涠洲岛造礁石珊瑚群落变化特征及其环境影响因子

以涠洲岛造礁石珊瑚群落为研究对象,分析其群落物种组成、多样性、Raunkiaer频度和种间Spearman轶相关,探讨群落组成与水环境因子的相关性,并结合近10年来涠洲岛造礁石珊瑚变化情况,找出涠洲岛造礁石珊瑚群落的主导影响因素。结果表明：（1）近10年来涠洲岛造礁石珊瑚覆盖率显著降低,珊瑚形态组成趋于块状化,尽管珊瑚群落多样性较高,但群落分布较松散,群落结构较不稳定,部分优势种种间竞争较激烈。（2）悬浮物含量是影响石珊瑚群落最显著的环境因子。石珊瑚优势种群在不同水深中分布差异显著,泥沙覆盖率、营养盐对不同石珊瑚种群影响差异较大,大型海藻覆盖率在局部区域对优势珊瑚形成较强的竞争关系。（3）营养盐和泥沙沉积物的增加与涠洲岛近海养殖业及生活排污、海岸工程及海岸侵蚀密切相关。     

广西涠洲岛鸟类自然保护区的两栖爬行动物

2008年5～6月对广西涠洲岛鸟类自然保护区的两栖爬行动物进行调查,共记录到两栖类7种,爬行类16种,隶属于3目11科.与18年前的调查结果对比,生境的变化使岛上两栖爬行动物的分布范围和多度发生一些改变.2008年初的冰冻灾害使涠洲岛的两栖爬行类损失较大.涠洲岛与邻近大陆的两栖爬行动物物种相似,无特有种.     

广西涠洲岛鸟类自然保护区的鸟类资源

先后于1989年10月和12月、1990年3～4月和7～8月、1991年4～5月、1994年4～5月、2003年1月和2008年5月对广西北部湾涠洲岛的鸟类资源进行了调查,在该保护区内共记录到鸟类186种,隶属16目52科.其中,旅鸟117种,冬候鸟48种,留鸟14种,夏候鸟7种.13种鸟类被IUCN列为受威胁物种,包括黑脸琵鹭(Platalea minor).国家重点保护鸟类29种.中日候鸟保护鸟类93种,中澳候鸟保护鸟类30种.涠洲岛鸟类自然保护区是沿太平洋西海岸迁飞候鸟的重要中途停歇地,具有非常重要的保护价值.     

珍稀濒危植物黄杉种群结构与空间分布格局北大核心CSCD

为了解珍稀濒危植物黄杉种群的生存现状和更新机制,对贵州省威宁县黄杉自然保护区内天然分布的黄杉(Pseudotsuga sinensis)群落的结构特征和空间分布格局进行了研究。结果表明,黄杉种群的中龄级个体数较多,幼龄级和老龄级个体相对较少,呈典型的“∩”型结构。种群结构动态指数V_(pi)(13.49%)和V′_(pi)(0.05%)均大于0,种群属于增长型,但增长幅度逐渐降低,对外界干扰敏感度较高。种群存活曲线趋于Deevey-II型,生命期望值单调下降,死亡率呈“V”型,有2个死亡高峰,第1个出现在I龄级,第2个出现在IX龄级。黄杉种群除部分样地(Q2和Q7)呈均匀分布外,大部分样地呈集群分布;随龄级的增加,空间分布格局由集群分布逐渐趋向于均匀分布。因此,黄杉种群濒危的主要因素是幼树个体无法及时补充种群,建议加强对幼苗的抚育和通过适度干扰,促进黄杉种群的更新。     

乌兰布和沙漠沙冬青种群结构和空间分布

对乌兰布和沙漠不同区域分布的沙冬青(Ammopiptanthus mongolicus)种群结构和空间分布格局进行了研究,根据大小结构图分析沙冬青种群动态,用平均拥挤度(m·)、丛生指数(I)、聚块性指标(m·/m)、Cassie指标(CA)、扩散系数C、负二项分布中的K指标判断格局类型,并根据双项轨迹方差法分析格局规模.结果表明:沙漠中部分布的沙冬青种群年龄结构完整,而其他区域分布种群结构均不完整;各区域分布种群均以中龄级个体居多,种群目前处于相对稳定的状态,但是由于幼龄级个体少,种群更新困难,且部分区域种群有"老龄化"的趋势.在西北边缘和沙漠北部分布的种群为聚集分布类型,而其他区域均为均匀分布;对各样地种群格局规模的分析也表明格局规模存在差异.     

