雷州半岛白骨壤遗传多样性的ISSR分

利用ISSR标记技术研究表明：雷州半岛5个白骨壤（Avicennia marina）种群具有较高的遗传多样性。种群之间遗传分化很低,遗传分化系数FST=0.081 2,遗传相似系数平均值为0.980 4,种群间具有较强的基因流（Nm=5.654 9）。通过UPGMA聚类将5个白骨壤种群分为三类,特呈岛种群和角尾种群为一类,企水种群和高桥种群为一类,和安种群单独为一类。和安白骨壤种群可能是雷州半岛最古老的白骨壤种群,应予以优先保护。     

广东白骨壤群落上的广州小斑螟生物学特性及种群数量消长规律研究

广州小斑螟是白骨壤群落上的重要害虫。室内饲养1年可完成7代,第1代至第6代虫历时33～42d,越冬代虫历时122d。幼虫危害嫩芽、嫩叶、叶片和果实,严重受害的白骨壤林成片枯死。在白骨壤群落,各地受害嫩芽和受害叶片数量变化规律不相同,广州小斑螟种群数量消长规律与受害嫩芽和受害叶片数量变化规律成正相关,受害嫩芽和受害叶片全年平均数保持为10．8—21．5片叶（个嫩芽）／m2,害虫数量全年平均数保持在4．4～20．4头／30个1m2样方。捕食性蜘蛛是控制广州小斑螟种群的重要天敌,蜘蛛数量全年平均数保持在5．9—10．8头／30个1m2样方,广州小斑螟种群数量与捕食性蜘蛛种群数量的比例为1：0．29～2．45,捕食性蜘蛛的比例越高,对广州小斑螟种群的控制作用就越大,害虫暴发成灾的可能性就越小。     

雷州半岛白骨壤自然种群遗传多样性的ISSR分析

利用ISSR标记技术研究表明:雷州半岛5个白骨壤(Avicennia marina)种群具有较高的遗传多样性。种群之间遗传分化很低,遗传分化系数FST=0.081 2,遗传相似系数平均值为0.980 4,种群间具有较强的基因流(Nm=5.654 9)。通过UPGMA聚类将5个白骨壤种群分为三类,特呈岛种群和角尾种群为一类,企水种群和高桥种群为一类,和安种群单独为一类。和安白骨壤种群可能是雷州半岛最古老的白骨壤种群,应予以优先保护。     

特呈岛白骨壤古树群的调查分析

特呈岛白骨壤古树群是我国极其珍贵的红树林资源,该古树群有510株古树,依据古树植株生长势可分为4级：Ⅰ级树势良好株46．47％、Ⅱ级树势正常株37．45％、Ⅲ级树势衰弱株13．92％、Ⅳ级垂死株2．16％。建议加强该古树群的保护复壮管理。     

Interactions between epibenthos and meiobenthos in a high intertidal Avicennia marina mangrove forest

Many studies in the muddy intertidal zone of temperate regions haveindicated meiofaunal communities to be mainly affected by epibenthicpredation and disturbance rather than competition. Few studies, however,have dealt with mangrove sediments of tropical areas. In addition to aparallel study in a Ceriops tagal (Perr.) Rob. zone, a manipulativeexclusion technique was used to trace the dominant biological interactionsstructuring the meiobenthos of an East African Avicennia marina (Forsk.)Vierh. mangrove forest.The densities of the major meiobenthic taxa and nematode genera and abroad range of environmental factors were monitored over a depth profile forone year of caging. Cages (1 m²) excluded all epibenthos (> 2 mm)for one year and were procedurally controlled. Procedural and exclusioneffects were traced, using a factorial and mixed ANOVA design. Significant exclusion effects were indicated for oligochaetes and for oneof the dominant epistratal feeding nematode genera. They are discussed interms of epibenthic composition and density, feeding behaviour, foodresources, and the abiotic environment. The conclusion is that the observed meiobenthos (especially oligochaetesand nematodes) is influenced mainly by exploitative or resource competitionwith the epibenthos. The common food source was indicated to be muddydetritus and microalgae. Consequently, the role of the meiobenthos is mainlysituated in an isolated, detrital food web with only minor energy fluxes tothe epibenthos.     

