广西北仑河口红树植物种群结构与动态特征

以广西北仑河口国家级自然保护区4种红树植物秋茄(Kandelia obovata)、桐花树(Aegiceras corniculatum)、白骨壤(Avicennia marina)和木榄(Bruguiera gymnorrhiza)为研究对象,在野外样地调查的基础上,采用高度级和大小级结构、静态生命表、存活曲线、时间序列分析和7种聚集强度指数等方法对4种红树植物的种群结构和动态进行了分析和预测,旨在阐明红树植物种群与群落的结构特征和动态变化规律以及潜在的驱动机制,为广西红树林生态系统的保护与恢复提供基础资料和科学依据。研究结果表明:木榄和秋茄种群更新良好,桐花树更新受到一定阻力,种群相对稳定,白骨壤种群更新不良,呈现明显的衰退趋势;4种红树植物种群不同龄级的存活量差别较大,存活量和生命期望一般随龄级的增加逐渐减少;白骨壤种群的存活曲线属于DeeveyⅠ型,其种群个体均能达到其平均生理寿命,木榄和秋茄种群属DeeveyⅡ型,各龄级个体具有相对一致的死亡率,而桐花树种群介于DeeveyⅠ型和DeeveyⅡ型之间,其幼龄期死亡率偏高,中龄期后死亡率逐渐接近;时间序列分析同样表明,白骨壤未来种群数量将明显降低,种群逐步衰退,桐花树未来种群数量将表现为稳中有降,而木榄和秋茄未来种群数量将趋于增加。4种红树植物不同龄级种群多呈现聚集分布,聚集强度往往随种群龄级的增加而趋于降低。上述结果表明,北仑河口4种红树植物的种群动态与群落所处演替阶段息息相关,先锋植物白骨壤种群处于较快衰退阶段,演替前中期的桐花树种群稳中有降,而演替中后期的秋茄和木榄种群出现不同程度的增长,反映出本次调查的红树林群落正处于演替的中期阶段,白骨壤和白骨壤+桐花树群丛将逐步演替为以木榄为优势种的群丛。此外,红树植物的种群动态受到自身繁殖特性、生境条件、种内和种间竞争、虫害等多种因素的调控。     

广东湛江红树林国家级自然保护区优势乔木群落的物种组成及结构特征

针对湛江红树林自然保护区的优势乔木群落, 根据优势种重要值大小对群落类型进行了划分, 进一步从立木、苗木和幼苗3 个层次对群落物种组成及结构特征进行了研究。结果显示: 4 科6 种红树植物组成11 个优势乔木群落。无瓣海桑群落分布最广, 平均胸径、高度和冠幅面积显著大于红海榄、秋茄、桐花树和白骨壤优势群落, 但无瓣海桑群落物种多度较低, 群落内无瓣海桑对秋茄有显著抑制作用; 白骨壤和秋茄优势乔木群落的多样性指数较高。红树林优势乔木群落林下层植被组成贫乏、结构简单, 以桐花树、秋茄和白骨壤为主; 林下苗木数量多于幼苗; 白骨壤幼苗占总量的67.1%。未来红树林恢复仍要重视本地红树物种, 建议加强白骨壤作为恢复物种的研究。     

广西的红树林

本文主要讨论广西沿海的红树林的植物种类成分、外貌、适应形态学特点、群落类型和演替规律,以及生产管理问题。 该地区的红树植物种类计有8科、12属、12种,以红树科植物占优势。群落类型有:白骨壤群落、桐花树群落、秋茄-桐花树群落、红海榄群落、木榄群落、木榄-桐花树群落、桐花树-海漆稀树群落和红海榄+秋茄-桐花树群落等。     

大亚湾红树林研究1.澳头港的红树植物群落

本文报道了大亚湾澳头港附近的红树植物群落的种类组成、结构、外貌及演替。该地区红树群落的主要类型有７个,即白骨壤群落、白骨壤桐花树群落、白骨壤＋秋茄桐花树群落、海漆木榄群落、海漆桐花树群落、桐花树群落、老鼠勒群落。     

