Decoupling of nutrient and grazer impacts on a benthic estuarine diatom assemblage

Strong interactions between top-down (consumptive) and bottom-up (resource supply) trophic factors occur in many aquatic communities, but these forces can act independently in some microphytobenthic communities. Within benthic estuarine diatom assemblages, the dynamics of these interactions and how they vary with abiotic environmental conditions are not well understood. We conducted a field experiment at two sites with varying habitat characteristics to investigate the interactive effects of grazers and nutrients on benthic estuarine diatoms. We crossed snail (Cerithidea californica) and nutrient (nitrogen and phosphorus) addition treatments in enclosures on a restored tidal sandflat and a reference tidal mudflat in Mugu Lagoon, southern California. We repeated the study in summer 2000 and spring 2001 to assess temporal variation in the interactions. Snails caused a large decrease in diatom relative abundance and biomass (estimated as surface area); nutrients increased diatom abundance but did not alter diatom biomass. Snails and nutrients both reduced average diatom length, although the nutrient effect was weaker and temporally variable, occurring in the reference mudflat in the spring. There were few interactions between snail and nutrient addition treatments, suggesting that links between top-down and bottom-up forces on the diatom community were weak. There were no consistent differences in diatom assemblage characteristics between the two study sites, despite marked differences in sediment grain size and other abiotic characteristics between the sites. The strong diatom response to herbivores and weaker responses to enrichment differed from the previous studies where cyanobacteria increased in response to nutrient enrichment, further dissolving the “black box” perception of microphytobenthic communities.     

Slow steps towards management of the world's largest tuna fishery

Today, the tuna fishery of the western and central Pacific is one of the world's largest fisheries. Annual catches exceed 2 million mt—approximately 50% of the global tuna catch—with an estimated landed value of USD 3 billion (in 2005). The fishery expanded rapidly from the mid 1980s, following the development of the purse-seine fishery. From the mid 1990s, it was recognised that a Regional Fisheries Management Organisation was required to facilitate cooperation in the management of the resource. Following almost a decade of negotiations and planning, the Western and Central Pacific Fishery Commission (WCPFC) was established in 2004. During the interim period, stock assessments for the key tuna species were developed and revealed that for two species (yellowfin and bigeye tuna) there was concern regarding the increased levels of fishing mortality. However, declarations and resolutions calling for restraint in the expansion of fishing effort were largely unheeded over the last decade and, to date, the WCPFC has been unable to introduce any measures to effectively reduce (or limit) the level of fishing mortality on yellowfin and bigeye tuna. This paper proposes a number of mechanisms for improving the performance of the WCPFC with respect to meeting the conservation and management objectives of the commission and argues that Pacific Island nations need to collectively take the lead to ensure the effective management of the resource.     

我国区域经济β-趋同的空间计量分析

运用Moran’s I指数检验了我国各省区人均GDP的空间相关性,结果表明,我国各省区的人均GDP存在显著的正空间相关,而传统的趋同检验方法未能消除异方差和自相关的影响。选用能消除异方差和自相关的空间计量模型对我国省际条件β-趋同进行检验,结果表明,我国各省区间存在条件β-趋同,趋同速度大约为2.05%,高于传统趋同经验研究得到的2%趋同速度。     

Regional cooperation for European seas: Governance models in support of the implementation of the MSFD

During the implementation process of the Marine Strategy Framework Directive (MSFD), Member States are expected to cooperate and coordinate at the regional sea level as wells as arrange stakeholder involvement. However, the MSFD does not specify any governing structures to do so. The aim of this paper is to address these key challenges of the MSFD by developing four governance models for regional cooperation and assess their impact on governance performance. The four models are based on the building blocks of stakeholder involvement (low or high) and decision-making power (binding or non-binding decisions): (1) Cross-border platforms; (2) Regional Sea Convention-PLUS; (3) Advisory Alliance and (4) Regional Sea Assembly. Secondly, the paper will do an ex ante assessment on how the alternative models will have an impact on governance performance. The assessment criteria for governance performance are: (a) costs to set up and run a model; (b) capacity to cooperate; (c) policy coordination; (d) institutional ambiguity; and (e) implementation drift. In addition to this assessment of the performance based on expert judgement (i.e. scientists of WP7 of the ODEMM project), 4 roundtable discussions have been undertaken in which stakeholders from the four regional seas did an assessment of the four models. The main conclusion is that increasing stakeholder participation, a much desired development in regional organisation of marine management as expressed by the stakeholder community, will increase the costs of the policy making process. If stakeholder participation is not embedded in a wider institutional setting in which the participation of stakeholders is directly related to the policy process and the degree to which decisions taken are binding, the increase of costs does not lead to a more smoothly running model.     

