耳螺的研究现状与展望

耳螺(Ellobiid)是一类特殊的原始有肺类软体动物,大多嗜盐,主要分布于海陆过渡区的高潮带和潮上带.耳螺在软体动物进化史上具有特殊地位,并且因其对环境变迁和人为干扰十分敏感,可作为环境评估的重要指标种.过去2个多世纪,众多学者已经对耳螺的形态学、解剖学、分类学和生态学等开展了系统的研究.本文概述了耳螺研究的3个阶段...     

中国红树林湿地:分布、种类组成及其保护

红树林作为重要的海岸湿地类型之一,具有极高的生态系统服务价值。过去的50年中,中国红树林曾遭到极大的破坏。本文简要介绍了世界红树林分布现状,对中国红树林的分布、面积及红树植物种类组成进行详细叙述,并就红树植物分类体系进行讨论,认为中国红树植物种类应为38种,其中真红树植物13科15属27种,半红树植物有9科11属11种;对中国红树林的保护现状进行分析总结,以期为红树林的研究和管理提供参考。     

海南红树林群系及分子生物技术在其研究中的应用

红树林是生长在热带亚热带海岸潮间带的木本植物群落。海南红树林是中国种类最多,分布和保存面积最大的区域之一,具有极为重要的研究价值。综述了海南红树林在种类、群落组成及红树林资源引种恢复以及分子生物技术等方面的研究,重点综述了分子生物技术在海南红树林植物研究中的应用,包括等位酶的应用、随机扩增多态DNA技术(RAPD)的应用和红树林植物耐盐性研究。     

广西红树林蜘蛛群落研究

广西红树林区及其近邻非红树林生境共采集到蜘蛛８２种,隶属于１３科４９属,其中红树林区有１３科３２属５５种。红树林区以园蛛科、非红树林区以猫蛛科和狼蛛科种类所占比例较高。角腹艾蛛是红树林区的优势种。物种多样性和丰富度红树林区比非红树林区高。     

中国红树林与典型区红树林群落重心迁移特征及共性关系

随着社会和经济的发展,红树林重心以及群落内部空间结构可能发生变化与调整.利用重心模型方法可以构建转移距离及方向,探索红树林及群落的重心空间转移特征及分布格局.本研究通过采用近25年多源、多时相遥感数据,利用GIS和遥感技术,提取了中国红树林信息,以及典型保护区漳江口的白骨壤、秋茄、桐花树、卡开芦和短叶茳芏信息.利用重心模型方法,从全局到局部,分析了中国红树林和典型保护区漳江口红树林群落的重心迁移特征与共性关系.结果表明:(1)红树林重心在东北方向上存在明显偏离,这种偏离主要体现在经度上,东西方向上不均衡.红树林重心主要位于入海口,且指向河网密集、经济繁荣的地区.(2)红树林群落重心受东南方向的主导作用,并指向群落高聚集区.红树林群落逐渐向北部和东部蔓延,重心表现出向北集聚的趋势.(3)省级红树林与典型区红树林群落重心迁移共性特征具有一致性、折回性和层次性,主要特征如下:红树林及群落的重心转移方向与海岸潮间带走向基本一致,且两者的轨迹方向指向受到良好波浪掩护的港湾或河口湾内;省级红树林及典型区红树林群落的重心分别在2005年和2011年后发生了不同程度的折回现象;典型区群落重心迁移在一定程度上属于省级红树林重心迁移的放大形势,前者反映了局部的内部结构特征,后者反映了全局的整体特征.研究有助于相关部门提出保护措施和方案,使红树林均衡、稳定、持续生长.     

