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).     

The distribution and composition of vascular plant communities on Heard Island

Summary Six major higher plant communities are defined for sub-Antarctic Heard Island: tussock grassland, meadow, herbfield, pool complex, cushion-carpet, fellfield. The communities were mapped at a scale of 1:50000, using colour aerial photographs and field observations. The floristic composition of twelve vegetation transects and of thirty sample quadrats along these is used to describe the communities and identify dominant or indicator species. The vegetation is compared with that of other sub-Antarctic islands.     

Limits to tree species invasion in pampean grassland and forest plant communities

Factors limiting tree invasion in the Inland Pampas of Argentina were studied by monitoring the establishment of four alien tree species in remnant grassland and cultivated forest stands. We tested whether disturbances facilitated tree seedling recruitment and survival once seeds of invaders were made available by hand sowing. Seed addition to grassland failed to produce seedlings of two study species, Ligustrum lucidum and Ulmus pumila, but did result in abundant recruitment of Gleditsia triacanthos and Prosopis caldenia. While emergence was sparse in intact grassland, seedling densities were significantly increased by canopy and soil disturbances. Longer-term surveys showed that only Gleditsia became successfully established in disturbed grassland. These results support the hypothesis that interference from herbaceous vegetation may play a significant role in slowing down tree invasion, whereas disturbances create microsites that can be exploited by invasive woody plants. Seed sowing in a Ligustrum forest promoted the emergence of all four study species in understorey and treefall gap conditions. Litter removal had species-specific effects on emergence and early seedling growth, but had little impact on survivorship. Seedlings emerging under the closed forest canopy died within a few months. In the treefall gap, recruits of Gleditsia and Prosopis survived the first year, but did not survive in the longer term after natural gap closure. The forest community thus appeared less susceptible to colonization by alien trees than the grassland. We conclude that tree invasion in this system is strongly limited by the availability of recruitment microsites and biotic interactions, as well as by dispersal from existing propagule sources.     

Rock outcrops in the southeastern part of the West Siberian plain as the northern limit of distribution and refuge of rare moss species

Foothill plains along the northwest periphery of Altai–Sayan Mountain Country are the northern limit of stony substrates in the West Siberian longitudinal sector. Rock outcrops in this area are rare; their areas usually do not exceed few dozens of square meters. Despite small areas, the rocky outcrops keep nearly half of the foothill moss flora. 119 moss species were recorded in the rocky habitat; 26 of them are rare both in Western Siberia and in its mountain ringing. An annotated list of species is given. Features of species distribution in the longitudinal sector of West Siberia are discussed.     

Vegetation structure and substrate of the northern part of the Great Dyke,Rhodesia environment and plant communities

Summary In the northern part of the Great Dyke, Rhodesia, the physiognomic and floristic differences between the vegetation types on serpentine and on non-serpentine substrates are very striking and the boundaries between these types are generally sharp. On either of the substrates there are also differences in the vegetation which correspond to differences in habitat. An outline of the Great Dyke environment is given. A number of plots, laid out in transects across the Great Dyke, were sampled according to the Braun-Blanquet approach. Six plant communities are distinguished and described in detail: one occurring on granite, two on pyroxenite and three on serpentine. The syntaxonomy of these communities is discussed. A riverine forest community which strongly differs from all these vegetation types is also described.Nomenclature is according to the present (1.1.1977) usage at the National Herbarium, Salisbury, Rhodesia.One of us (M. J. A. Werger) wishes to gratefully acknowledge the financial support for this study by the Netherlands Foundation for the Advancement of Tropical Research (WOTRO) and by the Faculty of Science, University of Nijmegen.     

Effects of environment,habitat configuration and forest continuity on the distribution of forest plant species

In present day European landscapes many forest plant species are restricted to isolated remnants of a formerly more or less continuous forest cover. The two major objectives of this study were (1) to determine the relative importance of habitat quality (mainly in terms of soil parameters), habitat configuration (patch size and isolation) and habitat continuity for the distribution of herbaceous forest plant species in a highly fragmented landscape and (2) to examine if groups of species with different habitat requirements are affected differently. Deciduous forest patches in northwestern Germany were surveyed for the presence of a large set of forest species. For each patch, habitat quality, configuration and continuity were determined. Data were analysed by Redundancy Analysis with variation partitioning for effects on total species composition and multivariate logistic regression for effects on individual species, for two different data sets (base‐rich and base‐poor forest patches). Overall, we found strong effects of habitat quality (particularly of soil pH, water content and topographic heterogeneity in the base‐rich forest patches; and of calcium content and disturbance in the base‐poor patches), but only relatively weak effects of habitat configuration and habitat continuity. However, a number of species were positively affected by patch area and negatively affected by patch isolation. Furthermore, the relative importance of habitat configuration tended to be higher for species predominantly growing in closed forests compared to species occurring both in the forest and in the open landscape.     

