Effects of area and isolation of woodland patches on herbaceous plant species richness across Great Britain

Richness of Ancient Woodland Indicator plant species was analysed in 308 woodland patches that were surveyed during the Countryside Survey of Great Britain carried out in 1998. The Countryside Survey recorded vegetation plots and landscape structure in 569 stratified 1 km sample squares and developed a remotely-sensed land cover map of the UK. Using these datasets, we tested the hypothesis that Ancient Woodland Indicator species richness in woodland fragments was limited by patch area, shape and spatial isolation and that woodland patches located in the lowland region of Great Britain would respond differently than those in the upland region. The variation in Ancient Woodland Indicator species richness in the British lowlands (n = 218) was mainly explained by patch area and two measures of connectivity, the length of hedgerows and lines of trees in the 1 km square and the area of woodland within 500 m of the vegetation plot. By contrast, variation in Ancient Woodland Indicator species richness in the British uplands (n = 90) was related to Ellenberg scores of the vegetation communities sampled – a surrogate for habitat quality – and no significant effect of spatial structure was detected. It therefore appears that the degree of fragmentation of woodland in the British lowlands limits the distribution of Ancient Woodland Indicator species, while in the uplands, failed colonisation is a matter of habitat quality rather than a result of landscape structure.This revised version was published online in May 2005 with corrections to the Cover Date.     

Characterizing historical and modern fire regimes in Michigan (USA): A landscape ecosystem approach

We studied the relationships of landscape ecosystems to historical and contemporary fire regimes across 4.3 million hectares in northern lower Michigan (USA). Changes in fire regimes were documented by comparing historical fire rotations in different landscape ecosystems to those occurring between 1985 and 2000. Previously published data and a synthesis of the literature were used to identify six forest-replacement fire regime categories with fire rotations ranging from very short (<100 years) to very long (>1,000 years). We derived spatially-explicit estimates of the susceptibility of landscape ecosystems to fire disturbance using Landtype Association maps as initial units of investigation. Each Landtype Association polygon was assigned to a fire regime category based on associations of ecological factors known to influence fire regimes. Spatial statistics were used to interpolate fire points recorded by the General Land Office. Historical fire rotations were determined by calculating the area burned for each category of fire regime and dividing this area by fifteen (years) to estimate area burned per annum. Modern fire rotations were estimated using data on fire location and size obtained from federal and state agencies. Landtype Associations networked into fire regime categories exhibited differences in both historical and modern fire rotations. Historical rotations varied by 23-fold across all fire rotation categories, and modern forest fire rotations by 13-fold. Modern fire rotations were an order of magnitude longer than historical rotations. The magnitude of these changes has important implications for forest health and understanding of ecological processes in most of the fire rotation categories that we identified.This revised version was published online in May 2005 with corrections to the Cover Date.     

7种园林植物的耐盐性研究

利用滨海盐碱土配制栽培土壤,采用大棚盆栽试验方法,对7种常见园林绿化植物的生长表现、存活率、高生长、叶绿素含量、相对含水量进行研究的结果表明:连翘、月季和四季桂的耐盐性较差,只能在含盐量不大于2.3 g/kg的土壤中正常生长;其次为金叶女贞,能在含盐量不大于4.6 g/kg的土壤中生长;雪松能在含盐量不大于4.9g/kg的土壤中正常生长;油松能在含盐量不大于5.8g/kg的土壤中正常生长;爬地柏耐盐性最强,能正常生长于含盐量高达8.7g/kg的土壤中.     

日本北海道北部寒温带森林流域林冠层凋落物及其养分归还量的景观格局(英文)

Within a forested watershed at the Uryu Experimental Forest of Hokkaido University in northern Hokkaido, overstory litterfall and related nutrient fluxes were measured at different landscape zones over two years. The wetland zone covered with Picea glehnii pure stand. The riparian zone was deciduous broad-leaved stand dominated by Alnus hirsuta and Salix spp., while the mixture of deciduous broadleaf and evergreen conifer dominated by Betula platyphylla, Quercus crispula and Abies sachalinensis distributed on the upland zone. Annual litterfall averaged 1444, 5122, and 4123 kg.hm^-2·a^-1 in the wetland, riparian and upland zones, respectively. Litterfall production peaked in September-October, and foliage litter contributed the greatest amount （73.4%-87.6 %） of the annual total litterfall. Concentrations of nutrients analyzed in foliage litter of the dominant species showed a similar seasonal variation over the year except for N in P glehnii and A. hirsuta. The nutrient fluxes for all elements analyzed were greatest on riparian zone and lowest in wetland zone. Nutrient fluxes via litterfall followed the decreasing sequence： N （11-129 kg.hm-2.aq） 〉 Ca （9-69） 〉 K （5-20） 〉 Mg （3-15） 〉 P （0.4-4.7） for all stands. Significant differences were found in litterfall production and nutrient fluxes among the different landscape components. There existed significant differences in soil chemistry between the different landscape zones. The consistently low soil C：N ratios at the riparian zone might be due to the higher-quality litter inputs （largely N-fixing alder）.     

人类活动对于农业景观生态系统的影响

人类活动和人类文明的发展,一方面对自然景观产生了破坏作用,另一方面对自然景观进行有目的改造和修饰,将自然景观改造为有利于人类生存的格局。由于人类活动影响的广泛性和深刻性,人类活动在景观演化过程中的主导地位日益突出。同时,随着科学技术的进步和农业生产力的提高,人类的生产生活对农业景观格局的变化以及农业景观生态系统的稳定产生了越来越多的影响。     

园林绿化工程建设造价的控制管理

从目前园林绿化工程建设造价控制管理上存在的诸多问题入手,论述了完善园林绿化造价控制管理的措施和方法及加强园林绿化工程造价控制管理的重要意义。     

安徽农业大学景观环境设计初探

针对安徽农业大学景观环境现状,在深入分析校园景观环境优势与劣势的基础上,结合实际,从塑造环境多样性,创造绿化情趣、改造现有绿化空间,开放绿化场地,提高环境利用率等方面提出了改造建议。     

陕西省潼关县窑上村景观规划设计

在新农村建设的大背景下,从生态学角度出发,探寻景观建设的理性的、科学的方法与途径,恢复农村自然生态环境,实现农村经济的可持续发展。     

草坪在园林中的应用

介绍了草坪的配置原则,探讨了草坪在园林绿地中的应用,阐述了草坪与其他景观要素的配置方法。     

运河影响下的常州古城景观体系研究

常州自古便是江南地区水陆交通的枢纽,其城市发展与运河息息相关.以常州古城为研究对象,首先梳理其从先秦到清末古代城市的发展演变与同时期运河的变迁,探究两者之间的关联.接着以清末为时间节点,从自然山水要素、人工营建要素和意向空间要素等不同要素入手,归纳了清末常州古城景观体系在"天心十道"的节点布局、"七厢三街"的功能分区和...