七子花种群遗传多样性和遗传分化的RAPD分析

 利用RAPD技术研究了浙江省9个七子花天然种群的遗传多样性和遗传分化。结果显示, 七子花遗传多样性水平较低, 种群间遗传分化明显, 9个种群可以聚为两个大的分支。分析认为, 七子花自身的生物学特点以及片断化时的取样效应是种群间遗传分化的主要原因。最后提出了两点当前应采取的七子花保护措施。     

Contracting-out in urban green-space management: Instruments,approaches and arrangements

Although contracting-out has become widespread among the OECD countries in the last couple of decades, there is limited knowledge about the arrangements chosen by urban green-space managers when contracting-out. In this paper, I take our current knowledge a step forward and present a comprehensive overview of the ‘infrastructure’ of contract designs used for contracting-out in urban green-space management. On the backdrop of a cross-national sample of a total of 14 cases from four countries, I build up a ‘toolbox’ of instruments, approaches and arrangements currently used by public clients for managing contracts with private contractors. In six major categories of instrument, I distinguish 41 specific instruments, and 15 embedded approaches for managing these instruments. Both instruments and approaches are grouped into standard and advanced kinds. Arrangements are categorized into three major types. Each type is characterized by a core combination of instruments and approaches and a limited range of variants. Finally, I explore national differences and organizational reasons supporting and directing the choice of overall contractual arrangement. For both the practitioner and the researcher, the paper can be used to inspect, compare, design and develop instruments, approaches and arrangements available in the toolbox of urban green-space management.     

The complex relationship between landscape and recreation

The relation between landscape and recreation is very complex. There are various, interrelated approaches to analyze this relation, such as land evaluation, impact analysis, spatial behaviour analysis, and assessment of the scenic quality of the landscape or landscape evaluation. In many of these approaches airphoto interpretation can be a useful tool.     

The value of linking paleoecological and neoecological perspectives to understand spatially-explicit ecosystem resilience

Context

Predicting ecosystem resilience is a challenge, especially as climate change alters disturbance regimes and conditions for recovery. Recent research has highlighted the importance of spatially-explicit disturbance and resilience processes to long-term ecosystem dynamics. “Neoecological” approaches characterize resilience mechanisms at relatively fine spatio-temporal resolutions, but results are difficult to extrapolate across broad temporal scales or climatic ranges. Paleoecological methodologies can consider the effects of climates that differ from today. However, they are often limited to coarse-grained spatio-temporal resolutions.

Methods

In this synthesis, we describe implicit and explicit examples of studies that incorporate both neo- and paleoecological approaches. We propose ways to build on the strengths of both approaches in an explicit and proactive fashion.

Results

Linking the two approaches is a powerful way to surpass their respective limitations. Aligning spatial scales is critical: Paleoecological sampling design should incorporate knowledge of the spatial characteristics of the disturbance process, and neoecological studies benefit from a longer-term context to their conclusions. In some cases, modeling can incorporate non-spatial data from paleoecological records or emerging spatial paleo-data networks with mechanistic disturbance/recovery processes that operate at fine spatiotemporal scales.

Conclusions

Linking these two complementary approaches is a powerful way to build a complete understanding of ecosystem disturbance and resilience.

     

Genetic isolation by distance and landscape connectivity in the American marten (Martes americana)

Empirical studies of landscape connectivity are limited by the difficulty of directly measuring animal movement. ‘Indirect’ approaches involving genetic analyses provide a complementary tool to ‘direct’ methods such as capture–recapture or radio-tracking. Here the effect of landscape on dispersal was investigated in a forest-dwelling species, the American marten (Martes americana) using the genetic model of isolation by distance (IBD). This model assumes isotropic dispersal in a homogeneous environment and is characterized by increasing genetic differentiation among individuals separated by increasing geographic distances. The effect of landscape features on this genetic pattern was used to test for a departure from spatially homogeneous dispersal. This study was conducted on two populations in homogeneous vs. heterogeneous habitat in a harvested boreal forest in Ontario (Canada). A pattern of IBD was evidenced in the homogeneous landscape whereas no such pattern was found in the near-by harvested forest. To test whether landscape structure may be accountable for this difference, we used effective distances that take into account the effect of landscape features on marten movement instead of Euclidean distances in the model of isolation by distance. Effective distances computed using least-cost modeling were better correlated to genetic distances in both landscapes, thereby showing that the interaction between landscape features and dispersal in Martes americana may be detected through individual-based analyses of spatial genetic structure. However, the simplifying assumptions of genetic models and the low proportions in genetic differentiation explained by these models may limit their utility in quantifying the effect of landscape structure.     