徐闻西岸造礁石珊瑚的组成及空间分布

2008年5-6月在徐闻西岸设置了25个站点,运用截线样带法调查了造礁石珊瑚的种类多样性和空间分布.本次研究共发现造礁石珊瑚57种,每个站位的种类数均不超过30种.Shannon-Wiener多样性指数和Pielou均匀度指数均值分别为1.79和0.42.二异角孔珊瑚(Goniopora duofasciata)、盾形...     

白桦种群空间分布格局的研究

根据在白桦种群分布区内所选择的四个代表性地区的定位观测资料,本文运用数学分析方法,采用电电子计算机进行运算,模拟,研究白桦种群的空间分布格局。结果表明：随着生境温度的逐渐降低或温度的逐渐升高,白桦种群由聚集分布过渡为随机分布;随着种群年龄的增加,种群空间分布格局表现出相同的变化规律。     

西沙群岛海域造礁石珊瑚物种多样性与分布特点

2006年3-5月,采用国际通用的截线样带法对海南省西沙群岛主要珊瑚礁海域的18个岛礁造礁石珊瑚进行了实地调查,共记录13科45属188种,其中62个新记录种.整合文献资料,该海域共记录造礁石珊瑚13科50属204种,基本包括分布在我国(不含台湾省)的所有造礁石珊瑚科属和绝大多数种类.造礁石珊瑚以生长速度快的分枝状珊瑚为主.物种多样性最高的是华光礁海域、金银岛海域和永兴岛海域.聚类分析可以把18个调查岛礁分成3个类群:有人类居住的大型环礁群、独立岛礁群和无人居住的大型环礁群(华光礁).为了有效保护珍稀的造礁石珊瑚资源,按照其种类多样性和分布特点重点保护关键海域是十分必要的.     

海南岛山区寄生蜱螨蚤群落结构与种群空间分布

我们于1992～1995年对海南岛山区寄生于鼠形动物体表的蜱、螨、蚤群落结构和种群空间分布进行了调查研究,结果如下。1研究方法选择有代表性的山地丛林、稻田旱地作物区及山村房舍等类型生镜,分别采用垂直法和等距法布鼠笼（240mm×100mm×110mm）,晚放晨收,每地连续2天。将捕获鼠宠一并装入白布袋内,带回实验室用氯仿麻醉鼠形动物,逐一检取其体表及袋内蝉、螨、蚤,编号、计数、鉴定[1～5],按不同生境、统计数量,计算种群组成比,分析群落结构和空间分布等。2结果2．1蜱、螨、蚤的群落结构：共检获寄生于鼠形动物体表蝉类2083只,革…     

珍稀濒危树种陆均松天然种群结构与空间分布格局

为研究陆均松(Dacrydium pectinatum)种群生存现状及分布格局,对BWL、DLS、JFL三种不同分布区域的陆均松天然种群进行了调查,分析了其天然群落乔木层物种多样性及优势种组成、龄级结构及分布格局三个方面的空间异质性,结果表明:(1)三种陆均松天然群落乔木层物种丰富度及多样性指数均较高,基本表现为BWL>JFL>DLS,且远高于中高纬度温带及亚热带森林群落;群落内多为小密度种群,少有占绝对优势地位的树种,符合热带山地雨林物种组成的一般规律。(2)龄级结构有所差异,BWL和JFL种群呈衰退趋势,共同特点是幼年树数量较少,成年和老年树比例较高;DLS种群幼年树数量在所有个体中比例最高,属于增长型种群。(3)BWL和DLS种群整体呈聚集分布,幼年至老年阶段由聚集分布转变为均匀分布,JFL种群整体及不同发育阶段均呈均匀分布状态;聚集强度表现为DLS>BWL>JFL,幼年树>成年树>老年树。陆均松是热带山地雨林的关键种和建群种,对研究海南热带雨林的起源及其区系特征具有重要意义,针对其生存现状,可根据实际情况,利用人工辅助措施如开辟林窗、合理疏伐...     

Length–weight relationship of five coral reef fish from the Weizhou Island,China

In the present study, the LWRs investigations were conducted for five fish species from Weizhou Island for four times seasonally during the period from April 2017 to January 2018. Samples were obtained using gillnets (25 × 12 m, mesh size 0.5 cm), trawl nets (50 × 12 m, mesh size 0.5 cm) and fishhooks (0.5 × 0.5 × 10 m, mesh size 0.5 cm mesh). Results indicate that mean LWR parameters b for these five coral reef fish varied from 2.847 to 3.525 and r² values varied from 0.972 to 0.988.     

