The dynamics of tree cover change in a rural Australian landscape

This study investigated the change in tree cover in a 130 000 ha rural landscape near Bathurst, New South Wales, Australia between 1954 and 1989. Using aerial photographs, tree cover was assessed using five cover classifications (<2% cover, 2.1–25%, 25.1–50%, >50% or exotic pine plantation), with the resulting data analysed using a Geographic Information System. Overall, there was a loss of woodland/forest and an increase in the area of cleared land and Pinus radiata plantations over 35 years. Although some regeneration of woodland/forest cover occurred on marginal farmland, the general trend of loss and fragmentation has serious ramifications for nature conservation and agricultural production. The eastern and western portions of the study area exhibited quite different patterns in tree cover change, highlighting the need for examining landscapes at appropriate spatial and temporal scales.     

Farmers,fires, and forests: a green alternative to shifting cultivation for conservation of the Maya forest?

When fires blazed through Mexico's forests in 1998, the country experienced a new sense of urgency in its attempts to combat ecosystem degradation and loss of biodiversity. Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT, the federal environmental protection agency) identified the use of fire in agriculture as a major contributor to the conflagration. Traditional “slash-and-burn” systems are still widely practiced in the southeast of Mexico, and finding a substitute for burning, especially in and near protected areas, became imperative (SEMARNAT, 2001). Experience from different parts of Central America indicated that green manure/cover crop systems (g/cc) could increase soil fertility, reduce erosion, control weeds and raise the yield of maize; the hope was that this system could replace slash-and-burn practices with their attendant risk of forest fires. We present the case study of a project introducing a green cover crop to traditional, resource-poor, maize farmers in one community of the Yucatan peninsula and preliminary results from a similar project in the Calakmul Biosphere Reserve, discussing the data in the light of the on-going debates concerning both fire policy and soil erosion. We conclude that, in spite of demonstrating some advantages, adoption in the peninsula has been hindered by environmental, economic and socio-cultural factors. Mexican efforts to eliminate fire from the forests must also be assessed with reference to the scientific literature by fire experts and historical ecologists, indicating that prohibition of small fires may actually decrease total biodiversity, while increasing the probabilities of catastrophic forest fires.     

Thermal comfort implications of urbanization in a warm-humid city: the Colombo Metropolitan Region (CMR), Sri Lanka

In this paper we analyze the historic trends in thermal comfort (measured in terms of Temperature–Humidity Index [THI] and Relative Strain Index [RSI]) in the Sri Lankan primate city of Colombo and correlate them with land cover changes in the region. Land cover is calculated form time-series aerial photographs in terms of “hard” cover (buildings, paved areas and roads) and “soft” cover (trees, green areas and waterbodies). The period selected for analysis includes pre-rapid (up to 1977) and rapid urban phases (1978 onwards) in the city. Contemporary Sri Lanka's urbanization is peculiar in that mid to late 20th century urban rates (approx. 22% of the population) had remained virtually unchanged till the economy was liberalized in 1977, but have recently intensified (currently at about 35%). This offers a unique window of opportunity to look at the thermal comfort transition consequent to urbanization. Since many tropical cities are at a similar stage of demographic transition, lessons from Colombo may generally be applicable to other tropical developing cities as well.

An increasing trend in thermal discomfort—particularly at night—is seen especially at the suburban station and it correlates well with hard land cover changes. The study also brings out the relative importance of land cover in city center vs. rural areas (e.g. hard cover has more effect on thermal discomfort in city center than in rural areas). Based on these findings, we postulate an outline for a climate-sensitive urban design policy for tropical cities.     

Defying legal protection of Atlantic Forest in the transforming landscape around the Atibainha reservoir, south-eastern Brazil

Remnants of Atlantic Forest occupy approximately 50% of the land surrounding Atibainha reservoir in Brazil. They are legally protected due to their location on margins of rivers and reservoirs, steep slopes and hilltops or, according to federal rules, when in medium or advanced stage of regeneration. Identifying where and to what extent forest legislation is being ignored is necessary to inform future land-use policy. Using data derived from aerial photographs, combined with ground surveys of forest fragments, we determined forests that should be protected due to their stage of regeneration. We then evaluated whether land use within the 188 catchments that surround the Atibainha reservoir is consistent with restrictions on deforestation determined by their location. Most forest fragments in the region are in medium stage of regeneration and therefore legally protected. The extent of illegal deforestation among catchments differed significantly based on the location criteria. Forest cover was higher where combinations of these criteria apply, such as steep slopes alongside rivers or reservoir. While this might reflect increased propensity to respect forest regulations where multiple restrictions apply, it is also possible that such locations coincide with the low attractiveness for agriculture and other economic activities at such areas.     

