基于人口模型的澳门固体垃圾产生量的初步模拟

垃圾问题是制约社会发展的一项因素。自2002年澳门特别行政区赌权开放后,澳门旅游业发展迅速,大量游客蜂拥而至,加上投资移民政策,为澳门经济的发展带来活力。然而,澳门本身地少人多,土地本身就是一种稀缺的资源。大量人口的拥入,除了人口本身以外,他们所产生的垃圾量亦与时俱增,为环境带来的问题日趋严重,同时亦增加了堆填区的压力。2007年,垃圾焚化中心平均每天要处理的垃圾量为790吨,已达其最大处理能力的88%。因此,确定澳门垃圾产生量的发展趋势对于制定合理的垃圾处理政策是很重要的。这次研究通过研究澳门垃圾产生的成分和过程,在历年垃圾数据的分析基础上,利用STELLA软体建立系统动力学模型去预测澳门垃圾产生量在未来的发展趋势。研究结果显示,2016年,澳门总垃圾的产生量为363 584吨,其中家庭垃圾的产生量为308 220吨,占总垃圾量的85%;其它垃圾(包括工商业垃圾和大件垃圾)的产生量为55 364吨,占总垃圾量的15%。若以现时澳门垃圾焚化中心的处理能力(每日900吨)来看,2012年澳门垃圾的产生量将超过垃圾焚化中心的处理能力。     

Implications of Rural–Urban Migration for Conservation of the Atlantic Forest and Urban Growth in Misiones,Argentina (1970–2030)

Global trends of increasing rural–urban migration and population urbanization could provide opportunities for nature conservation, particularly in regions where deforestation is driven by subsistence agriculture. We analyzed the role of rural population as a driver of deforestation and its contribution to urban population growth from 1970 to the present in the Atlantic Forest of Argentina, a global conservation priority. We created future land-use-cover scenarios based on human demographic parameters and the relationship between rural population and land-cover change between 1970 and 2006. In 2006, native forest covered 50% of the province, but by 2030 all scenarios predicted a decrease that ranged from 18 to 39% forest cover. Between 1970 and 2001, rural migrants represented 20% of urban population growth and are expected to represent less than 10% by 2030. This modeling approach shows how rural–urban migration and land-use planning can favor nature conservation with little impact on urban areas.     

A concept model to estimate the potential distribution of the Asiatic citrus psyllid (Diaphorina citri Kuwayama) in Australia under climate change—A means for assessing biosecurity risk

Increasing global temperatures as a result of climate change are widely considered inevitable for Australia. Despite this, the specific effects of climate change on Australian agriculture are little studied and the effects on agricultural pests and diseases are virtually unknown. In this paper we consider the impact of climate change on the Asiatic citrus psyllid (Diaphorina citri Kuwayama [Hemiptera: Psyllidae]); one of two known vectors of huanglongbing (citrus greening); a debilitating disease which is caused in Asia by a phloem-limited bacterium ‘Candidatus Liberibacter asiaticus’ (α-Proteobacteria). D. citri does not occur in Australia, but if introduced would pose a major threat to the viability of the Australian citrus industry and to native Citrus species. This paper presents an approach developed to understand how climate change may influence the behaviour, distribution and breeding potential of D. citri. Here we developed and describe an initial dynamic point model of D. citri biology in relation to its citrus host and applied it to a scenario of increasing temperatures, as indicators of climate change, on a continental scale. A comparison between model outputs for the three time frames considered (1990, 2030 and 2070) confirms that increasing temperatures projected under climate change will affect the timing and duration of new citrus growth (flush) necessary for psyllid development throughout Australia. Flushing will start progressively earlier as the temperature increases and be of shorter duration. There will also be a gradual southward expansion of shorter durations of the occurrence of flush. Increasing temperatures will impact on D. citri both directly through alteration of its temperature dependant development cycle and indirectly through the impact on the host flushing cycle. For the whole of Australia, a comparison between model outputs for the three scenarios considered indicates the seasonality of D. citri development will change to match changes in citrus flush initiation. Results indicate that the risk of establishment by D. citri is projected to decrease under increasing temperatures, mainly due to shortened intervals when it can feed on new leaf flushes of the host. However, the spatially heterogeneous results also suggest that regions located on the southern coastline of Australia could become more suitable for D. citri than projected under current temperatures. These results confirm the value of a linked host-pest approach as based on D. citri climatic requirements alone the model would have accounted only for shorter development periods and predicted an increased risk of potential distribution.