近10年来三峡消落带土壤氮、磷时空分布特征研究

消落带是位于水陆交错带的一种特殊生态系统.消落带土壤作为生态系统中氮、磷元素重要的“源”与“汇”,在生物地球化学循环研究中具有重要意义.该研究基于中国知网CNKI以及Web of Science数据库检索近10年三峡消落带土壤氮、磷研究文献,提取w（TN）、w（TP）数据并进行统计,从宏观尺度上分析w（TN）、w（TP）的时空分布特征.结果表明:①高程分布上,当高程高于155 m时,土壤w（TN）（0.75~1.17 g/kg）随着高程增加呈下降趋势,土壤w（TP）未发生显著变化（0.53~0.60 g/kg）;当高程低于155 m时,土壤w（TN）处于较低水平（0.66~0.86 g/kg）,但w（TP）维持较高水平（0.60~0.76 g/kg）.②时间分布上,消落带土壤w（TN）整体呈现逐年递减的趋势,Pearson相关系数为-0.64,但是w（TP）没有显著变化.③地区分布上,三峡上游库区消落带土壤w（TP）出现显著高值,下游库区w（TN）出现显著高值.研究显示:不同高程土壤受植物残体分解等因素影响,在落干期w（TN）上升,在浸没期向上覆水体释放TN;水位调节导致的淹没强度变化对消落带土壤中TN产生淋溶作用,而对TP的影响较小;对于消落带上游地区应更关注土壤中高w（TP）带来的环境风险,而对于消落带下游地区应更关注因水土流失和非点源输出导致的高w（TN）所致环境风险.      

Primary Productivity in the Golden Horn

The shores of the Golden Horn—once most important seaport of the region—represented throughout history a romantic and recreational venue. This tributary to the Bosphorus, however, became seriously polluted with the extensive industrialization and rapid population growth in Istanbul over the past century. Two main tributaries, the Alibeykoy and the Kagithane, dumped both liquid and solid waste from residential areas and industry (small and large-scale) into the Golden Horn. As a result of this pollution, the landward three to four kilometers of the estuary became swamped with sediment. The dominance of anaerobic activity resulted in a highly unpleasant smell, and the shallow depth as one progressed up the bay restricted navigation. In early 1997 The Istanbul Metropolitan Municipality began a dredging operation and gradually diverted all domestic and industrial wastewater discharge from the Golden Horn. Since then there have been remarkable improvements in water quality. This paper presents the state of eutrophication through the water body of the Golden Horn; parameters such as DO, TKN, NH₃-N, NO₃-N, the total phosphorus (TP) and dissolved phosphorus (PO₄-P), phytoplankton and chlorophyll-a have been were analyzed in samples of water taken from various points in the Golden Horn. The presence of DO and the phytoplankton, both indicators of primary productivity in an aquatic body, has been evaluated in relation to former conditions.     

Chemical transformation and flux of different forms of arsenic in the carb Carcinusmaenas

The amount of ingested arsenic assimilated and eliminated by the crab appeared to depend on chemical form of arsenic present in the food. Arsenic-74 was translocated rapidly with a high percentage located in hepatopancreas and exoskeleton. The speciation of radioarsenic determined by sequential extraction of experimental food, feces, muscle and hepatopancreas showed that there is no efficient mechanism within the crab which can covert lipid and water soluble arsenic to arsenite and residual arsenic or vice-versa. The biological mechanism in crab selectively and effectively excretes soluble form of arsenite and residual arsenic much more readily than organic arsenic.     

Estimation of critical submergence for an intake in a stratified fluid media by neuro-fuzzy approach

Most of the large surface reservoirs are stably stratified throughout most or all of the year. One means of assisting in the management is to allow for the selective withdrawal from the reservoir. The value of the intake’s submergence when the upper layer fluids begin to be drawn into the intake is known as “critical submergence”. In this study, the critical submergence for a circular intake pipe in a stratified body is investigated. Experiments were conducted on a vertically flowing downward intake pipe in a still-water reservoir. Experimental results are compared with that of the neuro-fuzzy models.     

Land cover types and ecological conditions of the Estonian coast

Detailed analysis of the land cover of the Estonian coastal zone is presented based on Estonian laws on coastal zone management, the CORINE Land Cover (CLC) system, the status of protected areas, and administrative division data of Estonia. By law the coastal zone is defined as a 200-m wide zone landward from the mean sea level line. The length of the Estonian coastline (including the islands) is 3794 km. The 200-m zone of the Estonian coast is very diverse. Out of the 34 CORINE land cover types represented in Estonia 30 are found in the coastal zone. Three dominating land cover types in the coastal zone of Estonia are inland marshes, coniferous forest and semi-natural grassland. Their total share is 47%; the other 27 land cover types represented here cover 53% of the coastal zone. The Estonian coastal zone is generally in a good natural condition. The proportion of artificial surfaces throughout the zone is merely 4.7%, while agricultural landscapes cover only ca. 10%. Land cover data for the coastal zone are also presented by county. Of the 200-m coastal zone 24% is under protection, which is more than twice the value for Estonia as a whole (11%). Legislative protection of the coastal zone is presently satisfactory. The use of the CORINE Land Cover system enables comparisons with other European regions since CLC data have been compiled for most of Europe.     

Quantitative SWOT analysis for prioritizing ecotourism-planning decisions in protected areas: Igneada case

As environmental problems and pressures on natural resources escalate, awareness building and efforts to protect natural areas have also became a major goal to ensure sustainability. Ecotourism is one of the major activities to protect natural and cultural resources, while also providing economic benefits to both local people and government. Successful ecotourism planning is a function of establishing sound goals and criteria. In this paper, we have presented the example of Igneada, Turkey, as a case to elaborate this point. Igneada a coastal town, located on the north-west Black Sea region of Turkey, was declared a national park in 2007. The park is well known for its longos forests (flooded), lagoons, endemic and endangered species, and wildlife. However, currently, unsustainable economic activities, overgrazing, and urbanization cause threats to its sensitive ecosystems. Promoting ecotourism is a sustainable approach to balance economic, social, and environmental aspects in the development of Igneada.

The aim of this study is to define a set of ecotourism criteria and propose an ecotourism vision for Igneada. The methodology in this research involves field observations and a strengths, weaknesses, opportunities and threats analysis with an Analytical Hierarchy Process. A survey study is conducted with both local people and experts to define a framework to generate a priority ranking for ecotourism-planning decision. The research generated 5 main criteria and 14 subcriteria, among which ‘Proposal of Igneada in Turkey’s 2023 Tourism Strategy Plan’ was the highest ranked opportunity for ecotourism planning and development in the town.     

Landscape Metrics for Assessment of Landscape Destruction and Rehabilitation

This investigation tested the usefulness of geometry-based landscape metrics for monitoring landscapes in a heavily disturbed environment. Research was carried out in a 75 sq km study area in Saxony, eastern Germany, where the landscape has been affected by surface mining and agricultural intensification. Landscape metrics were calculated from digital maps (1912, 1944, 1973, 1989) for the entire study area and for subregions (river valleys, plains), which were defined using the original geology and topography of the region. Correlation and factor analyses were used to select a set of landscape metrics suitable for landscape monitoring. Little land-use change occurred in the first half of the century, but political decisions and technological developments led to considerable change later. Metrics showed a similar pattern with almost no change between 1912 and 1944, but dramatic changes after 1944. Nonparametric statistical methods were used to test whether metrics differed between river valleys and plains. Significant differences in the metrics for these regions were found in the early maps (1912, 1944), but these differences were not significant in 1973 or 1989. These findings indicate that anthropogenic influences created a more homogeneous landscape.