Mesoscale variability related to iron speciation in a coastal Ross Sea area (Antarctica) during summer 2014

Dissolved iron (Fe) distribution and speciation was determined in water samples (0–200?m) collected in a coastal area near Terra Nova Bay during the austral summer of 2014. Nutrients, dissolved oxygen, chlorophyll-a, phytoplankton composition and prokaryotic biomass distribution were investigated in combination with measurements of the physical properties of the water columns and its dynamics. The dFe value was above the limiting growth concentration, ranging from 0.52 to 4.51?nM, and it showed a spatial variability with a horizontal length scale of about 10?km, according to the variability of the water column physical properties and to iron sources. The organic ligands (L) maintained the concentrations of dFe at levels much higher than the inorganic solubility of Fe, keeping it available for phytoplankton and the log K’_FeL values found (from 22.1 to 23.6) highlighted the presence of complexes of differing stabilities.     

Morphologic development, relative sea level rise and sustainable management of water and sediment in the Ebre Delta, Spain

The Ebre (Ebro) Delta is one of the most important wetland areas in the western Mediterranean. Ca. 40 % of the delta plain is less than 0.5 m above mean sea level and part of the southern margin of the delta is at mean sea level in an area protected by dikes. Both mean rates of secular subsidence in the Ebre Delta and eustatic sea level rise are ca. 1 – 2 mm/yr. Thus, the present annual relative sea level rise (RSLR) rate in the Ebre Delta may be at least 3 mm/yr. Measured accretion rates in the delta range from 4 mm/yr in the wetlands surrounding the river mouth to <0.1 mm/yr in impounded salt marshes and rice fields. The annual sediment deficit in the delta plain to offset RSLR is close to 1 million m³/yr. Accretion rates in the rice fields prior to the construction of large dams in the Ebre watershed were higher than RSLR rates, from 3 – 15 mm/yr. At present, >99 % of the riverine sediments are retained in the reservoirs and rice fields are losing ca. 0.2 mm/yr. Future management plans should take RSLR into account and include control of freshwater and sediment flows from the river in order to offset negative effects from waterlogging and salt intrusion, and maintain land elevation. This will include the partial removal of sediments trapped behind the Ribarroja and Mequinença dams. Stocks and inputs of sediments in the corresponding reservoirs are large enough for land elevation of ca. 50 cm in the whole delta plain. Advantages of this solution include (1) new sediments to the delta to offset subsidence (via rice fields) and coastal retreat, (2) enhanced functioning of the delta (productivity and nutrient processing), (3) avoidance of accumulation of sediments in the reservoirs. Hence, it is important to manage river discharges at the dams from an integrated viewpoint, whereas currently only hydropower and agricultural requirements are considered. It is also crucial to maintain periods of high discharge, to have enough river energy to transport as much sediments as possible.     

The Botanist Effect Revisited: Plant Species Richness, County Area, and Human Population Size in the United States

Abstract:  The "botanist effect" is thought to be the reason for higher plant species richness in areas where botanists are disproportionately present as an artefactual consequence of a more thorough sampling. We examined whether this was the case for U.S. counties. We collated the number of species of vascular plants, human population size, and the area of U.S. counties. Controlling for spatial autocorrelation and county area, plant species richness increased with human population size and density in counties with and without universities and/or botanical gardens, with no significant differences in the relation between the two subsets. This is consistent with previous findings and further evidence of a broad-scale positive correlation between species richness and human population presence, which has important consequences for the experience of nature by inhabitants of densely populated regions. Combined with the many reports of a negative correlation between the two variables at a local scale, the positive relation between plant species richness in U.S. counties and human population presence stresses the need for the conservation of seminatural areas in urbanized ecosystems and for the containment of urban and suburban sprawl.     

连云港海平面变化与地震相关性的探讨

为探索海平面变化与地震相关的前兆信息,利用了连云港验潮站长达４３年的验潮资料。结合华北地区４次７级以上强震和江苏及其以东黄海海域１８次中强以上地震的震例分析后认为：经基本消除主要干扰因素的连云港平均海平面变化,表征了与地震有关的地壳形变信息。它对监测华北地区强震和江苏及邻近地区的中强震,具有一定的参考价值。     

Restoration of Some Parameters in the Development of Benthos After Reduction of Anthropogenous Loading in the Ecosystem of the Sevastopol Bay in the Black Sea

Research on benthic communities have been carried out in the Sevastopol Bay of the Black Sea for a hundred years. The anthropogenous influence began to have an effect already in the 20–30^th. In this period, all oyster-banks were lost and the mussel-silt and mellina-silt communities have begun to degrade and were not found during almost seventy years in the Bay. The worst state of benthic communities was observed in the 60–90^th, when species of bottom animals were not found over some parts of the sea. In this period, only 10 macrozoobenthic species were registered in the Bay. Mollusks: Nassarius reticulatus, Bittium reticulatum, Cerastoderma glaucum and polychaetes: Nephtys hombergii, Neanthes succinea have proved the most enduring at high anthropogenous loadings The faunistic complex of benthic species registered in 1913 had the greatest similarity to the benthic species complex of 2002. Return of mussel, Melinna palmata polychaete and Ascidiella aspersa sea squirt in benthic communities of the Sevastopol Bay are responsible for the similarity between these faunistic complexes. The restoration of local populations of these benthic species has followed the significant decrease of the anthropogenous loading on the sea ecosystems as a result of the significant reduction of the military naval base in the Bay during the last five to ten years.     

