Ecological Supply Research Articles

Spatiotemporal change of ecological footprint and sustainability analysis for Yangtze Delta Region

In the urbanizing world, the Yangtze Delta Region (YDR) as one of the most developed regions in China, has drawn a lot of the world’s attention for the remarkable economic development achieved in the past decades. Nevertheless, the rapid economic development was certain to be accompanied by unprecedented consumption and loss of natural resources. Therefore, the analysis of the ecological situation and driving factors of environmental impact was of great significance to serve the local sustainable development decision-making and build a harmonious society. In this paper, the ecological footprint (EF) was taken as the index of the ecological environmental impact. With the help of Geographic Information System (GIS), we studied the spatiotemporal change of ecological footprint at two scales (region and city) and assessed urban sustainable development ability in YDR. Then we discussed the driving factors that affected the change of ecological footprint by the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. The results showed that increasing trends of regional ecological footprint during 1998–2008 (1.70–2.53 ha/cap) were accompanied by decreasing ecological capacity (0.31–0.25 ha/cap) but expanding ecological deficit (1.39–2.28 ha/cap). The distribution pattern of ecological footprint and the degree of sustainable development varied distinctly from city to city in YDR. In 2008, the highest values of ecological footprint (3.85 ha/cap) and the lowest one of sustainable development index (SDI=1) in YDR were both presented in Shanghai. GDP per capita (A) was the most dominant driving force of EF and the classical EKC hypothesis did not exist between A and EF in 1998–2008. Consequently, increasing in ecological supply and reducing in human demand due to technological advances or other factors were one of the most effective ways to promote sustainable development in YDR. Moreover, importance should be attached to change our definition and measurement of prosperity and success.

Spatial patterns of ecological carrying capacity supply-demand balance in China at county level

A balanced ecological carrying capacity and its understanding are important to achieve sustainable development for human kind. Here, the concept of ecological carrying capacity has been used for measuring the dependencies between human and nature. China’s ecological balance between supply and demand has become a global concern and is widely debated. In this study the ‘Ecological Footprint’ method was used to analyze the supply-demand balance of China’s ecological carrying capacity. Firstly, the ecological supply and demand balance was calculated and evaluated, and secondly, the ecological carrying capacity index (ECCI) was derived for each county of China in 2007, and finally this paper systematically evaluated the ecological carrying capacity supply-demand balance of China. The results showed that ecological deficit appeared to be the main characteristic of ecological carrying capacity supply-demand balance in 2007 of China at county scale. In general, more than four-fifths of the Chinese population was concentrated in less than one-third of the land area and more than two-thirds of the land area was inhabited by less than one-fifth of the population. The spatial distribution of the ecological carrying capacity demand-supply was unbalanced ranging from significant overloading to affluence from southeastern to northwestern part of China. It appeared to be more dominant in regions located at coastal areas which are attracted by migrants and had a generally higher population density. Along with the rapid development and urbanization trends in China, ecological deficits in these regions will become more severe.

Impact of Natural Forest Protection Program policies on forests in northeastern China

This study analyzes the effects of the Natural Forest Protection Program (NFPP) on the restoration of forest resources in the northeastern forest region of China, an important region because of its ecological and geographical location and timber supply in China, by using panel data sets of 35 forest farms of state-owned forest enterprises. Panel data analysis results show that related policies under the NFPP have had positive effects on forest resources. Planting activity had a statistically significant effect on forest growth and could be reinforced continually by planting tree species suitable for a warming climate in temperate forests. Forest management and protection played a powerful role in increasing the growing stock of the forests. In NFPP areas timber harvests, after implementation of the NFPP, were a positive factor in increasing forest resources if the harvests combined effective tending and thinning under a carefully guided management plan.

Ecological Supply Chains Performance Evaluation and Disruption Risk Management Strategies

ABSTRACT This article presents the ecological supply chain (ESC) model and demonstrates its benefits. The causes that make an ESC vulnerable to disruption risks are analyzed; the objective is to balance the cost and the disruption risk. Also, it provides supply management strategies, demand management strategies, product management strategies, and information management strategies. Practice in China is reviewed. Based on exergoeconomics theory, the ESC is regarded as a huge energy system providing new perspective. The sustainability of the ESC system is discussed under the circumstances of exergoeconomics. The metric of “system negative environment effect” is introduced to measure ESC system performance. Finally, a real case example is used to illustrate the models and get some conclusions.

An effect analysis of changes in the composition of the water ecological footprint in Jiangyin City, China

Ecological footprint (EF) analysis is an effective tool to assess ecosystem appropriation, but weaknesses still exist. In order to estimate a city's ecosystem appropriation, we made two modifications to EF: 1) including different types of freshwater area in the calculating framework; and 2) re-adjusting all equivalent factors in terms of different types of freshwater. The modifications are mainly concerned with changes in the composition of freshwater areas in EF analysis; that is, the proportion of aquaculture freshwater and tap freshwater. An assumption of 25% of aquaculture freshwater was used to conduct a sensitivity test. It shows that variation of the proportion leads to different equivalent and yield factors for tap freshwater areas. The variations not only change the EF of freshwater but also the total EF. The modified EF calculation served to assess ecosystem appropriation in Jiangyin city in 1998. By comparing the original and the modified EF, it was found that the ecological deficit was larger (2.19 ha per capita) in the modified calculation than in the original (2.16 ha per capita). The original calculation is an underestimate because direct consumption of freshwater was not fully included in its calculating framework. From the modified calculation, the EF for different categories of ecosystems decreased, from fossil energy land, arable land and pasture to built-up areas, which together occupy about 97.58% of the total EF. Fossil energy land occupied 68.55% of the total, while freshwater areas took only 0.62%. The main ecological deficits were from fossil energy land, arable land, pasture and marine areas. Ecological supply is lacking within Jiangyin and relies on ecosystems outside the city to survive. Ecosystem management is indispensable to optimise the efficiency of ecosystem use and to expand the biological capacity of the city. The modified EF could provide a more reasonable instrument in policy-making and implementing sustainable management of freshwater ecosystems.