Modeling the climatic effects of the land use/cover change in eastern China

This study aims to quantify the contribution of land use/cover change (LUCC) during the last three decades to climate change conditions in eastern China. The effects of farmland expansion in Northeast China, grassland degradation in Northwest China, and deforestation in South China were simulated using the Weather Research and Forecasting (WRF) model in addition to the latest actual land cover datasets. The simulated results show that when forestland is converted to farmland, the air temperature decreased owing to an increase in surface albedo in Northeast China. The climatic effect of grassland degradation on the Loess Plateau was insignificant because of the negligible difference in albedo between grassland and cropland. In South China, deforestation generally led to a decrease in temperature. Furthermore, the temperature decrease caused by the increase in albedo counteracted the warming effects of the evapotranspiration decrease, so the summer temperature change was not significant in South China. Excluding the effects of urbanization in the North China Plain, the LUCC effects across the entire region of East China presented an overall cooling trend. However, the variation in temperature scale and magnitude was less in summer than that in winter. This result is due mainly to the cooling caused by the increase in albedo offset partly by the increase in temperature caused by the decrease in evaporation in summer. Summer precipitation showed a trend of increasing–decreasing–increasing from southeast to northwest after LUCC, which was induced mainly by the decrease in surface roughness and cyclone circulations appearing northwest of Northeast China, in the middle of the Loess Plateau, and in Yunnan province at 700 hPa after forests were converted into farmland. All results will be instructive for understanding the influence of LUCC on regional climate and future land planning in practice.     

Discrepant chemical differentiation and magmatic-hydrothermal evolution of high-silica magmatism associated with Pb–Zn and W mineralization in the Lhasa terrane

High-silica (SiO₂ > 70 wt.%) granites (HSGs) are the main source of W, Sn, and rare metals. However, abundant HSGs, temporally, spatially, and genetically associated with Pb–Zn mineralization, in the Lhasa terrane (LT), provided an ideal opportunity to study the key factors responsible for Pb–Zn enrichment, instead of W–Sn enrichment. Here we contribute to this topic through U-Pb dating of zircon and garnet, and whole-rock and Sr–Nd–Hf isotopic geochemistry of ore-related quartz porphyries in the Bangbule deposit and compared these results with published data from large and giant Pb–Zn and W deposits in the LT. The magmatism-alteration-mineralization event in the Bangbule deposit was recorded by robust zircon U–Pb ages of 77.3 ± 0.9 Ma and hydrothermal garnet U–Pb ages of 75.7 ± 4.8 Ma, which is 10–15 Ma earlier than the main Paleocene metallogenic event and the first record of late Cretaceous Pb–Zn polymetallic mineralization in the LT. The late Cretaceous-Paleocene magmatism and mineralization events are a response to the subduction of Neotethyan oceanic lithosphere, which occurred as a result of the collision of the Indian and Asian plates. These HSGs related to Pb–Zn mineralization, with high total-alkalis and low magnesian contents, are enriched in Ba, Th, and Rb, but depleted in Ti, Eu, Sr, and P. They belong to either the S-type, or I-type granites. The Sr–Nd–Hf isotopic compositions of the Pb–Zn mineralized granites demonstrate that they were generated by the partial melting of Proterozoic basement with or without mantle-derived melt input. This was consistent with the postulated source of W enrichment in the LT. The Pb–Zn and W related granites have similar zircon-Ti-saturation temperatures, comparable low whole-rock Fe₂O₃/FeO ratios, and zircon oxygen fugacity. This indicated that the Pb–Zn–W enrichment in the high-silica magma system could be attributed to a relatively reduced magma. The Pb–Zn related HSGs, abundant quartz and feldspar phenocrysts, and weak fractionation of twin-elements in whole-rock analysis, can be used to reconstruct a model of the magma reservoir. We postulate that these features could be reproduced by silica-rich crystal accumulation in a magma reservoir, with a loss of magmatic fluids. The magma associated with W mineralization exhibited a higher level of differentiation compared to the Pb–Zn related magma; however, different groups of zircon texture with varying rare earth elements and concomitance of rare earth elements tetrad effect and high fractionation of twin-elements in whole-rock are formed by a magmatic-hydrothermal transition in highly evolved system. As the source and oxygen fugacities of the Pb–Zn and W related magmas are similar, the absence of a giant W–Sn deposit in the LT may indicate that parent magmas with a low degree of evolution and magmatic-hydrothermal transition are not conducive to their formation. This implies that the rocks that originated as highly evolved silicate-rich parent magmas, with a high degree of magmatic-hydrothermal alteration, would need to be targeted for W–Sn mineral exploration in the LT. In summary, our results emphasize that variations in chemical differentiation and the evolution of high-silica magmatic-hydrothermal systems can lead to differences in Pb–Zn and W enrichment. This has implications for the evaluation of the mineral potential of high-silica granites and hence their attractiveness as targets for mineral exploration.     