Back to Von Thunen: a Southern European perspective on mono-centric urban growth,economic structure and non-urban land decline*

This study assesses trends (1960–2010) in forest cover over a Mediterranean metropolitan region (Attica, Greece) with the aim to investigate the role of local contexts promoting changes in the use of land. Forest cover decreased in a spatially heterogeneous manner over the study period determining a land-use structure coherent with the Von Thunen mono-centric model. We used a multivariate exploratory analysis of 26 contextual variables to identify changes in the urban spatial structure at the local scale. The shift from a land-use structure based on urban–rural and cropland-forest polarizations in the early 1960s to a pattern based on the polarization in medium-density, mixed urban/agricultural areas and low-density, sparse forest land has been observed in the last 50 years. Urban expansion into rural land and the establishment of protected areas in economically marginal and remote districts has been identified as relevant drivers of landscape transformation in the area. Our study demonstrates that land-use changes driven by expansion of dispersed settlements may consolidate mono-centric urban structures. A concentric land-use distribution around the central city is compatible with urban sprawl and may be indirectly supported by ‘green belt’ regional planning and environmental policies protecting high-quality natural land.     

基于群落生态学原理的风景林景观更新 策略研究——以深圳市仙湖植物园为例

定位以风景旅游为主要功能之一的深圳市仙湖植物 园分布有较大面积的风景林，其质量高低对深圳市和仙湖植物 园的景观风貌优劣产生重要影响。运用群落生态学的相关调查 方法分析和评估风景林的群落演替趋势、结构稳定性、景观动 态变化等。研究结果显示，仙湖植物园风景林呈现退化趋势、 群落结构简单、乔灌木断层现象严重、植物多样性低、植物群 落中缺乏潜在优质的演替建群树种等问题，直接影响着仙湖植 物园风景林的景观质量。在此基础上，提出了仙湖植物园风景 林景观质量更新的原则和策略、目标与措施、建群树种选择及 群落的构建模式，以期为仙湖植物园及其他风景林提质更新提 供参考借鉴。     

Analysis of Eastern Mediterranean Oak Forests Over the Period 1965–2003 Using Landscape Indices on a Patch Basis

Although Eastern Mediterranean forests have been exploited for many years, the changing trends in the past 40 years require detailed investigations. Forests in the coastal zone of Lebanon are witnessing major changes mainly because of chaotic urbanisation. The study area at the coastal zone of Lebanon has 96% of its forest cover under oak coppice. The aim of this study is to investigate the applicability of landscape indices on oak forests especially their ability to detect changes between 1965 and 2003. It uses forest canopy closure as another indicator of forest destruction. The 1965 forest map was first checked for its accuracy before being used to extract patch delineations and canopy closures. Landcover types for 2003 were obtained by classifying a SPOT 5 satellite image. FRAGSTATS software was utilised on the 1965 map on a patch basis to calculate patch shapes and sizes. These indices and canopy closures data were investigated for correlation purposes with patterns of forest loss. The edge distances between forest patches in 1965 and new forest patches in 2003 were computed to analyze regeneration processes. Results show that although older forest patches have shown a 48% loss in area, total forest area reached 83%. Abandoned agricultural lands have become new forest. Smaller forest patches (< 40 ha) showed greater losses than large ones. Small and open forest patches recorded greater loss than large and dense patches. Shape indices show no correlation with forest loss. Clearance for agriculture covered 30% of the pre-existing forests, while urban developments accounted for just 4% of forest loss. This research highlights the great need for comprehensive studies of forests using landscape analyses. Such analyses help managers develop practical and relevant conservation measures.     

Planning New Standards of Fire Service Emergency Cover for the United Kingdom

For the past 60 years provision for emergency fire fighting response (i.e., fire cover) in the United Kingdom has been based on the density of the built environment, with highly developed city centres receiving the most provision for (and fastest response to) emergency calls and progressively less provision and speed of response being made for town centres, suburban areas, and country areas, respectively. (No cover is provided for remote rural and sparsely populated areas, where calls for emergency service receive a response from emergency resources allocated to more built-up areas. Unlike in built-up areas, there are no standards specified for weight of response and attendance time that the fire service must meet in responding to emergency calls from remote rural and sparsely populated areas.)Whilst these arrangements have generally worked well, fire safety legislation over the past 30–40 years has been effective in reducing the incidence of fire in public places, with the result that there is now a tendency for the present system to over-provide fire cover in city centres, whilst there is evidence of under provision in residential suburban areas, given that 75% of fire deaths currently occur in domestic dwellings.Against this background, it was suggested in 1995 that emergency cover should be allocated according to the geographic distribution of risk to life and property. This paper describes how the proposal has been taken forward. It is expected that the new risk-based system will be adopted nationally over the next 5–7 years.     

