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1.
This paper deals with the reaction of the contents of carbohydrate and nitrogenous compound in leaves of mangroves (Kandelia candel and Aegiceras corniculatum) to the change of seabeach soil salinity (range: 3-12) in the tidal swamp of Jiulongjiang River, Fujian Province, China.Results obtained show that: (i) contents of total sugar, starch and soluble sugar in the leaves of those mangrove plants would increase with increase in the soil salinity; (ii) with increase in the soil salinity, contents of total nitrogen and soluble protein in their leaves would decrease, but fluctuate at the soil salinity more than 10. 相似文献
2.
A Model for Environmental Impact Assessment of Land Reclamation 总被引：2，自引：0，他引：2
Land reclamation is a complex marine environmental engineering and has a huge impact on social, economic, and physical environment. Reclamation environmental impact assessment (REIA) is also a complicated project, including the assessment of social economic background, ocean engineering, coastal geomorphology, sediment transportation, marine hydrodynamics and marine ecosystem and so on. Nowadays, a large number of land reclaimed projects have been carried out or in the process of construction along the coastal zone, thus, it is necessary to build up a framework on REIA to evaluate and quantify the environmental changes, to contribute to reclamation program, to reduce marine environmental disasters, and to sustain development of coastal zone. This article focuses on the research of REIA framework theory and puts forward a REIA model on land reclaimed evaluation, at the same time, applies this assessment system in Shenzhen City, which is a highly developed coastal city with an expectation of land reclamation. By use of the Remote Sensing (RS) and Geographic Information System (GIS) techniques, along with the topographic map and in situ survey in reclamation area, it concludes that the area of 2680 hectares in total has been reclaimed in Shenzhen city by the end of the year 2000. Thus, reclamation is usually applied to meet the needs for infrastructure, such as harbors, industries and highways in Shenzhen City. However, some serious negative impacts have been created to the coastal environment shown clearly in the following aspects. Firstly, it caused the dramatic changes of tidal flat and channels along the western coast, made this area more unstable, which is threatening the function of the harbor in this area. Secondly, Tidal prism has decreased rapidly. During the 20 years of reclamation, the tidal prism has been reduced by 20%～30% along the western coast in the Lingdingyang Estuary, and 15.6% in the Shenzhen Bay. As a result, the velocity of the tidal current has also declined, and the direction of the tidal current has changed, which is harmful to the dilution and diffusion process of the contaminants. Thirdly, it has threatened the eco-environment finally. More than 147 hectares of mangrove area along the coast of Shenzhen Bay, accounting for 48.8% of the total mangrove reserve area in this region, has been reclaimed only during the short period from 1988 to 2000. Thus, the biodiversity is decreasing, and more and more plants and animals are disappearing. Based on the above analyses of the environmental impacts, strategies and suggestions for the future reclamation in this area have been put forward in order to support the sustainable development of the coastal zone. 相似文献
3.
To study the Taiwan Strait （TS）, an unusual sea area, the numerical model in marginal seas of China is used to simulate and analyze the tidal wave motion in the strait. The numerical modeling experiments reproduce the amphidromic system of the M2 tide in the south end of the Taiwan strait, and consequently confirm the existence of the degenerate amphidromic system. On this basis, further discussion is conducted on the M2 system and its formation mechanism. It can be concluded that the tidal waves of the TS is consisted of the progressing wave from the north entrance and the degenerate amphidromic system from the south entrance, in which the progressing wave from the north entrance dominates the tidal wave motion in the strait. Except for the convergent effect caused by the landform and boundary, the degenerate amphidromic system produced in the south of the strait is another important factor for the following phenomena： the large tidal range in the middle of the strait, the concentrative zone of co-amplitude and co-phase line in the south of the strait. The degenerate amphidromic system is mainly produced by the incident Pacific Ocean tidal wave from the Luzon strait and the action by the shoreline and landform. The position of the amphidromic point is compelled to move toward southwest until degenerating by the powerful progressing wave from the north entrance. 相似文献
4.
