Relationships among multiple trace elements in coastal Casuarina equisetifolia ecosystems on Hainan Island, South China

Forty-six trace elements in coastal Casuarina equisetifolia plant–soil systems at nine sampling sites on Hainan Island were analyzed using ICP-MS. The relationships among the trace elements of the same group or the same periodicity of the Periodic Table in the plants and soils were complex and no consistent patterns were found. More combinations of elements occurred with high positive correlation coefficients within the same periodicity than within the same group of the Periodic Table, and there were more high positive correlations in soils than in plants. However, there were many element combinations in Block d (transition elements) with high positive correlation coefficients in plants. Markedly high positive correlation coefficients between individual rare earth elements and Y and among Zr, Nb, Cd existed in both plants and soils. The dendrograms obtained by cluster analysis show that rare earth elements had very similar occurrence and distribution in both soils and plants. Thus, they behaved as a coherent group of elements both geochemically and biogeochemically. The transition elements were more coherent in plants than in soils.     

Occurrence, sources, and inventory of hexabromocyclododecanes (HBCDs) in soils from Chongming Island, the Yangtze River Delta (YRD)

Hexabromocyclododecanes (HBCDs) is a concern due to their large usage combining with physico-chemical properties and toxicity to wildlife and human. However, very limited data were reported on HBCDs in soils, especially from rural area. In this study, 22 soil samples were collected from Chongming Island at estuary of the Yangtze River Delta, to investigate the level, diasteroisomer profile, potential sources, and mass inventory of HBCDs. The total concentrations ranged from not detected to 93.8 pg g⁻¹ dry weight (dw) with a mean of 23.3 pg g⁻¹ dw, which was at the low end of the global levels. The wide distribution of HBCDs in soils suggested that the local emissions of HBCD-containing materials and/or the inputs via atmospheric transport from other regions were two possible sources. Variation of HBCDs levels was observed in different types of soils. Woodland, tideland and road soils contained slightly higher HBCDs than those of farmland and grassland. Overall, γ-HBCD was the dominant diasteroisomer in soils, followed by α-HBCD and β-HBCD. Significant but weak correlations were only found between α-HBCD and β-HBCD versus TOC content in soils. Currently, the mass inventory of HBCDs in soils of Chongming Island was 5.3 kg. Based on these data, we gave perspective on human intake of HBCDs via soil ingestion by age. Local resident’s intakes ranged from 15.5 to 97.8 fg kg body weight⁻¹ d⁻¹, in which children are exposed more than adults.     

论海岛旅游开发中的环境保护--以威海刘公岛为例

岛屿是一种特殊的旅游资源，具有很大的发展潜力，但因发展旅游而引起的环境问题也日益受到人们的关注。本文以国家级旅游风景区刘公岛为例，分析了海岛的旅游资源，并对如何加强海岛的环境保护进行了详细的论述。     

北部湾涠洲岛原油污染物的海水环境质量基准研究

选择9种我国本土海洋生物对北部湾涠洲岛原油污染物的急性生物毒性进行测试,并基于测试获得的毒性数据,利用美国水生生物基准推算方法,对该原油污染物的海水环境基准阈值进行推导,结果表明:原油样品对卤虫、褶皱臂尾轮虫、太平洋纺锤水蚤、中国对虾、三疣梭子蟹、彩虹明樱蛤、牙鲆、半滑舌鳎、青岛大扁藻的LC50(或EC50)分别为10.28, 2.37, 4.88, 0.31, 0.81, 65.88, 19.02, 9.10, 0.23mg/L;涠洲岛原油污染物的急性和慢性海水质量基准阈值分别为0.06,0.012mg/L.研究结果可为我国海上溢油事故损害评估提供科学依据.     

基于GIS的海岛生态脆弱性评价研究与实践——以海坛岛为例

基于生态敏感度、生态弹性度和生态压力度,构建了海岛生态脆弱性评价的指标体系,采用综合指数法和GIS相结合的方法对海坛岛的生态脆弱性进行了定量评价,并绘制了生态脆弱性等级分布图,分析了生态脆弱度的空间差异和不同区域生态脆弱性的主导成因.评价结果与该区域的生态环境状况较为一致,对于海坛岛的生态保护和资源利用具有一定的指导意...     

