Effects of Ecological Restoration of Mangrove Wetlands Using Native Mangrove Species to Replace Spartina alterniflora: A Case Study in Southern China

Within the expanse of China’s coastline, the invasive alien cordgrass species Spartina alterniflora has caused profound nationwide damage and has emerged as a critical factor contributing to the degradation of mangrove wetlands, especially in the study area in Beihai, Guangxi. However, current treatments for S. alterniflora remain less effective and limited research focuses on the preliminary changes after artificial plantation. A comprehensive approach combining physical interventions with biological control measures has been employed to eradicate smooth cordgrass and facilitate the restoration of native mangrove wetlands. The study involved the periodic monitoring of the growth conditions of mangroves and the biodiversity of avian and benthic organisms, conducted at three to four-month intervals following the artificial plantation with one-year-old seedlings and propagules of native mangrove species Rhizophora stylosa. Results indicated that through the allometric equation, the above-ground biomass of planted seedlings had a ~20 g increase in average but the growth conditions were not significant over an eight-month period. High percentage of important avian species underlined the potential of the study site to serve as a worthwhile habitat and notable seasonal variations were observed in the biodiversity of bird species. Biodiversity indices of bird and benthos species also followed a similar fluctuation and reached a peak in April 2023. This research underscores the initial lack of distinct improvements during the early stages of the ecological restoration project, thorough maintenance, long-term monitoring, holistic considerations on a larger scale would be imperative for ongoing projects in the future.

Mangrove wetlands distribution status identification, changing trend analyzation and carbon storage assessment of China

This research investigates the ecological importance,changes,and status of mangrove wetlands along China’s coastline.Visual interpretation,geological surveys,and ISO clustering unsupervised classification methods are employed to interpret mangrove distribution from remote sensing images from 2021,utilizing ArcGIS software platform.Furthermore,the carbon storage capacity of mangrove wetlands is quantified using the carbon storage module of InVEST model.Results show that the mangrove wetlands in China covered an area of 278.85 km2 in 2021,predominantly distributed in Hainan,Guangxi,Guangdong,Fujian,Zhejiang,Taiwan,Hong Kong,and Macao.The total carbon storage is assessed at 2.11×10^(6) t,with specific regional data provided.Trends since the 1950s reveal periods of increase,decrease,sharp decrease,and slight-steady increases in mangrove areas in China.An important finding is the predominant replacement of natural coastlines adjacent to mangrove wetlands by artificial ones,highlighting the need for creating suitable spaces for mangrove restoration.This study is poised to guide future mangroverelated investigations and conservation strategies.

Ecological indicators showing the succession of macrofauna communities in Sonneratia apetala artificial mangrove wetlands on Qi'ao Island at Zhuhai, South China

The Sonneratia apetala artificial mangroves in the intertidal zone of Da Wei Bay at Qi’ao Island of Zhu-hai, South China were chosen as the macrofauna succession plots while bare tidal flats of the same size were established as control plots in surrounding interference-free areas. Conventional change indicators of community structure, such as biomass and biodiversity, and indicators, such as exergy and specific exergy, which reflect the information change of overall communities, were used to analyze the succession of macro-fauna communities inS. apetala artificial mangroves. The similarities and differences in variation tendency of the different ecological indicators and their reflected ecological principles were compared. The results showed that from D-1 to D-1275 after plantingS. apetala, the biomass of the macrofauna communities first increased, which was then followed by an increase in the network relationship between the macrofauna communities （analysis of the Pielou evenness index and Shannon-Wiener diversity index）. The system in-formation （specific exergy） increased the slowest. Between D-1460 and D-2370 after plantingS. apetala, there was a decrease in biomass, network structure, and system information in the succession plots. After the decrease in the system information （the specific exergy）, there was a decline in the network relationships （Pielou evenness index and Shannon-Wiener diversity index）. Biomass was the last indicator to decrease. The similarities and differences among the different ecological indicators varied during the succession pro-cess, which reflected the relativity and differences among the indicators. This study suggested that, although the species diversity index can be an effective indicator of two types of changes （network structure and system information）, it was quite clear that species diversity measurement was not suitable for expressing the changes in biomass during the succession process. While exergy and specific exergy can provide useful information about the structural development of communities, they cannot identify the information state of the system. Therefore, when evaluating macrofaunal succession inS. apetala artificial mangrove wetlands, it would be better to apply a number of different ecological indicators, rather than just one single indicator.