大亚湾红树林研究I.澳头港的红树植物群落

本文报道了大亚湾澳头港附近的红树植物群落的种类组成、结构、外貌及演替。该地区红树群落的主要类型有7个,即白骨壤群落、白骨壤-桐花树群落、白骨壤+秋茄-桐花树群落、海漆-木榄群落、海漆-桐花树群落、桐花树群落、老鼠勒群落。     

不同红树植物群落中大型底栖动物群落的比较

2005—2006年对广东湛江红树林国家级自然保护区湿地三种红树植物群落(白骨壤 桐化树群落、桐花树群落、木榄 桐花树群落)的大型底栖动物群落特征进行了分析研究。白骨壤 桐化树群落大型底栖动物群落的物种数、栖息密度、生物量、丰富度指数和多样性指数均最高,优势度指数居中,均匀度指数略低于桐花树群落;桐花树群落大型底栖动物物种数急剧减少,尤其是底内型、底上附着型和穴居型种类减少明显,生物量和栖息密度下降到最低,由于个体数种间分配较为均匀而导致优势度指数下降而均匀度指数增高,虽丰富度指数略低于白骨壤 桐化树群落,但多样性指数接近于白骨壤 桐化群落;木榄 桐花树群落,大型底栖动物群落的物种数,尤其是穴居型和底内型种数继续减少,但生物量和栖息密度有所上升,个体数种间分配不均匀而使优势度指数增高而均匀度下降,加上丰富度指数最低,故多样性指数最小。白骨壤 桐化树群落优势种的生活型是底内型和穴居型;桐花树和木榄 桐花树群落优势种的生活型均是穴居型。三种红树植物群落中的大型底栖动物群落的GS/GSB分别为0.48、0.63、0.80。相同红树植物群落大型底栖动物群落结构都较为相似,木榄 桐花树群落的相似性最高,而不同红树植物群落大型底栖动物群落特征的差异明显,反映了不同红树群落对底栖动物群落作用的差别,同时也展示了各种大型底栖动物对不同红树群落生境的适应情况。     

广东湛江保护区红树林种群的生物量及其分布格局

本文研究了广东湛江红树林自然保护区高桥镇红寨村及德耀村海滩红树植物的种群分布格局与生物量。结果表明：５年生桐花树群落、白骨壤群落、秋茄群落、１０年生木榄群落、３０年生红海榄群落的总生物量分别为５５４７５ｇ／ｍ２、１６３７０１ｇ／ｍ２、６２６４４８ｇ／ｍ２、４１３８４３ｇ／ｍ２、９６１０２０ｇ／ｍ２;其中地下部分生物量占总生物量的比例依次为３２２８％、４５４５％、４１３１％、２９８５％和２８２９％。计算得Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ物种多样性指数为２２３２。种群的分布格局中桐花树、白骨壤、红海榄和秋茄种群为集群分布,而木榄种群为随机分布。     

福建亚热带红树林生态学的研究

福建亚热带红树林种类计有五科五属六种,即木榄、秋茄、海漆,老鼠簕、桐花树和白骨壤。主要群落类型有秋茄+木榄-桐花树群落、秋茄+桐花树群落、秋茄群落和白骨壤群落。秋茄高生长与土壤含氮量(%)的关系呈半对数线性正相关,回归公式为log y=0.9397+3.124x(y为树高、x为含氮量)。树高与土壤含盐量呈抛物线相关。红树林生态系统中,生物因子的作用是明显的。藤壶附着于叶面或树干上,严重危害秋茄生长发育。林下相手蟹等造穴活动,有利于林下土壤通气性。浒苔、颤藻等藻类繁殖,也会影响红树生长。引种栽培要选择适当的生境和适合本地的种类、才能保证较高的成活率。     

