1985年以来黄河三角洲孤东海岸演变与生态损益分析

研究围填海前后的海岸带生态系统服务价值变化对促进海域管理和海洋资源可持续发展具有重要意义。以黄河三角洲孤东海岸为例,依据1985—2005年该地区剖面地形实测资料以及利津水文站的水沙资料,利用海岸地形演变方法对冲淤数据进行了处理,并结合生态系统服务价值理论方法,分析了围填海前后的生态系统服务价值变化。结果表明:孤东海岸剖面表现为严重侵蚀下切,其中海洋作用占主导地位。根据冲淤演变结论,孤东海域可被分为堤内区、堤根区、堤前区和远岸区,1985—2005年各区生态系统服务价值变化情况表明,孤东海域围堤后生态系统服务价值损失巨大,并且随建堤时间增长而日益增大,而丁坝的修建可以有效改善沉积环境,减少生态损失。     

Spatiotemporal variations of inorganic nutrients along the Jiangsu coast,China, and the occurrence of macroalgal blooms (green tides) in the southern Yellow Sea

Large macroalgal blooms (i.e. green tides of Ulva prolifera) occurred in the southern Yellow Sea, China, yearly from 2007 to 2016. They were among the largest of such outbreaks around the world, and these blooms likely originated along the coast of the Jiangsu Province, China. Understanding the roles of nutrients in the onset of these macroalgal blooms is needed to identify their origin. This study analyzes the spatiotemporal variations in dissolved inorganic nitrogen and phosphorus (DIN and PO₄–P) and the N/P ratio along the Jiangsu coast from 1996 to 2014 during late-March to April, the months which corresponds to the pre-bloom period of green tides since 2007. A zone of high DIN and PO₄–P concentrations has developed along the Jiangsu coast, between the cities of Sheyang and Nantong, since 1996. There was an 18-year trend of increasing DIN concentrations during the pre-bloom period as well as a positive correlation between the U. prolifera biomass and DIN concentrations. Nutrient inputs from rivers and mariculture in the Jiangsu Province may have provided nitrogen that contributed the magnitude of macroalgal blooms that subsequently spread into the southern Yellow Sea.     

From castaways to throwaways: marine litter in the Pitcairn Islands

Pollution of the oceans by garbage is a serious problem. Worldwide, as many as 8 million items of garbage may enter the seas on a daily basis. These items may survive some time, drifting in the oceans and give rise to other environmental problems such as causing hazards to wildlife (through ingestion and entanglement) before being washed ashore. Surveys of beaches on Ducie and Oeno Atolls in the Pitcairn Islands were compared with a similar survey on a beach in S.W. Ireland. The three beaches were similar in the density and major categories of garbage to be found, but differed in subtle ways. For example the Pacific beaches had a greater proportion of bottles and buoys, whereas the Irish beach had a greater proportion of sweet wrappers and polythene bags. Although these remote islands may be thousands of miles from industrial centres their beaches are apparently as dirty as those in Europe.     

Governability Assessment for Fisheries and Coastal Systems: A Reality Check

In this article we argue that in order to understand why some governance systems deliver while others do not, we need to assess contributions and limitations of governability. Here, governability refers to a measure of how governable a particular fisheries and coastal system is. Such a system is always comprised of two parts: a system-to-be-governed and a governing system. Governability also depends on the interactions between these two systems. We provide key variables that must be assessed in order to determine governability related to these systems and their interactions. A governability assessment framework is proposed here to suggest that governance performance can only be judged from what is in the potential of the governing system, given the limitations of the governabiltiy of the system-to-be governed, the governing system itself, and their interactions. Such an assessment helps identify what exactly governing systems can and should do in order to enhance their performance.     

Changes in distribution of waterbirds following prolonged drought reflect habitat availability in coastal and inland regions

Provision of suitable habitat for waterbirds is a major challenge for environmental managers in arid and semiarid regions with high spatial and temporal variability in rainfall. It is understood in broad terms that to survive waterbirds must move according to phases of wet–dry cycles, with coastal habitats providing drought refugia and inland wetlands used during the wet phase. However, both inland and coastal wetlands are subject to major anthropogenic pressures, and the various species of waterbird may have particular habitat requirements and respond individualistically to spatiotemporal variations in resource distribution. A better understanding of the relationships between occurrence of waterbirds and habitat condition under changing climatic conditions and anthropogenic pressures will help clarify patterns of habitat use and the targeting of investments in conservation. We provide the first predictive models of habitat availability between wet and dry phases for six widely distributed waterbird species at a large spatial scale. We first test the broad hypothesis that waterbirds are largely confined to coastal regions during a dry phase. We then examine the contrasting results among the six species, which support other hypotheses erected on the basis of their ecological characteristics. There were large increases in area of suitable habitat in inland regions in the wet year compared with the dry year for all species, ranging from 4.14% for Australian White Ibis to 31.73% for Eurasian Coot. With over half of the suitable habitat for three of the six species was located in coastal zones during drought, our study highlights the need to identify and conserve coastal drought refuges. Monitoring of changes in extent and condition of wetlands, combined with distribution modeling of waterbirds, will help support improvements in the conservation and management of waterbirds into the future.     

