湛江市红树林资源及其可持续利用

广东省湛江市现有红树林面积7242.0hm²,人工造林未成林25.6hm²,天然更新红树林509.4hm²,另有红树林宜林地9688.6hm²。红树林及其伴生植物主要有木榄(Bruguiera gymnorrhiza)、秋茄(Kandelia candel)、无瓣海桑(Sonneratia apetala)等15科24种。由于毁林养虾、养鱼等导致1980～2001年占用红树林地面积6363.6hm²。从总体上看,湛江红树林种类多,群落类型丰富;红树林面积大幅减少,影响区域社会经济发展;除乡土种外,无瓣海桑是一种较成功的外来引树种;宜林地多,但人工造林保存率不高;破坏红树林,挖塘养殖依然较普遍。为了实现湛江红树林的可持续发展,需要加强下列工作:建立自然保护区加强对现有红树林湿地的保护;开展红树林湿地生态系统资源监测和鸟类环志;科学规划后加快红树林的恢复和重建;积极推动退塘还林并合理利用红树林;依法保护管理好红树林;多途径筹集保护资金;加强红树林、湿地的保护和宣传。     

乐清湾红树林和光滩大型底栖动物群落比较研究

2004年5月,对浙江乐清西门岛的人工红树林及周边滩涂进行大型底栖动物调查,共发现大型底栖动物18种,隶属6门7纲15科;主要是软体动物,节肢动物和环节动物.底上生活类群(groupofsurface,GS)种类数少于底内生活类群(group of surface below,GSB)种类数.通过在红树林、幼红树林和光滩三种生境的调查发现,幼红树林群落结构组成介于红树林和光滩之间,三种生境的大型底栖动物密度分别为452ind·m^-2,310ind·m^-2,620ind·m^-2,生物量分别为40.53g·m^-2,44.80g·m^-2和42.75g·m^-2.红树林区底栖动物的优势种为可口革囊星虫Phascolosoma esculenta和难解不等蛤Enigmonia aenigmatica.三种生境中,红树林的生物多样性和均匀度最高,优势度最小,造成这个现象的原因可能与红树林生境的复杂化有关.     

海南岛东寨港几种红树植物种间生态位研究

采用3种常见的生态位宽度和生态位重叠计测公式,以外来种无瓣海桑扩散区的秋茄+桐花树群落演替系列作为资源轴,定量计测了几种红树植物的生态位宽度和重叠值.结果表明,各树种生态位宽度值排序为桐花树(3.8357)＞秋茄(3.3421)＞木榄(3.3180)＞白骨壤(3.0975)＞无瓣海桑(2.9137)＞海桑(2.5724)＞角果木(1.8523)＞红海榄(1.6897)＞海莲(1.0000),很好地表征了其生态适应性和分布幅度.各树种重叠值中,以秋茄、桐花树、木榄、白骨壤之间的生态位重叠较大,表明其间存在较强的资源利用性竞争.无瓣海桑生态位宽度处于中等程度,与中低潮滩红树植物海桑、桐花树、秋茄和白骨壤的重叠值相对较高,与红海榄、木榄有中度重叠,与角果木有少量重叠,与海莲完全没有重叠.     

Characterisation and analysis of microsatellite loci in a mangrove species, Avicennia marina (Forsk.) Vierh. (Avicenniaceae)

An enriched microsatellite library of the mangrove species Avicennia marina was constructed, in which 85.8% of the clones contained microsatellite sequences. Of the microsatellite repeat sequences isolated, 55.0% were di-nucleotides, 34.2% were tri-nucleotides, 50.0% were perfect, 24.2% were imperfect, and 15.0% were compound. Four different di-nucleotide repeats were isolated with repeat lengths ranging from 5 to 33; ten different tri-nucleotide repeats were isolated with repeat lengths ranging from 3 to 25. The most common di-nucleotide was the AC/TG repeat; the most common tri-nucleotide was the CCG/GGC repeat. Sixteen microsatellite sequences were selected for primer design, and 6 primers were selected to investigate the polymorphism detected among 15 individuals of A. marina from three natural populations in Australia. A total of 40 alleles were detected at 6 microsatellite loci. The number of alleles per microsatellite locus ranged from 5 to 13. On average, 7 alleles were detected per locus. All microsatellite loci showed high levels of gene diversity (heterozygosity), with values ranging from 0.53 to 0.88; the mean value of gene diversity was 0.70. Microsatellite loci were also tested for conservation across Avicennia species. There was a decline in amplification success with increasing divergence between Avicennia species. The results indicate that microsatellites are abundant in the Avicennia genome and can be valuable genetic markers for assessing the effects of deforestation and forest fragmentation in mangrove communities, which is an important issue for mangrove conservation and afforestation schemes. Received: 8 June 1999 / Accepted: 21 September 1999     

