基于EOS-MODIS的广西全境石漠化信息提取方法研究

喀斯特石漠化是发生在亚热带岩溶地貌中的土地退化过程,其显著特征为土壤严重侵蚀、基岩裸露、植被退化、土地生产力下降。石漠化既制约当地的经济发展,又可能引起小环境气候的恶化,同时也破坏生物多样性,危及生态环境自然景观。因此,研究石漠化,分析其成因和分布特征对喀斯特地区的防灾减灾以及可持续发展具有十分重大的意义。EOS-MODIS数据所固有的优点(获取便捷、覆盖范围广、成像周期短),使其成为理想的大范围石漠化研究的潜在遥感数据源。     

喀斯特石漠化遥感信息提取方法综述

喀斯特石漠化是中国西南地区面临的重大生态顽疾,运用遥感技术进行石漠化信息提取是大范围监测不可或缺的手段。本文在分析相关科学文献的基础上,首先简述了喀斯特石漠化的分布概况及分级评价指标,然后对石漠化遥感信息提取方法进行了总结及对比分析,指出现有信息提取方法存在的不足,最后初步预测了未来石漠化遥感监测的发展趋势。     

Food utilisation by coastal fish assemblages in rocky and soft bottoms on the Swedish west coast: Inference for identification of essential fish habitats

The concept of essential fish habitats (EFHs) is widely accepted for conservational and management purposes. EFHs are often considered as high quality habitats for fisheries species and subsequently of high values for society. In this study, fish and Substrate-Associated Prey (SAP) were sampled during the productive summer season 1998 (fish) and 2003 and 2004 (SAP) in shallow coastal rocky- and soft-bottom habitats on the Swedish west coast. The aim was to study the spatial and monthly variation of SAP as well as abundance and biomass of fish, and to examine if food items found in the diet of the fish assemblage were derived from SAP. We also examined if the diet of Ctenolabrus rupestris, a resident and abundant fish species in the shallow coastal habitats, and the diet of four seasonally abundant and commercially important fish species (Gadus morhua, Pleuronectes platessa, Salmo trutta and Scomber scombrus) were derived from SAP. There were significantly higher mean species number and abundance of the SAP assemblage on rocky compared to soft bottoms and the highest values were found on the rocky bottoms in August and in the shallowest (0–3 m) depth strata. There were no significant differences in number of fish species caught in the two habitats, although mean number of fish and mean biomass were significantly higher on rocky bottoms. Both habitats showed the same seasonal variation and the highest values of number of fish species, abundance and biomass were observed in June. On rocky bottoms, gastropods and amphipods were the most frequent food items in the diet of the entire fish assemblage and these items were also the most abundant SAP in this habitat. The dominant food items of the soft-bottom fish assemblage were decapods and fish, which were not common SAP. However, except for S. scombrus, the diet of the selected fish species showed a strong association to the SAP availability. Gadus morhua displayed the strongest association to SAP on rocky bottoms and P. platessa and C. rupestris to SAP on soft bottoms. Further, for C. rupestris, multivariate statistical analysis showed a significant association to the SAP assemblage on both rocky and soft bottoms. These results provide vital new information for the management and conservation of Essential Fish Habitats on the Swedish west coast.     

闽粤交界的大埕湾岸滩稳定分析及岸滩防护对策

本文在实地调查的基础上，通过对大埕湾沿岸输沙率变化和岸线形态的分析，综合探讨了该海湾的泥沙来源，沿岸泥沙迁移特征，岸滩冲淤动态以及海岸的演变趋势．结果表明：该湾沿岸带形成了一股朝W向迁移的波生泥沙流，泥沙主要来自诏安湾和宫口湾；该湾海岸除东部沙坝泻湖岸段略有淤伸外，其余岸段均处于侵蚀状态：随着泥沙来源的减少，海岸内凹蚀退是今后岸线调整的自然过程．文中还对大埕湾岸滩的防侵蚀提出了相应的对策建议。     

Northern Adriatic Rocky Reef Fishes at Low Winter Temperatures

Abstract. The behavioural ecology of certain northern Adriatic fishes was observed from January to April at a water temperature of 7–11 ^oC. The fishes studied here do not migrate to deeper waters. Most of the benthic fishes show a similar distribution over the substrate in winter and in summer; in winter, however, they are very inactive and hide in the substrate. Suprabenthic fishes aggregate in littoral caves where they form dense, inactive, mixed aggregations. Certain hemipelagic and pelagic fishes join to form very dense aggregations at specific sites in the open waters of bays. Littoral predators display high feeding activity at a time when their prey is inactive. I present a hypothesis concerning possible implications of seasonally cyclic environmental temperatures for a sympatric community of non-migrating fishes.     

