在中国新发现的兜兰种类

全世界被发现的兜兰属植物约有80种,据《中国植物志》和《中国兰花全书》记录分布于中国的兜兰属植物有18种,其中杏黄兜兰（Paphiopedilum armeniacum）和白花兜兰（P．emersonii）为中国特有种,近年来新发现分布于中国的兜兰属植物还有9种：     

广西木论国家级自然保护区麻栗坡兜兰群落特征初步研究

运用群落学的调查方法,对广西木论国家级自然保护区麻栗坡兜兰的种群生存环境、种群结构和空间分布等群落学特征进行了初步调查分析。结果表明:麻栗坡兜兰产地的气候、植被、土壤和其它环境因子与麻栗坡兜兰的生存有着密切的关系,以聚集群居生长,分布于石灰岩森林的岩石宽缝中的积聚较多富含腐殖质的腐叶土层上。凡生长在保存度完好的森林环境且腐质层土厚度大于8cm的条件下,其植株长势旺盛,叶片肥厚、宽大。研究区内植物群落的科、属组成以单种属为主,属的成分与热带、亚热带的关系密切。麻栗坡兜兰生存与环境的关系以及导致濒危的原因还需更进一步研究。     

甘肃荚蒾属(Viburnum L. )观赏植物资源的调查研究

 在对甘肃荚蒾属植物资源调查的基础上, 整理并描述了27个分类群的生境、分布以及观赏性状, 包括叶、花、果实等, 并结合该属植物的资源现状, 提出了可持续开发利用的建议。     

兜兰原生种介绍

兜兰属（Paphiopedilum）又叫拖鞋兰、仙履兰等，全世界约有79个种，主要分布于亚洲热带地区至太平洋岛屿。兜兰属植物由于独特的花型、绚丽的花色、持久的花期而具有极高的观赏价值，     

四川攀西胡颓子属植物资源调查研究

2005～2011年在攀枝花市16个县市对胡颓子属植物资源进行了野外实地调查、采集标本、室内解剖观察、种类鉴定,并结合查阅标本室内的植物标本和相关资料进行了研究。结果表明:攀西地区有胡颓子属植物10种、1个亚种和1个变种,主要生长在海拔750～3 100m的范围内,广泛分布于攀枝花和凉山州各县、市。在野外调查的基础上,研究了攀西地区胡颓子属植物资源的种类、形态、生境、分布和综合利用价值,并为开发利用及保护提出了建议。     

西藏凤仙花属植物资源调查及园林应用

通过野外调查和文献整理,对西藏凤仙花属植物资源的分布、观赏特性和园林应用进行了研究。结果表明:西藏现有凤仙花属植物35种和3变种,其中含1种栽培植物。野生种占到全国凤仙花属植物总种数的13.28%;该属资源丰富度在全国范围内仅次于四川和云南,且均具有较高的观赏价值;其特有性较很高,中国特有种15种,其中包含西藏特有种7种,中国特有的比例达到40.54%,西藏特有也高达21.62%。在对其地理分布和观赏价值分析的基础上,提出了建立资源圃、保护野外生境、合理有序开发和尽快进行新品种培育等保护开发建议。     

贵州省野生岩生草本花卉资源调查研究

采用野外调查和资料整理分析等方法,对贵州省野生岩生草本花卉资源进行了调查研究。结果表明:贵州省野生岩生草本花卉资源包括蕨类植物和种子植物,总计26科66属190种,其中,蕨类植物17科31属83种(小型岩生蕨类花卉54种,中型岩生蕨类花卉29种),种子植物9科35属107种。生境特征主要有干旱环境生长种类、阴湿种类、溪沟边生长种类、林下生长种类、石面生长种类、石沟或石缝或石孔生长种类,生长在这些环境中的花卉是喷泉假山、水池假山、草地假山和山水盆景点缀的优良植物材料。垂直分布范围广,最低分布为200m,最高分布为2 600m。     

湖南九嶷山野生杜鹃花属植物资源调查与研究

湖南九嶷山野生杜鹃花属植物资源丰富,根据调查统计,有杜鹃花属植物16种,隶属于5亚属7组8亚组。对该区野生杜鹃花属植物种类、生活型、生境及分布、花期与花色、资源储量等情况进行分析,并提出资源保护和科学利用的建议,以期为区域杜鹃花属资源可持续利用提供参考。     

