种茎大小对山药产量影响研究

为了弄清山药种茎大小对产量的影响,按大小把山药种茎分成9个等级种植,分别编号为A:10～25 g/个、B:25～50 g/个、C:50～100 g/个、D:150～200 g/个、E:250～300 g/个、F:350～400 g/个、G:450～500 g/个、H:550～600 g/个、I:650～700 g/个。结果表明:种茎越大,总产量越高。当种茎重量达到一定值后,总产量增加趋缓,可供出售的商品产量则下降。通过比较,认为种茎重量在350～600 g/个范围内比较合理。     

Managing the potential for outdoor recreation: Adequate mapping and measuring of accessibility to urban recreational landscapes

Following the increasing public health concerns related to physical inactivity in the population, the relationship between outdoor recreation and public health has been increasingly acknowledged over the last decades. To improve public health, planners and policy-makers aim to provide good accessibility to recreational landscapes to facilitate outdoor recreational activity. At the same time, they are facing development pressure due to urban growth. In order for planners and policy-makers to secure people access to urban and near urban recreational areas, there is a need to map and measure access in a way that is adequate as a basis for decision-making in planning and design processes. Access is often defined as distance, or proximity, from residents’ homes to recreational areas. This paper explores different ways to map and measure distance to recreational areas, and aims to provide better decision support for planners and decision-makers. Moss municipality in Norway serves as a case study. We begin by addressing the meaning of the term ‘recreational landscape’ and how the choice of definition affects the results when mapping recreational areas. We also discuss who we are measuring distance for, and how different user groups will have different thresholds or critical distances affecting their frequency of visits to a recreational area. Last, we explore different methods for measuring distance within a GIS environment. The paper shows how the purpose of the analysis must be decisive when defining recreational landscapes and choosing methods for measuring access to recreational landscape, in order to provide valuable input to planners and policy-makers aiming at enhancing the possibility for outdoor recreation for people.     

Willingness to travel to avoid recreation conflicts in Danish forests

Conflicts among forest visitors have direct effects on the quality of a recreational experience. As the number of visitors to forests close to residential areas increases, as well as the number of different activities, so does the potential for perceived conflicts. According to the literature, expanding knowledge of conflict characteristics and their causes is important for recreation planners and managers who aim to reduce conflicts.In the present study, different forest user groups were identified and categorised according to their pursued activities, and for each group, causes of conflict were identified. Furthermore, a choice experiment was constructed to estimate the distance visitors are willing to travel to encounter few visitors as opposed to many visitors, and thereby potentially experience fewer conflicts. Comparing the marginal willingness to travel (WTT) of different user groups suggests that some groups have a WTT further than the average to reach a forest with ‘Few’ visitors. The average WTT to reach a forest area with ‘Few’ visitors. ‘Mountain bikers,’ ‘Peace and nature lovers’ and ‘Horse riders’ are willing to travel 4 km more than the average per visit to reach a less crowded forest. At the other end of the scale, we find that people who are doing physical exercise are willing to travel 2 km less than the average to reach a less crowded forest.     

Social disparities in tree canopy and park accessibility: A case study of six cities in Illinois using GIS and remote sensing

Easy access to green space and the presence of lush tree canopy in neighborhoods provide substantial psychophysical benefits to residents. However, these urban amenities are often unevenly distributed between white and racial/ethnic minority residents. In this study, we investigated racial/ethnic disparities in access to parks and tree canopy using a geographic information system (GIS) and remote-sensing techniques in six Illinois cities. An accessibility index based on a new Google Maps application programming interface (API) was used to calculate walking distances between points of origins and parks, and integrated classification techniques were applied to calculate the amount of tree canopy. Kernel-smoothing function was applied to both canopy and park layers to transform point value to continuous surface value. Both ordinary regression and spatial regression were used to find the relationship.The results of this study show that racial/ethnic minorities have less tree canopy in their neighborhoods, but it did not find significant differences in terms of access to parks. Spatial regression was determined to be an effective modeling approach for the data used in this study. Methods used in this study can be extended to study accessibility to various destinations using different means of transit, and the results can guide intervention programs to help reduce environmental inequity.     