典型红树林生态系统藻类多样性及其在生态过程中的作用

藻类是红树林生态系统重要的生物类群, 根据生态习性可分为浮游植物、底栖微藻和大型藻类三个生态类群, 它们在红树林生态系统生物多样性、初级生产、元素循环等方面起着重要作用。但在红树林生态系统中, 关注重点多集中在红树植物和动物, 对其中的藻类重视不够, 且多数研究集中在近20年以及亚洲的红树林区。事实上, 红树林生态系统藻类非常丰富, 其多样性研究有助于深入揭示红树林生态系统的结构与功能。本文介绍了红树林生态系统藻类的组成类群及其重要性, 重点对红树林区浮游植物、底栖硅藻和大型海藻的种类组成、地理分布及其与初级生产力、水质污染、元素循环、碳库形成等生态过程中的作用的研究动态和进展等进行了总结。根据已有研究, 红树林区浮游植物和底栖硅藻的种类数一般为几十到上百种, 其中硅藻在种类和数量上都占绝对优势, 它们是重要的初级生产者、饵料生物和水质污染指示生物; 红树林区底栖大型藻类主要由红藻、绿藻、褐藻、蓝藻组成, 绿藻的种类较多, 红藻在数量上占优势; 藻类是红树林湿地碳库的重要贡献者, 在红树林湿地生态系统碳汇和碳循环中起重要作用。红树林生态系统是个高度动态和异质的系统, 今后应加强红树林藻类多样性的长周期、大尺度变化及不同生境藻类的综合研究, 关注大陆径流和潮汐对藻类多样性和蓝碳的影响, 借助沉积物藻类记录, 探明红树林区藻类的长周期变化, 反演气候变化和人类活动对红树林生态系统的影响过程和机制。     

中国红树植物种质资源现状与苗木繁育关键技术

红树植物种质与种苗生产是所有红树林生态恢复工程的基础.本文根据工程实践并结合已有研究资料,采用聚类分析等方法,对中国红树植物资源现状与苗木繁育关键技术进行初步分析.结果表明:中国红树群落可分为低温广布型、广布型、嗜热广布型和热带分布型4种类型;资源分布可划分为琼东沿海、北部湾沿海、珠江口至粤东沿海、闽南和台湾沿海、闽东至浙南沿海5个区域.其中,北部湾沿海红树林种质资源占全国的75.3％.目前中国红树植物苗木种类开发利用率为52.6％,以胎生红树植物为主.红树林苗木生产应注意繁育方法、种实采集与储存、育苗方式、水分和盐度选择、病虫害防治及越冬防寒措施6个技术环节.结合调查和生产实践,归纳分析了中国现有5种红树林苗圃类型(旱地设施苗圃、红树林滩涂苗圃、光滩苗圃、基围塘苗圃和米草滩涂苗圃)的结构和用途特点,为红树林生态恢复工程的系统集成管理提供参考.     

深圳市红树林典型群落的物种组成及结构多样性研究

在深圳市红树林主要分布区设置8个调查样地, 以调查深圳市红树林典型群落的物种组成和生物多样性特征。结果表明: (1)秋茄为深圳市天然红树林的建群种或优势物种; 白骨壤及海漆是天然红树林的重要组成物种; 海桑及无瓣海桑是人工林的主要组成物种; 桐花树及老鼠簕是林下灌木层以及低发展程度的红树林群落的主要组成物种。(2)海桑、无瓣海桑、海漆及白骨壤等真红树植物丰富了以秋茄为建群种、优势种或伴生种的深圳市红树林的物种种类、垂直结构和径级结构, 从而提高了红树林的物种多样性和结构多样性, 使林分更加稳定性。在对红树林进行质量提升或营建红树林人工林时, 可以通过增加本土红树植物的种类和提高林分混交程度和结构多样性, 来提高红树林的生态稳定性和景观观赏价值。     

红树林植被对大型底栖动物群落的影响

大型底栖动物是红树林生态系统的重要组成部分,从红树林大型底栖动物种类、红树林与其周边生境大型底栖动物群落的比较,以及生境变化对动物群落的影响等方面阐述了红树林植被与大型底栖动物群落的关系.从物种数量上看,软体动物和甲壳类动物构成了红树林大型底栖动物的主要部分.影响大型底栖动物分布的环境因素包括海水盐度、潮位和土壤特性等,但在小范围区域,林内动物的分布更多地与红树林植被特性和潮位有关.因此,由于红树林植被破坏或者恢复引起的生境变化,将导致大型底栖动物群落和常见物种种群的变化,尤其对底上动物影响明显;随着人工恢复红树林的发育,林内底栖动物的多样性相应增加,优势种也发生变化.相比位于相同潮位的无植被滩涂,红树林可促进潮间带生物多样性.     