People’s preferences and perceptions toward low-input versus conventional park design approaches using 3D images and interview-based questionnaires

Future urban planning and public satisfaction will be significantly impacted by understanding people's preferences and perceptions of urban landscape design scenarios, particularly innovative sustainable development approaches. This study examined residents' preferences in Mashhad, Iran, for low-input park design versus conventional park design techniques. The research method integrated questionnaire-based interviews with 3D-simulated images of a site designed with the two approaches. Ninety-three respondents answered validated questions regarding their preference towards the planting and architecture of the parks, their perceptions about social sustainability, psychological feelings, and their perceptions of low-input and maintenance of the spaces. T-test analyses showed that people preferred the low-input park design more than the conventional design for the first four factors. However, the respondents needed to recognize significant differences between the two plans for the low-input and maintenance character of the parks. These results showed that people have positive views and perceptions toward sustainable design approaches like low-input park design. This approach can attract the public and meet their social, psychological, and aesthetic needs with appropriate planning and designs. However, people require education and awareness about the maintenance and sustainability aspects of landscape design approaches. Architecture and planting design visual preferences were suitable predictors for people's overall preference toward the low-input park design approach. The research outputs and the applied method provide insights into sustainable landscape planning in the urban environment.     

苹果蠹蛾和梨小食心虫迷向剂复合干扰在南疆‘库尔勒香梨’园的应用效果

‘库尔勒香梨’园苹果蠹蛾、梨小食心虫同域混合发生,均钻蛀隐蔽为害,且抗逆性强,致使化学农药使用频繁而防效低下,已严重制约南疆特色‘库尔勒香梨’产业发展。通过田间性迷向干扰试验,测定了苹果蠹蛾和梨小食心虫性迷向剂在阿克苏地区‘库尔勒香梨’园(约9hm²)的应用效果。结果表明:苹果蠹蛾在该果园1年发生4代,梨小食心虫1年发生5代;性迷向剂胶条600、900、1200个/hm²处理的迷向率均在94%以上,复合迷向干扰效果明显优于对照。蛀果率调查结果显示,7月10日和8月10日性迷向剂胶条600、900、1 200个/hm²处理的蛀果率分别为0.50%、0.25%、0.13%和0.38%、0.25%、0.13%,均显著低于对照,整体上随时间延续防效更为明显。综上,采用性迷向剂对苹果蠹蛾和梨小食心虫进行复合干扰迷向防治有良好的效果,且具有环境友好的优势,综合考虑成本,建议田间使用性迷向剂胶条900个/hm²为宜。     

Science for action at the local landscape scale

For landscape ecology to produce knowledge relevant to society, it must include considerations of human culture and behavior, extending beyond the natural sciences to synthesize with many other disciplines. Furthermore, it needs to be able to support landscape change processes which increasingly take the shape of deliberative and collaborative decision making by local stakeholder groups. Landscape ecology as described by Wu (Landscape Ecol 28:1–11, 2013) therefore needs three additional topics of investigation: (1) the local landscape as a boundary object that builds communication among disciplines and between science and local communities, (2) iterative and collaborative methods for generating transdisciplinary approaches to sustainable change, and (3) the effect of scientific knowledge and tools on local landscape policy and landscape change. Collectively, these topics could empower landscape ecology to be a science for action at the local scale.     

