The western Mediterranean climate: how will it respond to global warming?

The paper discusses the newly produced temperature and precipitation series from instrumental observations in the Western Mediterranean (WM) area, dating back to 1654. The two series had a continuous swing and unstable coupling passing from correlation to anti-correlation. Only after 1950 are they permanently anti-correlated with increasing temperature and decreasing precipitation. It is not clear how long this coupling will persist. The analysis of the correlation between the Northern Hemisphere (NH) and the WM temperature anomalies and their trends shows a certain variability from 1850 to 1950; later a strong coupling between NH and WM. Results suggest that the WM climate is approaching a turning point that might locally oppose the adverse effects of Global Warming.     

Modeling lateral circulation and its influence on the along-channel flow in a branched estuary

A numerical modeling study of the influence of the lateral flow on the estuarine exchange flow was conducted in the north passage of the Changjiang estuary. The lateral flows show substantial variabilities within a flood-ebb tidal cycle. The strong lateral flow occurring during flood tide is caused primarily by the unique cross-shoal flow that induces a strong northward (looking upstream) barotropic force near the surface and advects saltier water toward the northern part of the channel, resulting in a southward baroclinic force caused by the lateral density gradient. Thus, a two-layer structure of lateral flows is produced during the flood tide. The lateral flows are vigorous near the flood slack and the magnitude can exceed that of the along-channel tidal flow during that period. The strong vertical shear of the lateral flows and the salinity gradient in lateral direction generate lateral tidal straining, which are out of phase with the along-channel tidal straining. Consequently, stratification is enhanced at the early stage of the ebb tide. In contrast, strong along-channel straining is apparent during the late ebb tide. The vertical mixing disrupts the vertical density gradient, thus suppressing stratification. The impact of lateral straining on stratification during spring tide is more pronounced than that of along-channel straining during late flood and early ebb tides. The momentum balance along the estuary suggests that lateral flow can augment the residual exchange flow. The advection of lateral flows brings low-energy water from the shoal to the deep channel during the flood tide, whereas the energetic water is moved to the shoal via lateral advection during the ebb tide. The impact of lateral flow on estuarine circulation of this multiple-channel estuary is different from single-channel estuary. A model simulation by blocking the cross-shoal flow shows that the magnitudes of lateral flows and tidal straining are reduced. Moreover, the reduced lateral tidal straining results in a decrease in vertical stratification from the late flood to early ebb tides during the spring tide. By contrast, the along-channel tidal straining becomes dominant. The model results illustrate the important dynamic linkage between lateral flows and estuarine dynamics in the Changjiang estuary.     

Effect of agrochemicals on macroinvertebrate assemblages in Pampasic streams,Buenos Aires,Argentina

Agricultural practices have been intensified in recent decades in Argentina. The Pampa plain is the main agricultural region of the country. The effect of increased application of agrochemicals on the invertebrate fauna of the Pampasic streams remains unreported. In the present study, we compared the abundance and composition of invertebrate assemblages in seven Pampasic streams with contrasting soil use in their basins. Two streams run through intensively cropped plots, two drain basins with livestock fields, while the other three are located within a biosphere Reserve. Higher nutrient and insecticide concentrations were measured in the streams draining cropped basins, related with pesticide applications and crop fertilization. The invertebrate assemblage composition of the cropped streams differed significantly from the others and between the two. Present evidence suggests that the impact of agrochemicals results in a change in composition with decreased abundance or absence of sensitive species such as Hyalellidae, Caenidae, Baetidae and Curculionidae and increased abundance of more tolerant taxa: Ostracoda, Glossiphoniidae (Hirudinea), Ancylidae (Gundlanchia), Ampullariidae (Pomacea canaliculata), Sphaeriidae and Dugesiidae. Available information suggests that macrophyte cover and composition also influence the invertebrate assemblages of the Pampasic streams.     

