若尔盖辖曼－阿西高原沼泽自然保护区沼泽植物特征

若尔盖沼泽是世界上著名的高寒沼泽。我们对此地的纳勒乔沼泽、纳洛乔沼泽和哈丘湖附近的沼泽植物进行了考察。这里的沼泽植物共61种,隶属44属,21科。以莎草科、禾本科、菊科、毛莨科为主。沼泽植物的地理成分表明此地的植被偏向温带性质。苔草属是主要的沼泽植物。木里苔草、毛果苔草、乌拉苔草、藏蒿草、双柱头藨草为优势种。沼泽植物的生活型分为湿生植物、挺水植物、浮叶植物、沉水植物。沼泽植物群落包括9种类型。最后,作者建议将木里苔草、狸藻群落,木里苔草、条叶垂头菊群落,毛果苔草、睡莱群落,毛果苔草、狸藻群落列为重点保护的自然群落。     

巴音布鲁克天鹅湖保护区湿地植物群落研究

巴音布鲁克天鹅湖湿地植被类型在分类上属典型高寒沼泽草甸,可分为5个型。植被以湿生和水生植物为主构成,由5个层片结构组成。水沼泽植物群落的均匀度和优势度指数均高于丘状沼泽。植物群落物种重要性的大小依次为:黑穗苔草(Carex melanantha)>细刺苔草(Carex microglochn)>嵩草(Kobresia filifola)>囊状苔草(Carexvesicula)>马先蒿(Pedieularis albevti)>水麦冬(Triglochin plustre)>报春花(Primula sibirica)。在巴音布鲁克高寒沼泽草地植物群落中,水沼泽草地的鲜草产量高于丘状沼泽,分别为646.2g·m^-2和496.7g·m^-2,平均鲜草量571.5g·m^-2。群落的地下生物量较大,为13608.8 g·m^-2,0cm¹⁰cm土层中的地下生物量约占69.89%,10cm²⁰cm的地下生物量约占15.9%,20cm³⁰cm的地下生物量约占7.27%,30cm⁵⁰cm的地下生物量仅占6.94%。植物种类以莎草科植物较多(占总生物量的78.7%),大部分属于下繁性草类。物种组成简单,平方米植物种为13种,一般8种~11种。     

The Phytocommtunity and the Relations of the Element Contents Between Plants and Soils at Qing Chengzi Mining Area of Liaoning Province

The types of plant community and the floristic compositions in the leadzine abnormal and normal areas identified by geochemical exploration are basieally similar. According to the chemical analysis the contents of Pb, Zn, Cu, Cd of plants and soils in abnormal areas are higher than in normal areas. The absorption coeffieients of heavy metal elements by plants change with various chemical element, in the order of Cd>Zn, Cu>Pb. The results of the correlation analysis showed that the linear relationship between the contents of Pb, Zn in plant communities and in soil are singnifieant. There is a considerable linear correlation of Pb, Zn, Cu, Cd in soil and in Carex callitrichos, Sangnisorba officinalis, Polyoinum lopothitolium, Spirea pubescens, respectively. A close correlation presented in the contents of Pb, Zn, Cu, Cd between Carex callitrichos and soils. The multiple correlation coefficient is 0.999 (N=8, P<0.01). It may be suggested that Carex callitrichos can indicat the contents of Pb, Zn in soils.     