白骨壤古树群资源可持续利用管理对策的研究

通过对广东省湛江市特呈岛白骨壤古树群可持续利用资源实地调查表明,该资源的利用方式有9种,而林中沙虫等采挖和采集薪柴等破坏行为要加以严格禁止,从而科学利用、加强管理该珍稀古树群资源及其它红树林资源。     

红树植物白骨壤木材解剖特性及其变异性研究

对采自广西北海禾沟红树林培育基地的白骨壤(Avicennia marina)木材进行解剖特性和变异研究.结果表明:白骨壤木纤维长度属"甚短级",宽度属于"一级",纤维分子长度、宽度、长宽比、双壁厚、壁腔比、腔径比平均值分别为674.20 μm、15.30 μm、44.16、6.87 μm、0.85、0.55;导管分子长度和宽度分别属于"很短"和 "甚小"级别,导管分子长度、宽度、长宽比、双壁厚、壁腔比平均值分别为174.02 μm、39.89 μm、4.63、4.05 μm、0.12;白骨壤木材的木纤维比量、木射线比量、导管比量、薄壁组织比量平均值分别为71%、7%、22%、1%.不同年轮间纤维和导管的分子长度、宽度、长宽比、双壁厚、壁腔比具有不同程度的变异.     

白骨壤的沙地育苗技术

白骨壤为红树林植物中的广布种、先锋树种,其沙地育苗技术尚未见报道,文章结合白骨壤的沙地育苗,总结了种子采集及处理、育苗基质、播种、苗期管理和炼苗出圃等技术要点.     

不同滩面高程和光照条件下白骨壤幼苗的早期生长差异

对厦门杏林曾营海岸低、中、高3个高程(分别为厦零3.35 m、3.74 m和4.15 m)滩面上红树人工幼林林内、林外自然生长的白骨壤2月龄幼苗的生长状况进行对比分析。结果表明:在林外,中高程滩面上的白骨壤幼苗单叶面积、基径、茎高、叶生物量、茎生物量和总生物量均最大;低高程滩面上叶片较厚,肉质化程度高,叶片数最多;3个高程的根生物量差异不显著。在林内,不同高程间幼苗生长差异主要体现在叶片和茎高,低、中高程之间差异不大,但比高高程的叶片厚,肉质化程度高,叶片数多。除茎高外,林外3个高程的其它指标都明显高于林内。光照对幼苗生长的影响大于高程的影响。综合分析结果表明,厦门海域白骨壤红树林生态恢复的适宜高程为厦零3.74 m(相当于本研究的中高程样地),且白骨壤为不耐阴植物,人工造林时,应为后代幼苗的自然更新预留空间。     

广州小斑螟幼虫和蛹空间分布型的研究

广州小斑螟Oligochroa cantonella Caradja是红树林的灾害性害虫之一。为了研究该虫在广西白骨壤林内的空间分布情况,在广西合浦县山口镇白骨壤林对该幼虫进行了调查研究,应用扩散系数(C)等6种指标分析,确定了该虫在白骨壤林中空间分布型为聚集分布。在此基础上,给出了不同虫口密度以及不同误差要求的最适抽样数。     

白骨壤中性糖蛋白的分离鉴定及生物活性研究

以白骨壤树枝为材料,经提取、分离和纯化等一系列步骤得到一中性多糖组分HAM-3-IIa,经高效凝胶过滤色谱(HPGFC)和凝胶柱层析Sephacryl(S-400)鉴定为均一组分,其重均相对分子质量(Mw)为97 600.化学组成分析表明,HAM-3-IIa为中性糖蛋白,含蛋白4.9%,含多糖95.0%;由阿拉伯糖(Ara)、半乳糖(Gal)和木糖(Xyl)组成;β-消去反应说明HAM-3-IIa中糖链以O-糖肽键连接到苏氨酸上的;补体结合实验表明,该多糖通过经典途径和替代途径共同作用产生显著的抗补体活性,呈一定的剂量效应关系,并研究确定该活性不是由于纯化过程中所产生的微生物所造成的.     

白骨壤酸性多糖的分离纯化及抗补体活性研究

采用热水浸提,乙醇沉淀,超滤,三氯乙酸脱蛋白,DEAE-纤维素柱层析脱色,再经DE-AE-Sepharosefastflow和SephacrylS-400层析,从白骨壤树枝分离纯化得到多糖化合物HAM-3-Ⅱb-Ⅱ,经高效凝胶过滤色谱法和比旋光度测定法鉴定为均一性组分,其重均相对分子质量(Mw)为105200,比旋光度为 27.54°。糖组成分析表明它为酸性杂多糖,主要由半乳糖醛酸、阿拉伯糖、半乳糖和鼠李糖组成。紫外光谱表明其不含核酸和蛋白质等杂质成分;红外光谱证实它是一种酸性果胶类多糖,以α型差向异构为主;补体结合实验表明,该多糖通过经典途径和替代途径共同作用产生显著的抗补体活性,并呈一定的剂量效应关系。     

