Public perception of spontaneous vegetation on brownfields in urban areas—Results from surveys in Dresden and Leipzig (Germany)

Urban brownfields are found in all parts of the world. They suffer from a negative image, generally being viewed as problem areas. However, urban brownfields also offer potentials for new uses as well as for the ecological regeneration of cities. Especially urban brownfields with spontaneous vegetation can contribute to biodiversity and ecosystem services in dense urban environments. Whether and how this potential is exploited depends on the perception and preferred uses of brownfields by local residents.Through surveys undertaken in Dresden and Leipzig, this paper examines the perception and use of brownfields and their spontaneous vegetation by the urban population. Results show a range of views on brownfields with spontaneous vegetation from negative to positive evaluations. Many residents make use of brownfields, have concrete ideas about how such areas should be utilized or designed and are even prepared to take part in the transformation. The paper suggests that the use and design of green space should be rethought in unconventional ways, and discusses how the ecological and social potential of brownfields with spontaneous vegetation can be best exploited for urban residents.     

The impact of urban expansion on the regional environment in Myanmar: a case study of two capital cities

Context

This study examines the spatio-temporal patterns of urban expansion for Yangon and Nay Pyi Taw, the former and new national capitals of Myanmar, and its impact on the regional environment between 2000 and 2013.

Objectives

The objective is to examine different driving forces of urban expansion for Yangon and Nay Pyi Taw, and their environmental consequences during Myanmar’s transitional economy.

Methods

Classified time-series Landsat images are used to evaluate urban expansion processes. Environmental parameters being evaluated in this study include five sets of remotely sensed MODIS land products that are land surface temperature (LST), percent tree cover (PTC), evapotranspiration (ET), terrestrial ecosystem net primary productivity (NPP), and aerosol optical depth (AOD). A time-series trend analysis technique is used to examine the environmental consequences.

Results

The built-up areas in Nay Pyi Taw and Yangon exhibit exponential and polynomial increase, respectively. A 1% increase of built-up area could potentially cause an increase of daytime LST of 0.7 °C, a PTC loss of 2.3%, a decrease in NPP of 34.3 kg/m², and an ET decrease of 42.2 mm for Yangon. Similarly, for Nay Pyi Taw, a 1% increase in built-up area could potentially cause a daytime LST increase of 0.3 °C, a nighttime LST increase of 0.06 °C, a PTC loss of 2.5%, a decrease in NPP of 15.1 kg/m², and a decrease of 19.2 mm ET. No significant change was observed for AOD for either city.

Conclusions

Both cities have experienced extensive urban expansion but with different spatial and temporal characteristics, and their effects on the regional environment are different. Urban expansion of Nay Pyi Taw mainly was government-induced municipal infrastructure development. Yangon’s expansion is mainly caused by population pressure and migration from rural areas. The urban expansion in Yangon was mainly due to reconstruction and renovation, as well as infill development during the study period.

     

Stress recovery and restorative effects of viewing different urban park scenes in Shanghai,China

ObjectivesMany studies have found that natural environments benefit human health and wellbeing, but few have measured restorativeness of specific landscape components, especially in Chinese settings. Because the rapid urbanization of China is accompanied by increasing predomination of hardscape components in cities, the restorative quality of urban green space is a crucial issue. This study explored the stress recovery effects of different videotaped scenes, using six urban parks and one urban roadway scene. Potentially restorative urban park scenes were controlled for nature-based vs. hardscape components, presence/absence of people, and level of openness.MethodsSubjects were Chinese university students (N = 140) aged 18–24. After completing an oral exam as a stressor, an equal number of males and females were randomly assigned to watch one of the seven videotaped scenes during a stress recovery stage, while data were collected on changes in stress and attentional levels. Physiological responses were measured by Electrocardiography (ECG) and Skin Conductance Response (SCR). Psychological responses were measured by the state (short-term) version of the State-Trait Anxiety Inventory (STAI-S), the Digit Span Backwards (DSB) test, and the Perceived Restorativeness Scale (PRS).ResultsIn a Chinese sample, this study confirmed previous findings that nature-based urban park scenes relieved stress and restored attentional levels, while viewing an urban roadway increased negative feelings. Overall perceived restorativeness was significantly higher in two scenes depicting a Lawn without people and a Small Lake, compared with a paved Plaza with or without people, confirming previous findings that restorativeness is associated with predominance of nature-based landscape components. This study also confirmed previous findings that outdoor scenes without people were more restorative than scenes depicting people.DiscussionThis study found different levels of restorativeness associated with different landscape features, and helped confirm that nature-based components are more likely to reduce stress than hardscape components, using Chinese urban scenes with a Chinese population. Findings can be used in future planning and design of urban spaces in China, emphasizing the value of parks and green spaces in relevant contexts.     