基于 SPOT5影像的红树林种类图谱特征分析和制图

本文以英罗港为研究区,利用 SPOT5假彩色合成影像,结合现场踏勘,提取了研究区内分布较广且面积较大的4种红树林种类（白骨壤、桐花、秋茄和红海榄）的图谱特征,并建立了相应的遥感解译标志。利用SVM方法开展了研究区内红树林的分类制图,采用样点验证方法评价提取精度,结果显示,对4种红树林的总体分类精度为86．67％,Kappa 系数为0．82。     

The Loss of Species: Mangrove Extinction Risk and Geographic Areas of Global Concern

Mangrove species are uniquely adapted to tropical and subtropical coasts, and although relatively low in number of species, mangrove forests provide at least US $1.6 billion each year in ecosystem services and support coastal livelihoods worldwide. Globally, mangrove areas are declining rapidly as they are cleared for coastal development and aquaculture and logged for timber and fuel production. Little is known about the effects of mangrove area loss on individual mangrove species and local or regional populations. To address this gap, species-specific information on global distribution, population status, life history traits, and major threats were compiled for each of the 70 known species of mangroves. Each species'' probability of extinction was assessed under the Categories and Criteria of the IUCN Red List of Threatened Species. Eleven of the 70 mangrove species (16%) are at elevated threat of extinction. Particular areas of geographical concern include the Atlantic and Pacific coasts of Central America, where as many as 40% of mangroves species present are threatened with extinction. Across the globe, mangrove species found primarily in the high intertidal and upstream estuarine zones, which often have specific freshwater requirements and patchy distributions, are the most threatened because they are often the first cleared for development of aquaculture and agriculture. The loss of mangrove species will have devastating economic and environmental consequences for coastal communities, especially in those areas with low mangrove diversity and high mangrove area or species loss. Several species at high risk of extinction may disappear well before the next decade if existing protective measures are not enforced.     

广西红树林的病原真菌及其生态学特点

报道了广西沿海的山口、钦州、北仑河口 3个主要红树林分布区的病原真菌及其生态学特点 :共鉴定红树林病原真菌 1 4属 2 6个种 (菌株 ) ,其中主要是炭疽菌、拟盘多毛孢菌、交链孢菌和叶点霉菌。 3个分布区红树林病原真菌的物种丰富度指数 DMA在 2 .82 65～ 4 .70 0 4之间 ,多样性指数 H'为 0 .971 8～ 1 .2 768,均匀度指数JSW为 0 .90 0 5～ 0 .91 58;其中山口病原真菌的种数 ( 1 2 )最少 ,物种丰富度指数 ( 2 .82 65)和物种多样性指数( 0 .971 8)最小。红树林病原真菌分布的主要特点是 :高潮地带的较低潮地带的为多 ,尤以河口最多。侵染寄主的部位主要集中在树冠上部 ,叶斑病最常见 ,枝梢病害次之 ,根茎部的病害很少。桐花和海漆的病害种类最多 ,红海榄和老鼠筋最少。     

Local Mangrove Planting in the Philippines: Are Fisherfolk and Fishpond Owners Effective Restorationists?

Local fisherfolk and fishpond owners have been practicing “restoration” of mangrove forests in some parts of the Philippines for decades, well before governments and non‐government organizations began to promote the activity as a conservation tool. This paper examines ecological characteristics of these mangrove plantations and compares them to natural mangroves in the same areas. Mangrove planters were interviewed and plantation and natural mangrove forests were surveyed to measure forest structure, composition and regeneration. Compared with natural forests, mangrove plantations were characterized by high densities of small stems, shorter and narrower canopies, and fewer species. For both economic and ecological reasons, the vast majority of people dispersed and planted only Rhizophora mucronata/stylosa and, furthermore, they often thinned other species out of planted areas. There was remarkably little subsequent recruitment of other, nonplanted mangrove species into plantations up to 50 and 60 years of age. This pattern held across a diversity of sites, including plantations that had not been selectively cut or weeded. Important ecological and economic benefits result from local mangrove planting, but catalyzing diverse forest regeneration—at least in the short to medium term—is not one of them. The lesson: if you want to restore diverse mangrove forests, you have to plant diverse mangrove forests.     

