Wildlife corridors as a connected subgraph problem

Wildlife corridors connect areas of biological significance to mitigate the negative ecological impacts of habitat fragmentation. In this article we formalize the optimal corridor design as a connected subgraph problem, which maximizes the amount of suitable habitat in a fully connected parcel network linking core habitat areas, subject to a constraint on the funds available for land acquisition. To solve this challenging computational problem, we propose a hybrid approach that combines graph algorithms with Mixed Integer Programming-based optimization. We apply this technique to the design of corridors for grizzly bears in the U.S. Northern Rockies, illustrating the underlying computational complexities by varying the granularity of the parcels available for acquisition. The approach that is introduced is general and can be applied to other species or other similar problems, such as those occurring in social networks.     

The responses and prospects of sustainable development for Guangzhou and Hong Kong

The ability to achieve urban sustainability has become an indication of the competence of a municipal government aiming to gain world class status for the city. While both Guangzhou and Hong Kong are Chinese cities having their own formulation of urban sustainability, the implementation details and the actual sustainability blueprints are very different. As a result, the outcomes and prospects for urban sustainability are also different.

Hong Kong has adopted a less integrative and more institutionally-oriented approach for urban sustainability. Guangzhou has used the conventional approach to formulate an integrated sustainability programme for its local Agenda 21. Hong Kong's action plan emphasizes improving coordination, making objective assessments and achieving consistency in policy-making. Guangzhou, on the other hand, emphasizes the meeting of concrete environmental targets. Unfortunately, the new institutional arrangement and monitoring tools adopted by Hong Kong have not been able to achieve the original intent and neither is there the intention to go too far beyond the weak sustainability approach. On the contrary, Guangzhou has planned and attempted to incorporate industrial ecology in its development regime while heavily investing into pollution control programmes and pushing forward a green community programme at the grass-roots level.     

A novel living agricultural concept in urban communities: Family Business Garden

During the process of urbanization, people are subject to the indiscriminate use of resources due to competition. The present trend in global population growth predicts that the situation will be aggravated as many people prefer living in towns and cities to resource-poor rural areas. In consequence, limited space, high percentage of ageing population, urban poverty, environmental pollution, changes in urban lifestyles and varied consumption patterns have to be dealt with in sustainable development strategies. In this context, urban agriculture can play a vital role by visualizing the urban homestead as a potentially viable production unit of agriculture. In order to live with limited urban infrastructure facilities, environmental conditions and socio-economic situations, the concept of the Family Business Garden justifies the necessity of its presence through the experience in the Western Province of Sri Lanka. Having a proper mix of environmental and commercial agricultural concerns, the concept paves the way not only to address family food requirements but also to produce for markets under liberalized economies by promoting agro-entrepreneurship and social capital development attempts in urban communities.     

Expert views on sustainability and technology implementation

The role of non-timber forest products in sustaining rural economies of the southern African region has been underestimated because of inadequate policy recognition. As a result, factors affecting the sustainability of these important resources are being undermined. The aim of the paper is to examine trade in two selected NTFPs and implications for sustaining the resource base in Zimbabwe and South Africa. In eastern Zimbabwe, baobab (Adansonia digitata) bark is harvested for craft purposes, but in danger of destruction in the short term as a result of harvesting and trade arrangements. Unless appropriate harvesting and marketing mechanisms including harvesting cycles and adaptive management are adopted, the baobabs and livelihoods of humans will be threatened in the next decade. For wood products from communal woodlands in the South African study, uncontrolled trade poses danger to sustaining the natural woodlands. In both case studies, the role of non-resident NTFP dealers is a source of inevitable threat in promoting sustainable harvesting and trade. Market forces of demand and supply factors are identified as opportunities or threats and presented in a conceptualised framework. Additionally, the NTFP sector management will need to include opportunistic improvement of small-scale agropastoralism.     

The systems approach for sustainable development at catchment and parish group levels

SUMMARY

Sustainable development considers the development of urban and rural areas, and agriculture is an important element in reaching that aim. After decades of using synthetic pesticides, fertilisers and growth hormones in agriculture, farmers as well as the public, policy and decision makers require options to minimise the negative impacts of agricultural practices on the environment and humans consistent with so called sustainable development. Such options are possible, but require time and a range of approaches. Agricultural production systems in Kent belong to a system and so the systems approach becomes useful to solve their problems. Agricultural activities are interrelated, considering their hierarchical levels and their interactions. Hence, agroecology as a discipline using a systems approach suggests the catchment level as an appropriate unit for the analysis, design, development and evaluation of the ecological and socioeconomic interactions that take place within it. This kind of analysis ideally requires a multidisciplinary team, using disciplinary tools such as GIs and many sources of data. The combination of such a wide range of types of data in a systems approach to sustainability is described as a way to support the public, researchers, policy and decision makers.     