华北平原分区适宜性农业节水技术与潜力

华北平原现状农田灌溉水利用率为43 1 % ,节水潜力较大。论文通过分区诊断与适应性农业节水技术评价计算 ,提出了2010年和2030年水平年分区适宜性农业节水技术发展的综合排序 ,并以现状为基点 ,计算与分析了两个水平年分区不同农田灌溉技术的发展规模和相应的节水量     

东海区小黄鱼总允许渔获量初探

根据1991~2003年中国渔业统计年鉴以及东海区渔业资源动态监测网各网站监测产量和捕捞努力量(投网次数)数据,通过同时期东海区小黄鱼产量对海区总捕捞努力量进行标准化,运用剩余产量模型中的Fox模型估算东海区小黄鱼最大持续产量(MS Y)、最适产量(Y0.1)和总允许渔获量(TAC)。结果表明,东海区小黄鱼的最大持续产量为116 565 t,相应捕捞努力量(fMSY)为4 988 315网次,最适产量为113 068 t,相应捕捞努力量(f0.1)为3 890 886网次,TACMSY=99 317 t,TAC0.1=77 468 t。建议以东海区小黄鱼总允许渔获量(TAC0.1)作为渔获量限额指标,对小黄鱼的总允许渔获量进行管理。     

华北山区环境综合整治与生态建设

华北山区位于华北平原与陕甘黄土高原以及内蒙古高原之间，是我国经济欠发达地区之一。它又是我国华北平原、京津唐等大城市工农业和生活用水的主要源地，生态环境类型复杂多样，但由于人类活动频繁，自然植被破坏严重，生态系统结构紊乱，功能脆弱，自身恢复能力较弱。积极开展华北山区的环境综合整治与生态建设不仅对解决当地人民的生活和生存问题具有重要的意义，而且对于我国华北地区经济的发展也具有重要的战略意义。本文详细分析了华北山区的生态系统特点和存在的问题，并在此基础上提出在该区环境综合整治与生态建设的具体措施和途径。     

Seasonal Fluctuation in Heavy Metal Pollution in Iran´s Siahroud River - A Preliminary Study (7 pp)

Background The management of its available water resources has become a key issue for Iran. During the last few decades, the water quality of Siahroud River in the coastal plain of the Caspian Sea in Gilan Province in Northern Iran has significantly degraded. The scarcity of water has been compounded by rapid population growth and increasing pollution from fertilizers, pesticides, and municipal and industrial wastes. One of the sources of this degradation is the movement of heavy metals from the river's watershed into the various water systems supported by the river, including the water system for Rasht City. Methods To study the magnitude of heavy metal pollution in the Siahroud River, seven heavy metals including Zn, Cu, Pb, Cd, Mn, Fe, and Ni were measured in duplicate from replicated water samples collected over five consecutive seasons and analyzed by Atomic Absorption Spectrometry. In situ measurements of pH were taken with the samples and total organic carbon (TOC) was analyzed by IR gas measurement. Results The results demonstrated that four of the seven heavy metals including Pb, Fe, Cd, and Mn exceeded permissible safe levels as established by the United States Environmental Protection Agency. Multivariate factor analysis suggested that industrial land-use was the main contributing factor for the high levels of Fe and Mn in the Siahroud River, whereas, Cd was principly from agricultural activities in the watershed. The data also suggested that pH and TOC had an important role in the behaviour of Pb and Mn, and that the elevated levels of these two heavy metals in Siahroud River was the consequence of other anthropogenic sources. Only negligible levels of Zn, Cu and Ni were detected. Finally, all the sampling stations were subjected to cluster analysis. The results indicated that three different zones could be distinguished according to the levels of pollution. In addition, it was shown that the urban areas did not have a significant impact on the heavy metal pollution in the river. This observation stems from the fact that the data from the sampling stations before and after Rasht City were not significantly different. Recommendation . Preventive measures need to be undertaken in the land-use systems and watersheds of the Siahroud River to reduce the pollution levels of Pb, Cd, Mn and Fe.     

污水在水体中的稀释扩散及稀释度的计算

结合长江白龙港水域水力模型试验对污水排海工程中污水稀释扩散的机理进行了描述，并对污水的两种稀释度（浓度释稀度和体积稀释度）进行了分析比较，得出了在污染物本底值存在时两种稀释度之间的关系。