Research Advances on Marine Ecological Effect and Repairing Techniques of Coastal Mangrove Wetland

Coastal mangrove wetland is one of the areas whose global ecological environmental conditions have severely changed. Its ecosystem is vulnerable to damaged. The international community has paid attention to conservation and wisely use of mangrove wetland. This paper describes five parts of coastal mangrove wetland at home and abroad,including seawater's purification effect of nitrogen and phosphorus,seawater's adsorption of heavy metals,the functions of carbon sequestration and climate regulation,implant restoration techniques and the status of protection and management. And research trends of coastal mangrove wetland were proposed,in order to provide reference for the restoration and protection of China's coastal mangrove wetland.

The Mangroves of the East of Madagascar: Ecological Potentials and Pressures

With 213,000 ha of remaining mangroves in 2016, Madagascar has about 4260 ha of mangrove on its Eastern coast. The purpose of this article is to provide essential data on the spatial distribution of this ecosystem of Eastern Madagascar, its ecological potentials and the pressures on its resources. Five Eastern Mangrove sites were selected, from South to North, because of their accessibility and their spatial position: Foulpointe, Sainte Marie, Manompana, Mananara Nord and Rigny. Eastern mangroves regenerate quite well, with a regeneration rate of over 500%. Their height and basal area range respectively between 1.7 - 12 m and 7 - 42 m2·ha-1. The aboveground biomass perfacies can go up to 47 t·ha-1, or even more, at the level of the large homogeneous mangrove of Mananara and Rigny (>70 t·ha-1), whereas this one does not exceed 10 - 20 t·ha-1 in the sporadic mangroves of Foulpointe and Manompana. The carbon sequestration capacity of the aboveground biomass is estimated at more than 5 - 20 t·ha-1, along a South-North gradient, equivalent to a minimum sequestration potential of 21,300 to 85,200 t for the whole East. Despite these ecological potentials and the low annual clearance rates observed for some sites, this ecosystem is subject to anthropogenic pressures linked to urbanization, timber harvesting and irrational exploitation of fishery resources.

Ecological Relationship between Mud Crab Scylla serrata (Forskal) and Mangroves and the Pattern of Utilization

The ecological relationship between mud crab Scylla serrata(Forskal)and mangroveswas described in this paper.Mangrove swamps are important reproductive places for mud crabs,where zoeae,megalopae,juveniles from 1st to 14th instar,adult crabs and ovigerous female crabswere found.Mangrove roots and the leaf litter are the shelters of the mud crab.The zoeae andmegalopae of mud crab can normally grow and develop on the plankton and debris that are well-supplied in mangrove swamps.There are a lot of Phascolesoma,Mollusca and Crustacea whichconstitute the delicious foods of the mud crab in mangrove swamps.The larger crabs have apreference for Ostrea,Balanus and Vignadula which usually amply adhere and endanger themangroves,so the mud crab is helpful for the development of the mangrove communties.Finallya pattern of ecological culture of the mud crab in mangrove swamps was suggested.