Limiting factors and landscape connectivity: the American marten in the Rocky Mountains

In mobile animals, movement behavior can maximize fitness by optimizing access to critical resources and minimizing risk of predation. We sought to evaluate several hypotheses regarding the effects of landscape structure on American marten foraging path selection in a landscape experiencing forest perforation by patchcut logging. We hypothesized that in the uncut pre-treatment landscape marten would choose foraging paths to maximize access to cover types that support the highest density of prey. In contrast, in the post-treatment landscapes we hypothesized marten would choose paths primarily to avoid crossing openings, and that this would limit their ability to optimally select paths to maximize foraging success. Our limiting factor analysis shows that different resistant models may be supported under changing landscape conditions due to threshold effects, even when a species’ response to landscape variables is constant. Our results support previous work showing forest harvest strongly affects marten movement behavior. The most important result of our study, however, is that the influence of these features changes dramatically depending on the degree to which timber harvest limits available movement paths. Marten choose foraging paths in uncut landscapes to maximize time spent in cover types providing the highest density of prey species. In contrast, following landscape perforation by patchcuts, marten strongly select paths to avoid crossing unforested areas. This strong response to patch cutting reduces their ability to optimize foraging paths to vegetation type. Marten likely avoid non-forested areas in fragmented landscapes to reduce risk of predation and to benefit thermoregulation in winter, but in doing so they may suffer a secondary cost of decreased foraging efficiency.     

Potential Corridors for the Rusty Crayfish, <Emphasis Type="Italic">Orconectes Rusticus</Emphasis>, in Northern Wisconsin (USA) Lakes: Lessons for Exotic Invasions

We sampled 35 lakes in northern Wisconsin to determine the presence of Orconectes rusticus, the rusty crayfish, and related this pattern to several parameters pertaining to potential invasion routes that could influence the distribution of these crayfish in the lakes. The presence of rusty crayfish in lakes was positively related to an index of human use and negatively related to the length of stream connections to other lakes containing the crayfish. Humans appear to act as vectors allowing crayfish to travel along discontinuous routes that otherwise would be inaccessible to them, and thus, provide crayfish with spatially discontinuous corridors that increase the probability of movement by channelizing the space between lakes. In contrast, streams correspond closely to the traditional definition of terrestrial corridors, in that they are spatially continuous. This distribution pattern suggests colonization operating via two corridors with two spatial scales, making management of the invasion of rusty crayfish complex.     

基于CiteSpace可视化分析的我国新一轮退耕还林工程发展脉络及展望

为进一步发掘新一轮退耕还林工程的研究热点及趋势,以新一轮退耕还林为主题,基于2012-2022年CNKI平台中的数据库,取300条样本,运用CiteSpace可视化分析的方法,深入解析我国新一轮退耕还林相关研究,包括研究机构合作网络、作者合作网络、关键词聚类图谱、关键词时区图谱和关键词突现图谱等方面。结果表明：(1)有关退耕还林的相关文献数量呈现先增加后下降的趋势。(2)有关我国新一轮退耕还林的研究文献主要围绕“后续产业”“农户收入”“生态效益”等问题展开,高频关键词显示新一轮退耕还林需要转变发展方式,要向高质量、可持续发展的方向转变,一味地扩大生态林规模并不可取。(3)退耕还林研究以对社会经济状况与初期退耕还林措施的综合改进分析为始发点,逐渐转变为以社会经济和生态效益的相互交织并存,并逐渐向以生态效益为主题逐步细分进行发展。所以,科研理念、方法之间的交融与并行以及怎样继续巩固和拓展退耕还林成果,如何合理的扩大退耕还林规模、保障农村环境安全、提高退耕农户增收,成为了今后科学研究发展的重要关键。     