广西英罗湾红树植物群落的研究

 对广西英罗湾红树植物群落的种类组成、类型、外貌、结构、物种多样性和演替等进行了较系统的探讨。组成群落的优势红树植物有木榄、红海榄、秋茄、桐花树、白骨壤和海漆6种,隶属6属4科。主要的群落类型有木揽群落、木榄+红海榄群落、红海榄群落、红海榄+秋茄群落、秋茄群落、秋茄+桐花树群落、秋茄+白骨壤群落、桐花树群落、白骨壤群落、白骨壤+桐花树群落和海漆群落等11个群系。群落外貌由单叶、革质、全缘、中型叶的高位芽植物决定。群落层次结构简单．单层或两层。和陆地植物群落相比较,组成群落的红树植物的物种多样性较低。受潮滩土壤质地、养分状况、环境盐度和潮淹程度以及红树植物自身对盐渍生境的适应性等因子制约,群落的分布形成了明显的生态系列。随着海平面的相对降低和土壤理化性质的改善,群落具有向陆生植物群落演化的趋势。     

福建亚热带红树林生态学的研究

福建亚热带红树林种类计有五科五属六种,即木榄、秋茄、海漆,老鼠簕、桐花树和白骨壤。主要群落类型有秋茄+木榄-桐花树群落、秋茄+桐花树群落、秋茄群落和白骨壤群落。秋茄高生长与土壤含氮量(%)的关系呈半对数线性正相关,回归公式为log y=0.9397+3.124x(y为树高、x为含氮量)。树高与土壤含盐量呈抛物线相关。红树林生态系统中,生物因子的作用是明显的。藤壶附着于叶面或树干上,严重危害秋茄生长发育。林下相手蟹等造穴活动,有利于林下土壤通气性。浒苔、颤藻等藻类繁殖,也会影响红树生长。引种栽培要选择适当的生境和适合本地的种类、才能保证较高的成活率。     

Differential Distribution of Metals and Enzymes in Quanzhou Bay Estuarine Wetland Soils under Three Mangrove Species

This study aimed to investigate the effects of three dominant mangrove species (Avicennia marina, Aegiceras corniculatum, and Kandelia obovata) on the distribution of the metal elements Fe, Mn, Cu, and Zn and the enzymes urease, phosphatase, polyphenol oxidase, and catalase. Concentrations of the metallic elements and enzymatic activities were quantified in soils under the three mangrove species in the Quanzhou Bay estuarine wetland, a typical coastal wetland in China. Results showed that A. corniculatum promoted aggregation of Mn, urease, and phosphatase, while K. obovata contributed to accumulation of Cu, urease, and phosphatase. Furthermore, A. marina induced activation of Zn and accumulation of urease, phosphatase, and catalase. The characteristic enzyme and metal distributions induced by the different mangrove species are likely to result from different planting times, root systems, and soil pH and salinity. Moreover, the three mangrove species were found to influence the diversity of elemental and enzymatic stoichiometry through differences in the soil microenvironment, which can promote biodiversity in wetland ecosystems. These findings provide a useful guideline to develop strategies for restoration of estuarine wetlands.     

Seasonal occurrence and diel locomotor activity in littoral Cladocera in a mesohumic lake in Norway

The community structure and standing crop biomass of a mangrove forest in Futian Nature Reserve, Shenzhen, the People's Republic of China was studied. This mangrove, located towards the northern latitudinal limit of the mangrove development (22°N), had relatively simple structure and low diversity (the Shannon-Wiener index was 0.78). The three dominant species, namely Aegiceras corniculatum, Kandelia candel and Avicennia marina, possess importance values of 72, 19 and 9%, respectively. The average height of the mangrove community was 4.5 m with no vertical stratification. The values of tree density of A. corniculatum and A. marina were found to be 5290 and 260 ha^–1, respectively. The biomass of both A. corniculatum and K. candel was best estimated from regression equations using a combination of height and diameter at breast height as the independent variables. For Avicennia marina, there was no simple correlation between biomass and height or diameter. The regression models suggested by previous workers did not give satisfactory estimation of biomass of A. marina in this mangrove forest. The total biomass of this mangrove forest was 12.1 kg m^–2, with 73% of such production contributed by A. corniculatum and 8% by A. marina. Because of its small percentage, the inaccuracy in estimating biomass of A. marina did not affect the overall determination of biomass of the whole community. Average above-ground biomass was 8.7 kg m^–2 (72% of the total biomass) and the major components were aerial woody tissues, stems and branches. The root:shoot ratio of this plant community was 0.4:1.     