基于关键物种与生境质量评估的昆明市 中心城区绿色空间生物多样性分布格局 研究

随着城市化进程的加快,城市生物多样性受到严重威胁,生物多样性热点分布区域的识别在城市生物多样性保护方面起着重要作用。以昆明市中心城区为例,首先对绿色空间进行解译,再运用MaxEnt模型识别关键物种分布区域,同时使用InVEST模型对生境质量进行评估,最后将绿色空间、关键物种适生区、生境质量分布进行叠加,分析昆明中心城区绿色空间的生物多样性分布格局。结果显示：生物多样性热点分布区占中心城区面积的38%,占中心城区绿色空间面积的89.5%。高生境质量绿色空间及核心绿色空间主要分布在城郊山地区域,整体性较强。关键物种分布绿色空间主要分布在建成区内城市绿地、河流或水面周围,分布较为零散。研究结果为城市绿色空间未来规划中的保护与发展提供了新的思路和理论支撑。     

Remaining tree species from the indigenous vegetation of Ankara, Turkey

The city of Ankara is located in the geographic centre of Anatolia, Turkey. In the state of nature, Anatolia was covered with forests. Due to the destructive effects of civilisations passing through Anatolia over the centuries, the forest vegetation was gradually transformed to a steppe formation. After it became the capital city, a rapid planned urbanisation process was initiated in Ankara. In the first development plan, efforts were concentrated on the south axis of the city, which harbored the greatest concentration of indigenous plant cover in the valleys.In 1974, the embassy gardens and parks on the north–south axis were declared a “Natural Conservation Area”. Despite the conservation act, change and denuding of indigenous vegetation continued all along the axis due to highly increasing development. However, these conservation areas still include tree species from the indigenous vegetation. In this study, the presidency gardens, the embassy gardens and parks in Ankara that were declared a “conservation area” were evaluated in terms of the remaining tree species from the indigenous plant cover. The study aims to indicate the level of conservation of natural habitat in Ankara and to determine whether the concept of “Natural Conservation Areas” includes the protection of biodiversity or not. Moreover, the research results aim to reveal still existing tree species of indigenous vegetation, which will enlighten us regarding future landscape planning in Central Anatolia. Trees were examined by age, height and exposition. The results show that remaining indigenous tree species of the study area grow along the former ncesu River and that the terrain on which the trees stand is mostly exposed to the southwest and southeast. The indigenous tree species which do not exist in the study area are scattered in valleys along the river trails or on the hills of Ankara’s rural lands.     

A habitat model for Parus major minor using a logistic regression model for the urban area of Osaka, Japan

We developed a habitat model for Great Tits, Parus major minor, in an urban area of Osaka, Japan. Although Great Tits play an important role in the urban food web, there are few in most of Osaka and downtown Tokyo, areas that have low vegetation cover. We derived a habitat model for Great Tits using a logistic regression model with GIS. A bird survey was conducted twice in 85 urban parks using the line census method in the breeding season, May–July 2000. A GIS base map was created from aerial photographs. The following variables were measured for each park from public records and GIS for predicting the habitat: park properties (age, distance to the nearest mountains, distance to the nearest forest of more than 10 ha), the number of other habitats occupied by the tits within 500 m and 1 km and area of tree cover (within it and surrounding parks). Number of nearby habitats and distance from the nearest mountains and forest of more than 10 ha are variables related to the regional populations of the tits. Area of tree cover was measured for five radii (50, 100, 150, 200, 250 m) from park centers, and a logistic regression model was calculated for each of these radii. Variables were selected by a stepwise method. The best fitting model of the five models was selected using Akaike’s Information Criteria. In the bird survey, the tit was recorded in 12 parks. The areas of parks occupied by the tit were 0.56–136.0 ha (mean: 26.0 ha±42.06 S.D., n=12). Variables selected in the best fitting model were area of tree cover in a radius of 250 m from park center and the number of other habitats within 1 km as positive factors. This model shows that area of tree cover within a certain range and number of nearby populations are the keys to the distribution of Great Tits. From this model obtained, 6.0 ha (31%), 4.0 ha (20%), 2.6 ha (13%) and 1.8 ha (9%) of tree area are needed to achieve probability of 0.5 in a radius of 250 m when numbers of other habitats within 1 km was 0–3, respectively. A realistic target figure is 10% of tree cover throughout urban areas to create an ecologically sustainable city.     