我国百里香属植物资源调查分析

在资料分析、实地考察和引种栽培基础上,对我国11个省(自治区)32个县(市)分布的百里香属野生植物资源进行了研究。结果表明:我国现有记载百里香属植物资源为17种2变种,主要分布于北纬32°～48°、东经82°～133°之间,不同种间常具有一定的分布范围、海拔、气候及生境特点。该研究将为今后我国百里香属植物资源的深入研究、科学开发及多样性保护工作奠定一定基础。     

甘肃省风毛菊属植物多样性研究

以分布于甘肃省内的风毛菊属植物为研究对象,采用多次野外实地考察及统计方法,参阅以往甘肃省内采集的标本和记录,并结合《中国植物志》、《中国高等植物图鉴》、《甘肃植被》等文献资料,鉴定了部分标本,初步探讨了甘肃省风毛菊属植物的物种多样性。结果表明:甘肃省风毛菊属植物物种适应多种生境,其多样性在中等海拔高度最大,且不同亚属分布海拔范围及生境均有差异。     

The distribution of plant species in urban vegetation fragments

(1) The presence and absence of 22 plant species of various growth forms and habitat associations were analysed in 423 habitat fragments totalling 10.4 km² in a 268 km² urban and suburban region, in Birmingham, UK. (2) Multivariate logistic regressions were used to assess the effects of patch geometry and quality on the species distributions. Measures of geometry were area, shape (S-factor), distance from open countryside and various measures of isolation from other patches. Potential habitat for each species was determined quantitatively, and the distribution of each species was considered within a subset of patches containing potentially suitable habitat types. There was found to be a significant positive correlation between the density of patches available to a species and the proportion of these patches which were occupied. (3) Logistic analyses and incidence functions revealed that, for many of the species, occupancy increased with site age, area, habitat number and similarity of adjacent habitats, while increasing distance to the nearest recorded population of the same species decreased the likelihood that a species would be found in a patch. (4) Patterns of occupancy are consistent with increased extinction from small sites, and colonisation of nearby habitats, coupled with an important role for site history. We conclude that spatial dynamics at the scale of the landscape are of importance to the long-term persistence of many plant species in fragmented landscapes, and must be seriously considered in conservation planning and management. These results have direct implications for the siting and connectivity of urban habitat reserves.     

Dispersal traits determine plant response to habitat connectivity in an urban landscape

Identification of trait syndromes that make species vulnerable to habitat fragmentation is essential in predicting biodiversity change. Plants are considered particularly vulnerable if their capacities for persistence in and for dispersal among local habitats are low. Here we investigated the influence of easily measured functional traits on the presence of 45 plant species in an urban landscape in north-west Germany where patches were separated by distances consistent with regular plant dispersal range. To describe the spatial configuration of patches we calculated species-specific patch connectivities. Then we assessed plant connectivity responses in distribution models calculated from connectivities and environmental predictors. Twenty (45%) of the analysed species showed a positive connectivity response after accounting for species-specific habitat requirements. These species differed from non-responsive species by functional traits associated with dispersal, including reduced seed numbers and higher terminal velocities relative to non-responsive species. Persistence traits played however no role which we attribute to the environmental conditions of urban habitats and their spatiotemporal characteristics. Our study underlines that even ruderal plants experience dispersal limitation and demonstrates that easily measured functional traits may be used as indicators of fragmentation vulnerability in urban systems allowing generalizations to larger species sets.     