云滴数浓度对超级单体龙卷影响的数值模拟研究

为了探讨云滴数浓度对于龙卷发生、发展的影响,利用ARPS（Advanced Regional Prediction System）模式,通过调整云滴数浓度（分别取高3000 cm-3、中1000 cm-3和低100 cm-3）的变化,对2003年7月8日安徽省无为县超级单体龙卷进行理想模拟试验。研究表明:三组试验都模拟出超级单体风暴的特征结构如钩状回波和V型入流缺口;云滴数浓度高的试验中上升气流更强、风暴较先发展且持续时间长,近地面涡度也较其他两组试验更大;从三组试验中找到4个龙卷涡旋,其中云滴数浓度高的试验中有两个,涡旋总持续时间接近30 min,最大近地面风速为46.93 m s-1,最大涡度值为0.42 s-1;高云滴数浓度情况下地面冷池弱,更有利于龙卷产生,并对龙卷的发生、发展有促进作用。     

Created unequal: China's regional pay inequality and its relationship with mega-trend urbanization

The relationship between inequality and mega-trend urbanization in China is complicated. At least in the first two decades of economic reform, urbanization is one of primary drivers of rising inequality across the country. Using between-and within-group components of Theil's T-statistics measured across regions and sectors, this paper provides new estimates of the evolution of China's regional inequality during the reform period. We particularly analyze the associations between inequality and China's megacities-oriented urbanization strategy. We find that China's overall pay inequality started to rise rapidly in the early 1990s, that it peaked in 2008, with the between-provinces component peaking as early as 2002. Since 2008 overall pay inequality has decreased, with between-province and within inequality both showing steady declines. In these respects, the evolution of pay inequality in China mirrors the trajectory expected under the hypothesis of a Kuznets' curve.     

Spatial analysis of residential fuel prices: Local variations in the price of heating oil in Northern Ireland

Spatial disparities in the price of residential heating fuel may have considerable impacts on social well-being. Dependence on relatively expensive fuels in off-gas grid contexts may be linked to high rates of fuel poverty, making it a key policy issue. However, fuel prices in the off-grid sector have received relatively little research attention. This study investigates pricing structures within the heating oil market in Northern Ireland, a region with high rates of fuel poverty, using applied spatial analysis. The results indicate significant spatial variations in the price of heating oil at local level. High prices occur in remote rural areas and urban areas with high rates of gas heating. Prices appear to arise from a complex set of interacting factors related to local market structures, supply costs, market competitiveness and socio-economic factors which affect demand. This study makes a significant contribution to the literature on off-gas residential heating. Although further research is needed, the results presented here suggest that policy responses such as price regulation may have only limited impacts on fuel poverty levels, emphasizing the importance of maximising access to more affordable fuels (e.g. mains gas or renewables) as part of a sustainable energy solution.     

Network configurations and R&D activities of the ICT industry in Suzhou municipality, China

This paper analyzes the network structure and R&D activities of the information and communication technology (ICT) industry in Suzhou municipality, known previously for its local state-directed Sunan model of development. Suzhou, however, has been undergoing dramatic restructuring to remake itself into a globalizing production center. We highlight the significance of the Chinese state and local/regional assets in shaping the trajectories of globalization and regional development, and the increasing importance of domestic markets and regional clusters/agglomeration for foreign ventures. We have found that Suzhou’s development path, heavily dependent on external forces, has made Suzhou a TNC (transnational corporation) satellite district. We also find that the ICT industry in Suzhou has a dual-structure, segmented between foreign-invested enterprises (FIEs) and domestic firms. TNCs tend to network among themselves and their interfirm networks are increasingly domestic and regionally embedded in the Yangtze River Delta, while the linkages between TNCs and local firms are weak. We argue that there is a series of technological, structural, spatial, and institutional “mismatches” that limits the establishment of “global pipelines” of knowledge exchange. We hold that the nature of global-local networks is contingent upon regional endogenous capacities and the specific ways in which global capital interacts with local institutions. Therefore, perspectives on TNCs’ local embeddedness must be positioned in their regional/external networks. We also analyze the constraints placed on Suzhou’s development into an innovative city and promote the integration of global and local/regional assets through development of indigenous capacities.