深圳福田无瓣海桑与海桑人工林鸟类群落研究及生态评价

报道深圳福田无瓣海桑＋海桑人工林和天然林树林鸟类群落的组成特征、密度、相似性、生物多样性等方面的调查研究结果。并通过比较的方法,从鸟类群落学的角度,对无瓣海桑＋海桑人工林的生态功能进行了初步分析和评价。认为：从目前情况看,无瓣海桑和海桑作为深圳沿海人工造林的主要引进树种,对原有红树林生态系统的结构和功能暂时没有不利影响,对尽快恢复和发展红树林地的面积,提高原有红树林生态系统的生物多样性具有积极的作用。建议：①必须采取有效措施防止生态的入侵;②在大面积种植无瓣海桑＋海桑人工林时间种适当面积的当地红树树种。     

Spatial variations in macrobenthic fauna recolonisation in a tropical mangrove bay

Recolonisation by crab species and sediment-infauna taxa (at class level) in artificially regenerated mangrove stands of Avicennia marina, Rhizophora mucronata and Sonneratia alba (5 yr old) were studied using respective bare sites (open without mangroves or denuded) and natural sites (relatively undisturbed) as controls. The controls were chosen based on site history, physical proximity and tidal inundation class in reference to the particular reforested mangrove stand and samples randomly taken. A number of environmental variables were measured; interstitial water salinity and temperature (measured at low tide) were lower, whereas sediment organic matter content was higher in the areas with mangrove cover, with the natural sites having the highest content. The bare sites were generally sandier, whereas the areas with mangrove cover had higher proportions of clay and silt. Generally, there was a higher crab density in the reforested sites than in the bare sites, whereas crab species diversity (Shannon diversity index) did not vary from one site to another for any of the mangrove species. In terms of crab species composition, the reforested sites were more similar (Sørensen similarity coefficient) to the natural sites and less to the bare controls. For sediment-infauna, the reforested sites had a significantly higher density than the respective bare controls, while the natural sites had the highest density. The number of sediment-infauna taxa in both the reforested and natural sites of all the mangrove species was similar and higher than in the comparable bare sites. The results suggest that the reforested sites are supporting more faunal recolonisation, and therefore becoming more akin to the natural mangrove sites in terms of the investigated functional indicators. The findings seem to support the use of artificial mangrove regeneration (in areas where natural regeneration has been impeded by physical conditions or otherwise) as an effective management tool in the restoration and conservation of the functional integrity of degraded mangrove habitats.Key words: Crabs, Environmental variables, Kenya, Recolonisation, Restored mangroves, Sediment-infauna     

Trophic analysis and trophodynamic functioning of mangrove fish fauna of New Caledonia]

Fish communities from geomorphologically different mangrove forests showed distinct trophic structures. A mangrove area located near fringing reefs (Bouraké) was dominated by large invertebrate (> 2 mm) feeders (40.7% of total wet weight of the fish fauna) and herbivores (26.7%) whilst an estuarine mangrove (Ouenghi) was characterized by detritus feeders (28.2%), piscivorous (18.2%) and large invertebrate feeders (17.9%). In spite of these differences in trophic structure, similar food webs occurred in both areas, whereas the intensity of fluxes between trophic compartments was different. Resident species were usually at the base of the trophic structure. This component of the fish fauna used available sources of energy, such as microalgae in Bouraké or detritus and phytoplankton in Ouenghi. In contrast, transient species were high level predators, mainly piscivorous and large invertebrate feeders. These species actively contributed to net exports of energy from mangrove areas to nearby coastal habitats. Food webs and energy fluxes associated with trophic migration of fishes were particularly important in non-estuarine mangrove forests because of hydrologic conditions (salinity and turbidity) which were more suitable to the invasion of numerous marine foraging species (carangids, lutjanids, sphyraenids).     

