Self-organization of tropical seasonal rain forest in southwest China

How to measure development of ecosystems is both a theoretical and practical question in ecology. Species richness and biomass accumulation are familiar figures of merit, but they cannot be instant watched. Self-organization is a tacit character. However, methods to measure the degree of self-organization of ecosystem are problematic. To this end Lin et al. (2009) have devised indicators of energy capture and dissipation so that self-organization defined via maximum energy dissipation can be quantified easily. Here the method is used to analyze long-term data (2004-2006) of a tropical seasonal rain forest included in the ChinaFLUX program. Three years of average self-organization values were clearly separated by seasonal variation. Reflection and long wave radiation are the main two pathways of energy loss. For tropical seasonal rain forest studied, long wave radiation contributed most to energy loss, and was negatively correlated with energy capture ability (Rn/DR). The nocturnal difference between canopy and air temperatures had a strong negative correlation with the long wave radiation loss ratio. However, the long wave radiation loss ratio was slightly lower than the reflection loss ratio in rainy season, when values were very low. Precipitation and wind had significant impact on energy dissipation ability in the hot dry season, but the correlation coefficients between precipitation and wind with thermal response numbers (TRNs) were very low. The results indicated that the self-organization estimation system based on “maximum energy dissipation theory” is applicable for tropical forest.     

Low carbon transition options for Australia

A rapid and sustained transition to new energy systems for Australia was explored using the OzECCO model implemented in a systems dynamics simulation package. OzECCO simulates the close relationship between energy use and economic productivity at a sectoral level to explore scenarios of economic and biophysical function based on a calibration period of 1981-2005 and a scenario period 2006-2051. The core scenarios showed that a fully renewable (the renewables transition) or an advanced fossil and nuclear transition (the conventional wisdom transition), can reduce accumulated CO2 emissions from the Australian economy for the period 2006-2051 by 50%. Adding a low growth economy where GDP averages less than 1% annually extends this to a 60% reduction. Extensive reforestation of more than 50 million hectares extends the total reduction to 70% over the 45 year period and provides at 2051 a per capita emissions level of one to two tonnes which will be necessary if developed and developing countries are to converge on equal atmospheric impacts with reasonable lifestyle opportunities. Central to both the renewables and conventional-wisdom scenarios are substantial reductions in the physical dimensions of personal consumption, and the transfer of these avoided consumption opportunities to an intergenerational sovereign wealth fund. This fund, held outside day-to-day domestic activities, can buffer Australian society and future generations against shocks, financial or physical, that might lie waiting and unanticipated in our future. This study did not explore phasing out Australia's extensive coal and natural gas exports although their impact on global atmospheric concentrations is significant. Domestic combustion and exported fuels will add 82 billion tonnes of CO2 to the atmosphere in the scenario period 2006-2051, equivalent to a 20 ppm rise in atmospheric concentrations. The low-growth renewables transition with unconstrained exports reduces this rise to 15 ppm. The continued expansion of fuel exports thus expands atmospheric risk in physical terms but also entrains policy and strategic risks should carbon-based industries become pariahs in international commerce and political relations.     

Integrative trophic network assessments of a lentic ecosystem by key ecological approaches of water chemistry, trophic guilds, and ecosystem health assessments along with an ECOPATH model

The objective of this study was to describe the trophic structure and energy flow in a lentic ecosystem in South Korea. Physicochemical water conditions were evaluated along with the reservoir ecosystem health using a multimetric IBI model. Nutrient analyses of the reservoir showed a nutrient rich and hypereutrophic system. Guild analysis revealed that tolerant and omnivorous species dominated the ecosystem. Tolerant fish, as a proportion of the number of individuals, were associated (R² > 0.90, p < 0.01) with TN and TP, the key indicators of trophic state in lentic ecosystems. The mean Reservoir Ecosystem Health Assessment (REHA) score was 19.3 during the study, which was judged as in ‘fair to poor’ condition. A trophic analysis of the reservoir estimated by the ECOPATH model shows that most activity in terms of energy flow occurred in the lower part of the trophic web, where there was intensive use of primary producers as a food source. Consequently, of the 10 consumer groups, nine fell within trophic levels <2.8. Trophic levels (TL) estimated from the weighted average of prey trophic levels varied from 1.0 for phytoplankton, macrophytes, and detritus to 3.25 for the top predator, Pseudobagrus fulvidraco. Our integrated approach to trophic network analysis may provide a key tool for determining the effects of nutrient influx on energy flow pathways in lentic ecosystems.     

Modeling the vegetation-atmosphere carbon dioxide and water vapor interactions along a controlled CO2 gradient

Ecosystem functioning is intimately linked to its physical environment by complex two-way interactions. These two-way interactions arise because vegetation both responds to the external environment and actively regulates its micro-environment. By altering stomatal aperture, and therefore the transpiration rate, plants modify soil moisture and atmospheric humidity and these same physical variables, in return, modify stomatal conductance. Relationships between biotic and abiotic components are particularly strong in closed, managed environments such as greenhouses and growth chambers, which are used extensively to investigate ecosystem responses to climatic drivers. Model-assisted designs that account for the physiological dynamics governing two-way interactions between biotic and abiotic components are absent from many ecological studies. Here, a general model of the vegetation-atmosphere system in closed environments is proposed. The model accounts for the linked carbon-water physiology, the turbulent transport processes, and the energy and radiative transfer within the vegetation. Leaf gas exchange is modeled using a carbon gain optimization approach that is coupled to leaf energy balance. The turbulent transport within the canopy is modeled in two-dimensions using first-order closure principles. The model is applied to the Lysimeter CO₂ Gradient (LYCOG) facility, wherein a continuous gradient of atmospheric CO₂ is maintained on grassland assemblages using an elongated chamber where the micro-climate is regulated by variation in air flow rates. The model is employed to investigate how species composition, climatic conditions, and the imposed air flow rate affect the CO₂ concentration gradient within the LYCOG and the canopy micro-climate. The sensitivity of the model to key physiological and climatic parameters allows it to be used not only to manage current experiments, but also to formulate novel ecological hypotheses (e.g., by modeling climatic regimes not currently employed in LYCOG) and suggest alternative experimental designs and operational strategies for such facilities.     