The influence of three mangrove species on the distribution of inorganic nitrogen and phosphorus in the Quanzhou Bay estuarine wetland soils

This study aims to investigate the effects of region and three regional dominated mangrove species(Avicennia marina, Aegiceras corniculatum and Kandelia candel) on the distribution of inorganic nitrogen and phosphorus. Measurement of the inorganic nitrogen and phosphorus and enzymatic activities was carried out in soils covered by three mangrove species in the Quanzhou Bay estuarine wetlands, a typical coastal wetland in China.Species with a higher biomass in upstream and midstream absorb more nitrogen from soils, and the retention of the available phosphorus in the soils of different regions causes the regional variation of phosphorus. In areas dominated by A. marina, nitrate nitrogen is lower while available phosphorus is higher. Meanwhile, nitrate nitrogen and available phosphorus are higher in the soils covered by K. candel.Moreover, all three species affect the elemental and enzymic stoichiometry. The mangrove species influences the diversity of the elemental and enzymic stoichiometric relationship through differential microenvironments, which induce the biodiversity of wetland ecosystems. Thus, this study may facilitate a better understanding of the transformation ability of mangroves to nitrogen and phosphorus and will therefore be beneficial for providing a basis for the ecological restoration of estuarine wetlands.

Qualitative Assessment of Table Salt Production Techniques in Southern Benin Republic, and Related Mangrove Destruction and Health Issues

This research was conducted in the framework of the feasibility study related to FOCUSED-Benin project, the 5th work package of the YES-PV NIG BEN project financed by the German Government through its Ministry of Research and High Education (BMBF). The FOCUSED Benin project’s major objective is to protect the environment through the utilization of solar energy for drying agricultural products and table salt harvesting. Salt is important in human daily life. It is used for conservation of food, softening water, industrial processes, road de-icing, food seasoning, etc. Seawater evaporation, salt mining, and salt brine are the major sources of salt production worldwide. However, in West Africa, particularly in Benin Republic, table salt is produced using methods that negatively impact the ecology of the mangrove. This study aimed at investigating the current status of salt production in Benin Republic, its impact on the mangrove and its related health issues. Field visits, meeting with associations of women salt producers in the coastal region of the country, allowed to quantify the number of women associations dealing with salt production, their difficulties, and the impacts on the mangrove. Salt is a seasonal activity and is produced from January to May. One kilogram salt production, along with health issues reported by salt producers, requires approximately 1 kg of firewood obtained by cutting down mangrove. Salt price varies from 250CFA (€0.38) to 400FCFA (€0.61) per kg depending on the season. The women salt producers are not aware of the ecological consequences of mangrove destruction. Sources of firewood are becoming increasingly scarce and prices prohibitive. Sensitization is not efficient. An alternative method of harvesting salt by solar drying and new ideas for implementing this activity in a participatory approach was discussed with the different associations of salt producers.

Mangroves Restoration and Observation in Kaohsiung Jhong-Dou Wetland

The ecosystems of Kaohsiung are rich and diverse. Examples of ecosystems include the tropical rainforest ecology, marine ecology of the coastal forests, and the estuary type ecology of mangrove forests. The Jhong-Dou Wetland Park is situated in the Jhong-Dou Redevelopment Zone, 2.5km from the Lover River Estuary. This area is defined by brackish aquatic environments--a mixture of fresh and salt water, and fulfills the criteria for mangrove restoration. It is expected that the current restoration project will recreate an epitome of the once-diverse, co-existing mangrove species of Kaohsiung＇s past, and improves upon the functions of environmental education. The initial mangrove species planned for restoration are the existing Kandelia obovata, Rhizophora stylosa, Avicennia marina and the Lumnitzera racemosa populations of the Kaohsiung area. These plants will be placed in experimental habitats that correspond to the unique micro-climates required for the growth of each species, and the mangrove-associated plants will also be restored concurrently in the terrestrial environments behind the mangrove forests. The process of restoration will be monitored by academia, as well as providing reference for subsequent mangrove environment restoration efforts. The main purpose of this research in these four mangrove species of this wetland park is to understand their adaptation to the rehabilitating environment, and be able to feedback these information to the design and maintenance team of the park. The research method is to observe and record their growing status, also execute a survey on the nearby mangrove habitation. The observation has started on December 1 st of 2010, and still has been continued carry on since then. From the research result, it shows that the A vicennia marina （Forsk.） Vierh. and Lumnitzera racemosa Willd. are the two species that had been well adapted to this wetland park. It was recommended to the Kaohsiung City Government that the restoration of the extinct Ceriops tagal and Bruguiera gymnorrhiza can be achieved through foreign species exchanges （the species must be identified before introduction）, and that plans for monitoring the flora and fauna in the park should be drafted to record the ecological alterations of the Jhong-Dou Wetlands. This will pronounce the ecological importance of Kaohsiung on a global, geographical scale. Lastly, the Government should draw up plans of mangrove forest maintenance in order to sustain the ecological and landscape recreational functions of the Jhong-Dou Wetland Park.