Assessment of key parameters in municipal solid waste management: a prerequisite for sustainability

Municipal solid waste management was studied for 1 year in a representative urban area of Lahore city for environmental sustainability. The effects of financial status of the household and the seasonal variations on generation rate and compositions of municipal solid waste (MSW) were determined. MSW generation rate and the economic status of the households were positively correlated (p < 0.05). Seasonal variations observed were significant only for organics (p = 0.001), plastics (p = 0.008) and food waste fractions (p = 0.009) in MSW. Response surface regression model developed and analysed by Minitab-15® showed that the interaction of season and different economic zones of the town on the MSW generation rate was non-significant (p = 0.334). Elemental and heating value analyses of the mixed organic fractions in kitchen waste had carbon 47.93%, hydrogen 6.20%, nitrogen 2.24%, sulphur 0.23%, oxygen 39.01%, and C and N ratio 27.78. Findings concluded that food waste was 56% of total MSW with 71.03% moisture content and a modest heating value of 5566 J/g. Existing temporary storage capacity of MSW is 51% of the total MSW generated considering the weighted MSW generation rate of 0.57 kg/person/day calculated in this study. Composting could be a possible final disposal option due to high moisture and organic content and can be studied in future research. Development of a transfer station, introduction of home composting programmes and awareness towards proper segregation and reduction of waste at the household level is suggested to attain sustainability in the MSW management system.     

生态示范区可持续发展指标体系和数学模型--以安徽省岳西县国家级生态示范区为例

为评价、监控和考核生态示范区可持续发展水平、进程和成效,构建了一套量化评价指标体系和指数叠加、功效系数、模糊综合评价等三种数学模型,并以安徽省岳西县国家级生态示范区为例研究生态示范区多时空尺度的可持续发展态势。结果表明在基准水平年（2000）、近期目标年（2005）和远景目标年（2010）生态示范区复合系统的可持续发展度（0.268、0.541、0.859）、可持续功效系数（0.711、0.812、0.949）和可持续发展隶属度（0.129、0.332、\{0.671\}）都逐步增加,而且在不同规划年限中均以自然子系统可持续发展态势为最优,这与该县生态环境优越、经济社会水平低、发展潜力大的客观实际非常符合。     

Capital assets and intercultural borderlands: socio-cultural challenges for natural resource management

In their design or implementation, many natural resource management (NRM) programs ignore critical socio-cultural dimensions of the challenge to advance sustainability. Building on particular ideas about culture and human ecosystems, we combine the strengths of the capital assets model of sustainability and the idea of intercultural borderlands to respond to this gap. To advance our thesis about the utility of these tools, we critically reviewed and analysed a cross-disciplinary literature relating to the socio-cultural dimensions of NRM. This paper stems from that labour and examines particular tensions that arise in land management as a result of Australians' specific colonial and postcolonial legacies. These tensions--related to ethnicity, gender, population, age and health--are among the threads in the larger tapestry that comprises the socio-cultural dimensions of NRM. For the Australian case, they are central, longstanding and persistent, and thus worthy of analysis; and they are applicable in general terms to other places with similar histories of settlement and land use.     

Reaching National Kyoto Targets in Germany and Sustainable Development

Within this paper, we analyze the fulfillment of the Kyoto emissions reduction commitment particularly in Germany and its implication on the long-term paths of all macro-variables. Germany, like all other industrial or Annex-B countries, must reduce its emissions by 2010 according to what we call a Kyoto Forever scenario. We specifically investigate tradable permits as reduction measures in a national overlapping generations (OLG) model, where we change the discounting technique by using generation adjusted discounting (GAD) in comparison to conventional OLG discounting. We show that within our model framework Germany is able to develop along growing paths of, for example, gross domestic product (GDP) in sharp contrast to conventional results of OLG simulations. At the same time, current generations must share higher burdens in terms of lower GDP, per capita consumption and employment which can be initially interpreted as contemporary costs for reaching sustainable paths and, second, contributions for internalizing external effects. However, all costs in terms of lower macro-variables for current living generations are re-compensated through higher future values. This effect can be interpreted as an intergenerational application of full cost bearance, or, in other words, the polluter pays principle which is oriented towards sustainability of greenhouse gases abatement.