盐度对木榄幼苗某些金属元素累积的影响及钙的效应

通过对 40 0mmol·L^-1NaCl及不同浓度CaCl² 溶液处理的沙基培养的红树植物木榄幼苗各器官的K、Ca、Na、Mg含量的测定分析,结果表明,木榄幼苗在 40 0mmol·L^-1NaCl培养时各器官中积累大量的Na,造成K/Na和Ca/Na比值降低,幼苗干物质积累下降.补充Ca能减少Na在幼苗体内的累积,提高K/Na和Ca/Na,增加干物质积累,从而缓解盐胁迫,10～15mmol·L^-1CaCl² 为适宜浓度.本文的结论是在高盐度培养时木榄幼苗能够吸收大量的无机离子,增强渗透调节能力,保持对K/Na的高选择吸收性.这些特性是木榄对河口、海岸高盐度生境适应的主要生理机制,而生境土壤中适宜的Ca/Na也是其能够生存繁衍的重要原因之一.     

Cytochalasins from mangrove endophytic fungi Phomopsis spp. xy21 and xy22

Chemical investigation of the mangrove fungal endophytes, Phomopsis spp. xy21 and xy22, afforded four new cytochalasins, named phomopsichalasins D-G, along with six known analogues. The structures of these cytochalasins were elucidated on the basis of HRESIMS and extensive NMR spectroscopic data. Phomopsichalasins D (1) and E (2) represent the first two 10-phenyl[11]-cytochalasans containing a 12-carboxyl function. All of the isolates were evaluated for their cytotoxicities against eight human cancer cell lines by the MTT method. Phomopsichalasin G (4) exhibited inhibitory activities against HCT-8, HCT-8/T, A549, MDA-MB-231, and A2780 cancer cell lines with IC₅₀ values of 7.5, 8.6, 6.4, 3.4, and 7.1 μM, respectively.     

A unified framework for the restoration of Southeast Asian mangroves—bridging ecology, society and economics

The effect of intensive human intervention, poor socio-economic conditions and little knowledge on mangrove ecology pose enormous challenges for mangrove restoration in Southeast Asia. We present a framework for tropical mangrove restoration. Our proposed restoration framework addresses the ecology, economy and social issues simultaneously by considering the causes of mangrove degradation. We provide a step by step guideline for its restoration. We argue that although, ecological issues are of prime importance, economic and social issues must be considered in the restoration plan in order for it to be successful. Since mangrove ecology is not adequately studied in this region, local ecological knowledge can be used to fill the baseline information gaps. Unwanted human disturbance can be minimized by encouraging community participation. This can be ensured and sustained by facilitating the livelihood of the coastal community. We translated the restoration paradigm into a readily available practical guideline for the executors of the plans. We provide an example of mangrove restoration project that is closely related to our proposed framework. We are optimistic that this framework has the potential for universal application with necessary adjustments.     

红海榄红树林的蒸腾作用与生态因子的关系

在海南东寨港应用气孔计对红海榄红树群落的蒸腾速率、气孔导度和几个生态因子日变化同步进行测定。在12月19日晴天条件下,冠层叶的蒸腾作用上午10—11时达到最高值4.27—4.34μg·cm~(-2)s(-1),午间蒸腾速率下降。群落总蒸腾速率与光合有效辐射、叶内外水汽压差、气温、相对湿度、叶温和风速等因子的复相关达到极显著;对蒸腾速率影响显著的生态因子是光合有效辐射,相对湿度和叶内外水汽压差。红海榄群落日平均蒸腾速率为2502gH_2O·m~(-2)d~(-1),其中冠层叶的蒸腾占总量的63％。     

广西海岛红树林资源的调查研究

广西海岛有红树林植物２０种,分隶１４科、１９属;按生态外貌和优势种的原则,可划分为８个群系,１１个群落．     

红树植物秋茄和桐花树抗寒力的越冬变化

采用电导法定量测定了福建省九龙江口红树植物秋茄和桐花树抗寒力的越冬变化 ,探讨了抗寒力与水分、叶绿素、可溶性蛋白质含量及过氧化物酶活性的相关性 .结果表明 ,1 988年 9月至 1 989年 4月越冬期间 ,秋茄和桐花树抗寒力随气温下降而增强 ,分别于1月和 1 2月达到最大 ,低温处理 1h ,半致死温度为 - 9.3℃和 - 9.0℃ ;其后 ,抗寒力随气温回升而迅速下降 .冬季秋茄和桐花树抗寒力的提高与束缚水含量增加或自由水含量减少密切相关 ,并伴随可溶性蛋白质含量的增加和过氧化物酶活性的增强 .束缚水与自由水、叶绿素a与b含量的比值变化可以反映红树植物抗寒力变化 :两种比值越高 ,抗寒力越强 .