The exposed area of intertidal zone varies with tidal water level changes. If intercomparisons of
satellite images are adopted as a method to determine geomorphological changes of the intertidal
zone in response to accretion or erosion processes, then the e?ect of water level variations must be
evaluated. In this study, two Landsat TM images overpassing the central Jiangsu coastal waters on
2 January and 7 March 2002, respectively, were treated by the changing detection analysis using
Image Di?erencing and Post-classiˉcation Comparison. The simultaneous tide level data from four
tide gauge stations along the coast were used for displaying the spatial variations of water levels
and determining the elevations of waterlines. The results show that the spatial variations of water
levels are highly signiˉcant in the central Jiangsu coastal waters. The huge di?erences of tidal land
exposure patterns between the two imaging times are related mainly to the spatial variations of
tidal water levels, which are controlled by the di?erences in tidal phases for di?erent imaging times
and the spatial variations of water level over the study area at each imaging time. Under complex
tidal conditions, e.g., those of the central Jiangsu coastal waters, the tide-surge model should be
used to eliminate e?ectively the e?ects of water level variations on remote sensing interpretation of
geomorphological changes in the intertidal zone. 相似文献
5.
Influence of waterlogging time on the growth of Kandelia candel(L.) Druce seedlings grown for 70 d in the artificialtidal tanks‘ simulated semidiurnal tide under greenhouse is studied. Sand and soil act as the substrate and artificial seawater with salinity of 15 is used in cultivation. Shorter waterlogging time (inundated for about 2 ～ 4 h) promotes the growth of K candel seedlings, while longer time (inundated more than 8 h) or no waterlogging (0 h) inhibits their growth. The number and length of aerating roots increase with the increase of waterlogging time. Under existing conditions, the optimal waterlogging time for the growth of K. candel seedlings is about 2 ～ 4 h in every tide cycle. Compared with other treatments, the 2 h sanded treatments obtain the highest biomass of seedlings, have the lowest mass loss ofhypocotyl and broaden the photosynthetic area by increasing the area per leaf after 70-d cultivation. And the soil treatments have the similar tendency. However, waterlogging for 8h in every tide cycle is critical for normal development of seedlings.K. candel seedlings are highly tolerant to waterlogging and a proper waterlogging is beneficial to the growth of K. candel seedlings. 相似文献
6.
Zuming Huang Zhijun Dai Riming Wang Xiaoyan Zhou Wenhong Pang Jiejun Luo Bingbin Feng Baoqing Hu 《海洋学报(英文版)》2023,(7):103-115
Mangrove forest is one of the most important ecological and environmental resources by effectively promoting tidal flat deposition and preventing the coastal region from typhoon. However, there have been mass loss of mangrove forests due to anthropogenic activities. It is an urgent need to explore an effective way for mangrove restoration. Here, three rows of bamboo fences with hydro-sedimentary observation set over Aegiceras corniculatum mangrove tidal flat of the Nanliu Delta, the largest delt... 相似文献
7.
Observations of fluid mud were made in the lower North Passage of the Yangtze Estuary in February 2000, on 10 -11 August 2000, on 30 - 31 August 2000 (after two strong typhoons), on 21 - 24 August 2000 (neap tide) and on 3 -6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km^2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary. 相似文献
8.
Rapid changes in the near-bottom water temperature are important environmental factors that can significantly affect the growth and development of species in the bottom culture. The object of this research is to investigate the mechanism causing these rapid changes within a bottom culture area near the Zhangzi Island. The hydrographic transects observations in the North Yellow Sea(NYS) suggest that our mooring station is very close to the tidal mixing front. The horizontal advection of the tidal front has induced the observed tidal change of bottom temperature at the mooring station. Analysis of the mooring near-bottom temperature and current measurements show that the angle between the tidal current horizontal advection and the swing of the tidal front is crucial in determining the variation trend of temperature. When the angle equals 90°, the horizontal tidal current advects along the isotherms so the temperature remains the same. When the angle is between 0° and 90°, the seawater moves from deep water to the warmer coastal zone and the temperature decreases. In contrast, the horizontal tidal advection moves the coastal warm water to the mooring station and the water temperature increases when the angle is between 90° and 180°. The amplitude of the temperature change is proportional to the magnitude of the horizontal temperature gradient and the tidal excursion in the direction of the temperature gradient. This study may facilitate the choice of culture area in order to have a good aquaculture production. 相似文献
9.
