Distribution, habitat and biomass of Pittosporum undulatum, the most important woody plant invader in the Azores Archipelago

Pittosporum undulatum Ventenat (Pittosporaceae) is a tree or shrub native to Australia introduced in the Azores Islands in the 19th century, presently naturalized in the nine islands. According to a random survey of vascular plants in the Azores, the invader is present throughout the archipelago, in 62% of 547 1-km² samples. It was found in pure or mixed stands, forming groups and also as isolated trees. P. undulatum was frequently found in native scrubland (62%), mixed woodland (39%) and hedgerows (25%). The altitudinal range extended from sea level up to about 800 m a.s.l., with the highest frequency between 100 and 400 m. The woody species more strongly associated with P. undulatum included characteristic native and endemic species as well as non-indigenous and invasive taxa. Based on a forest inventory, 49% of the forested area in the Azores, about 24,000 ha, is occupied by P. undulatum. Considerable areas inside Island Natural Parks are covered by this species. The estimated annual P. undulatum biomass production in the Azores might range from only about 150 Mg in the small island of Corvo up to more than 60,000 Mg in Pico Island. The heating value of its wood and its chemical composition make it a good candidate for use in combustion or gasification processes. Since there are no resources available to control this large-scale invasion, using P. undulatum biomass for energy production might be an important factor to stimulate the progressive and sustainable cutting of its stands and its replacement by Macaronesian species.     

基于熵权物元模型的黄芩适宜生境区划

[目的]黄芩(Scutellaria baicalensis Georgi)是中国3级野生保护药材物种。利用生境适宜性评价模型对黄芩的适宜生境进行区划,并计算各适宜生境面积,为保护和实现黄芩资源的可持续利用提供科学依据。[方法]利用熵权物元模型,建立黄芩标志性药用成分黄芩苷(C21H18O11)含量与15个环境评价因子之间的模糊隶属函数,采用熵值法确定各评价因子权重,结合GIS空间分析模拟中国黄芩生境适宜区地理空间分布。[结果]中国黄芩不适宜生境、低适宜生境、中适宜生境和高适宜生境的面积分别为5.07×106,1.65×106,1.88×106和1.00×106 km2,其中高适宜生境主要集中在秦岭—淮河一线以北,以河南、山东、辽宁、陕西中南部、河北、吉林、黑龙江南部、山西南部等地区为显著代表,此外云南、安徽等省也有少量分布,与实际分布范围极为吻合。[结论]评价因子中平均日较差、降水季节性变化、最湿月降水量以及坡向基本控制了黄芩的地理空间分布。     

基于PSR模型的能源-生态复合区生态安全预警研究——以山西省忻州市为例

[目的]以山西省忻州市为例,探讨能源与生态复合区生态安全预警,为区域生态保护规划及区域高质量发展提供依据。[方法]基于PSR概念模型框架,从人口、资源、经济、环境、生态要素选取了21个指标建立了能源—生态复合区生态安全预警评价指标体系,采用熵值法确定权重,对山西省忻州市2000—2018年生态安全预警进行分析。[结果]①2018年忻州市14县综合预警值介于0.356 2～0.587 0之间,平均值为0.491 2,预警等级处于中警至轻警范围内。其中忻府区、定襄、五台、繁峙、静乐5县(区)警情为中警状态,其余7县(市)均为轻警状态,忻州市整体生态安全并不乐观,生态安全等级较低。②2000—2018年忻州市生态安全预警值呈波动缓慢上升趋势,警情为中警等级的县减少,轻警等级的县增加。[结论]研究区生态安全空间上呈现不均衡性,警情整体趋于改善,主要取决于系统压力中的经济、资源、环境压力趋缓。     