Estimation and prediction of plant species richness in a mosaic landscape

Traditional agricultural mosaic landscapes are likely to undergo dramatic changes through either intensification or abandonment of land use. Both developmental trends may negatively affect the vascular plant species richness of such landscapes. Therefore, sustainable land-use systems need to be developed to maintain and re-establish species richness at various spatial scales. To evaluate the sustainability of specific land-use systems, we need approaches for the effective assessment of the present species richness and models that can predict the effects on species richness as realistically as possible. In this context, we present a methodology to estimate and predict vascular plant species richness at the local and the regional scale. In our approach, the major determinants of vascular plant species richness within the study area are taken into consideration: These are according to Duelli's mosaic concept the number of habitat types and of habitat patches within area units. Furthermore, it is based on the relative frequencies of species within habitat types. Our approach comprises six steps: (i) the determination of present habitat patterns within an observation area, (ii) the creation of a land-use scenario with simulated habitat patterns, (iii) the determination of species frequencies within habitat types of this area, (iv) a grouping of habitat-specific species, (v) the estimation of the probabilities for all species (or habitat specialists) to occur, either in stepwise, exponentially enlarged landscape tracts (local scale), or in the entire observation area (regional scale), and (vi) the validation of the estimated species numbers. The approach will be exemplified using data from the municipal district of Erda, Lahn-Dill Highlands, Germany. The current species numbers to be expected on the basis of probability calculations were compared with those recorded on the basis of extensive field work. This comparison shows that, on the basis of our simple calculations, the current local plant species richness can be predicted well, with a slight underestimation. This revised version was published online in May 2005 with corrections to the Cover Date. This revised version was published online in July 2006 with corrections to the Cover Date.     

Determinants of plant species richness and patterns of nestedness in fragmented landscapes: evidence from land-bridge islands

Land-bridge islands formed by dam construction are considered to be “experimental” systems for studying the effects of habitat loss and fragmentation, offering many distinct advantages over terrestrial fragments. The Thousand Island Lake in Southeast China is one such land-bridge system with more than 1000 islands. Based on a field survey of vascular plant richness on 154 land-bridge islands during 2007–2008, we examined the effects of island and landscape attributes on plant species richness and patterns of species nestedness. We also examined the different responses of plant functional groups (classified according to growth form and shade tolerance) to fragmentation. We found that island area explained the greatest amount of variation in plant species richness. Island area and shape index positively affected species diversity and the degree of nestedness exhibited by plant communities while the perimeter to area ratio of the islands had a negative effect. Shade-tolerant plants were the most sensitive species group to habitat fragmentation. Isolation negatively affected the degree of nestedness in herb and shade-intolerant plants including species with various dispersal abilities in the fragmented landscape. Based on these results, we concluded that the effects of habitat loss and fragmentation on overall species richness depended mostly on the degree of habitat loss, but patterns of nestedness were generated from different ecological mechanisms due to species-specific responses to different characteristics of habitat patches.     

Modelling multi-species response to landscape dynamics: mosaic cycles support urban biodiversity

The importance of the spatial as well as the temporal structure of habitat patches for urban biodiversity has been recognised, but rarely quantified. In dynamic environments the rate of habitat destruction and recreation (i.e. the landscape turnover rate), the minimum amount of potential habitat, its spatial configuration as well as the environmental conditions determining habitat quality are crucial factors for species occurrence. We analysed species responses to environmental parameters and to the spatio-temporal configuration of urban brownfield habitats in a multi-species approach (37 plant and 43 insect species). Species presence/absence data and soil parameters, site age, vegetation structure and landscape context were recorded by random stratified sampling at 133 study plots in industrial areas in the city of Bremen (Germany). Based on the field data, we predicted species occurrences by species distribution models using a multi-model inference approach. Predicted species communities were driven by successional age both at the scale of a single building lot and at the landscape scale. Minimum average succession time of brownfield habitats required to support all and especially regionally rare species depended on the proportion of available open space; the larger the potential habitat area the faster the acceptable turnover. Most plant, grasshopper, and leafhopper species modelled could be maintained at an intermediate turnover rate (mean age of 10–15 years) and a proportion of open sites of at least 40%. Our modelling approach provides the opportunity of inferring optimal spatio-temporal landscape configurations for urban conservation management from patch scale species-environment relationships. The results indicate that urban planning should incorporate land use dynamics into the management of urban biodiversity. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Riparian plant composition in an urbanizing landscape in southern California,U.S.A.