LiangShichu WangBosun 《海洋通报(英文版)》2003,5(2):54-61
The fractal characteristics of the canopy structure o! B. gymnorrhiza population are investigated by fractal dimension analysis in the National Shankou Mangrove Nature Reserve. The 3-year-old branches have box dimensions between 1.22 and 1.55, showing thecomplexity degree of branching structure and the ability of occupying and utilizing ecological space. It may be considered that fractal dimension provides a useful index for the study of light utilization efficiencies and growth processes of B. gymnorrhiza. Calculated by using the two-surface method, the fractal dimensions for the crown pattern of individuals with ages of 20 to 50 years range from 2.21 to 2.54, indicating that the filling degree of foliage to a tree crown is relatively low and B. gymnorrhiza has the property of a sun plant.Along with the increase of ages of individuals, the filling degree of foliage to a tree crown changes from high to low, and so does the fractal dimeilsion. The box dimensions obtained from the grayscale curves of population canopy are between 1.47 and 1.61. The greater the box dimension, the more loosely organized the canopy spatial structure, and the more the light spots. The canopy structural information and complexity of a population can be effectively captured by box dimensions obtained from canopy grayscale curves. 相似文献
10.
Mangrove wetlands can reduce heavy metal pollution by trapping heavy metals. In this study, the concentration,transport and bioaccumulation of Cr, Cd, Cu, Zn and Pb in the sediments and different parts of Aegiceras corniculatum at four different sites in the Qinzhou Bay in southwestern China were investigated. The results showed that although the potential ecological risk of all five heavy metals was slight, the concentration of Cr was at a moderate pollution level due to the emissions of industries and aquaculture waste water. Core sediment records indicated that the concentrations of heavy metals at the depth of 0–20 cm were relatively high, showing an increasing trend of heavy metals over the past 20–30 years. Cr, Cu, Pb and Cd accumulated mainly in the roots of A. corniculatum, while Zn accumulated mainly in the stems. Aegiceras corniculatum showed the strongest transport capacity for Zn and Cu and the strongest bioaccumulation ability for Cd. Compared with other mangrove communities, A. corniculatum can be chosen as a restoration species in tropical and subtropical coastal zones polluted by Zn, Cu and Cd. 相似文献
11.
红树植物次生木质部的结构与进化 总被引：12，自引：0，他引：12
研究了红树科Rhizophoraceae的木榄Bruguiera gymnorrhiza、海莲Bruguiera sexangula、角果木Ceriops tagal和秋茄Kandelia candel;马鞭草科Verbenaceae的白骨壤Avicennia marina;紫金牛科Mysinaceae的桐花树Aegiceras corniculatum和海桑和Sonneratiaceae的海桑Sonneratia caeseolaria次生木质部的结构与进化关系,红树科植物的次生木质部结构比马鞭草科、紫金牛科和海桑科的植物原始;红树科中的竹节树属Carallia和山红树属Pellacalyx为陆生的非红树植物,它们次生木质部结构比海生的红树料红树植物木榄属、秋茄属、角果木属更为进化,即导管为单穿孔、管间纹孔式为互利式纹孔.单穿孔的导管存在,是长期的进化过程中,遇到干旱环境而产生的特化现象,而海生红树科植物进入海滩沼译后,木质部仍具有原始性状. 相似文献
12.