Variation of soil fertility and carbon sequestration by planting Hevea brasiliensis in Hainan Island, China

The development of rubber industry depends on the sustainable management of rubber plantation. To evaluate the environmental effects of planting Hevea brasiliensis on a subsystem of tropical forest ecosystem, the variation of soil fertility and carbon sequestration under rubber plantation within 30-year life period were investigated in Hainan Island. Results showed that （1） with the increase of stand age of rubber plantation, soil fertility decreased all along. From 1954 to 1995, soil organic matter, total N, available K and available P decreased by 48.2%, 54.1%, 56.7% and 64.1%, respectively. （2） If the complete return of litters was considered without additional fertilizer application to the soil of the rubber plantations, the consumption periods for P, N, K, Mg were only 825 years, 329 years, 94 years and 65 years, respectively~ To improve soil fertility is essential for rubber plantation development. （3） The C sequestration of rubber trees per hectare accounts for 272.08 t within 30-year life period and 57.91% of them was fixed in litters. In comparison with C sequestration by rain forest （234.305 t/hm^2） and by secondary rain forest （150.203 t/hm^2）, rubber forest has more potentials for C fixation. On the base of above results, the following measures would benefit the maintenance of soil fertility and the development of rubber industry, including applying fertilizer to maintain the balance of soil nutrients, intercropping leguminous plant to improve soil fertility, reducing the collection of litters, optimizing soil properties to improve element P availability such as applying CaCO3. The information gathered from the study can be used as baseline data for the sustainable management of rubber plantation elsewhere.     

被动式采样器在大区域大气VOC监测中的应用

应用VOC被动式采样器监测了地中海东部塞浦路斯岛大气中挥发性有机化合物(volatile organic compounds,VOC)的浓度。通过岛上设置的80个VOC采样点对苯,甲苯,对、邻、间二甲苯(Benzene、Toluene、o-xylene、m,p-xylene,BTX)数次采样及分析结果表明,其被动采样器中BTX回收率>95%,BTX平行实验的相对标准偏差<6.28%,采样和分析方法准确。得到的污染物分布图较准确地反映了塞浦路斯岛实际污染情况。     

宁波大榭岛邻近水域生态现状

通过对大榭岛附近海域水环境因子的调查和评价,发现该海域呈富营养化状态,无机氮、无机磷的含量已达发生赤潮临界条件,但与大榭岛开发前相比,浮游植物和浮游动物的结构组成及优势种并未发生明显变化,浮游植物和浮游动物的多样性指数H＇分别为0.97～3.00和1.98～2.75,平均值分别为2.27和2.35.     

Island biogeographical theory: Can it be used to predict lotic recovery rates?

Classic island biogeographic theory predicts that equilibrium will be reached when immigration and extinction rates are equal. These rates are modified by number of species in source area, number of intermediate islands, distance to recipient island, and size of intermediate islands. This general model has been variously modified and proposed to be a stochastic process with minimal competitive interaction or heavily deterministic. Predictive models of recovery (regardless of the end point chosen) have been based on the appropriateness of the MacArthur-Wilson models. Because disturbance frequency, severity, and intensity vary in their effect on community dynamics, we propose that disturbance levels should first be defined before evaluating the applicability of island biogeographical theory. Thus, we suggest a classification system of four disturbance levels based on recovery patterns by primary and secondary succession and faunal organization by primary (invasion of vacant areas) and secondary (remnant of previous community remains) processes. Level 1A disturbances completely destroy communities with no upstream or downstream sources of colonizers, while some component of near surface interstitial or hyporheic flora and fauna survive level 1B disturbances. Recovery has been reported to take from five years to longer than 25 years, when most invading colonists do not have an aerial form. Level 2 disturbances destroy the communities but leave upstream and downstream colonization sources (level 2A) and, sometimes, a hyporheic pool of colonizers (level 2B). Recovery studies have indicated primary succession and faunal structuring patterns (2A) with recovery times of 90–400 days or secondary succession and faunal structuring patterns (2B) with recovery times of 40–250 days. Level 3 disturbances result in reduction in species abundance and diversity along a stream reach; level 4 disturbances result in reduction of abundance and diversity in discrete patches. Both disturbance types lead to secondary succession and secondary faunal organization. Recovery rates can be quite rapid, varying from less than 10 days to 100 or more days. We suggest that island biogeographical models seem appropriate to recovery by secondary processes after level 3 and 4 disturbances, where competition may be an important organizing factor, while models of numerical abundance and resource tracking are probably of better use where community development is by primary succession (levels 1 and 2). Development of predictive recovery models requires research that addresses a number of fundamental questions. These include the role of hydrologic patterns on colonization dynamics, the role of nonaerial colonizers in recovery from level 1 disturbances, and assessment of the impact of changes in the order of invasion by colonizers of varying energetic efficiencies. Finally, we must be able to assemble these data and determine whether information that guides community organization at one level of disturbance can provide insights into colonization dynamics at other levels.     

海岛土地与土地系统生态设计刍议

本文依据生态学理论对海岛土地及土地系统生态功能进行了重新的认识,并探讨了海岛土地系统生态设计的依据、原则和模式.设计中强调以土地系统生态保护性功能为主体,以海岛土地系统高层次调合发展作为海岛建设的最终目标.