太岳山油松林火烧迹地恢复初期植物群落结构特征

为研究山西太岳山油松（Pinus tabuliformis）林过火后恢复初期林下草本植物群落结构,以2019年3月太岳山油松林火烧迹地为研究对象,采用群落相似性指数、多样性指数、稳定性系数、TWINSPAN数量分类和DCA排序等方法对群落组成、多样性、类型及稳定性等进行了研究。结果表明：（1）火烧迹地恢复初期以低矮灌木和多年生草本植物为主,其中又以地面芽植物占比最大。优势植物主要为大披针薹草（Carex lanceolata）和多花胡枝子（Lespedeza floribunda）;（2）火烧迹地恢复初期各样地植物群落相似性系数和多样性指数相对较小,均匀度指数较大,但各样地恢复效果不尽相同,样地6和样地7的植物群落各项指标相对大于其他样地;（3）TWINSPAN数量分类将火烧迹地植物群落划分成：I.大披针薹草+南牡蒿（Artemisia eriopoda）+地榆（Sanguisorba officinalis）群丛、II.多花胡枝子+大披针薹草+二色棘豆（Oxytropis bicolor）群丛、III.多花胡枝子+大披针薹草+米口袋（Gueldenstaedtia verna）群丛、IV.多花胡枝子+大披针薹草+荠苨（Adenophora trachelioides）群丛、V.大披针薹草+白莲蒿（Artemisia stechmanniana）+狗娃花（Aster hispidus）群丛、VI.白莲蒿群丛、VII.大披针薹草+狗娃花+野艾蒿（Artemisia lavandulifolia）群丛;（4）DCA排序结果表明,火烧迹地恢复初期植物群落结构单一,沿样地和坡位变化较小,仅区分出样地7和其他样地两大类植物群落。（5）火烧迹地恢复初期植物群落处于不稳定的状态,但各样地间群落稳定性存在一定差别,其中样地1最大,样地5最小。总之,研究区植物群落处于演替初期,各样地间植物群落稳定性较差,多样性和整体相似性较小,但优势种群相似性较高,植物群落结构仍处于动态变化之中。研究揭示了太岳山火烧迹地恢复初期植物群落结构特征,积累了该区域火烧迹地植物群落生态学数据,同时可为该区域生态恢复提供科学依据。     

Plant community distribution along water table and grazing gradients in montane meadows of the Sierra Nevada Range (California, USA)

This study aimed to identify dominant plant communities across five wet and mesic meadows in the Sierra Nevada Range (California, USA) and examine the impacts of environmental and grazing gradients on plant community distribution and diversity. Species composition and environmental conditions were recorded in 100 plots over two years. Classification and ordination analyses were used to classify plant communities and identify relationships between community types and both environmental and grazing gradients. We identified the following six plant community types: Carex jonesii, Carex leporinella, Carex nebrascensis, Carex utriculata, Eleocharis pauciflora, and Veratrum californicum. We found strong connections between plant communities and water table variables, with low water table (r ²?=?0.56) and mean water table (r ²?=?0.30) significantly correlated with Axis 1 while high water table (r ²?=?0.29) and elevation were correlated with Axis 3 (r ²?=?0.49). We found significant differences among community types for all three water table variables and for elevation. We found no correlation between grazing and community type classification, but there was a significant difference in grazing levels among community types. The plant communities and relationships to water table found in this work may aid managers in understanding present conditions and identifying future changes in meadow ecosystems.     

The effect of habitat fragmentation and abiotic factors on fen plant occurrence

Human landscape modification has led to habitat fragmentation for many species. Habitat fragmentation, leading to isolation, decrease in patch size and increased edge effect, is observed in fen ecosystems that comprise many endangered plant species. However, until now it has remained unclear whether habitat fragmentation per se has a significant additional negative effect on plant species persistence, besides habitat loss and degradation. We investigated the relative effect of isolation, habitat size, and habitat edge compared to the effect of habitat degradation by including both ‘fragmentation variables’ and abiotic variables in best subsets logistic regression analyses for six fen-plant species. For all but one species, besides abiotic variables one or more variables related to fragmentation were included in the regression model. For Carex lasiocarpa, isolation was the most important factor limiting species distribution, while for Juncus subnodulosus and Menyanthes trifoliata, isolation was the second most important factor. The effect of habitat size differed among species and an increasing edge had a negative effect on the occurrence of Carex lasiocarpa and Pedicularis palustris. Our results clearly show that even if abiotic conditions are suitable for certain species, isolation of habitat patches and an increased habitat edge caused by habitat fragmentation affect negatively the viability of characteristic fen plant species. Therefore, it is important not only to improve habitat quality but also to consider spatial characteristics of the habitat of target species when deciding on plant conservation strategies in intensively used landscapes, such as fen areas in Western Europe and North America.     

Species dependent root decomposition in rewetted fen soils

Experiments in a rewetted fen show large differences in root decomposition rates among Phragmites australis, Carex paniculata, and Carex riparia. With equal water table fluctuations no differences in decomposition were observed in the two rewetting variants, with temporary standing and constantly flowing water. The marked differences among species are therefore attributed to differences in plant material quality, though C/N ratio is shown not to be of main influence. Based on low decomposition rates, Phragmites australis proved the species most suitable for (renewed) peat accumulation under sufficient wet conditions. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date.     