红树植物繁殖体发育过程的能量变化 总被引：3，自引：0，他引：3
探讨了桐花树 (Aegicerascorniculatum)、秋茄 (Kandeliacandel)、角果木 (Ceriopstagal)、海莲 (Bruguierasexangula)和木榄 (Bruguieragymnorrhiza)5种红树植物繁殖体的热值及其动态变化。结果表明 :(1)海南东寨港5种红树植物繁殖体的热值大小不同 ,其中花的热值最高是桐花树 ,为20.423kJ/g,花的热值最低是木榄 ,为19.214kJ/g;果的热值最高是角果木 ,为20.255kJ/g,果的热值最低是木榄 ,为18.582kJ/g;成熟胚轴的热值最高是角果木 ,为19.792kJ/g,成熟胚轴的热值最低是桐花树 ,为16.827kJ/g。 (2)随着纬度的增加 ,桐花树各期繁殖体热值略为提高 ,而秋茄则相反略为降低。 (3)随着繁殖体从花、果至胚轴发育过程 ,热值逐渐降低 ,而单个繁殖体的生物量及其能量贮量则随之提高。 相似文献
13.
深圳福田几种红树植物繁殖体与不同发育阶段叶片热值研究 总被引：5，自引：0，他引：5
对深圳福田红树林区的秋茄 (Kandelia candel)、木榄 (Bruguiera gymnorrhiza)、桐花树 (Aegiceras corniculatum)、无瓣海桑 (Sonneratia apetala)、海漆 (Excoecaria agallocha)、银叶树 (Heritiera littoralis)不同发育阶段叶片以及秋茄、木榄、桐花树、无瓣海桑、海漆繁殖体的灰分含量和热值进行研究.结果表明( 1)不同发育阶段叶片的灰分含量变化趋势没有一定的规律性, 6种红树植物中老叶灰分含量均不是最低;植物繁殖体的灰分含量低于成熟叶;( 2)秋茄、无瓣海桑、木榄、桐花树繁殖体的干质量热值和去灰分热值基本上低于不同发育阶段叶片,而海漆繁殖体的干质量热值和去灰分热值高于不同发育阶段叶片;( 3) 6种红树植物不同发育阶段叶片的干质量热值与灰分含量具有极显著的线性负相关( P<0.01),不同发育阶段叶片和繁殖体的干质量热值与灰分含量具有显著线性负相关( P<0.05). 相似文献
14.
九龙江口红树植物叶片重金属元素含量及动态 总被引：11，自引：0，他引：11
本文探讨了福建九龙江口潮间带秋茄、木榄、红海榄、白骨壤和桐花树等红树植物叶片重金属元素Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ、Ｍｎ的含量及动态。结果表明，该河口红树林区表层土壤沉积物元素含量顺序为Ｍｎ〉Ｚｎ〉Ｐｂ〉Ｃｕ〉Ｃｄ；５种红树植物叶片元素含量顺序为Ｍｎ〉Ｚｎ〉Ｃｕ〉Ｐｂ〉Ｃｄ；不同物种叶片元素含量大都有明显差异；叶片对土壤元素富集系数，以Ｍｎ、Ｃｄ较高，Ｐｂ最低；随叶片从幼叶－成熟叶－黄叶的生长发育，Ｍｎ 相似文献
15.
采用聚丙烯酰胺凝胶电泳方法对广西英罗港内滩和中滩红树林中的白骨壤Avicennia marina、桐花树Ae-giceras corniculatum和秋茄Kandelia candel叶片的过氧化物酶(POD)同工酶、超氧化物歧化酶(SOD)同工酶进行了电泳分离及酶活力测定,同时测定了红树植物采样点土壤的Mn、Cr、Cd、Pb、Cu和Zn 6种重金属元素的含量。结果表明:(1)内滩的3种红树植物叶片的POD同工酶的带数或酶活力均大于中滩;桐花树和秋茄SOD同工酶的变化趋势与POD相似,但酶活力变化幅度小于POD。(2)土壤中各种重金属含量的大小顺序是Mn>Cr>Zn>Pb>Cu>Cd,中滩高于内滩。(3)桐花树POD同工酶活力变化可对土壤重金属污染起指示作用。 相似文献
16.