厦门下潭尾红树“实验林”研究成果分析和启示

为了研究林鹏院士2005年在厦门市下潭尾开展的红树林“实验林”对厦门市红树林红树林生态修复工作的指导作用,本研究分析了该“实验林”的乡土种秋茄(Kandelia obovata)和引进种无瓣海桑(Sonneratia apetala)生态恢复影响、乡土种与引进种不同搭配种植模式的生态效果,以及其各阶段植被演变的状况。结果表明,无瓣海桑在厦门海域扩散能力差,未见生态入侵的危害,并有逐渐生态归化趋势;通过加强监控、扬长避短,因地制宜、分区施策、适地适树,合理规划,可以充分发挥外来植物的正面作用。

万宁市小海红树林生境适宜性评价及修复分析

【目的】定量分析评估复杂环境条件与红树林分布特征之间的交互作用,探索一定区域尺度上红树林生境适宜性及适生区空间分布格局。【方法】以万宁市小海为研究区,选取水文动力、水质底质、地形高程3个大类环境变量,通过层次分析法搭建评价结构模型,结合德尔菲法获得各指标权重,并将各环境指标经归一化处理后基于GIS技术获取小海红树林适生区的空间分布。【结果】影响小海红树林生长分布的主要环境变量为水深高程、潮位、潮差、盐度等因子;研究区港北口门附近区域红树林生境适宜性较高,面积约121.6 hm 2;西南侧及东南侧区域适宜性适中,面积约328.5 hm 2;南侧及中间部分区域适宜性较低,面积约137.2 hm 2。【结论】小海区域的气候、水质和水文动力条件均较适宜红树林存活、生长,相当一部分清退的养殖塘具备红树林种植修复的基本生态条件,但需进行生境改造,并依据生态位原理合理搭配红树物种,以期达到修复效果。

红树林生态重建效果预测研究新模式

红树林是生态文明建设的组成部分,对实现碳中和目标意义重大,近年来实施了大量的保护和修复工程。然而,目前缺少一种预测方法来比选有效的保护措施,以指导红树林的生态重建工作。因此,提出了一种“数值模拟模型+分类模型”的研究新模式。在模式应用中,模拟了广东省柘林湾一年的水沙动力环境。通过考虑淹没时间、相对峰值底床切应力和底床高程变化,描述了红树定植过程中所受到的胁迫,对4种条件下笠港潮汐汊道内侧滩涂红树林的生态重建效果做出了预测。结果表明,恢复汊道水深会轻微改变区域的水动力和泥沙冲淤环境,导致生态重建成功率降低了3.12%;提高区域底床高程会显著减小流速并加剧外侧冲刷,提高0.5m和1.0m的高程分别使生态重建成功率提升了16.43%和32.75%。

