Plant-to-plant direct competition for belowground resource in an overlapping depletion zone

In response to limited availability of soil resources in basal root zone, plant extends its roots into nearby resource-rich zones to fulfill essential resource demands for survival and reproduction. This root proliferation into that enriched zones occupied by other plants constitutes interplant overlapping rooting zones and thereby the overlapping depletion zones, causing reduction in resource uptake by neighboring plants. By incorporating this mechanism into the classic resource competition model, we study interplant direct competition through their rooting system in an overlapping depletion zone. The model results indicate an extension of Tilman’s R* rule that has already been proved true when plants compete indirectly through their effect on shared resources. The results reveal that plant’s direct competitive ability (i.e., the ability to occupy an overlapping depletion zone by excluding others) can be characterized by its R*-value, where a best competitor having lowest R*-value excludes others from an overlapping zone and occupies the zone by depleting the resource level to the lowest as in its non-overlapping depletion zone. By analyzing the model, we find a suite of traits that confers R* variation among directly competing plants. This suite of traits would be a useful proxy measure for R* that do not necessarily require to establish equilibrium field monoculture—a requirement for R* measurement in the field.

The depletion of coastal environmental resources by human activities and its monetary evaluation

The marine environment provides rich and varied resources and services or functions for human’s produc-tion and life. Many countries have competitively exploited and utilized sea and ocean to develop marine economy for someyears. The over-exploitation of marine environment and the overuse of marine resources have led to resource degradation,environmental pollution and ecosystem destruction. Considering the depletion of coastal environmental resources dur-ing planning, governing and decision-making is an important measure to promote the harmonious and sustainabledevelopment of coastal environmental resources and social economy, the main precondition of which is that the depletionof coastal environmental resources by human activities has been monetarily evaluated. Firstly, this paper summarizesrelevant references in this field and analyzes different sorts of depletion of coastal environmental resources caused byhuman activities and the necessity and importance of the monetary evaluation. Finally, this paper extensively discussesthe corresponding evaluation models of the depletion of marine mineral resources, marine organism resources, mari-time transport resources, intertidal zones and shallow seas, and marine environmental functions and services includingenvironmental capacity, gas regulation, disturbance prevention, recreation and biodiversity.

Theory and practice of value management and its innovation for natural resources from the perspective of sustainable development

The supreme obstacle for sustainable development of natural resources is the scarecity, bottleneck. So how to promote the sustainable utilizing and increase the using efficiency of natural resources is worth studying. This paper suggests that we should improve the model and means of evaluating method and value management based on th~ theory of natural resource compensation. This paper discusses the User Cost Method based on the microeeonomicaspect which can change the evaluating method for natural resources. From the perspective of value managemen model, we should use the User Cost Method to realize the linkage and integration of micro and macro eompensation for natural resources. Based on the evaluating and aecounting idea User Cost Method, this paper presents a theo. retical framework to harmonize and link micro and macro compensation for natural resources. At present, we should seek the new approach and method to manage natural resources, so can we realize the capitalization managemen focusing on the vahte management for natural resources.

National Ecological Deficit Accounting of China with Detailed Ecological Footprint

Ecological footprint is a new method to assess sustainable development quantitatively. It translates production into biologically productive areas offering material flows to measure the utilized degree of nature by humankind. At present, China runs ecological deficits because footprints required for consumption are larger than available ones. In the paper, the ecological footprint model is applied to calculate the deficits by resource, environment and import-export accounting. It is clear that the deficits have caused enormous pressure to resource and environment, which would become bigger with more factors of resource and environment being accounted. In the primary production and energy trade, import footprint turned from deficit to surplus after 1996, which benefited the conservation of national resource. But compared with the huge depletion caused by resource and environment, they had small effects on deficits.

A preliminary study on the inter-era fair of sustainable development

Since the conception of sustainable development was advanced. its basic meaning has been extensively accepted. Sustainable development is a focus that all social circles pay close attention to In general, sustainable development is to satisfy the needs of contemporary era. but not to damage the requirement of later generations. It is quite evident that we should correctly handle the issues of interera retationship. In this paper, the authors have made a preliminaly approach to the inter-ere fair by calculating the coordinated degree of a city and accounting the resources' depletion.

Resource Tax Reform:A Case Study of Coal from the Perspective of Resource Economics

Using the adjusted E1 Serafy user cost approach to estimate the depletion cost of coal resources, this paper demonstrates that user cost exists in the exploitation of China＇s coal resources and has increased rapidly with the substantial growth of coal output. It is necessary to levy a resource tax that reflects the real cost of coal resources. The results of our calculations show that from 1992 to 2009, the theoretical ad valorem coal tax rate determined in accordance with the user cost fluctuated between 2 and 14 percent. A further analysis of the impact of an ad valorem coal tax on the Chinese macroeconomy with a dynamic computable general equilibrium （CGE） model shows that a tax rate of 5-12 percent for coal resources would better reflect the cost of depletion of coal as a scarce resource, with the macroeconomic impact falling within the acceptable range. Therefore, resource tax reform is significant for China＇s sustainable development.

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The availability of resources for economic activities differs between regions, and the importance of the resources is consequently observed to be different within regions compared to a global scale. With the current situation in Chinese mining industry and its statistic characteristics, the characterization procedures of abiotic resource in life cycle impact assessment (LCIA) have demonstrated certain limita-tions in the Chinese materials industry. The aim of this paper is to propose new characterization and normalization factors for abiotic resource depletion categories such as metals and non-renewable en- ergy resources in a Chinese context. The actual production of abiotic resources calculated by a modi- fied model is compared to the reserve base in line with the new national standard to determine char- acterization factors in equivalence units, with antimony as the reference mineral. The normalization factors are based on the total base reserves of the most important minerals in China. A case study on primary magnesium production using the Pidgeon process is used to compare LCIA results for abiotic resource categories that are between current LCIA factors and the new Chinese factors. These factors not only reflect the importance of abiotic resource with respect to region-specific resource depletion, but also can compare with the global factors.