Forward Modeling with Forced Neural Networks for Gravity Anomaly Profıle

In this paper, we introduce a new method called Forced Neural Network (FNN) to find the parameters of the object in geophysical section respect to gravity anomaly assuming the prismatic model. The aim of the geological modeling is to find the shape and location of underground structure, which cause the anomalies, in 2D cross section. At the first stage, we use one neuron to model the system and apply back propagation algorithm to find out the density difference. At the second level, quantization is applied to the density differences and mean square error of the system is computed. This process goes on until the mean square error of the system is small enough. First, we use FNN to two synthetic data, and then the Sivas–Gürün basin map in Turkey is chosen as a real data application. Anomaly values of the cross section, which is taken from the gravity anomaly map of Sivas–Gürün basin, are very close to those obtained from the proposed method.     

Sea surface temperature anomalies in the South China Sea during mature phase of ENSO

Based on the 18-year(1993–2010) National Centers for Environmental Prediction optimum interpolation sea surface temperature(SST) and simple ocean data assimilation datasets,this study investigated the patterns of the SST anomalies(SSTAs) that occurred in the South China Sea(SCS) during the mature phase of the El Ni?o/Southern Oscillation.The most dominant characteristic was that of the outof-phase variation between southwestern and northeastern parts of the SCS,which was influenced primarily by the net surface heat flux and by horizontal thermal advection.The negative SSTA in the northeastern SCS was caused mainly by the loss of heat to the atmosphere and because of the cold-water advection from the western Pacific through the Luzon Strait during El Ni?o episodes.Conversely,it was found that the anomalous large-scale atmospheric circulation and weakened western boundary current during El Ni?o episodes led to the development of the positive SSTA in the southwestern SCS.     

Antialgal and antilarval activities of bioactive compounds extracted from the marine dinoflagellate <Emphasis Type="Italic">Amphidinium carterae</Emphasis>

With the global ban on the application of organotin-based marine coatings by the International Maritime Organization, the development of environmentally friendly, low-toxic and nontoxic antifouling compounds for marine industries has become an urgent need. Marine microorganisms have been considered as a potential source of natural antifoulants. In this study, the antifouling potential of marine dinoflagellate Amphidinium carterae, the toxic and red-tide microalgae, was investigated. We performed a series of operations to extract the bioactive substances from Amphidinium carterae and tested their antialgal and antilarval activities. The crude extract of Amphidinium carterae showed significant antialgal activity and the EC₅₀ value against Skeletonema costatum was 55.4 μg mL^?1. After purification, the isolated bioactive substances (the organic extract C) exhibited much higher antialgal and antilarval activities with EC₅₀ of 12.9 μg mL^?1 against Skeletonema costatum and LC₅₀ of 15.1 μg mL^?1 against Amphibalanus amphitrite larvae. Subsequently, IR, Q-TOFMS, and GC-MS were utilized for the structural elucidation of the bioactive compounds, and a series of unsaturated and saturated 16- to 22-carbon fatty acids were detected. The data suggested the bioactive compounds isolated from Amphidinium carterae exhibited a significant inhibiting effect against the diatom Skeletonema costatum and Amphibalanus amphitrite larvae, and could be substitutes for persistent, toxic antifouling compounds.     

Impacts of tourism development on the physical environment of Mussoorie,a hill station in the lower Himalayan range of India

Tourism in mountainous regions is a significant source of revenue generation. However, it has also been associated with many adverse environmental consequences. This study aims at assessing the negative impacts of the incessant upsurge in tourism development on the physical environment of Mussoorie, a well-known mountain tourist destination in India. The impact indicators for the region were identified and assessed by qualitative and quantitative analysis of field observations. The observations indicated the aggravation of traffic congestion, atmospheric pollution, undisposed solid waste, water scarcity and infrastructure unavailability as the prevalent issues, especially during the peak tourist months. The extent of the consequential damage to the environment was evaluated by conducting an assessment of tourism-induced human disturbance on the natural landscape of the town. Slope, slope aspect, vegetation cover, road network and drainage network were incorporated as the determining landscape attributes to prepare thematic maps of landscape quality (perceivable intrinsic properties) and landscape fragility (vulnerability to anthropogenic disturbances) using GIS technique. An absorption capacity map was finally prepared to characterize the study area into regions of different conservation needs. The results identified the need for planning appropriate preservation strategies for different tourist places in the town. The study can be used by the policy makers for implementing the regulatory measures against potential disturbances due to mass-tourism.     