Restoration of mangrove plantations and colonisation by native species in Leizhou bay,South China

To examine the natural colonisation of native mangrove species into remediated exotic mangrove stands in Leizhou Bay, South China, we compared soil physical–chemical properties, community structure and recruitments of barren mangrove areas, native mangrove species plantations, and exotic mangrove species—Sonneratia apetala Buch.Ham—between plantations and natural forest. We found that severely degraded mangrove stands could not regenerate naturally without human intervention due to severely altered local environments, whereas some native species had been recruited into the 4–10 year S. apetala plantations. In the first 10 years, the exotic species S. apetala grew better than native species such as Rhizophora stylosa Griff and Kandelia candel (Linn.) Druce. The mangrove plantation gradually affected soil physical and chemical properties during its recovery. The exotic S. apetala was more competitive than native species and its plantation was able to restore soil organic matter in about 14 years. Thus, S. apetala can be considered as a pioneer species to improve degraded habitats to facilitate recolonisation by native mangrove species. However, removal to control proliferation may be needed at late stages to facilitate growth of native species. To ensure sustainability of mangroves in South China, the existing mangrove wetlands must be managed as an ecosystem, with long-term scientific monitoring program in place.     

Mapping and characterization of mangrove plant communities in Hong Kong

Ecological surveys were carried out to investigate the distribution and characterization of remaining mangrove stands in Hong Kong. The field studies indicate that 43 mangrove stands, excluding Mai Po Nature Reserve, still remained along the coastline of Hong Kong despite tremendous reclamation and development which occurred in the past 40 years. Most mangrove stands were found in Deep Bay (western part)and Sai Kung District (eastern coasts). The total areas occupied by these mangrove stands were 178 ha,varying from a very small stand (with 1–2 mangrove shrubs) to fairly extensive mangroves in Deep Bay (> 10 ha). It appeared that mangrove stands located in Deep Bay area were larger than those in the eastern coasts. Twenty plant species were identified from these stands, with 13 being exclusive or associate mangrove species. The major constituent species were Kandelia candel, Aegiceras corniculatum, Excoecaria agallocha and Avicennia marina. Rare species such as Heritiera littoralis were only found in a few mangrove stands. Out of the 43remaining mangrove stands, 23 were more worthwhile for conservation and their plant community structures were further investigated by transect and quadrat analyses. The importance values (sum of relative abundance,frequency and dominance) show that K. candel was the most dominant species. Species richness and Simpson's indices together with tree height, tree density and canopy area fluctuated significantly between mangrove stands. These values were used to prioritize the conservation potential of the remaining mangrove stands in Hong Kong. This revised version was published online in August 2006 with corrections to the Cover Date.     

粤东沿海红树林物种组成与群落特征

南海地区是全球红树林分布的中心区域之一。粤东沿海位于南海地区的北界,红树林物种组成和群落结构具有边缘性。利用卫星影像解译辅助技术,对筛选的23处红树林群落进行样地调查,记录了真红树植物12种,半红树植物6种,伴生植物7种。各群落平均高度为1.50—8.60 m,林相以灌丛、小乔木林为主。红树林群落Shannon-Wiener多样性指数为0.533—1.239,均匀度指数为0.662—0.957,天然林和人工林之间数值差异不显著。等级聚类分析将粤东沿海的红树林划分为演替早期人工林、演替早期天然林、演替中期天然林和演替后期天然林4个类别,各群落立地条件差异较大,沉积物总有机碳、盐度、总氮含量与群落分布状况的相关性较高。与1985年的报道相比,尽管该地区记录的红树林植物种类从20种增加至24种,但个别伴生植物消失以及半红树植物种群萎缩说明该地区红树林面临较大的环境压力。在物种多样性和均匀度均方面,粤东沿海红树林群落低于成熟红树林。过去数十年的围垦导致天然红树植物种群萎缩、生境破碎化是主要因素。基于该地区红树林群落的现状,未来人工林和残次天然林的优化改造是红树林恢复重建的重点,红树林恢复和保育的重点区域包括深圳湾的福田、范和港的蟹洲和韩江口的六合围。