Wetland changes and mangrove restoration planning in Shenzhen Bay, Southern China

Mangrove forests and associated gei wai (excavated ponds used for shrimp and fish farming) provide important ecosystem services in Shenzhen Bay. Much of the mangrove and gei wai wetlands, however, have been lost because of intensified human activities in the past 30 years. Using five-phase remote-sensing images, we describe the recent history of the spatial–temporal dynamics for the wetlands in the bay. From 1986 to 2007, mangrove area increased from 1.8 to 4.8 km², while the area of gei wai decreased from 36.6 to 17.2 km². Reclamation of gei wai mainly occurred in western and northern Shenzhen Bay, and changed the tidal water environment. The bay has five typical mangrove communities: Avicennia marina + Kandelia candel + Aegiceras corniculatum, Kandelia candel + Aegiceras corniculatum + Acanthus ilicifolius, Bruguiera gymnorrhiza + Excoecaria agallocha, Aegiceras corniculatum, and Sonneratia apetala + Sonneratia caseolaris. The distribution of these communities and their dominant species in the bay exhibit a spatial pattern and temporal (successional) sequence. We describe a mangrove restoration program based on the mangrove successional sequence and the interaction of mangrove and gei wai in the bay. We have planned six mangrove protection and restoration projects in closed areas, semiclosed areas, and open areas to reconstruct the ecological integrity of the entire Shenzhen Bay.     

Isolation and characterization of chloroplast microsatellite markers in four mangrove species,Aegiceras corniculatum,Avicennia marina,Acanthus ilicifolius and Lumnitzera racemosa

One, three, seven, and six of polymorphic chloroplast microsatellite (cpSSR) markers were developed from four mangrove species, Acanthus ilicifolius, Aegiceras corniculatum, Avicennia marina, and Lumnitzera racemosa, respectively. Characterization of 229, 509, 369, and 216 individuals of A. ilicifolius, A. corniculatum, A. marina, and L. racemosa, collected from different natural mangrove populations (A. ilicifolius, 6; A. corniculatum, 14; A. marina, 10; L. racemosa, 6) in the southern coastline of China showed that these loci provide cpSSR markers with polymorphisms ranging from two to four alleles per locus and gene diversity between 0.005 and 0.675. Combining the polymorphic cpSSR loci of each species, 3, 5, 11, and 4 of cpSSR haplotypes were separately detected in populations of A. ilicifolius, A. corniculatum, A. marina, and L. racemosa in the southern coastline of China. These cpSSR markers will be useful for analyzing the maternal lineage distributions and population genetic structures of these four species.     