红树林种群的组成和分布对于红树林生态系统的保护和恢复至关重要。本研究以漳江口红树林保护区为研究对象,通过获取无人机高光谱影像,进行光谱特征分析、光谱微分变换和包络线去除,提取了911组17个光谱特征参数,通过逐步判别分析筛选出13个用于决策树构建的特征参数,最终通过C5.0决策树模型获得了研究区红树林种群的分布状况。结果表明,漳江口红树林保护区植被种群呈现自上到下不同类型的分布情况,研究区上部以桐花树和秋茄混合类型为主,中间区域呈现白骨壤、桐花树和秋茄三者共生的现状,研究区下部则以白骨壤分布为主,伴生有少量的秋茄。通过混淆矩阵计算,得到研究区总体分类精度为 87.95%,Kappa系数为 83.81%,具有较好的精度。研究结果可为区域红树林湿地保护提供数据支撑,为红树林种群识别研究提供方法参考。 相似文献
17.
为探讨泉州湾洛阳江口桐花树和秋茄2种红树林生境的大型底栖动物群落是否存在明显差异,于2011年4月至2012年1月对2种红树林生境的大型底栖动物进行了季度定量调查.结果表明：4个季度在2种红树林生境定量取样获得大型底栖动物49种,其中多毛类15种,腹足类8种,甲壳类15种,鱼类3种,昆虫2种,刺胞动物、扁形动物、纽形动物、星虫动物、寡毛类和双壳类各1种.寡鳃齿吻沙蚕（Nephtys oligobranchia）、短拟沼螺（Assiminea brevicula）、弧边招潮蟹（Uca arcuata）、指海葵（Actinia sp.）等在2种生境均有较高的栖息密度,可口革囊星虫（Phascolosoma esculenta）是2种生境的常见种,但栖息密度不高.虽然秋茄生境的大型底栖动物平均生物量高于桐花树生境,但桐花树生境的大型底栖动物群落的物种数、栖息密度、多样性指数（H’）、均匀度指数（J）和丰富度指数（d）均高于秋茄生境.单变量双因素方差分析（Two-way ANOVA）表明,2种红树林生境的大型底栖动物群落的多样性指数和均匀度指数有显著的季节差异、生境差异以及生境×季节差异.聚类分析表明,2种红树林生境的大型底栖动物群落组成的相似性较高,其原因是它们所处的潮区相同、沉积物类型相似和底质粒径相近. 相似文献
18.
北部湾大风江与南流江河口红树林空间分布格局研究 总被引：1，自引：1，他引：0
生长在潮间带的红树植物在河口植物群落构成、海岸防风消浪中具有重要价值。本文基于本地种桐花树胚胎浸泡下沉实验与北部湾南流江和大风江河口段水体盐度、沿线潮间带植物群落结构与地貌分析，探讨红树林在河口空间分布及影响因素。结果主要表明:南流江河口和大风江河口红树林自海向陆基本展现“红树林纯林(桐花树、秋茄、无瓣海桑种类混生)→红树植物与半红树植物(黄槿、苦朗等)混生→红树植物、半红树植物与非红树植物混生→红树植物镶嵌→稀疏红树林小苗”的分布格局，但大风江河口向陆界限主要以红树、红树幼苗及半红树混生为主。此外，红树被浸淹时长是控制河口红树空间分布结构的主要因素。潮水上溯时长影响红树向陆生长的极限位置，宜林滩地是红树发育生长的必要条件。 相似文献
19.
大亚湾红树林及海岸植物叶片盐腺与表皮非腺毛结构 总被引：1，自引：1，他引：0
光镜下观察研究了大亚湾地区部分红树林和海岸植物叶片的盐腺（腺毛）和非腺毛的结构及部分种类的发育过程,结果表明：在２１种植物中,叶片具盐腺的有桐花树、老鼠勒、白骨壤、黄槿、假茉莉、海南刺、二叶红薯,具非腺毛的有黄槿、白骨壤、钝叶豆腐木、草海桐。不同植物盐腺和表皮非腺毛的基本结构一致,反映出对难生境的趋同适应。 相似文献