三亚鹿回头石珊瑚物种多样性的空间分布

对三亚鹿回头珊瑚岸礁沿垂直岸线的5条断面上84个调查样方观测照相和室内判读分析,鹿回头岸段石珊瑚共有13科24属69种,珊瑚分布不均,少数种类优势明显.石珊瑚优势种为澄黄滨珊瑚,其重要值百分比为36.62%;优势属为滨珊瑚属(43.85%)和鹿角珊瑚属(22.88%).各断面间多样性格局差异明显,并存在明显的垂直分带现象:东北部第1、2断面石珊瑚种类分布较为均匀,多样性指数值高于中南部第3、4、5断面;礁坪为珊瑚稀疏生长带,种类较少且滨珊瑚为绝对优势属(重要值百分比＞50%);礁坡为珊瑚密集生长带,种类较多以鹿角珊瑚最占优势(28.33%),滨珊瑚仅次之(26.71%).近年来该岸段珊瑚礁衰退趋势明显,不合理的破坏性人类活动是重要原因.石珊瑚多样性的空间差异除因礁坪礁坡不同的自然环境外,主要与受到不同类型和强度的人类活动有关.礁坪大潮低潮时暴露,环境恶劣,且受人类采挖、践踏活动影响较频繁和明显;礁坡环境适宜,人类活动影响也相对微弱.养殖、捕捞和近岸排污等人类活动在岸段中南部较为突出,对珊瑚多样性的影响比东北部明显.在尊重珊瑚礁发育的自然规律基础上不断加大力度制止养殖、不合理捕捞和近岸排污等破坏性人类活动,才能更好地科学保护和管理该岸段珊瑚礁.     

Different responses of scleractinian coral Acropora pruinosa from Weizhou Island during extreme high temperature events

Ecological surveys observe coral “winners” and “losers” in global coral bleaching events. However, the key contributors to holobiont tolerance and interactions between symbionts remain unclear. Herein, we compared bleaching and unbleaching Acropora pruinosa corals from Weizhou Island, during an extreme high-temperature event in the northern South China Sea in 2020. We found the dominant Symbiodiniaceae subclade in the bleaching and unbleaching corals to be C1; however, the density of Symbiodiniaceae in the latter was significantly higher than that in the former. Additionally, the symbiotic bacteria α diversity in the unbleaching coral was significantly higher than that in the bleaching coral, with a reorganized bacterial community structure. Core microbiome analyses revealed 55 bacterial core operational taxonomic units (OTUs), of which 10 were significantly differentially enriched between the two coral groups. The significantly enriched bacterial core OTUs in the unbleaching coral were primarily nitrogen cycling related, while those enriched in the bleaching coral were associated with antimicrobial activity. RNA-Seq analyses revealed that significantly upregulated genes in the bleaching coral were primarily associated with diseases and autophagy, while those in the unbleaching coral were associated with immune defense and maintenance of the symbiotic relationship between corals and symbionts. We propose that the differences in tolerance of A. pruinosa result from the cooperation between coral host, Symbiodiniaceae, and symbiotic bacteria. In extreme high-temperature events, unbleaching corals may maintain stable symbiotic relationships by increasing the diversity of symbiotic bacteria, regulating the structure of the symbiotic bacteria community, improving the interaction between coral host and symbiont and enhancing host immunity, thus avoiding coral bleaching. This study illuminates the relationship between the coral symbiont and tolerance differences of coral holobionts, providing new insights for further exploration into the adaptability of scleractinian corals in the context of global warming.

     

Spatial pattern of coral diversity in Luhuitou fringing reef, Sanya, China

84 quadrats from 5 vertical transects of Luhuitou fringing reef are investigated in detail by using video-quadrat and indoor-interpretation methods. The results show that (1) the reef consists of 69 species of hermatypic corals belonging to 24 genera and 13 families which are unevenly distributed in abundance. (2) Among all the corals, Porites lutea is the most dominant species with importance value percentage up to 36.62%; Porites and Acropora are dominant genera with importance value percentages 43.85% and 22.88%, respectively. (3) There exist distinct spatial differences in coral communities. Both the coral covers and coral diversity indices on the northeastern transects are higher than those on the central and southern transects. (4) Coral communities also show remarkable zonal characteristics with less coral species occurring on reef flat than on reef slope. The importance value percentage of the sole dominant coral genus, Porites, is over 50%, while on the reef slope, the importance value percentages are 28.33% for the first dominant genus Acropora and 26.71% for the second dominant genus Porites. Our further analysis suggests that the spatial and zonal differences of coral diversity pattern are correlated with both natural environmental changes and human activities. The shallow water reef flat is frequently exposed at low tide and it receives more anthropogenic influences (including dredging and trampling) than the deep water reef slope. Thus, the coral community on the reef flat is not as well developed as that on reef slope. The relatively poor coral covers and coral diversity indices on the central and southern transects are closely related to heavy human activities around these sites such as aquaculture, fishing and coastal sewage drainage. Therefore, the impact of human activities must be taken into account in developing strategies for the protection of this coral reef.     