半夏组织培养方法的比较研究

研究半夏块茎组织培养,探讨不同灭菌方法对半夏成活率的影响及不同培养基对形态发生的影响,结果表明:0.1%的升汞灭菌15min效果最佳;2,4-D 0.5 mg/L(单位下同)与KT 1.0组合有利于愈伤组织形成,诱导率最高;6-BA 1.0 mg/L(单位下同)与NAA 0.2组合有利于愈伤组织增殖,增殖效果好;2,4-D 0.2与6-BA 1.5组合有利于芽的分化;IBA 0.3或NAA 0.2诱导生根效果好.     

探究湖北省城市水生态景观设计方法

如何合理有效的建立水生态景观?如何改造以往固化而发臭的河道与过水区、修复退化的生态湖泊与湿地并设计出行之有效的生态水域景观改良方式方法?如何根据自身环境的不同,将人与水环境、人的亲水性相结合,构建更绿色的城市水景,打造和谐的人居环境,是摆在环艺工作者面前最现实、最紧迫的课题。     

Brownfield regeneration to greenspace: Delivery of project objectives for social and environmental gain

In Europe and North America regeneration of brownfield land is an important objective of government policy. Regeneration to greenspace in particular, has been used to help reverse social and environmental decline, with typical benefits including increased flood retention capacity, temperature regulation, habitat for wildlife, building communities, encouraging local engagement and providing space for play and recreation.Regeneration project objectives are set to maximise the benefits of greenspace creation for a given location; setting the right objectives is critical to lever funding required to pump-prime activity. However, opportunities to heighten benefits delivered through the process of regeneration can be overlooked. This research identified that there was a disconnect between practices required to meet the defined objectives for a specific site and regeneration activity. This was often due to gaps in the project delivery plans: tasks which are important to realise improvement were missing. Emphasis was often found to be on site delivery, with a benign assumption that the benefits will arise as a result of project completion. Although there are some examples of practices to optimise benefits, a lack of consistency indicates scope for improvement.A logic model was co-produced with practitioners in a bid to address this issue and support project delivery planning. The model maps the social and environmental objectives for a site against specific project delivery stages. The model was refined through a workshop exercise involving discussion with practitioners who were planning new urban greenspaces on brownfield land.This paper presents the logic model to demonstrate what needs to be considered to improve the project delivery planning process, signposting the steps required to translate project objectives into outcomes, to optimise social and environmental benefits delivered during and after regeneration. The model could support those involved in project delivery planning and help raise the overall quality of new greenspace.     

A new data aggregation technique to improve landscape metric downscaling

Scale is a fundamental concept in landscape ecology and considerable attention has been given to the scale-dependent relationships of landscape metrics. Many metrics have been found to exhibit very consistent scaling relationships as map resolution (i.e., pixel or grain size) is increased. However, these scaling relationships tend to break down when attempting to ‘downscale’ them, and the scaling function is often unable to accurately predict metric values for finer resolutions than the original data. The reasons for this breakdown are not well understood. This research examines the downscaling behavior of metrics using various data aggregation techniques in an attempt to better understand the characteristics of metric scaling behavior. First, downscaling performance is examined using the traditional method of aggregation known as ‘majority rules’. Second, a new data aggregation technique is introduced that utilizes fractional land cover abundances obtained from sub-pixel remote sensing classifications in order to capture a greater amount of the spatial heterogeneity present in the landscape. The goal of this new aggregation technique is to produce a more accurate scaling relationship that can be downscaled to predict metric values at fine resolutions. Results indicate that sub-pixel classifications have the potential to transform data aggregation to allow more accurate downscaling for certain landscapes, but accuracy is linked to the spatial heterogeneity of the landscape.     