Assessing the consequences of global change for forest disturbance from herbivores and pathogens

Herbivores and pathogens impact the species composition, ecosystem function, and socioeconomic value of forests. Herbivores and pathogens are an integral part of forests, but sometimes produce undesirable effects and a degradation of forest resources. In the United States, a few species of forest pests routinely have significant impacts on up to 20 million ha of forest with economic costs that probably exceed $1 billion/year. Climatic change could alter patterns of disturbance from herbivores and pathogens through: (1) direct effects on the development and survival of herbivores and pathogens; (2) physiological changes in tree defenses; and (3) indirect effects from changes in the abundance of natural enemies (e.g. parasitoids of insect herbivores), mutualists (e.g. insect vectors of tree pathogens), and competitors. Because of their short life cycles, mobility, reproductive potential, and physiological sensitivity to temperature, even modest climate change will have rapid impacts on the distribution and abundance of many forest insects and pathogens. We identify 32 syndromes of biotic disturbance in North American forests that should be carefully evaluated for their responses to climate change: 15 insect herbivores, browsing mammals; 12 pathogens; 1 plant parasite; and 3 undiagnosed patterns of forest decline. It is probable that climatic effects on some herbivores and pathogens will impact on biodiversity, recreation, property value, forest industry, and even water quality. Some scenarios are beneficial (e.g. decreased snow cover may increase winter mortality of some insect pests), but many are detrimental (e.g. warming tends to accelerate insect development rate and facilitate range expansions of pests and climate change tends to produce a mismatch between mature trees and their environment, which can increase vulnerability to herbivores and pathogens). Changes in forest disturbance can produce feedback to climate through affects on water and carbon flux in forest ecosystems; one alarming scenario is that climate warming may increase insect outbreaks in boreal forests, which would tend to increase forest fires and exacerbate further climate warming by releasing carbon stores from boreal ecosystems. We suggest a list of research priorities that will allow us to refine these risk assessments and adopt forest management strategies that anticipate changes in biotic disturbance regimes and mitigate the ecological, social, and economic risks.     

The role of ethnic retailing in retrofitting suburbia: case studies from Toronto,Canada

Today’s immigrants to Canada are increasingly and directly settling into suburban areas of major cities; a trend that has resulted in new retail opportunities: suburban ethnic shopping centres are a growing phenomenon in areas with major immigrant settlement. This paper discusses the development and retrofitting processes of three suburban Chinese shopping malls in the Toronto area. The paper explores how these malls successfully regenerated areas once affected by business decline and how they can act as a catalyst to develop a new urban form that makes the suburban landscape less uniform and more sustainable. Various perspectives from key players involved in ethnic retail activities and developments were collected, including surveys with entrepreneurs and shoppers, and semi-structured interviews with city councillors, city planners, developers and an architect. The paper suggests that municipalities could invest in established ethnic retail places as an innovative means of “retrofitting suburbia.”     

Human Comfort of the Inner and Outer Fokienia hodginsii Forests in Summer

This study analyzed the microclimate factors and human comfort index of the inner and outer Fokienia hodginsii forests and of a city square.The results showed that:(1) In terms of the average daily temperature, the inner and outer forests and the city square ranked as follows: square > outer forest > inner forest.The temperature of the inner forest was 8.21–11.73 ℃ lower than that of the city square, and the temperature of the outer forest was 7.41–10.34 ℃ lower than that of the city square.The inner forest was cooled by 24.21% and 1.37% respectively than the outer forest and the city square.(2) In terms of the average daily relative humidity, the inner and outer forests and the city square ranked as follows: square < outer forest < inner forest.The average daily relative humidity of the inner forest, the outer forest, and the city square was 68.57, 84.91, and 88.27, respectively.(3) In terms of the average daily wind speed, the inner and outer forests and the city square ranked as: square > outer forest > inner forest.Their daily variation ranges were 0–0.75, 0.18–0.43, and 0.12–0.31 m/s, respectively.(4) In terms of the daily average illumination intensity, the inner and outer forests and the square ranked as: square > outer forest > inner forest.Their average daily illumination intensities were 371.68, 4,582.01, and 17,641.63 lux, respectively.     

