Measurement of ecological capital of Chinese terrestrial ecosystem based on remote sensing

The biosphere of the Earth is the material founda-tion of human survival and development.With the increasing problems of the resources,the environment and population,most countries in the world have paid special attention to the measurement and evaluation of ecological capital,which refers to the sum of the direct natural resources value and the indirect ecosystem services value.Ecological capital depends on not only the quality of the national ecological environment,butalso the social recogni…     

江苏盐城自然保护区滨海湿地生态系统的特征与健康设计

本文所论及的滨海湿地指的是广义沿海滩涂湿地,不仅指全部潮间带,还包括潮上带和潮下带可供开发利用的部分,其作为新生的土地资源(有一定范围、面积),主要发育于潮滩—平原海岸与河流的三角洲地区.     

新生产力——一个新的海洋学研究领域

新生产力的概念最初由Dugdale等(1967)提出,近年来由于全球变化研究的发展,赋予了新的含义。它不仅反映了海区的群落净生产能力,同时也是海洋真光层对于大气中CO_2的净吸收的一种度量。新生产力研究已经成为当今海洋研究的前沿领域,它涉及海洋生态学、生物海洋学、生物地球化学和物理海洋学的研究,具有重要的理论意义和实际意义。新生产力的基本研究方法是~(15)N示踪法,此外,还可应用沉积物捕集器法、f比推算法、物理模型法、真光层净产氧量法、~(234)Th滞留时间法、物质通量模型法以及遥感等方法进行观测或推算。新生产力的研究已被纳入一些国际重大联合研究计划,如JGOFS,GLOBEC等,在短短的几年时间里已取得了迅速的发展,90年代将在更大范围和深度上展开研究,并将对全球新生产力水平有一个较精确和全面的了解。     

Effects of CO<Subscript>2</Subscript> Enrichment on Marine Phytoplankton

Rising atmospheric CO₂ and deliberate CO₂ sequestration in the ocean change seawater carbonate chemistry in a similar way, lowering seawater pH, carbonate ion concentration and carbonate saturation state and increasing dissolved CO₂ concentration. These changes affect marine plankton in various ways. On the organismal level, a moderate increase in CO₂ facilitates photosynthetic carbon fixation of some phytoplankton groups. It also enhances the release of dissolved carbohydrates, most notably during the decline of nutrient-limited phytoplankton blooms. A decrease in the carbonate saturation state represses biogenic calcification of the predominant marine calcifying organisms, foraminifera and coccolithophorids. On the ecosystem level these responses influence phytoplankton species composition and succession, favouring algal species which predominantly rely on CO₂ utilization. Increased phytoplankton exudation promotes particle aggregation and marine snow formation, enhancing the vertical flux of biogenic material. A decrease in calcification may affect the competitive advantage of calcifying organisms, with possible impacts on their distribution and abundance. On the biogeochemical level, biological responses to CO₂ enrichment and the related changes in carbonate chemistry can strongly alter the cycling of carbon and other bio-active elements in the ocean. Both decreasing calcification and enhanced carbon overproduction due to release of extracellular carbohydrates have the potential to increase the CO₂ storage capacity of the ocean. Although the significance of such biological responses to CO₂ enrichment becomes increasingly evident, our ability to make reliable predictions of their future developments and to quantify their potential ecological and biogeochemical impacts is still in its infancy. This revised version was published online in July 2006 with corrections to the Cover Date.     

Dynamics of microphytobenthic biomass in a coastal area of western Seto Inland Sea, Japan

This study focused on the causes of the variation in microphytobenthic biomass and the effects of this variation on macrobenthic animals in the western Seto Inland Sea, Japan, where the importance of microphytobenthos as the primary food source for benthic animals has been recently reported. We investigated the microphytobenthic biomass together with light attenuation of seawater, phytoplanktonic biomass, macrobenthic density and biomass at eight stations (water depth = 5–15 m) during four cruises in 1999–2000. The increased light attenuation coefficient of the water column associated with increased concentration of the phytoplanktonic Chl-a caused a decrease in light flux that reached the seafloor. The biomass of the microphytobenthos within the upper 1 cm of the sediment, 1.9–46.5 mg Chl-a m⁻², was inversely correlated with the phytoplanktonic biomass in the overlying water column, 10.9–65.0 mg Chl-a m⁻². Thus, interception of light by phytoplankton is considered to be a main cause of the variation in the microphytobenthic biomass. The microphytobenthos biomass showed a significant positive correlation with the macrobenthic density (78–9369 ind. m⁻²) and biomass (0.4–78.8 gWW m⁻²). It appears that the increase in oxygen production by the microphytobenthos allowed macrobenthic animals to become more abundant, as a consequence of oxygenation of the organically enriched muddy sediments (14.5 ± 2.69 mg TOC g⁻¹). This study suggests that the variation in the microphytobenthic biomass is influenced by the phytoplanktonic biomass due to shading effect, and the balance between these two functional groups might affect the variability in the macrobenthic density and biomass.     

海洋围隔生态系中叶绿素a的变化及其影响因素

本文论述了在海洋围隔生态系中叶绿素a含量的变化及其影响因素。结果表明,叶绿素a含量与浮游植物细胞个数变化有较好的正相关。无机氮含量在14μmol/L以上时,对叶绿素a的影响不大,叶绿素a与活性磷含量有明显的正相关。光照是影响叶绿素a含量的重要因素之一。叶绿素a与食植性浮游动物个数变化关系密切。     

浅海环境物理学与生物学过程相互作用研究

分析浅海物理环境与浮游生物动力学过程的互相影响，讨论相互作用过程在生态系模型中的定量化表示方法，探讨胶州湾的生态系统动力学特征。