Urban residents value multi-functional urban greenspaces

Urban greenspaces are multifunctional spaces, providing services to people and biodiversity. With space in urban areas being limited creation and maintenance of urban greenspaces relies on understanding the preferences of urban residents for their characteristics. Such preferences are expected to vary with current availability, and the availability of alternatives to greenspaces such as gardens or gyms. We carried out a nationwide discrete choice experiment with Scottish urban residents to estimate values associated with greenspace attributes of: recreational features; plants and natural features; trees; accessibility; time to walk from home and size, to test the hypotheses that: (i) people are willing to pay to maintain greenspace, (ii) people have willingness to pay for greenspaces with multiple functions, including features for direct use (e.g. play equipment) and biodiversity (e.g. wildflowers), (iii) willingness to pay for individual greenspace will vary according to socioeconomic characteristics and (iv) vary with the amount of greenspace or substitute facilities available. We find a positive willingness to pay to maintain greenspace in general, and higher willingness to pay for larger greenspaces closer to home, which are multifunctional and contain both direct use features (e.g. children’s play park) and biodiversity features. Although we find significant heterogeneity in willingness to pay for maintaining greenspace, this is not well explained by either socioeconomic characteristics or the availability of substitute facilities. Our results have relevance for urban natural capital accounting, and demonstrate to urban planners the importance of the design and maintenance of multi-functional greenspaces for urban populations and would benefit from future research that further explores heterogeneity, including perceptions of greenspace access and substitutes, and greenspace quality.     

Using machine learning to identify urban forest crown bounding boxes (CBB): Exploring a new method to develop urban forest policy

Collecting and managing individual tree data is a critical activity for green sustainability strategies. Local governments are able to easily collect detailed public tree inventories, however data on trees located on private land are much more challenging and costly to collect. This means that new regulations to limit the removal of trees on private land go untested prior to their implementation, or fail to pass regulatory review processes. Without knowledge of the location of trees or the range of their different sizes, Local Government Authorities (LGAs) are unable to predict where a new policy to prohibit the removal of trees of a certain size is likely to have the greatest effect, where enforcement should be concentrated, or to convince government, the development sector and local communities of the need for action to preserve trees.The aim of this study was to explore the potential of a supervised machine learning algorithm as a cost-efficient method to understand tree sizes and locations on private land and to discuss how this information could be used for sustainable urban greening. We conclude by discussing some of the affordances of this approach to better target native vegetation protection and protect large trees; and report on the precision and recall of the detection of the urban forest.     

居室盆花的选择及装饰

主要介绍在利用盆花装饰居室时,如何根据不同居室的环境条件来选择盆花、盆花在室内的摆放位置及如何利用不同盆花装饰不同居室环境。     

红富士苹果树冠枝(梢)叶分布与温度、湿度的关系

以12a生红富士苹果(Malus.domestica Borkhcv.Red Fuji)为试材,研究了北京地区树冠不同层次和部位温度、相对湿度的分布、动态变化与枝叶数量间的关系。结果表明,树冠不同层次温度从上到下逐渐降低,同一层次内温度从内膛到外围逐步增大,树冠不同层次相对湿度从上到下逐渐增大,同一层次内相对湿度从内膛到外围逐步减小;树冠温度日变化呈白天低-高-低的趋势,相对湿度的日变化呈白天高-低-高的趋势,夜晚树体温度、相对湿度趋于一致;7—8月份冠层温度、相对湿度高于5—6月份和9—10月份。应用多元统计分析的方法建立了树冠温度、相对湿度与枝(梢)叶量关系的回归方程,冠层内不同层次、部位的温度、相对湿度受冠层内枝(梢)叶数量和分布的影响,冠层内温湿度与累计长、中、短枝(梢)量和叶面积系数成线性负相关,而相对湿度与之成线性正相关。综合分析,冠层有良好温度和相对湿度的群体结构参数为生长季每hm2总枝(梢)量100万左右,叶面积系数控制在3.5～4.0,长、中、短枝(梢)比例分别为73～77、10～12和13～15。     

Landscape characteristics explain large-scale variation in demographic traits in forest grouse