间伐修枝对拉关木林下乡土红树植物的影响

为探究保护区内对外来红树拉关木(Laguncularia racemosa)人工林不采取剧烈扰动生境的皆伐措施,而通过间伐修枝处理使拉关木逐渐退出更替为乡土红树林的新途径的影响,该研究以海南东寨港国家级自然保护区内拉关木林为研究区域,依托保护区对拉关木林进行间伐修枝,研究拉关木林间伐修枝的调控措施对恢复乡土红树群落的生态效应。结果表明:(1)间伐修枝后拉关木残桩萌枝的无性繁殖削弱了处理效果,但一次干预(50%强度的间伐修枝)和两次干预(50%强度的间伐修枝之后追加一次修枝)2种处理之间,拉关木残桩萌枝的效果没有显著差异。(2)间伐修枝能丰富林下灌木层的乡土红树种类,以及促进其生长,并且两次干预比一次干预的促进作用明显,但对草本层红树幼苗自然更新无显著影响。(3)在未间伐、间伐修枝和林缘3种样地中人工种植乡土红树苗木,间伐修枝对红海榄(Rhizophora stylosa)、秋茄(Kandelia obovata)幼苗的存活率有一定的促进作用;间伐修枝对红海榄的生长有接近林缘条件的效果,但效果有限。综上所述,建议在50%强度间伐修枝的基础上加大间伐强度或修枝频率,在林下适当进行乡土红树植物的人工种植,同时清除拉关木残桩萌生的枝条,这样更有利于拉关木林向乡土红树林的转化。

广东饶平海山河口区红树林潮沟鱼类时空生态位

鱼类作为红树林湿地的一个重要组成部分,有关其种间关系的研究报道极少。本研究以分布于广东饶平海山河口区红树林鱼类为例,于2022—2023年对该红树林潮沟鱼类进行春、夏、秋、冬四季的采样调查,计测鱼类物种的时空生态位宽度和种间重叠值,阐明湿地鱼类分布和种间关系对环境因子作用的响应。结果显示:渔获鱼类有14种,隶属6目12科,其中优势种(IRI≥500)6种,常见种(500>IRI≥100)3种,少见种(100>IRI≥10)2种,偶见种(IRI<10)3种。海山红树林潮沟渔获鱼类的时空生态位宽度变化范围为0.000~2.428,变化幅度较大,其中,广生态位种(B_(ij)≥2.0)1种,为尼罗罗非鱼(Oreochromis niloticus);中生态位种(1.0≤B_(ij)<2.0)2种,为红狼牙鰕虎鱼(Odontamblyopus rubicundus)和中华乌塘鳢(Bostrichthys sinensis);其余11种为窄生态位种(0<B_(ij)<1.0)。海山红树林潮沟鱼类物种之间的时空生态位重叠值为0.000~0.956,变化幅度较大;其中,显著重叠的(重叠值>0.6)有43对,占总对数的47%,重叠有意义的(0.3<重叠值<0.6)有21对,占总对数的23%,两者合计占总对数的70%。时空生态位重叠值最高的是黄斑篮子鱼(Siganus oramin)和弹涂鱼(Periophthalmus cantnensis),高达0.956;而完全不重叠包括尼罗罗非鱼和鲬(Platycephalus indicus)、中华乌塘鳢和鲬、须鳎(Paraplagusia bilineata)和鲬。BIOENV分析发现与研究区鱼类丰度最为匹配的环境因子组合是水体的水温、盐度、pH和叶绿素a含量的相关系数为0.475,RELATE检验结果显著(R=0.461,P<0.05),表明这4个环境因子是影响鱼类分布的重要因子。综合而言,饶平海山红树林湿地鱼类时空生态位以窄生态位种为主,不同鱼类之间的时空生态位重叠以显著重叠和重叠有意义的占多数,水体的水温、盐度、pH和叶绿素a含量是影响林区湿地鱼类分布的重要环境因子。