西北农业高校图书馆信息化建设

本文从信息资源建设、信息化人力资源建设、信息资源共享体系等几个方面，探讨西北农业高校图书馆信息化建设。     

Spatially targeting the distribution of agricultural input stockists in Malawi

Developing the rural agricultural input markets in sub-Saharan Africa can improve the current low productivity of smallholder farmers. Malawi has seen significant efforts in addressing the availability of agricultural inputs at village level in the last few years; for example, the improvement of rural agro-dealer networks. Nevertheless inputs are still difficult to obtain for many remote smallholder farmers. Spatial analysis can help in the expansion of input stockists, especially agro-dealer networks, by assessing the coverage of existing input outlets and deriving optimum locations for village-level input stockists.We address three research questions. First, what is the locational efficiency of the current village-level stockists of inputs (Citizens Network for Foreign Affairs – Rural Agricultural Market Development Trust trained network of agro dealers and public sector)? Secondly, how many village-level stockists of markets are needed to reach 60% of the population in the central region of Malawi within one hour? Finally we address the potential spatial components of the sustainability of input stockists relating to the potential demand from smallholder farmers and the access to bulk supplies. The problem of finding the optimum location for village-level stockists of markets is addressed in two stages, using spatial analysis in conjunction with location–allocation models. First, the locational efficiency of the existing network of stockists of inputs is determined, followed by the establishment of a set of optimal sites for village-level stockists of inputs. A final step explores the viability of stockists and calculates the population surrounding the stockists taking into account competition from other sources of inputs and the accessibility of the selected stockists to potential wholesalers who are bulk distributors of farm inputs.Our results show that locational efficiency can be assessed in terms of the differential access of households to resources and transport. Often, these differences are not considered in covering problems and can have a large effect on the physical access to inputs. The results can be used to define which areas are inherently difficult to serve with agricultural inputs and could inform efforts to provide incentives to remote areas. Further implications for input policies in Malawi are that improvements in road infrastructure might not directly benefit the poorest farmers (if they are walking) but could serve to reduce the wholesale prices and therefore the retail price. In addition, the improvement in roads might increase the number of potential customers of any particular stockist, with economies of scale allowing the reduction of prices while ensuring a satisfactory profit margin for the stockist. The results of our models imply that Citizens Network for Foreign Affairs may need to train stockists over a wider area to increase the access to inputs of those smallholder farmers with least resources.     

安徽省蚕桑病虫害防治网络专家咨询系统的研制

本文介绍了蚕桑病虫防治网络专家资询系统的基本结构、运行、功能特点.总结蚕桑专家的理论知识及实践经验,借助网络系统技术建立人机交互咨询服务系统,将桑蚕病虫害防治知识展示给用户,以指导蚕桑生产,减少损失.     

电子政务环境下的档案信息特点及其管理初探

随着信息技术的发展,电子政务建设也在快速发展。本文根据我国电子政务和档案信息化建设的现状及电子政务环境下的档案信息特点,描述了档案信息管理的各种模式,并对档案信息管理的人才要求、网络建设标准、信息安全等问题提出了自已的见解。     

运用信息熵构建森林消防物资储量优化模型的研究

森林消防物资储备是森林火灾预防和扑救的物质基础.该文针对森林火灾预防和扑救的特点、规律,运用信息熵原理,构建森林消防物资储量优化模型,为今后森林消防部门合理储备森林消防资源提供了合理的计算方法和科学的依据,从而确保森林消防物资储备更加切实合理、科学高效.     

农业信息化的智力核心--农业专家在线

实现全面农业信息化已成为当今解决“三农”问题的有效途径,作为农业信息化的智力核心,农业专家在此过程中将起到决定性的作用。本文详实论述了东北农业大学农业专家在线网站自2002年初运行至今近三年的情况,旨在找到实现农业信息化的智力支持的方法。     

吉林省实施"农技110"信息服务模式的探讨

从吉林省农业信息化建设实际情况出发，积极探索运用新型呼叫中心运行系统、信息共享服务平台、新闻媒体和现有农技推广模式，建立适合吉林省省情的有效的“农技110”信息服务体系，并在实施“农技110”信息服务模式的保障体制方面进行了有益的探索和创新。