海南岛北部潮间带红树林对重金属的累积特征

对海南岛北部潮间带红树林湿地7种红树植物（根、茎、叶）及其根系沉积物中重金属元素含量进行了分析,结果表明：研究区湿地沉积物中Ni、Cu、Zn、As和Cd的变异系数大于0.50,沉积物中重金属分布很不稳定。其中Cr、Cu、Zn、As和Cd的含量均高于海南水系沉积物背景值,可能存在外源的输入。仅有Pb的含量略低于海南水系沉积物背景值。总体来看,大部分植物显示了对Cd元素的较强的富集能力（BAC〉1）,瓶花木对重金属元素的吸收能力总体上要比其他红树植物强一些,木果楝对重金属元素的吸收能力总体上最弱。其中,瓶花木（Scyphiphora hydrophyllacea）对Cr、Zn、As和Cd的吸收能力较强,莲叶桐（Hernandia sonora）对Cr和Ni的吸收能力较强,角果木（Ceriops tagal）对Pb的富集能力较强。角果木（Ceriops tagal）和桐花树（Aegiceras corniculatum）对Cd和Pb的运输能力较强,瓶花木（Scyphiphora hydrophyllacea）对Cu、Zn和Cd的运输能力较强,尖瓣海莲（Bruguiera sexangula）对Cr、Ni、Cd和Pb的运输能力较强,木榄（Bruguiera gymnorrhiza）对Ni、Cu、Cd和Pb的运输能力较强,木果楝（Xylocarpus granatum）对Cr、Zn和Cd的运输能力较强,莲叶桐（Hernandia sonora）对Cr也有较强的运输能力。但此次所研究的红树植物对As元素的运输能力均很弱,建议适量引入适宜在研究区生长并且对As元素富集能力较强的植物。     

高位池养虾对土壤微生物脂肪酸和土壤酶活及其表征的土壤质量的影响

为评价高位池养虾对土壤质量的影响,通过脂肪酸分析和土壤酶活测定比较海南岛白马井镇高位池土壤与原始土壤微生物群落结构与活性的变化.结果显示,高位池土壤的pH值和盐分含量显著升高,有机质和总N显著下降(P<0.05).脂肪酸分析表明,高位池土壤中细菌、真菌、放线菌和微生物总量都显著下降(P<0.05),尤其真菌急剧下降(P<0.05),放线菌未检测到.土壤脱氢酶、脲酶和酸性磷酸酶活性在高位池土壤中也显著下降(P<0.05).总之,微生物群落结构显著变化,微生物生物量和活性在高位池土壤中都显著下降,表明长期的高位池养虾导致了土壤质量的下降.     

Persistent organic pollutants in soils and sediments from James Ross Island, Antarctica

Soil and sediment samples from James Ross Island were analyzed for their PCB, OCP and PAH contents. Soil concentrations ranged between 0.51 and 1.82 ng g(-1) for seven indicator PCB congeners, between 0.49 and 1.34 ng g(-1) for HCH congeners, between 0.51 and 3.68 ng g(-1) for the sum of p,p'-DDT, DDE, and DDD, and between 34.9 and 171 ng g(-1) for the sum of 16 EPA PAHs. Sediment levels from 0.32 to 0.83 ng g(-1) were found for PCBs, from 0.14 to 0.76 ng g(-1) for HCHs, from 0.19 to 1.15 ng g(-1) for DDTs, and from 1.4 to 205 ng g(-1) for PAHs. A prevalence of low-mass PAHs, less chlorinated PCBs, and more volatile chemicals indicates that the long-range atmospheric transport from populated areas of Africa, South America, and Australia is the most probable contamination source for the solid matrices in James Ross Island.     

Assessing species reintroduction sites based on future climate suitability for food resources

The reintroduction of a species that is extinct in the wild demands caution because reintroduction locations may be associated with threats, such as hunting, poor-quality habitat, and climate change. This is the case for Cyanopsitta spixii (Spix's Macaw), which has been extinct in the wild since 2000. The few living individuals were created in captivity and will be used in a reintroduction project within the species’ original distribution area, the Caatinga domain (Brazil). Because the occurrence records for this bird are old and inaccurate, we investigated the current and future environmental suitability of the 14 plant species used by C. spixii as resource. These plants are key elements for the long-term reestablishment of the species in the wild, so the use of models helps in the assessment of the effects of climate change on the availability of these resources for the species and informs selection of the best places for reintroduction. We based our models of environmental suitability on 19 bioclimatic variables and nine physical soil and topography variables. Climate projections were created for the present and for the year 2070 with an optimistic (SSP2-4.5) and a pessimistic (SSP5-8.5) climate scenario. Both future climate scenarios lead to a reduction in area of environmental suitability that overlapped for all the plant species: 33% reduction for SSP2-4.5 and 63% reduction for SSP5-8.5. If our projections materialize, climate change could thus affect the distribution of key resources, and the maintenance of C. spixii would depend on restoration of degraded areas, especially riparian forests, and the preservation of already existing natural areas. The Caatinga domain is very threatened by habitat loss and, for the success of this reintroduction project, the parties involved must act to protect the species and the resources it uses.     