广西典型沙生红树林总初级生产力变化特征及其对气象因子的响应

红树林是海岸带生态系统中单位面积总初级生产力最高的植被生态系统。广西红树林总面积位居全国第二位,研究红树林GPP变化特征,深入探究其对气象因子的敏感性,以期为全面了解红树林碳循环动态和制定相应气候变化适应策略提供科学依据,为红树林的保育管理和生态修复提供参考。目前,尚未见有基于涡度相关技术开展广西红树林GPP研究的相关成果。以广西北海市沙生红树林为研究对象,研究区同时也是红树林生态修复区,采用涡度相关技术结合冠层实景观测技术,系统分析红树林GPP的月平均日变化特征、季平均日变化特征、月累积变化特征及年累积变化特征,并利用单因子相关分析和多因子通径分析,研究光合有效辐射、气温、地表5 cm温度、饱和水汽压差和降雨量在日、月尺度与GPP的响应模型。结果表明,GPP的平均日变化曲线在月和季尺度上呈倒“U”型分布,月累积年内呈现“双峰一谷”的变化趋势,春季和秋季为波峰,夏季为波谷;红树林冠层植被指数的分析表明,夏季波谷是由于虫害爆发导致GPP下降。2019-2022年GPP年累积分别为1.28×10^(3)、1.29×10^(3)、1.36×10^(3)、1.38×10^(3)g∙m^(-2)∙a^(-1)(以C计,下同),年累积量均值为1.33×10^(3)g∙m^(-2)∙a^(-1),GPP呈缓慢增加的趋势,但GPP显著小于东南沿海观测站点,这与研究区的土壤类型、群落结构以及观测站区域外部扰动有关。对红树林GPP产生直接影响最大的气象因子为光合有效辐射和气温,产生间接影响最大的因子为地表5 cm温度。综上,北海沙生红树林GPP与东南沿海相比较弱,随着生态修复工作的实施,GPP缓慢递增,但病虫害对红树林GPP影响较大,应及时开展病虫害防治工作,有利于红树林碳汇功能的提升。

湛江红树林生态产品价值的游客感知与补偿意愿研究

近年来,湛江积极打造“红树林之城”,并探索生态保护、旅游发展等多重背景下的红树林生态产品价值实现机制,然而现有研究对游客感知与补偿视角下的红树林生态产品价值关注仍存在着不足。本研究以湛江红树林为研究对象,设计了一份调查问卷,基于游客主体视角获取489份问卷样本,以此分析湛江红树林生态产品价值的游客感知评价状况,并利用多元线性回归方法,进一步探讨生态产品价值感知的游客补偿意愿及其影响关系,研究发现:(1)湛江红树林生态产品价值的游客总体感知度相对较低,不同类型红树林生态产品价值感知评价从高到低依次为调节类、文化类、供给类;(2)游客生态补偿意愿相对较强,年龄、学历、职业、收入和游玩次数对补偿意愿存在显著影响,性别与来源地则无显著影响;(3)文化类生态产品价值感知、地方依恋情感对游客补偿意愿有着显著的正向影响,而调节类、供给类生态产品价值感知、积极心理情绪则对游客补偿意愿不存在显著影响关系。

红树林生态修复工程中的景观塑造技术——以厦门市下潭尾红树林公园景观地标为例

当前我国东南沿海正掀起红树林生态修复工程建设热潮,但工程设计中往往较少考虑景观塑造,削弱了项目的影响力。本研究以厦门市下潭尾红树林公园景观地标为例,介绍红树林生态修复工程中的景观塑造技术,以提升滨海人工湿地的景观效果和内涵。根据连片人工滩涂的大小和形状设计“I”、“”和“五星”景观图案,寓意“我爱中国”。图案整体的朝向考虑周围地形和空中航道的视角,并使用AutoCAD将卫星遥感图和造滩施工图进行叠加,在叠加图上进行设计图案的移动和缩放,使线条均落在适宜红树林生长的1.77~2.33 m(1985国家高程基准)等高线内,获得图案的最终设计方案。在种植工程中,结合造滩施工图进行轮廓点定位和现场放样,在生态安全评估的前提下选用不同树形、色调和生长速度的树种搭配间种,以拉关木(Laguncularia racemosa)和无瓣海桑(Sonneratia apetala)等速生红树植物凸显线条,以本地乡土树种秋茄(Kandelia obovata)作为背景,经过一段时间的科学管养,红树群落成林后便形成“我爱中国”的永久性景观地标,使公园兼具社会效益、生态效益和爱国主义宣传效果,将海洋生态文明融入到红树林湿地的建设中去。厦门市下潭尾红树林公园建设的实践证明,通过特定的图案设计和种植技术进行景观塑造,能够增加红树林生态修复工程的社会效益。