山东蓬莱沿海岩相潮间带贝类的垂直分布

蓬莱 ( 37°2 5’N～ 37°4 9’56”N ,1 2 0°34’4 4”E～ 1 2 1°0 9’E)位于山东半岛的北端 ,黄渤海交界处。作者通过对蓬莱沿海潮间带生物的调查 ,初步分析了岩相潮间带贝类种类及其垂直分布特点 ,依潮间带的不同区域而呈带状分布 (高潮带为滨螺群落 ,中潮带为牡蛎群落 ,低潮带为贻贝 -锈凹螺群落 )并简单分析了主要经济贝类的分布状况 ,为潮间带贝类资源合理开发与保护提供了基础资料 ,供海洋生态学、环保、水产部门参考     

Distribution of Sessile Invertebrates in a Rocky Sublittoral Community off Rimsky‐Korsakov Islands (Sea of Japan)

Abstract. The dependence of the vertical distribution of sessile macrobenthos upon environmental physical factors was studied in a community inhabiting rocky substrata at 2 to 15 m depth near the Rimsky‐Korsakov Islands (Peter the Great Bay, Sea of Japan). Three separate groups of species were distinguished within this community. The main dominant species are the anthozoan Metridium senile and the mussel Crenomytilus grayanus. Water movement, bottom inclination and topographic position of the studied sites in respect to prevailing water flows influence the spatial structure of sessile invertebrates. No vertical zonation in the scale of the studied sublittoral area below the 2 m depth level was observed. The studied factors are believed to condition the observed mosaic of patches characterized by specific composition, with a single species being dominant.     

Absorption Efficiencies of the Intertidal Mangrove Dwelling Mollusk Melampus coffeus LINNÉ and the Rocky Intertidal Mollusk Acanthopleura granulata GMELIN

Abstract. .The absorption efficiencies of the intertidal mangrove dwelling mollusk Melampus coffeus and the rocky intertidal dwelling mollusk Acanthopleura granulata were calculated by a modification of CONOVER'S (1966) equation. M. coffeus tended to consume fresh mangrove leaves indicating that M. coffeus may obtain much of its energy from the actual substrate material rather than from associated bacteria and meiofauna on decaying leaves. Obtaining energy directly from the substrate may be a mechanism for M. coffeus to utilize its food source more efficiently. In contrast, chitons (A. granulata) may utilize the higher energy components of their limited intertidal microflora! food source. Using the high energy component of a food source may be an additional mechanism by which organisms efficiently utilize a food source.     

Mediterranean Marine Reserves: Fish Indices as Tests of Protection Efficiency

Abstract. The fish assemblages of a strictly protected area and of a neighbouring fished area, located off a Mediterranean urbanized coast (Carry-le-Rouet, France), were compared in order to select the most evident, constant, and easily recorded indices of the 'reserve effect'. Visual censusing was repeated simultaneously at both sites eight time a year during 3 years along four permanent transects layed on shallow rocky bottoms (9–14 m). Overall species richness was 16% higher in the reserve, but differences in average instantaneous richness were only marginally significant. The most contrasting results were shown by the occurrence frequency, abundance, and demographic structure of two types of target species. The type A target species group comprises 16 large meso- and macrocarnivores particularly threatened by spearfishing, including the common nectobenthic sparids Diplodus spp. Type B target species are represented by two small territorial fishes particularly impacted by angling: the serranid Serranus cabrilla and the terminal phase males of the labrid Coris julis . The size structure of Diplodus spp., S. cabrilla , and C.julis subpopulations strongly argues for the role of protected areas as a reservoir of large spawners. Fishing pressure is assumed to modify the social conditions of the C. julis local populations and to induce earlier sex change.