Divergent biogeography of native and introduced soil macroinvertebrates in North America north of Mexico

To improve understanding of the biogeographical consequences of species introduction, we examined whether introduced soil macroinvertebrates differ from natives in the relationship between species richness and key environmental predictors, and whether such differences affect the relationship between native and introduced species richness. For North America north of Mexico, we summarized jurisdiction occurrence data for seven macroinvertebrate taxa with strong influences on soil biodiversity or processes. We analysed the relationships of native and introduced species richness to each other using linear regression; to latitude using Gaussian regressions; and, using the residuals of the richness–latitude regressions, to distance from coasts, human population density, and human population size using regression and correlation. We found weak to strong positive relationships between native and introduced species richness. This variation was related to divergent relationships of native and introduced species with latitude, human population density, and distance from coasts. Native species richness declined with increasing latitude for all taxa, as did introduced species richness for taxa with predominantly lower‐latitude origins (ants, termites, non‐lumbricid earthworms). In contrast, introduced species richness peaked at higher latitudes for four taxa of predominantly Palearctic origins (weevils, ground beetles, lumbricid earthworms, isopods). Partitioning introduced taxa within these groups based on region of origin, we found that Palearctic taxa were distributed at higher latitudes than non‐Palearctic taxa. Thus source region appears to strongly influence introduced species richness–latitude relationships. Compared to natives, introduced species exhibited more positive relationships with human population density and negative relationships with distance from coasts, but did not differ in relationships with human population size. Thus coastal, densely populated regions are likely to have a higher proportion of introduced soil macroinvertebrate species. These differences between distribution of native and introduced species tend to weaken positive correlations between native and introduced species richness, especially for taxa dominated by Palearctic introductions.     

江门市砂质海岸外来入侵植物分析

[目的]掌握江门市砂质海岸外来植物入侵现状,为江门市砂质海岸外来入侵植物早期预警、防控和生态系统的保护修复提供基础数据。[方法]采用实地调查、植物群落样方调查和查阅资料相结合的方法对江门市砂质海岸外来入侵植物的种类组成、原产地、区系及功能性状等进行统计和分析。[结果]江门市砂质海岸外来入侵植物共有22种,隶属12科22属,种类最多的是菊科(6种)、禾本科(3种)和豆科(3种),分别占总种数的27.27%、13.64%和13.64%;出现频度最高是鬼针草(90.91%)。危害等级以恶性入侵(Ⅰ级)和严重入侵种(Ⅱ级)占比最高,合计占总种数的68.18%。科和属的区系分布类型均以泛热带、热带亚洲及热带美洲类型占主导地位,原产地以美洲地区的频次最多,占总种数的83.33%。生长型以草本植物为主,占总种数的68.18%;生活型以地面芽和一年生植物种数最多,合计占总种数的54.54%;果实类型以瘦果居多,占总种数的31.82%。[结论]江门市砂质海岸外来植物入侵形势严峻,对其生态系统造成极大的威胁。建议加强江门市砂质海岸外来入侵植物科学防治,因地制宜开展受损生境改造,推广乡土植物应用,建立海岸防护林。     

<Emphasis Type="Italic">Fauchea guiryi</Emphasis> Selivanova sp. n.: The first record of a species of the family Faucheaceae (Rhodophyta: Rhodymeniales) in the Far Eastern Seas of Russia

Fauchea guiryi Selivanova sp. n. (Rhodymeniales, Faucheaceae) from the Commander Islands (Russian Pacific coast) is described and illustrated. The new species is compared with closely related taxa of the family Faucheaceae and the genus Fauchea, among them those from the Pacific coast of North America.     

红树林生长带与潮汐水位关系的研究

根据海南东寨港林市村,廉江车扳镇那肋村,深圳锦锈中华等３个实验点１０条横断面红树林潮滩高程水准测量,林市村潮汐水位观测,潮汐特征水位及浸淹频率分布计算,参照有关港点潮汐实测或预测报资料,确定红树林外边界为平均海面或稍上,内边界（或林内最大高程）为回归潮平均高高潮位（或大潮平均高潮位）对国内外有关报道进行了评述,指出国内许多红树林文献中使用的“高潮位”,“中潮位”“低潮位”用潮汐学术语表述应为“回归     

Does the Mediterranean killifish Aphanius fasciatus (Teleostei: Cyprinodontidae) fit the one-dimensional stepping-stone model of gene flow?

Five samples (30 individuals each) of the Mediterranean cyprinodontid fish, Aphanius fasciatus, were analysed by allozyme electrophoresis for a study concerning genetic structure and gene flow among populations. Forty-three loci, twelve of which were polymorphic at P_0.99 level, were analysed. A. fasciatus showed low levels of genetic polymorphism, with expected heterozygosity values ranging from 0.027 (SE = 0.013) to 0.064 (SE = 0.023). The modified Rogers' genetic distances ranged from 0.053 to 0.202. The observed pattern of genetic differentiation among populations, obtained by multidimensional scaling of the modified Rogers' genetic distances, was consistent with geographic distribution. Coancestry coefficient ( = 0.302, SE = 0.045) indicated a very high degree of genetic subdivision among populations and the estimate of gene flow (the effective number of migrants per generation, Nm = 0.445), computed by Wright's method, showed very restricted gene flow among populations. The regression analysis carried out using log-transformed values of geographic distance against M^ (pairwise values of Nm) gave a regression coefficient, b = –1.03, indicating that a restricted migration rate among populations can occur according to the one-dimensional stepping-stone model. The amount and modality of gene flow in A. fasciatus inferred from the results of the present study are consistent with the absence of dispersal stages and with the fragmented nature of brackish-water habitats along the coasts.