Management of interacting species: regulation under nonlinearities and hysteresis

We consider the optimal regulation of an open access fishery when biomass dynamics are combined with fishing effort dynamics. The interaction of inelastic demand and backward bending nature of the ecological supply curve introduce nonlinearities that could lead to multiple bionomic equilibria and hysteresis effects. We obtain convergence results for general bionomic models and indicate cases where hysteretic regulation failure could be a problem when economic dynamics are slow enough relative to biological dynamics. We show that when biological dynamics are slow enough relative to the economic dynamics, the social optimum can be achieved by a time dependent landing fee.

Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

Systeme bäuerlicher Wald- und Agroforstwirtschaft in Zentralamerika als potenziell nachhaltige Landnutzungsformen

Abstract Agroforestry and small scale farm forestry systems in Central America as forms of a potentially sustainable land use: Extended deforestation has caused severe ecological and wood supply problems in Central America. Examples of natural forest management, plantation forestry, tree lines, live fences, shade trees for cocoa and coffee and silvopastoral systems are presented from Costa Rica and Panama. Information and data highlight the important economical and ecological functions of timber trees as an integral part of farm economies as well as the presently wide and growing use of such trees

Analyzing, Mapping, and Managing Environmental Impacts along Supply Chains

SummaryThis article reports on research toward a pragmatic and credible means for analyzing, mapping, and managing environmental impacts along supply chains. The results of this research include a management tool called “ecological supply chain analysis” (EcoSCAn) that is presented here for the first time. Its structure bears a passing resemblance to that used in some streamlined life‐cycle assessments, but its operation and purpose are quite different. The EcoSCAn tool frames a comparative environmental analysis of products capable of performing broadly equivalent functions. The analysis occurs over complete extended supply chains and within defined supply chain stages at a product level and, to some extent, at a site level. The results are mapped with data confidence indicators. A range of tactical and, where data quality is sufficient, strategic supply chain actions are prompted. Actions to mitigate environmental stress are possible in the absence of good quality data across entire product life cycles, although the extent to which management actions are limited is made plain.

Determination of an economic energy supply structure based on biomass using a mixed-integer linear optimization model

Biomass can be used for heat or power generation or for a combined heat and power generation in order to substitute fossil fuels. As a result of the low fossil fuel prices and the higher investment and operating costs of biomass-fired plants, the energy use of biomass has to be checked for every case in each application area. The preferred field of application is the rural area because of the reasonable relation between the potential of biomass and the transportation distances that have a great influence on the economic viability. The knowledge about the location of consumers as well as of the energy plants and the possible laying of a district heating pipe is important for the clarification of an optimal heat supply structure in an isolated area. A mixed-integer linear optimization model based on the dynamical evaluation of economic efficiency can help to find the most economical and ecological supply structure. The model has to be developed for three different types of operating companies. The influences of different parameters on the target function can be analyzed by defining scenarios and by running sensitivity analyses. The results show that the energy prices have the greatest influence on the economy.

Oxygen Consumption of the Eggs of Four Non-diapausing Blackfly Species (Diptera: Simuliidae)

The respiration of the eggs of the 4 non-diapausing blackfly species Simulium erythrocephalum (De Geer 1776), Simulium ornatum (Meigen 1818), Simulium morsitans Edwards 1915, and Simulium equinum (Linnaeus 1758) was studied, using a Twin-Flow-Micro-respirometer. All species were studied at 21°C. Additionally, S. morsitans was studied at 18°C and S. erythrocephalum at 14°C. The respiratory rates vary species specifically in correlation with the egg phases : from laying until phase 3A they increase, during phases 4 and 5 they remain almost constant, and shortly before hatching they increase again. Only in S. ornatum the oxygen consumption keeps increasing also during phases 4 and 5. The lowest respiratory rates are found in S. equinum (36 pmolO 2 /h/10 -3 mm 3 in phases 4-5), the highest in S. erythrocephalum (68 pmolO 2 /h/10 -3 mm 3 ). S. morsitans is intermediate (45 pmolO 2 /h/10 -3 mm 3 ), and S. ornatum has initial values slightly above those of S. equinum, but finally reaches the same level as S. erythrocephalum. All respiration values were calculated for the initial egg volume directly after laying. At lower temperatures, the respiratory rates decrease in correlation with the prolongation of development. The total oxygen consumption calculated over the entire development is about equal in S. erythrocephalum and S. morsitans and independent of the incubation temperature. An oxygen summation rule is suggested on the assumption of consistent total oxygen needs of the eggs of each species at different temperatures. The ecological factor oxygen supply appears to be as important for the egg development of blackflies as the factor temperature.