Concepts and methods for landscape multifunctionality and a unifying framework based on ecosystem services

The potential of landscapes to supply multiple benefits to society beyond commodities production has received increasing research and policy attention. Linking the concept of multifunctionality with the ecosystem services (ES) approach offers a promising avenue for producing scientific evidence to inform landscape planning, e.g., about the relative utility of land-sharing and land-sparing. However, the value for decision-making of ES-based multifunctionality assessments has been constrained by a significant conceptual and methodological dispersion. To contribute towards a cohesive framework for landscape multifunctionality, we analyse case studies of joint ES supply regarding ten criteria designed to ultimately answer four aspects: (i) the multifunctionality of what (e.g., landscapes), (ii) the type of multifunctionality (e.g., based on ES synergies), (iii) the procedure of multifunctionality assessments, and (iv) the purpose of multifunctionality. We constructed a typology of methodological approaches based on scores for criteria describing the evaluation method and the level of stakeholder participation in assessments of joint ES supply. Surveyed studies and underlying types of methodological approaches (spatial, socio-spatial, functional, spatio-functional) differed in most criteria. We illustrate the influence of methodological divergence on planning recommendations by comparing two studies employing contrasting approaches (spatial and functional) to assess the joint supply of wildlife habitat and agricultural production in the Argentine Chaco. We distinguish between a pattern-based and process-based multifunctionality, where the latter can only be detected through approaches considering the ecological processes (e.g., ES complementarities) supporting the supply of multiple ES (functional and spatio-functional). Finally, we propose an integrated approach for assessing a socially-relevant process-based multifunctionality.     

Wetland vegetation distribution modelling for the identification of constraining environmental variables

Wetland ecosystems are of primary concern for nature conservation and restoration. Adequate conservation and restoration strategies emerge from a scientific comprehension of wetland properties and processes. Hereby, the understanding of plant species and vegetation patterns in relation to environmental gradients is an important issue. The modelling approaches in this study statistically relate vegetation patterns to measured environmental gradients in a lowland wetland ecosystem. Measured environmental gradients included groundwater quantity and quality aspects, soil properties and vegetation management. Among this variety, the objective was to identify the key environmental gradients constraining the vegetation, using recently developed methodologies within the modelling approaches. Comparison of results indicated that different environmental gradients were considered to be important by different methodologies.     

A new agent-based model provides insight into deep uncertainty faced in simulated forest management

Landscape Ecology - Exploratory modeling in forestry uses a variety of approaches to simulate forest management. One important assumption that every approach makes is about the deep...     

Threshold and weighted-distance methods: a combined multiscale approach improves explanatory power of forest carabid beetle abundance in agricultural landscape

Landscape Ecology - To analyze the scales at which landscape structure influences ecological processes, two approaches with different underlying ecological assumptions exist; the usual threshold...     

Sustainable landscape pattern: a landscape approach to serving spatial planning

Landscape Ecology - Spatial planning system needs the support of approaches toward achieving sustainability, with sustainable landscape pattern (SLP) for one potential spatial approach. However,...     

Re-integrating ecology into integrated landscape approaches

Landscape Ecology - Integrated landscape approaches (ILAs) that aim to balance conservation and development targets are increasingly promoted through science, policy, and the donor community....     

以“大园林”理念建设豫东生态宜居城市

阐述城市园林建设的地位与作用,联系商丘市的实际,分析当前城市园林绿化存在的问题;提出科学推进生态宜居城市的思路与措施。     

The influence of landscape context on the production of cultural ecosystem services

Landscape Ecology - Recent efforts to apply sustainability concepts to entire landscapes have seen increasing interest in approaches that connect socioeconomic and biophysical systems. Evaluating...     

Spatial units and scales for cultural ecosystem services: a comparison illustrated by cultural heritage and entertainment services in Scotland

Landscape Ecology - The diverse use of spatial units and scales in cultural ecosystem service (CES) assessments hinders the development of systematic approaches and the comparability of CES studies...     

Vertical farming: a summary of approaches to growing skywards

Pressure on agricultural land from a rising global population is necessitating the maximisation of food production per unit area of cultivation. Attention is increasingly turning to Vertical Farming (VF) approaches in an attempt to provide a greater crop yield per square meter of land. However, this term has been used to cover a broad range of approaches, from personal- or community-scale vegetable and herb growing to vast skyscrapers for commercial production of a wide range of crops. This article summarises the main categories of VF in order to help clarify this emerging but sometimes confusing area of agriculture and discusses how scientific investigation of the potential of VF is currently lacking and will be required to help determine its feasibility as a method to assist meaningfully in global food production.