Spatial pattern of coral diversity in Luhuitou fringing reef, Sanya, China

84 quadrats from 5 vertical transects of Luhuitou fringing reef are investigated in detail by using video-quadrat and indoor-interpretation methods. The results show that (1) the reef consists of 69 species of hermatypic corals belonging to 24 genera and 13 families which are unevenly distributed in abundance. (2) Among all the corals, Porites lutea is the most dominant species with importance value percentage up to 36.62%; Porites and Acropora are dominant genera with importance value percentages 43.85% and 22.88%, respectively. (3) There exist distinct spatial differences in coral communities. Both the coral covers and coral diversity indices on the northeastern transects are higher than those on the central and southern transects. (4) Coral communities also show remarkable zonal characteristics with less coral species occurring on reef flat than on reef slope. The importance value percentage of the sole dominant coral genus, Porites, is over 50%, while on the reef slope, the importance value percentages are 28.33% for the first dominant genus Acropora and 26.71% for the second dominant genus Porites. Our further analysis suggests that the spatial and zonal differences of coral diversity pattern are correlated with both natural environmental changes and human activities. The shallow water reef flat is frequently exposed at low tide and it receives more anthropogenic influences (including dredging and trampling) than the deep water reef slope. Thus, the coral community on the reef flat is not as well developed as that on reef slope. The relatively poor coral covers and coral diversity indices on the central and southern transects are closely related to heavy human activities around these sites such as aquaculture, fishing and coastal sewage drainage. Therefore, the impact of human activities must be taken into account in developing strategies for the protection of this coral reef.     

Scleractinian coral diseases in south Florida: incidence, species susceptibility, and mortality

There are limited quantitative data available documenting the natural, or non-epizootic, occurrence of scleractinian coral diseases over multiple years. Individual coral colonies exhibiting black band disease (BBD), white plague (WP), dark spots syndrome (DSS), and white band disease (WBD) were monitored 3 times per year on 5 south Florida reefs over a 2 yr period. Surveys included measurements of coral population composition, coral diversity, disease type, coral species affected, colony size, percent of colony affected, and the number of lesions or active infections per colony. Data on re-infections of the same colonies, multiple infections per colony, disease duration, disease-associated tissue mortality, and coral recruitment are also presented. A total of 674 coral colonies exhibiting coral diseases were tagged and monitored. DSS was the most common syndrome (n = 620 infected colonies), but BBD and WP infections caused the largest amount of coral tissue death. The only disease that exhibited a linear increase in incidence with elevated temperature was BBD. DSS and BBD were the most persistent conditions, and WP infections were comparatively short-lived, with obvious signs of disease typically disappearing after 2 to 3 mo. The only disease that caused total colony death as oppposed to partial mortality during the survey period was WBD. WP and DSS incidence was significantly positively correlated with the relative frequency of the species most commonly affected by each disease at each study site. Of the 61 colonies examined in the recruitment survey, only 5 scleractinian coral recruits were identified. The most commonly recorded colonizer of exposed coral skeleton was filamentous/turf algae, thus indicating the potential for a shift towards algal-dominated reef communities.     

涠洲岛42年来海面温度变化及其对珊瑚礁的影响

涠洲岛位于南海珊瑚礁分布的北缘温度是影响其珊瑚礁生态系统发育的重要因素,对器测温度分析发现,近42年来涠洲岛海面温度(SST)与全球气候变暖呈准同步变化趋势,存在3～4年与7～8年的变化周期,20世纪80年代后期以来,涠洲岛SST上升比较明显。其月平均最高SST的持续上升将使本区珊瑚生长处于一种非常敏感的边缘,加上人类活动(建筑取材、炼油、旅游、捕鱼、养殖等)对涠洲岛珊瑚礁的潜在不利影响,则可能导致珊瑚礁的退化。此外,在系统的野外调查基础上,描述了涠洲岛现代珊瑚礁的分布范围。