山东半岛滨海沙滩前缘的野生植物

滨海沙滩是以海水影响为基本过程的地貌类型,适应这种环境的植物类群与适生于内陆的沙地植物可能存在巨大差别。在野外调查的基础上,分析了山东半岛滨海沙滩前缘的植物种类及其种间关系。结果表明：（1）滨海沙滩前缘具有独特的优势种库,包括沙钻苔草（Carex kobomugi）、肾叶打碗花（Calystegia soldanella）、粗毛鸭嘴草（Ischaemum bartatum）、单叶蔓荆（Vitex trifolia var.simplicifolia）、矮生苔草（Carex pumila）和沙引草（Messerschmidia sibirica）等;（2）优势种库的成员都是潜在优势种,它们之间主要呈抑制效应,对库外物种几乎没有抑制效应,甚至有互补或互利效应。在进化过程中,这些潜在优势种可能已适应风暴潮的干扰,不会因受风暴潮灾害而灭亡。当植物适应风暴潮后,滨海沙滩不再是灾难环境,反而变为适宜生境。为持续利用这些物种,不仅要保护其赖以生存的天然生境,还要开展引种栽培,消除人们对野生资源的采挖动机。根据物种间的天然联系,栽培时宜将具有互利或互补关系的物种间混种植,不宜将具有抑制关系的物种间混种植。     

Variability of perigynium morphology of Central European members of Carex sect. Phaestoglochin (Cyperaceae) from variable plant communities

The number and range of taxa belonging to the Central European section Phaestoglochin (Carex L.) differ significantly among systematic classifications. Our study revealed that all of the quantitative morphological features of perigynia of Carex spicata Huds., Carex muricata subsp. muricata L., Carex muricata subsp. lamprocarpa ?elak., Carex divulsa subsp. divulsa Stokes, and Carex divulsa subsp. leersii Koch., had statistically significant differences among taxa. However, this differentiation did not reflect the known taxonomic divisions of the group and therefore, it did not represent a determining criterion for distinguishing the particular taxa. It also did not confirm the close and significant connections between subspecies within the species studied. Based on morphological features of perigynia, we showed that C. divulsa is a well-distinguished taxon, while the other taxa form a complex group. Analysis of the differentiation of perigynium features among the taxa studied against the background of the plant communities where the plants were grown indicated a distinct effect of the habitat conditions on the morphological features of perigynia.     

Heavy metal accumulation and distribution in forest understory herb species of Carpathian beech ecosystems

Abstract

This study addresses the issue of heavy metal (HM) accumulation and distribution for three different plant species, Carex pilosa, Dentaria bulbifera, Galium odoratum, in Carpathian beech ecosystems. Data are presented on HM concentrations in forest understory vegetation and a preliminary insight into different HM allocation patterns is provided. Bioaccumulation factors (BCFs) and shoot/root ratios differed considerably among the species and between polluted and unpolluted regions. HMs were accumulated in forest plants as follows: Cu > Zn > Cd >Pb in unpolluted areas and Zn> Cd > Cu >Pb in polluted areas. Zn was preferentially distributed to roots and Cu to shoots. The distribution of Cd and Pb in different plant parts was specific in terms of the species-dependence. Cd and Pb levels in Carex pilosaand Galium odoratumwere more strictly controlled in the transfer zone of root-shoot, compared to Dentaria bulbifera.The highest BCFs were found in Carex pilosafor Cu (5.9) and in Dentaria bulbiferawas found the highest shoot/root ratio for Cd (3.1).     

Enhanced nitrogen loss may explain alternative stable states in dune slack succession

Ecological theory emphasizes competitive interactions between plant species when explaining primary succession in plants. Ecosystem processes, such as nutrient accumulation, are often regarded as independent, steering successional changes without being affected by the interacting plant species. We present experimental evidence that plant species in wet dune slack systems are able to affect ecosystem processes in their favor by reducing the rate of nitrogen accumulation by coupled nitrification–denitrification, promoting their competitive position. We compared denitrification rates of two early successional species having radial oxygen loss (ROL) with two non-ROL late successional species in a mesocosm experiment. The denitrification rates were significantly higher in mesocosms planted with early successional species Littorella uniflora (P<0.001) and Schoenus nigricans (P<0.05), relative to the rates found in the presence of non-ROL species, Carex nigra and Calamagrostis epigejos . We analyzed the consequences of enhanced nitrogen loss on the competition between an early and a late successional species by means of a simple theoretical model. Our analysis revealed that early successional species capable of ROL might retard successional changes and lock the ecosystem in an unproductive state for an extended period of time. We emphasize that understanding of ecosystem processes is crucial in successful conservation of high biodiversity vegetation in wet dune slacks.     