Proposing an agricultural belt to protect a city’s semi-rural characteristics: The example of Bartın,Turkey

Urban sprawl, a type of urban expansion, is perceived as a global problem due to changes in land conversions and landscape patterns. Farms, forests and shores have been converted into urban areas; this transformation affects energy flow, biochemical cycles and climatic conditions. To follow and evaluate the physical, social and ecological results of urban sprawl, we identified and measured temporal changes in land use and land cover. This is especially important for urban planning policies. In this study, temporal change is identified in the city of Bart?n using remote sensing and landscape metrics. An analysis of land cover and land transformation was done with LANDSAT5 TM/ETM satellite images from 1985 and 2015. These images were used to identify agricultural areas as land that has most commonly undergone drastic changes. Bart?n is a small semi-rural city that has undergone significant changes. Among the most important reasons for these changes were uncontrolled urban sprawl due to political and administrative decisions that lacked long-term planning and a comprehensive city plan. This study examined the risk factors for loss of semi-rural characteristics using the example of Bart?n city. To protect semi-rural city characteristics and control urban sprawl, we propose an agricultural belt based on spatial suitability and an evaluation of landscape metrics.     

Study on Urban Forest Construction Concepts and Layouts in Taizhou City

Taizhou is an economically-developed port city on the golden coastline of China, characterized by typical coastal and combined green cores, mountains and waters, and special plants. This paper analyzed natural conditions and city features of Taizhou, assessed current construction of local urban forests, and proposed pertinent construction concepts in view of diversifi ed needs of urban development on forest construction. On the basis of the city development, principles of urban forest layout were put forward, and the overall structure of "one core, one belt, two rings, three corridors, four groups, fi ve windows, and multiple bases" was given for the construction of urban forest in coastal landscape cities, in addition, the effect and feasibility of the layout were analyzed.     

超长海底隧道无竖井排烟及补风量优化研究

摘 要：超长海底隧道结构特殊,排烟补风成为制约超长海底隧道发展的关键因素。依托烟大海底隧道提出超长海底隧道无竖井排烟系统,并设计新型的海中无竖井排烟补风方案——采用离心式空气压缩机将火灾烟气高速加压后排到海水中,并通过压缩空气进行额外补风。采用FDS对不同排烟量和补风量下56组工况进行模拟,通过分析烟气层厚度、排烟效率和能见度,寻找最优的排烟补风方案。结果表明：排烟量在140~180,190~210 m3/s,补风量分别占排烟量的50%、70%时,系统排烟效果最优;其中,排烟量180 m3/s,补风量50%和排烟量200 m3/s,补风量70%情况下的排烟效果最优,且后者优于前者。实际工程应用中,可以考虑设计排烟量为200 m3/s,补风量为140 m3/s。     

探索创新与时俱进--浅谈上海中心城区公园绿地特色

以发展的眼光看待上海城市公园绿地建设的得与失.提出构建以乔木林为主体的上海城市公园绿地的总体构思,引入国际先进设计理念,结合上海实际,注重历史保护和文脉延续,体现生态园林特点,创造新意境,合理利用有限空间,形成上海城市公园绿地特色.     

A GIS-based multi-criteria decision making approach to forest conservation planning at a landscape scale: a case study in the Kinabalu Area, Sabah, Malaysia

This paper presents a geographic information system (GIS)-based multi-criteria decision making approach for forest conservation planning at a landscape scale. This approach enables decision makers to evaluate the relative priorities of conserving forest areas based on a set of preferences, criteria and indicators for the area. Compromise programming techniques are used to integrate the forest conservation priority maps of decision groups where a separation distance is calculated. A clustering analysis was applied to identify potential conservation areas as the basis of delineating potential new protected areas. The study was conducted in the Kinabalu area, Sabah, Malaysia where two polygons neighboring the Kinabalu Park were delineated. A group of 11 polygons totaling 2050 ha has also been detected in the western part of Kinabalu Park. The study recommends the inclusion of a forest polygon (359 ha) neighboring Kinabalu Park and another (4361 ha) to the west of the park as new protected areas. A green corridor linking the potential new protected areas and Kinabalu Park should also be constructed to facilitate animal movement and interaction. This study reveals that riparian vegetation is an important aspect to forest conservation and the legislation to protect riparian zones should be strengthened.