福建漳江口3种红树植物光合作用日变化特性研究

应用Li-6400XT便携式光合作用测定系统,首次对漳江口红树林天然群落中秋茄、白骨壤、桐花树在自然生境中夏季晴天的叶片净光合速率(Pn)、气孔导度(Cond)、蒸腾速率(Tr)、胞间CO2浓度(Ci)生理因子的日变化进程及其相互关系,以及环境因子对净光合速率的影响等进行研究。结果表明:秋茄、桐花树叶片净光合速率(Pn)的日变化趋势相似,两者Pn的峰值出现在8∶00和14∶00,而白骨壤Pn的峰值出现在8∶00和16∶00,日均Pn大小为白骨壤>秋茄>桐花树;3种红树的蒸腾速率(Tr)日变化规律各不相同,秋茄和桐花树Tr值最高均出现在8∶00,白骨壤Tr值最高出现在10∶00,日均Tr大小为白骨壤>桐花树>秋茄;水分利用效率(WUE):秋茄和白骨壤16∶00时最高,而桐花树12∶00时最高,日均WUE大小为秋茄>白骨壤>桐花树;植物的Pn和Tr不仅受到环境因子的影响,同时还受到内在生理因子的调节。相关分析结果表明,对Pn和Tr影响最高的环境因子是光合有效辐射(PAR),生理因子则为气孔导度(Cond)。     

印度西部5种热带干落叶林中凋落物中生物元素和返回到绿叶中的季节性变化(英文)

本文对印度西部5种热带干落叶林中凋落物里生物元素的季节性变化和它们返回到新鲜叶中季节性变化进行研究。对5个树种:阿拉伯金合欢(Acacia nilotica L.)、金合欢(Acacia leucophloea Roxb.)、柚木(Tectonagrandis L.f.)、绒毛野独活(Miliusa tomentosa Roxb.)和紫矿(Butea mono-sperma Lain.)中凋落物的成熟叶、枝和再生部分的N、P、Ca、Mg、K和Na的浓度,以及老叶和幼叶中浓度间的关系进行调查。对这些树种的总干物质进行记录,并分析它们所含的N、P、Ca、Mg、K和Na的含量。其中阿拉伯金合欢叶子中N的含量最高,而金合欢的叶子里Ca和Mg含量最高。叶中含P最多的是阿托伯金合欢、金合欢和紫矿,而含P最少的是柚木和绒毛野独活。K和Na含量在这些树种中没有明显的区别。观察发现,N、P和K的浓度随季节变化大,但Ca和Mg则不然。唯有钾在所有树种中都是最稳定的,吸收N和P可以用于来年新叶的生长。从老叶和凋落物中吸收的营养会支持新叶的生长,并增加土壤的肥力。图1表4参30。     

Mangrove species zonation and soil redox state,sulphide concentration and salinity in Gazi Bay (Kenya), a preliminary study

The relationship between soil redox state, sulphide concentration, salinity and spatial patterns of mangrove species distribution was investigated in the mangrove forest of Gazi Bay (Kenya). Field measurements were conducted to examine the relationship between species distribution along a band transect of 280m and soil redox potential (Eh) and sulphide patterns, as well as the indirectly related (through flooding regimes) soil salinity. Of the three major species Avicenniamarina, Ceriops tagal and Rhizophoramucronata present along the transect, only the distribution of the latter correlated with the measured soil variables, R. mucronata being absent from the lessreduced zone with high salinity. Bruguieragymnorhiza and Heritieralittoralis occur in minor populations, they are restricted to the saline, sulphidepoor and lessreduced substrates. From the results it is concluded that soil redox potential (Eh), sulphide concentration and salinity may contribute to structure mangroves through the distribution of dominant species, however in combination with other environmental conditions and processes of vegetation dynamics.     

三江平原典型湿地毛果苔草养分含量及累积特征

以三江平原典型湿地毛果苔草群落为研究对象,在2007年5月至2008年9月研究了毛果苔草植物地上和地下部生物量季节动态以及养分（氮、碳、磷）特征。结果表明：毛果苔草地上生物量随着植物的生长符合二次函数模型,地下生物量随着植物的生长符合指数增长模型。毛果苔草地上、地下部分有机碳含量随植物生长均呈显著正的线性相关,相关系数分别是0.983和0.746。地上、地下有机碳累积量随着植物生长的变化趋势与其生物量的变化是一致的,随着植物的生长符合二次函数模型。毛果苔草地上、地下部分总氮含量和积累量随着植物的生长分别符合指数递增模型。毛果苔草磷含量随着植物的生长分别符合二次函数模型,但是磷累积量随着植物的生长分别符合线性增长模型。植物生长季毛果苔草植物体碳/氮的大小与其总氮含量呈反比关系,碳/磷的大小与其总磷含量呈反比关系,研究表明氮含量是毛果苔草生长过程中的限制性养分。     