In coastal southern California, natural riparian corridors occur in a landscape mosaic comprised of human land uses (mainly urban and suburban development) interspersed among undeveloped areas, primarily native shrublands. We asked, does the composition of the landscape surrounding a riparian survey point influence plant species distribution, community composition, or habitat structure? We expected, for example, that invasive non-native species might be more abundant as the amount of surrounding urbanization increased. We surveyed 137 points in riparian vegetation in Orange County, California, along an urbanization gradient. Using logistic regression we analyzed 79 individual plant species’ distributions, finding 20 negatively associated and 12 positively associated with the amount of development within a 1-km radius around the survey points, even after accounting for the effects of elevation. However, after summarizing plant community composition with Detrended Correspondence Analysis we observed that, overall, community composition was not statistically correlated with the amount of development surrounding a survey point once the association between development and elevation was taken into account. Non-native species were not particularly associated with increasing development, but instead were distributed throughout vegetation and urbanization gradients. However, the extent of the tree and herb layers (structural attributes) was associated with development, with the tree layer increasing and the herb layer decreasing as urbanization increased. Thus, although the degree of surrounding urbanization appears to influence the distribution of a number of individual plant species, overall composition of the community in our study system seemed relatively unaffected. Instead, we suggest that community composition reflected larger-scale environmental conditions, such as stream order and other variables associated with elevation, and/or regional-scale disturbances, such as historic grazing or enhanced atmospheric deposition of nitrogen.     

8种适合在广东地区种植的优良园林植物

本文从形态特征、地理分布、生态习性、观赏价值等方面介绍了8种适合广东地区种植的园林植物,以此促进其在园林上的开发利用。     

Interactions between past land use, life-history traits and understory spatial heterogeneity

Past land use has contributed to variability in the distribution of herbaceous species by reducing plant abundance and altering species’ chances of recolonizing suitable habitat. Land use may also influence plant heterogeneity by changing environmental conditions within stands. We compared the variability of understory herb abundance in southern Appalachian forests with different land-use histories to examine how past land use influenced plant heterogeneity. The cover of eleven focal species or genera was estimated and mineral soil concentrations were determined during 2001 and 2002 in eight stands that were farmed, logged, or had no disturbance history (reference) in western North Carolina. Analysis of the coefficients of variation revealed that the abundance of understory plants was more heterogeneous in disturbed stands compared with reference stands. However, when nutrient availability differences were accounted for by detrending the plant cover data, understory variability within stands declined, and no differences between disturbed and reference stands could be distinguished. This finding suggests that nutrient availability has important effects on plant heterogeneity, which depend on past land use. Species dispersal, seed size, and phenology also explained variability in the spatial heterogeneity of plants, but generally only before soil nutrient differences were statistically controlled. In addition to demonstrating that past land use has long-term effects on plant heterogeneity, these results indicate that soil nutrients may play different roles in determining vegetation patterns in historically altered and unaltered forests.     

Prediction of total and rare plant species richness in agricultural landscapes from satellite images and topographic data

The diversity of future landscapes might depend on our ability to predict their potential species richness. The predictability of patterns of vascular plant species richness in a Finnish agricultural river landscape was studied using generalized linear modeling, floristic records from fifty-three0.25-km grid squares in the “core” study area, and environmental variables derived from Landsat TM images and a digital elevation model. We built multiple regression models for the total number of plant species and the number of rarities, and validated the accuracy of the derived models with a test set of 52 grid squares. We tentatively extrapolated the models from the core study area to the whole study area of 601 km² and produced species richness probability maps using GIS techniques. The results suggest that the local ‘hotspots’ of total flora (grid squares with > 200species) are mainly found in river valleys, where habitat diversity is high and a semi-open agricultural-forest mosaic occurs. The ‘hotspots’ of rare species (grid squares with > 4 rare species) are also found in river valleys, in sites where extensive semi-natural grasslands and herb-rich deciduous forests occur on steep slopes. We conclude that environmental variables derived from satellite images and topographic data can be used as approximate surrogates of plant species diversity in agricultural landscapes. Modeling of biological diversity based on satellite images and GIS can provide useful information needed in land use planning. However, due to the potential pitfalls in processing satellite imagery and model-building procedures, the results of predictive models should be carefully interpreted. This revised version was published online in July 2006 with corrections to the Cover Date.