防城港红树林湿地沉积物重金属分布特征及生态风险评价

【目的】了解防城港红树林沉积物中重金属的污染水平,评估潜在生态风险程度并对重金属来源进行解析,为红树林湿地保护和预防污染提供参考。【方法】通过测定研究区沉积物重金属含量,分析重金属含量水平。运用地累计指数法、污染负荷指数法评价重金属污染程度,运用潜在生态风险指数法综合评价重金属潜在生态风险,并应用PCA-MLR模型对重金属进行定量溯源。【结果与结论】研究区红树林沉积物中Cu、Pb、Zn、Cd、As和Hg的质量分数均值分别为20.40、18.50、52.20、0.09、11.95和0.036μg·g^(-1),与国内其他典型红树林分布区对比,研究区红树林湿地重金属含量处于相对较低水平;污染评价表明大部分站位均存在轻微及以上程度的污染,且污染站位多分布在人类活动相对密集的区域;引起潜在生态危害的元素主要为Cd和Hg;Zn、Cd和Pb主要来源于工业和农业源的污水排放,As和Hg主要来源于海水养殖业,Cu主要来源于船舶运输业,3种来源的相对贡献率分别为46.25%、27.09%和26.66%。

潮汕海岸带红树林小型底栖动物的群落特征及生态环境质量评价

红树林是海岸带的重要生态屏障,也是气候变化和人类活动的敏感区;底栖动物是对环境变化最直接的响应群体。基于2021年4月在潮汕海岸带红树林分布区7个站位的现场观测和样品采集,对沉积物环境、小型底栖动物的群落特征、空间分布及生态环境质量进行了分析。研究区共发现15个小型底栖动物类群,自由生活海洋线虫占丰度上的绝对优势(90.32%);多毛类在生物量上居首(58.44%)。小型底栖动物平均丰度较其他红树林略高,其丰度分布和海洋线虫丰度,叶绿素a、脱镁叶绿酸、有机碳和重金属(Cd、Zn、Cu、Cr和Hg)含量具有相似的空间格局:中部区域莲阳河北岸最高,向南向北均降低。不同斑块间的动物群落相似性较高(70%),解释其群落结构差异分布的最佳环境因子是重金属Pb。海洋线虫与桡足类的丰度比(N/C)、潜在生态风险指数和沉积物质量分级结果均表明研究区环境质量整体较差。

厦门筼筜湖不同修复时期人工秋茄林的碳储量

1999年起,厦门筼筜湖开展了多次红树林人工修复的种植工作以进行该湖的环境治理。这些人工修复的红树林生长状况良好,使得筼筜湖生态修复成为国内成功的典范案例。为探究不同修复时期人工红树林碳储量的变化规律并获得筼筜湖人工修复红树林碳汇能力的基础数据,本研究对筼筜湖4片不同林龄(10、11、12、14 a)的人工秋茄(Kandelia obovata)林地(对应林龄分别编号为P10、P11、P12、P14)进行碳[植株组分碳、凋落物碳和沉积物总有机碳(TOC)]储量的分析。结果表明:单株红树植物秋茄生物量、林地单位面积生物量及年凋落物产量均随着林龄的增长而增加。植株组分的平均碳含量随着林龄的增长而增加,P14(346.29 g/kg)>P12(327.93 g/kg)>P11(313.63 g/kg)>P10(297.84 g/kg)。凋落物平均碳含量与林龄也呈现类似的正相关关系,P14(310.28 g/kg)>P12(300.44 g/kg)>P11(282.28 g/kg)>P10(279.22 g/kg)。沉积物中TOC含量为5.13~12.02 g/kg,呈垂直向下递减的分布格局。沉积物TOC含量随着林龄的增长而增大,同一深度不同林龄沉积物中的TOC含量存在显著差异(P<0.05)。在不同修复时期的人工林中,林龄对各组分的碳储量及碳密度有显著的影响。本研究有助于进一步理解潟湖人工修复红树林的动态发育过程和生态系统服务功能。有关不同修复时期潟湖人工红树林碳储量的研究对红树林的保护和修复具有重要的科学意义。