广西西端海岸四种红树植物天然种群生境高程

在广西防城港市东湾渔洲坪、石角、交东3个样地平行海面方向共设置18条剖面对4种红树植物白骨壤(Avicenniamarina)、桐花树(Aegiceras corniculatum)、秋茄(Kandelia obovata)、木榄(Bruguiera gymnorhiza)在沿海滩涂生长带高程测量和群落调查。调查结果表明:由于人类活动造成东湾渔洲坪和交东两个样地的坡度变化较大,分别从-0.37变化为-0.05和-0.72变化为-0.10,而地处北仑河口保护区内的石角样地受到保护,没有人为因素的影响,坡度从-0.23变化为-0.10变化不大。石角和交东两个样地中的桐花树集中出现在高程15至40 cm和33至36 cm范围内;秋茄集中出现在高程43至60 cm和37至51cm范围内;木榄集中出现在高程94至106 cm和111至119 cm范围内。所有样地中的白骨壤在高程60至80 cm范围内,树高最高达到220 cm,且分布密集;桐花树在高程20至40 cm范围内,树高最高达到200 cm,且分布密集;秋茄在高程40至80 cm范围内,树高最高达到200 cm,且分布密集;木榄在高程60至100 cm范围内,且分布密集,树高最高达280 cm。通过对各样地剖面上红树植物种类出现频度的分析和林木高度的测量,4种红树植物天然林临界滩涂高程分别为:桐花树为-7 cm;秋茄为+33 cm;白骨壤为+23和+26 cm;木榄为+44 cm。对应的浸淹时间分别为8.5、7.0、7.0、6.0h。在石角和交东分别有30.0%和56.7%的桐花树分布于平均海平面以下,秋茄也能分布在此高程下,平均株高也达1.75 m。根据现场实际调查结果,桐花树、秋茄可以大量生存在平均海平面以下的滩涂上。     

八种红树植物幼苗的叶片可溶性蛋白和抗氧化酶活性对光强的响应

红树林湿地生态系统的恢复与重建是我国南方海岸带生态恢复研究的重点领域之一。为明确红树植物光适应的生理生态策略，该文选取无瓣海桑(Sonneratia apetala)、秋茄(Kandelia obovata)、木榄(Bruguiera gymnorhiza)、桐花树(Aegiceras corniculatum)、老鼠簕(Acanthus ilicifolius)、卤蕨(Acrostichum aureum)、银叶树(Heritiera littoralis)和黄槿(Hibiscus tiliaceus)作为研究对象，通过遮荫控制试验，探究这8种红树植物一年生幼苗在不同光照强度(自然光强的100%、45%、30%、10%)处理下的叶片可溶性蛋白含量和抗氧化酶活性的响应特征。结果表明：(1)随光照强度下降，木榄、老鼠簕和卤蕨的叶片可溶性蛋白含量受到的影响较小，而无瓣海桑、秋茄、桐花树、银叶树和黄槿的叶片可溶性蛋白含量则表现出下降趋势。(2)木榄、老鼠簕和卤蕨的超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)等抗氧化酶活性在10%光照强度处理下的活性与对照无显著差异，而无瓣海桑、秋茄...     

Root anatomy and spatial pattern of radial oxygen loss of eight true mangrove species

The root anatomical features of eight mangrove species in Hong Kong were similar, with large aerenchymal lacunae in the cortex for efficient internal oxygen transfer and an outer barrier consisting of an epidermis and hypodermis to prevent oxygen loss. The spatial pattern of radial oxygen loss (ROL) was also comparable, with more oxygen lost from the tip than that from the basal and mature zones. However, the aerenchyma in the cortex, the barrier and the extent of ROL varied along the root and these variations were species-specific. The whole root of Avicennia marina (Forsk.) Vierh., Acanthus ilicifolius L., Aegiceras corniculatum (Linn.) Blanco, Kandelia obovata Sheue, Liu & Yong (previously known as Kandelia candel (L.) Druce) and Heriteria littoralis Dryand. ex W. Ait. had schizogenous aerenchyma, while the aerenchyma of Lumnitzera racemosa Willd. and Bruguiera gymnorrhiza (L.) Poir changed from schizogenous in the root tip to lysigenous in the other parts of the root. Excoecaria agallocha L. displayed the opposite pattern, from lysigenous in the root tip to schizogenous further up. Among the eight species, the roots of A. marina and A. ilicifolius had the largest areas of aerenchyma air spaces, but they also had the weakest barrier. On the other hand, H. littoralis had the least longitudinal oxygen transfer because of its smaller area of aerenchyma air spaces in its root. The tolerance of mangrove species to waterlogged soil followed the order of A. marina (most foreshore species) > A. ilicifolius > K. obovata > A. corniculatum > B. gymnorrhiza > E. agallocha > L. racemosa > H. littoralis (most landward species), which is related to their anatomical features of root cortex, epidermis and hypodermis.     