喀斯特山地草地资源遥感调查及常态化监测研究——以灌阳县为例

以广西壮族自治区桂林市灌阳县为研究区,采用第二次全国土地调查成果和高分辨率遥感影像(Worldview-Ⅰ和Worldview-Ⅱ),叠加数字高程模型(DEM)、坡度和土壤等数据,利用面向对象方法遥感解译获取喀斯特山地草地资源的类型、面积及空间分布,建设灌阳县草地资源调查数据库;通过构建草地资源分类和土地利用现状分类的对应关系,借助第二次全国土地调查的年度变更调查成果,实现了喀斯特山地草地资源调查的常态化监测,拓展第二次全国土地调查及年度变更调查成果的应用领域。结果显示,2012年灌阳县草地资源面积为20829.42 hm²,其中热性草丛类面积为711.09 hm²,热性灌草丛类面积为16246.76 hm²,热性稀树灌草丛类面积为3871.57 hm²,与1986年第1次草地资源普查相比减少了32125.05 hm²;借助2012-2016年土地利用变更调查成果,实现了灌阳县草地资源调查数据库的动态更新,2016年灌阳县草地资源面积更新为20744.18 hm²,与2012年相比减少了85.24 hm²。农业结构调整、未利用地开垦和城镇建设用地扩张等人为活动以及山体滑坡等自然灾害导致了灌阳县草地资源面积的减少。通过灌阳县喀斯特山地草地资源遥感调查和土地利用变更调查成果扩展利用的研究,实现了草地资源信息化管理和动态监测,为喀斯特山地草地资源的开发、利用及政府决策提供了可靠的数据基础。     

Green infrastructure practices for improvement of urban air quality

Green Infrastructure (GI) practices have shown to be promising in mitigating the air pollution in urban areas of several cities across the world. GI practices such as trees, green roofs and green walls are widely used in United States and Europe to mitigate the air pollution. However, there is yet limited knowledge available in identifying the most suitable GI strategy for an urban area in improving the air quality. Furthermore, it is evident that Australia is still lagging behind in adapting GI to mitigate air pollution, compared with US and Europe. Therefore, this study analyzed the air quality improvement through several GI scenarios consisting of trees, green roofs and green walls considering a case study area in Melbourne, Australia by using the i-Tree Eco software. The results were compared with case studies in different cities across the world. The results showed that the i-Tree Eco software can be successfully applied to an Australian case study area to quantify the air quality improvement benefits of GI. The results were further assessed with several environmental, economic and social indicators to identify the most suitable GI scenarios for the study area. These indicators were quantified using different methods, to assess the effectiveness of different GI scenarios. The results showed that, trees provided the highest air pollution removal capability among the different GI considered for the study area. Combination of different GI such as green roofs and green walls with trees did not provide a significant increment of air quality improvement however, has provided more local benefits such as building energy savings. The results obtained from this study were also beneficial in developing policies related to future GI applications in major cities of Australia for the air quality improvement.     

都市农场景观在北京华润五彩城南部广场改造设计中的应用

本文介绍了都市农业现状及发展趋势,对国内外三个小型都市农场景观案例进行了系统的分析。详细阐述了北京华润五彩城南部广场改造为"五彩田园"都市农场的设计方案,期景观设计分为四个功能区:魔方植盒区、田园菜畦区、科普互动课堂、迷你动物社。建成后的农场将兼具艺术、经济、教育和生态功能,是城市景观可持续发展的有效途径之一。     

An optimization model for the management of a South African game ranch

Management of a game ranch is an important issue as many game ranches operate on meagre profits, and some even at a loss, as their part-time owners subsidize the ranches from other sources of income. In this paper, we address the sustainable game ranching problem in a South African context through an optimization model. To obtain a faithful picture of reality, the model includes conflicting objective functions, and takes into account the fact that annual rainfall is known only stochastically. An approach for solving the resulting multiobjective integer linear stochastic program is discussed and illustrated by means of a numerical example from a Northern Cape ranch.     

Co-occurrence of earthworms in urban surroundings: A null model analysis of community structure

Diamond's assembly rules predict that competitive interaction between species lead to a non-random co-occurrence of patterns. Earthworms were sampled in five lawns of Roosevelt Avenue (city of Brussels, Belgium) to test the reduced level of co-occurrence of species among earthworm communities. We used null model to generate patterns expected in the absence of species interactions. With the model algorithm that maintains fixed row sums and fixed column sums, species co-occurrence in two out of five islets (5 and 10), was less than the expected; whereas in islets 3, 8 and 9, species assemblage seemed random. This study indicates that the non-random selection observed in the two lawns is because there is an interaction between species close to the same ecological category.