The effects of landscape composition on species and populations have become increasingly important due to large and rapid habitat changes worldwide. In particular, concern is raised for several forest-dwelling species such as capercaillie and black grouse, because their habitats are continuously changing and deteriorating from human development. Conservation of these species is linked to sustainable forest management that seeks to benefit multiple species, which demands knowledge about demographic rates in relation to forest composition and structure. We related the spatial variation in adult density and chick production of capercaillie and black grouse to landscape characteristics from 13 areas within the boreal forest of Norway. Linear mixed effects models showed that black grouse and capercaillie had similar associations to landscape characteristics. Adult density of both species was positively related to the proportion of old forest (>80 years), but only if the area had large proportions of mid to high productive forests. Chick production was negatively related to the proportion of old forest, but positively to habitat diversity and more so for black grouse compared to capercaillie. However, the result for chick production suggest that other forest types also are important, and that forest grouse needs a variety of habitats during their life history stages. Management that seeks to simultaneously conserve populations of black grouse and capercaillie needs to ensure a matrix of various forest types. A special focus must be on the critical life history of local populations to successfully preserve viable populations, for black grouse and capercaillie this implies protection of old and mid to high productive forest while keeping a heterogeneous landscape.     

植物群落配置在西北高校景观中的运用

目前在我国的校园建设中,校园景观成为建设的一个重点。如何对植物群落进行优化配置已经成为关系到校园景观建设能否取得成功的关键。植物群落配置的意义在于将校园内的植物进行合理的规划和调配,通过统一的规划布局和设计,最终达到美化校园景观的目的。通过对西北地区校园的实际分析,列举在西北地区校园中现有的植物群落,并探讨如何对植物群落实现优化配置,最终达到优化校园景观建设的目的。     

Evaluating the role of ecosystem services in participatory land use planning: proposing a balanced score card

The application of the ecosystem services (ES) concept in land use planning has great potential to enhance the awareness of planning actors on their interactions. At the same time it can contribute to improve the linkage between the role of land use patterns and the understanding of land system functioning and its contribution to human well-being. The concept should be developed in a way that can be applicable in socio-ecological systems where nature and society are capable of enhancing their roles mutually. The objective of this paper is to suggest a standardized scheme and generalizable criteria to assess how successful the application of the ES concept contributed to facilitate participatory planning. We consider three potential advantages and three critical aspects for how to improve the applicability and relevance of the ES concept in planning. Hereon based, we present a balanced score card tool for which we broke down to advantages and risks into concrete questions. We illustrate the application of this approach with two case studies, representatives of two major governance schemes in relation to land use planning. We demonstrate that the balanced score card approach helps to reveal potential imbalances regarding the consideration of different ES groups. It supports testing the potential of the ES concept to enhance or not interactions of local and regional actors. We conclude that the framework should be reconsidered after a set of case studies to be developed into a monitoring tool for supporting planning practices.     

The advantage of mobile technologies in crowdsourcing landscape preferences: Testing a mobile app to inform planning decisions

Urban green spaces are vital for cities to achieve sustainability. Optimal design and management of green space is necessary to counter pressure from increased use due to urban densification and therefore needs to account for the preferences of its potential users. However, preference is inherently subjective and difficult to measure. This study tested a crowdsourcing method using a mobile app for on-site data collection to study the use of, perception of, and preferences for different green configurations in the Rembrandtpark, a large urban park in Amsterdam. Responses obtained through the mobile app were compared to those obtained through more traditional on-site and postal surveys to identify differences in sampled population and results. We found clear differences in respondent samples and in stated preferences when comparing the mobile app and the traditional survey methods. Mobile app respondents (n = 154) were younger and more willing to become more involved with park management. They were also less satisfied with most aspects of locations and found them more noisy. On-site survey respondents (n = 146) appeared more susceptible to response bias in their answers to certain questions. Employing different recruitment methods is important to engage different park user types and account for multiple perceptions.