrations of senescent branchlets ranged from (3.97±0.21) to (8.64±0.58) mg g-1 and (0.04±0.03) to (0.10±0.03) mg g-1,respectively.N∶P ratios of mature branchlets ((18.67±3.24)--(37.98±1.32)) were all above 16 through the year,showing P was more limiting than N.Nitrogen resorption efficiency (REN) and phosphorus resorption efficiency (REP) were from (51.02±4.66)% to (63.00±8.61)% and from (81.24±5.08)% to (91.78±5.84)% through the year,respectively,and REP was significantly higher than REN.There is no significant correlation between REN and REP.REN is not correlated with either N concentration or N:P ratios in mature branchlets,no correlation was also found between REP and either P concentration or N∶P ratios in mature branchlets.While the significant negative correlation was observed in senescent branchlets.国家“十一五”科技支撑计划资助项目(2006BAD03A14-01);福建省科技重大资助项目(2006NZ0001-2);国家林业局南方山地用材林培育重点实验室资助项