煤矿采掘废弃物对地下水的影响

对抚顺矿区西舍场地下水做了调查及水质分析，结果表明：舍场地下水水质极差，为高矿化度、高硬度、重盐碱的硫酸盐型水，已失去饮用和工农业生产使用价值，成为域内地下水运移有害成分的载体。     

北京西单立体交通工程施工安全风险模糊分析

随着我国大规模城市地下空间的开发 ,需要分析和研究城市地下空间施工的安全风险。笔者结合北京西单立体交通工程 ,采用层次分析理论 ,探讨和分析施工过程的安全风险 ,定义施工中涉及的六大类主要安全风险 ;运用数学集合理论 ,建立风险因素集合论域U和分析评判集合论域V ,采用模糊数学理论 ,将风险因素集合论域U和分析评判集合论域V建立模糊映射关系和模糊关系 ,从而确定数学模型 ;根据西单立体交通工程施工安全风险调查采样分析 ,统计计算风险权重和建立模糊矩阵 ,定性、定量地比较了 3种施工方法的安全风险 ,经过归一化处理 ,给出施工方法的安全风险量 ,明确了适合西单地区的施工方法。     

广州与香港的环境经济能值分析

利用国际生态学最新发展的能值分析理论方法及各种能值指标，从资源基础、能值福利、对外贸易和环境压力四个角度对广州和香港的各种生态流进行比较研究。结果表明广州在自然资源和社会资源方面明显优于香港，具有较大的经济发展潜力。从能值理论和宏观角度分析，广州应将内地丰富的土地资源和科技力量与香港充裕的资金、信息和管理能力融合，充分发挥两地的分散生产要素和资源优势。本研究为促进广州和香港的共同繁荣和优化组合提供理论依据和科学指导。     

Renewable Energy Legislation in China:Politicaland Institutional Strategy for EffectiveImplementation

Over the past decade, the Chinese government has developed several plans regulations and policy measures related to the development of renewable energy technologies and has implemented a series of pilot projects. Chinese policymakers have spent several years studying how renewable energy policy models that have been used internationally could be implemented in China. Programs are currently underway to implement pilot renewable portfolio standards, or mandatory market shares (MMS) for renewable energy, in several provinces. This paper examines the primary institutions that are involved in promoting renewable policies in China, the structure of the policies that currently are being drafted, and the status of the complementary, national-level renewable energy law being drafted to provide a legal basis for ongoing local and national-level policies. It then examines the legal requirements for promoting renewable energy legislation under the Chinese law-making system. Finally, it provides recommendations for     

Energetic valorization of SRF in dedicated plants and cement kilns and guidelines for application in Greece and Cyprus

A debate is still open on issues of waste to energy methodologies aiming to answer to questions of particular relevance, such as whether the concept of SRF/RDF production can be applied directly to MSW through the Mechanical–Biological Treatment (MBT) process, when selective collection acts as a virtual pre-treatment of the same, or if the use of SRF/RDF as alternative fuel in cement kilns is the most sustainable solution. In this study, two scenarios were analyzed and compared: (a) the use of SRF in a new dedicated thermal plant for electricity production and (b) the use of SRF as an alternative fuel in an existing cement plant. The comparative assessment was based on principles of Sustainable Waste Management embracing technical and cost issues, environmental protection, industrial ecology and symbiosis. The application of SWOT analysis showed that the use of SRF in cement kilns is more sustainable compared to its use in a new dedicated plant for electricity production.     

Energy and CO2 from high performance recycled aggregate production

The use of recycled concrete aggregates (RCA) in applications other than road sub-layers is limited by two factors: the high porosity of RCA in comparison with natural aggregates, and the restrictions set forth in standards and building codes. Research efforts aimed at alleviating these restrictions are focused on improving the quality of coarse RCAs by reducing the amount of adhered cement pastes, which is the weakest element in this system and influences the rheological behaviour.This paper presents an analysis of the environmental impacts of the recent mechanical and thermo-mechanical processing techniques which produce high performance RCA by reducing the volume of adhered cement paste. Based on published data, processing scenarios were established. These scenarios permit making rough estimates of energy consumption, CO₂ emissions, fines generation and product quality. Using these data and the available emission factors from several countries, an objective comparison was made between these innovating processes and conventional recycling.The production of fines increases from 40% up to as much as 70% as the volume of adhered cement paste on the RCA is reduced. Fuel fed thermo-mechanical process energy consumption, per tonne of recycled aggregate, varies between 36 and 62 times higher than conventional recycling processes. Mechanical processing, combined with microwave heating, increases energy consumption from 3 to a little more than 4 times conventional recycling. Consequently, CO₂ emissions released by conventional coarse aggregate production go from 1.5 to 4.5 kgCO₂/t, to around 200 kgCO₂/t, for that of fossil fuel fed thermo-mechanical treatments.Mechanical and mechanical/microwave treatments appear to have the greatest environmental potential. Notwithstanding, the further development of markets for fines is crucial for reducing environmental loads.