Marsh surface sediment deposition and the role of tidal creeks: Implications for created and managed coastal marshes

The need to understand the processes contributing to marsh sedimentation has become more urgent with the recent recognition of the role of tidal marshes as sea defences, as well as the many restoration efforts currently under way. This study was designed to build upon previous sedimentation work at Scolt Head Island by Combining techniques for measuring short-term sedimentation, with detailed assessment of hydroperiod, previously used only in comparison with longer-term accretion measurements or in micro-tidal systems. Measurements of water level, sediment deposition (at various distances from the creek margin) and suspended sediment concentration (SSC) (creek margin and an interior site) were made at Hut Marsh over three sequential over-marsh tides during May 1994. Sediment trap data show a significant trend of declining sediment deposition away from the creek when data from all three tides are combined. All tides show higher SSC on the flood tide than on the ebb tide at the creek margin location. There is little difference in flood and ebb SSCs at the interior site. An order of magnitude decrease in sediment deposition within 20 m on the creek shows the rapidity with which sediment is deposited on these marshes. Higher tides influence both the magnitude and pattern of marsh surface sediment deposition. Increased creek velocities on higher tides provide more potential for resuspension within the creek and increase the supply of sediment to the marsh surface. This study suggests that the design of tidal creeks may be essential for the development of sustainable coastal marshes in restoration projects.     

Water resources issues of small island developing states

The water resources of most small island developing states (SIDS) are often very limited and require special consideration to ensure that they are developed and managed in a sustainable manner. Many small islands, typically located in the humid tropics, have no surface water resources and rely on limited groundwater resources in the form of thin freshwater lenses. The exposed location of small islands makes them particularly vulnerable to natural disasters such as cyclones, floods and droughts. Pollution from population centres and from agricultural and other activities is an increasing problem. This article provides an overview of the water resources of small islands, and the main problems and issues related to water resources. Some suggested solutions, based on practical experiences, are offered for water resource assessment and monitoring programmes, and water resource development. Water resource policy, planning and management issues are also addressed, and suggested approaches for resolving some of the major water resource problems presented.     

Small island developing states and sustainable development of ocean resources

Because of their economic and environmental vulnerability, small island developing states (SIDS) have peculiar developmental problems that severely affect their ability to implement the measures necessary for attaining sustainable development as recommended in UNCED's Agenda 21. Although this has been recognised by the Commission on Sustainable Development (CSD), and although there has been international acceptance of a SIDS Programme of Action (POA), SIDS have not been the focus of adequate attention by international and donor agencies. As a result, progress toward implementing the POA has been disappointing. This study examines the question of how sustainable management and development of ocean resources can contribute significantly to the achievement of the objectives of the SIDS POA.     

丽水市大气环境中的城市干、湿岛效应初探

利用丽水城区中心及其近郊2个站点的逐时水汽压资料,定义了干(湿)岛强度指数及干(湿)岛强度等级,并发现了丽水小城区干(湿)岛变化强度、频次及时空分布规律,研究发现城区中心的干岛现象与热岛现象之间存在着正相关.湿岛的形成与露、雾、结冰、霜、雨等天气现象有关.     

垦殖后洲滩湿地生态恢复的景观设计途径——以长江新济洲滩为例

长江南京段新济洲滩是一处由心滩不断扩大形成的洲滩湿地,由于人类长期垦殖、修筑垸堤等活动,导致洲滩湿地的景观格局和过程发生根本性改变,湿地生态系统服务退化。从景观生态学的角度出发,参照Steinitz景观设计六步骤模式,构建了描述、过程、评价、改变、评估和决策模型,探讨洲滩湿地的生态恢复途径,指出拆除垸堤、去除人类过分干扰是新济洲滩生态恢复的关键,恢复自然洪水过程、让自然做功、恢复季节性湿地及生境是其基本途径。模拟维持现状、拆除圩堤、拆除防洪堤3种预景,分析不同预景洲滩湿地面积、生物栖息地面积变化,结果表明拆除防洪堤将使洲滩季节性、洪水泛滥湿地面积所占比重分别将由5%、4%增加到56%、24%,长江鱼类、龟鳄类、涉禽类栖息地面积所占比重由7%、11%、5%分别增加到21%、75%、56%。湿地是重要的景观生态系统,利用Steinitz六步骤模式进行生态恢复途径的探讨,对其他湿地生态恢复的规划和设计也有重要的借鉴意义     

近60年来崇明岛东部淤涨速率初探

崇明岛作为我国最大的河口冲积岛,其形成发育与长江来水来沙息息相关。历史上就有崇明岛围垦筑堤的记载,近60年来崇明岛东部地区所筑大堤主要有54大堤、64大堤、68大堤、92大堤和98大堤。选取正东、东北、东南不同方向的4个断面,以大堤位置代表所筑年份海岸线位置,对崇明岛东部淤涨速率及滩地淤涨面积变化进行计算,结果表明:(1)近60年来崇明岛东部整体淤涨速率约为200 m/a,淤涨面积年均增长率为2.80 km~2/a;(2)不同断面上淤涨速率存在差别,其中正东方向断面上淤涨最快;(3)不同时段崇明岛东部各断面淤涨速率存在快慢变化。各断面上,20世纪90年代的淤涨速率均最大。对比发现,20世纪50~80年代崇明岛东部淤涨速率的变化趋势,与同期长江年入海泥沙量的变化趋势基本一致;但20世纪90年代,由于围垦强度加大,两者变化趋势不一致。以海堤研究岸线变迁的工作尚不多见,此方法将为研究长时间尺度的岸线变迁提供借鉴。