4个油茶无性系叶片内各营养元素含量变化研究

为给油茶理论研究和生产实践提供参考依据,以油茶的4个无性系——岑软2号、岑软3号、湘林8号、阳春5号为试验材料,连续1年定期采集各树种7年生叶片,测定其叶片内氮、磷、有机质、可溶性糖及淀粉等营养元素的含量,并研究了各营养元素含量的变化规律。结果表明:自当年6月至次年5月,叶片中的氮和可溶性糖含量均呈下降—升高—下降—升高的变化趋势;磷含量呈升高—下降—升高的变化趋势;淀粉含量在6月份最高,随之下降,之后又开始波动上升;有机质含量在5月份最高。     

Field measurements of gas exchange in Avicennia marina and Bruguiera gymnorrhiza

Diurnal gas exchange characteristics were measured simultaneously in two mangrove species, Avicennia marina and Bruguiera gymnorrhiza, over 7 d in summer (February–March), to compare their productivity. The study was undertaken in the Beachwood Mangroves Nature Reserve, Durban, South Africa, using fully expanded leaves of young and mature trees at the top of the canopy. Gas exchange was strongly influenced by photosynthetic photon flux density (PPFD), leaf temperature and the accompanying leaf to air vapour pressure deficit ( w). Carbon dioxide exchange was saturated at a PPFD of about 600 mol m^-2s^-1 in B. gymnorrhiza compared to 800 mol m^-2s^-1 in A. marina. Maximal CO₂ exchange occurred between 12h00 and 14h00 and was consistently greater in A. marina (8.8 mol m^-2s^-1) than in B. gymnorrhiza (5.3 mu;mol m^-2s^-1). Mean internal CO₂ concentrations ( c_i) were 260 l l^-1 in A. marina and 252 l l^-1 in B. gymnorrhiza. Photorespiratory activity was 32% in A. marina and 30% in B. gymnorrhiza. Mean water use efficiency (WUE) was 8.0 mol mmol^-1 in A. marina and 10.6 mol mmol^-1 in B. gymnorrhiza. Diurnal leaf water potentials ranged from –0.8 to –3.5 MPa and were generally lower in A. marina.     

Spatial patterns of biomass and soil attributes in an estuarine mangrove forest (Yingluo Bay,South China)

Mangrove ecosystems are well developed in the estuarine environment of Yingluo Bay, South China. However, little is known about the spatial patterns of vegetation biomass, soil organic carbon (SOC) stocks and soil attributes along the environmental gradient from upstream to downstream positions. To characterize the spatial pattern of these factors, four transects (transects I, II, III and IV) were established between upstream and downstream positions. The result showed clear spatial patterns occurred in this estuarine mangrove. In general, vegetation biomass, TN concentration and SOC concentration and stocks decreased from upstream to downstream positions unless transect I, with the increase of soil salinity. This may be attributed to a consequence of increasing environmental stress due to the change of soil elevation. Vegetation biomass and its carbon, SOC concentration and stocks, and TN concentration showed clear trends of decrease first and then gradually tended to be stable along each transect from landward to riverward positions. These results indicate that soil position/elevation in the estuarine mangrove greatly affects soil attributes and mangrove growth. In each transect, change of soil salinity showed some distinct characteristics, in comparison with SOC and TN. SOC concentrations were significantly correlated with vegetation biomass and silt contents. Compared to that in the mangrove-covered area, SOC concentrations and stocks were much lower in the bare flat. It was indicated that an increase of vegetation biomass will raise the mangrove-derived SOC, and reforestation with mangroves is a friendly strategy provided coastal protection.     

桉树不同成熟度叶片营养元素内循环特征

揭示桉树人工林不同成熟度的叶片器官所需营养元素变化以及土壤肥力对其影响,对于桉树营林和科学施肥具有重要的生产指导意义。选取广西隆安县小林镇和田东县思林镇的桉树2代萌芽林作为研究对象,测定两个人工林嫩叶、成熟叶、黄叶的C、N、P、K、B、Ca、Mg以及土壤C、N、P、K、Ca、Mg元素含量,并进行相关分析。结果表明,植物叶片的N、P、K、Mg营养元素转移规律是黄叶向成熟叶和嫩叶转移,但C、Ca、B营养元素则是随着叶片的生长发育逐渐积累,黄叶中含量最高,说明施肥时应关注Ca、B元素的持续和有效供给。两片人工林都表现出类似的规律,说明土壤肥力的差异不影响桉树人工林叶片营养元素的内循环规律。桉树嫩叶营养元素含量及其生态化学计量比学特征具有与成熟叶和黄叶不同的表征,在营养物质研究中应予以足够重视。