Polyphenols, tannins and antioxidant activities of eight true mangrove plant species in South China

Background and aims

(i) compare the concentrations of total polyphenols (TP) and condensed tannins (CT), and CT profiles in different organs of mature trees and seedlings of eight true mangrove species in Hong Kong; (ii) examine the antioxidant activities of CT and (iii) relate the non-enzymatic antioxidative defence system with the vertical zonation pattern of mangrove species.

Methods

Mature trees and seedlings of eight species were collected from a Hong Kong mangrove swamp to determine TP and CT concentrations and the antioxidant activities of CT.

Results

According to TP concentrations, the true mangrove species could be broadly classified into three groups, (i) Lumnitzera racemosa and Aegiceras corniculatum > (ii) Heritiera littoralis, Excoecaria agallocha, Bruguiera gymnorrhiza and Kandelia obovata > (iii) Acanthus ilicifolius and Avicennia marina. The last two are pioneer species in the most foreshore location. They also had significantly lower antioxidant activities, CT concentrations and different CT profiles than the other six species in mid- and low-tides.

Conclusions

Classification of the eight true mangrove species into three groups based on polyphenols was similar to their vertical zonation from land to sea. The relationships between these antioxidants and zonation should be further verified by transplantation studies.     

Effect of an integrated mangrove-aquaculture system on aquacultural health

Mangroves are unique intertidal halophyte formations growing in sheltered tropical and subtropical coastal areas. Due to the increasing population and economic development, mangroves have faced degradation and loss, which has been mainly caused by land conversion into aquaculture ponds in Asia. In the past several decades, the rapid growth of aquaculture has induced water pollution. Using mangroves for effluent treatment from coastal aquaculture ponds could be a suitable approach for wastewater treatment and healthy aquaculture development. An Integrated Mangrove-Aquaculture System (IMAS) was established to test whether the idea of a mangrove in situ treatment for aquaculture wastewater is feasible. The monocultures of three mangroves, Sonneratia caseolaris, Kandelia obovata, and Aegiceras corniculatum were established with area proportions of 45%, 30%, or 15%, respectively. One control pond without mangroves was also set up. The results indicated that the mangroves had different tolerabilities to long-term inundation. The aquaculture ponds had different fishery yields, considering the mangrove species and area proportions. The water quality of most of the experimental ponds was better than the control pond, except for the planted Sonneratia. It is concluded that mangroves can reduce the concentration of dissolved inorganic nitrogen and phosphate, buffer the pH value and increase the concertration of dissolved oxygen in aquaculture water bodies effectively. It is suggested to use 15% of the Aegiceras corniculatum area to conduct in situ purification of aquaculture wastewater and to enhance aquaculture production.     

Relationships between height and girth of mangroves and soil-water conditions in the Mary and Hawkesbury River estuaries,eastern Australia

Abstract The height and diameter at breast height (DBH) of mangroves on the Hawkesbury River, New South Wales and the Mary River, Queensland were related to soil-water salinity, soil-water content and distance from the mouth of the estuary. On the Hawkesbury River, both Avicennia marina and Aegiceras corniculatum declined in height and DBH with increasing soil-water salinity and soil-water content, and increased in height with distance from the mouth of the estuary. Both species showed an extensive range of all variables. On the Mary River, where species diversity was higher, no relationship was found between the height and DBH of A. marina and A. corniculatum and soil-water salinity and soil-water content. Both species increased in height with increasing distance from the mouth of the estuary, a characteristic shared with all other species studied (Excoecaria agallocha, Ceriops tagal var. australis, Rhizophora stylosa). The results suggest that growth characteristics of mangroves are not a simple response to salinity gradients in diverse systems and that other variables such as nutrient availability may be important controls on mangrove growth.