EFFECTS OF WATER TABLE AND NITROGEN ADDITION ON CO2 EMISSION FROM WETLAND SOIL

Soil respiration is a main dynamic process of carbon cycle in wetland. It is important to contribute to global climate changes. Water table and nutritious availability are significant impact factors to influence responses of CO₂ emission from wetland soil to climate changes. Twenty-four wetland soil monoliths at 4 water-table positions and in 3 nitrogen status have been incubated to measure rates of CO₂ emission from wetland soils in this study. Three static water-table controls and a fluctuant water-table control, with 3 nitrogen additions in every water-table control, were carried out. In no nitrogen addition treatment, high CO₂ emissions were found at a static low water table (I) and a fluctuant water table (IV), averaging 306.7mg/(m²·h) and 307.89mg/(m²·h), respectively, which were 51%–57% higher than that at static high water table (II and III). After nitrogen addition, however, highest CO₂ emission was found at II and lowest emission at III. The results suggested that nutritious availability of wetland soil might be important to influence the effect of water table on the CO₂ emission from the wetland soil. Nitrogen addition led to enhancing CO₂ emissions from wetland soil, while the highest emission was found in 1N treatments other than in 2N treatments. In 3 nutritious treatments, low CO₂ emissions at high water tables and high CO₂ emissions at low water tables were also observed when water table fluctuated. Our results suggested that both water table changes and nutritious imports would effect the CO₂ emission from wetland. Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 90211003) and the Knowledge Innovation Program of Chinese Academy of Sciences (No. KACX3-SW-332) Biography: YANG Ji-song (1978-), male, a native of Chengwu of Shandong Province, Ph.D. candidate, specialized in environmental ecology and wetland biogeochemistry. E-mail: yangjisong@neigae.ac.cn     

Nodes and Field of Tourist Origins to Ancient Village——A Case Study of Huangcheng Village in Shanxi Province of China

Based on Hagget's theory of spatial structure,researches on the nodes and field of tourist origins to Huang-cheng Village in Shanxi Province of China have been explored.Nodal hierarchy structure of tourist origins is analyzed with cluster analysis and the gravity model.And field of tourist origins is analyzed with attraction radius index(R)and geography concentration index(G).In the field analysis,R and G of Huangcheng Village are compared with Xidi Village that is a world heritage located in Huangshan City of Anhui Province in China.According to comparison of loca-tions of two areas,influential factors for field area of Huangcheng Village are identified.It is concluded that:1)cluster analysis and gravity model can be complementary methods to each other for nodal hierarchy structure analysis of tour-ist origins;and 2)as far as location is concerned,the weak intensity effect of tourism resources in the tourist region is a major cause for explaining why tourist origins to Huangcheng Village are mainly its neighboring areas.Moreover,it is suggested that the regional effect of tourist resources should be regarded as a component of destination attractiveness when applying gravity model.     

CATASTROPHIC ECO-ENVIRONMENTAL CHANGE IN THE SONGNEN PLAIN, NORTHEASTERN CHINA SINCE 1900S

Although the Songnen Plain in the northeastern China was developed relatively late in the temperate zone of the world, its eco-environment has changed greatly. This paper analyzes the changes of land cover and the rates and trends ofdesertification during the past 100 years in the Songnen Plain. According to the macroscopic analysis, we find that the eco-environment in the plain has reached to the threshold of catastrophic change since the 1950s. The Thorn Needle Catastrophic Model was used to determine and validate this conclusion. Human activities, including large-scale construction projects, such as huge dams and dikes, and excessive grazing were the primary factors contributing to regional eco-environmental catastrophe. And irrational reclamation of the wilderness also affected the eco-environmental change. The results reveal the complex human-land interactions.