山东半岛滨海沙滩前缘的野生植物

滨海沙滩是以海水影响为基本过程的地貌类型, 适应这种环境的植物类群与适生于内陆的沙地植物可能存在巨大差别。在野外调查的基础上, 分析了山东半岛滨海沙滩前缘的植物种类及其种间关系。结果表明: (1) 滨海沙滩前缘具有独特的优势种库, 包括沙钻苔草(Carex kobomugi)、肾叶打碗花(Calystegia soldanella)、粗毛鸭嘴草(Ischaemum bartatum)、单叶蔓荆(Vitex trifolia var. simplicifolia)、矮生苔草(Carex pumila)和沙引草(Messerschmidia sibirica)等; (2) 优势种库的成员都是潜在优势种, 它们之间主要呈抑制效应, 对库外物种几乎没有抑制效应, 甚至有互补或互利效应。在进化过程中, 这些潜在优势种可能已适应风暴潮的干扰, 不会因受风暴潮灾害而灭亡。当植物适应风暴潮后, 滨海沙滩不再是灾难环境, 反而变为适宜生境。为持续利用这些物种, 不仅要保护其赖以生存的天然生境, 还要开展引种栽培, 消除人们对野生资源的采挖动机。根据物种间的天然联系, 栽培时宜将具有互利或互补关系的物种间混种植, 不宜将具有抑制关系的物种间混种植。     

三江平原典型湿地植物中汞的分布与库存量

分析了三江平原典型植物中的总Hg浓度．结果表明,各种植物中总Hg浓度差别较大,苔藓>藻类>苔草>禾草>灌木;干湿环境是影响总Hg浓度的重要因素;湿地植物总Hg浓度高于水稻和玉米等农作物．较高的土壤总Hg浓度是近地面大气中Hg的重要来源,间接地影响到植物中Hg的浓度．植物各构件中总Hg浓度具有立枯>根>叶>茎的特点．在植物整个生长季总Hg浓度先增加后减少．估算了三江平原湿地植物Hg的库存量．小叶章湿地植物地上部分库存量为24．9μg·m^-2;毛果苔草湿地植物地上部分库存量为35．8μg·m^-2,高于加拿大实验湖泊湿地．     

Conservation priority of Italian Alpine habitats: a floristic approach based on potential distribution of vascular plant species

In the European Union, the Directive 92/43/EEC defines a number of species and habitats of community interest that are worthy to be preserved because in danger to disappear or because they are representative of the different European bio-geographical regions. In the light of the limited economic resources generally allocated to conservation efforts, there is the necessity to prioritise conservation actions in order to avoid deterioration of protected areas. To this aim, in the present study the most representative habitats of the Italian Alps are compared on the basis of vascular plant biodiversity and a conservation priority index is proposed for each habitat taking into account the potential distribution of 252 threatened vascular plant species. Rocky slopes, screes and alpine grasslands resulted to have the greatest percentage of endemic plant species so reflecting the general distributional pattern of endemic plant species at high altitudes in Eurasian mountains. The relationship between the conservation priority index and the corresponding habitat extent within the Natura 2000 network suggests that peatlands, arid grasslands, wet meadows and freshwater habitats deserve a higher priority in conservation actions. Although vascular plant biodiversity is not necessarily a surrogate of overall biodiversity of Alpine habitats, the results here reported can be used as an initial reference framework for prioritising conservation actions, so as to accomplish the provisions of Article 6 of Habitats Directive.     

Effect of light on seed germination of eight wetland Carex species

BACKGROUND AND AIMS: In wetland plant communities, species-specific responses to pulses of white light and to red : far-red light ratios can vary widely and influence plant emergence from the seed bank. Carex species are the characteristic plants of sedge meadows of natural prairie wetlands in mid-continental USA but are not returning to restored wetlands. Little is known about how light affects seed germination in these species-information which is necessary to predict seed bank emergence and to develop optimal revegetation practices. The effects of light on germination in eight Carex species from prairie wetlands were investigated. METHODS: Non-dormant seeds of eight Carex species were used to determine the influence of light on germination by examining: (a) the ability of Carex seeds to germinate in the dark; (b) the effect of different lengths of exposures to white light on germination; (c) whether the effect of white light can be replaced by red light; and (d) whether the germination response of Carex seeds to white or red light is photoreversible by far-red light. KEY RESULTS: Seeds of C. brevior and C. stipata germinated >25 % in continuous darkness. Germination responses after exposure to different lengths of white light varied widely across the eight species. Carex brevior required <15 min of white light for > or =50 % germination, while C. hystericina, C. comosa, C. granularis and C. vulpinoidea required > or =8 h. The effect of white light was replaced by red light in all species. The induction of germination after exposure to white or red light was reversed by far-red light in all species, except C. stipata. CONCLUSIONS: The species-specific responses to simulated field light conditions suggest that (a) the light requirements for germination contribute to the formation of persistent seed banks in these species and (b) in revegetation efforts, timing seed sowing to plant community development and avoiding cover crops will improve Carex seed germination.     

The effect of nutrient level on plant structure and production in a wet grassland: a field study

Since the 1950s, agricultural intensification has affected the structure and functioning of ecological systems including wet grasslands. Our study site, a wet grassland near Třeboň, Czech Republic, was historically a sedge meadow, but increased nutrient additions, a long-lasting flood in 2002 and changed mowing patterns resulted in domination by Phalaris arundinacea. The aim of the study was to determine how different nutrient conditions may affect plant structure and production in a wet grassland used for hay production. Species composition and percent cover were determined from line intercepts. Aboveground biomass was harvested six times each in 2007 and 2008 and primary production then calculated. Ingrowth core bags were used to determine belowground production. Aboveground production was two times greater in the high nutrient versus the low nutrient area in both years, while belowground production was very similar. The high nutrient area was still dominated by P. arundinacea, but Carex gracilis was now a co-dominant in the low nutrient area. However, other factors, such as water level and mowing regime, may interact with nutrient level to govern wet grassland structure and function.     

Response of Plant Height,Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands,Northeast China

Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region.     

Survival types of high mountain plants under extreme temperatures

Extreme temperatures are a main factor limiting plant growth in high mountain habitats. During winter, the risk of frost damage is highest at windblown and often snow-free sites. During summer, actively growing plants are particularly endangered by episodic cold spells, but also by short-term overheating. The current review gives an overview of extreme temperatures in the European Alps and observations of temperature damage on plants in their natural habitats. Furthermore, seasonal time courses of frost and heat resistance derived from laboratory tests on different plant growth forms are presented. Study species were the cushion plants Silene acaulis, Minuartia sedoides, Saxifraga oppositifolia and Carex firma collected on wind-exposed ridges; the rosette plant Soldanella alpina collected on snow-protected sites, and three Sempervivum species collected in xerothermic habitats.     

Migratory pathways,stopover zones and wintering destinations of Western European Nightjars Caprimulgus europaeus

Little is known about the wintering distribution of the European Nightjar Caprimulgus europaeus. We combined geolocator and GPS‐logger data from different sites in Western Europe to analyse migration routes and migration timing of this trans‐equatorial migrant. Nightjars followed a loop migration route during which they cross two ecological barriers, and converged near common stopover zones in Northern, Central and Western Africa, where they stayed for 2–3 weeks. Nightjars used the same stopover sites as several other European migrants, relying on small and discrete wintering areas within the Democratic Republic of Congo. This confirms the importance of these specific zones and highlights the vulnerability of Western European populations to habitat loss in their non‐breeding areas.     

Increasing substrate heterogeneity as a bet‐hedging strategy for restoring wetland vegetation

Mimicking the natural heterogeneity of wetland substrates, e.g. by roughening surface soil or constructing hummocks, has been shown to facilitate wetland plant establishment. We asked if incorporating substrate heterogeneity could also help plants withstand variation in moisture levels. In a wetland with Carex stricta (tussock sedge) as the main restoration target, we manipulated substrates to create different soil moisture environments for planted C. stricta plugs. Our artificial mounds mimicked tussocks formed by C. stricta in natural meadows (circa 10–40 cm in height); we also varied mound compositions and created shallow depressions. Monitoring demonstrated variation in soil moisture among our treatments and natural differences in soil moisture between experimental blocks. Additionally, rainfall varied from severe drought in year 1 to extreme rainfall in year 2. Plug survival, flowering, cover, biomass, leaf length, and growth rate all varied with treatment, block, and/or year. Interactions among those factors were common. Planting plugs in shallow depressions exacerbated stress in a wet block during a wet year, causing low survival. Planting plugs in moisture‐retaining peat pots allowed them to survive and sustain growth even in a dry block during a dry year. We conclude that heterogeneous substrates can be used to hedge against environmental variability by widening the range of microsites available within a restoration site and thereby moderating stressful conditions in some areas.