A new model estimating stonefly species production in the West Carpathian torrents

Samples of stoneflies were collected from 15 streams of Slovakia during 1976–2000. The model of growth rate is based on 219 data of 50 stonefly species. The non-linear relationship among growth rate (G) of stoneflies and monthly mean water temperature (T) and body mass (W) is described by equation: G = 0.014W ^−0.19 T ^0.25. The model estimates the species production of the families Taeniopterygidae, Nemouridae, Capniidae, Leuctridae and Perlodidae. This model is combined with Morin’s & Dumont’s (1994) model for Perlidae and Chloroperlidae. There is positive evidence that the total stonefly production of mountain and submountain streams increases with discharge. On the other hand, increasing altitude has a negative influence on production.     

A phytosociological analysis of woody species in forest communities of a part of Kumaun Himalaya

This paper reports on a detailed phytosociological analysis of forests in the NW catchment of the Gola River in Kumaun Himalaya, 29°19–29°27N and 79°32–79°42E. Fourteen sites and 56 stands at elevations ranging from 1200 to 2523 m and covering the following five forest types were investigated: Pinus roxburghii, mixed, Quercus leucotrichophora, Q. lanuginosa, and Q. floribunda. The basal cover of the forests differed according to slope position and aspect. The three oak forests had more basal cover than the other two, and Q. lanuginosa had the most. The performance of individual tree and shrub species and the number of saplings and seedlings differed according to slope position and aspect. The mixed forest had the greatest tree diversity, and among the others diversity increased with increasing basal cover. The diversity of trees, saplings, and herb layer was greatest on aspects with intermediate temperature and moisture conditions; whereas that of shrubs and seedlings increased towards the cooler (and wetter) and warmer (and drier) exposures. There was a positive relation between the diversity of shrubs plus seedlings and trees plus saplings in P. roxburghii and mixed forests; whereas this relationship was inverse in the three oak forests. In general, the dominance-diversity curves for the tree layer followed a geometric series conforming to the niche pre-emption situation in communities of low diversity. Among the forests, the regeneration was best in Q. lanuginosa and worst in Q. leucotrichophora.Nomenclature follows: Osmaston (1926).Finacial support from the Council of Scientific and Industrial Research, New Delhi and the Indian Space Research Organisation, Banglore is gratefully acknowledged.     

Different aspects of plant diversity show contrasting patterns in Carpathian forest openings

It has long been known that α- and β-diversity are driven by different ecological processes. Recently, several theoretical papers have suggested that β-diversity can be expressed in many different ways, and that these measures might have different meanings and behaviours. In terms of ecological understanding, it is important to test how these diversity measures behave in different settings, yet this has been rarely attempted. We investigated this question using forest openings in the Trasc?u Mountains, Romania, which contain species from grasslands of high nature value. The sampling was conducted in 40 openings, using edge-to-interior transects composed of 1-m² plots (α-diversity), from which we calculated five β-diversity measures at transect level. As predictor variables, we used canopy openness (from hemispherical photos), tree litter cover, heat load index, altitude, and bedrock type for α-diversity, and the means and ranges of these for β-diversity. Generalized linear mixed models showed that α-diversity was mostly explained by the first two variables. Amongst the β-diversity measures, the classical additive and multiplicative measures differed, the latter being similar to the Sørensen-based multiple-site dissimilarity. None of the predictors explained the slope of distance decay or Simpson-based multiple-site dissimilarity, except when considering ecological subsets of the species. We discuss the possible ecological processes underlying the different results, and the implication of our findings for nature conservation in the region. In conclusion, we support the joint application of different measures of α- and β-diversity, as long as their particular properties are taken into account.     

Factors influencing the spatial distribution of forest plant species in hedgerows of North-western Germany

In North-western Germany woodland fragmentation has caused a decline in many forest plant species. Hedgerows partly offer a similar environment as forests and have been identified as potential habitats for forest plants in various studies from North America and Western Europe. The objective of this study was to examine whether this applies also to Central Europe and which variables affect the spatial distribution and abundance of forest plant species in hedgerows on a local scale. Three hedgerow networks north of the city of Bremen, Germany, were selected as study areas and divided into totally 515 hedgerow segments. In each segment we recorded all vascular plants and a large number of explanatory variables relating to structure, spatial configuration, environment and management. Averaged across species there was a predominant effect of environmental factors on the occurrence of forest species in the hedgerows, followed by spatial configuration and management. Hedgerow structure was found to be less important. In general, forest species were favored by low nutrient and light availability as well as high connectivity with other hedgerows or forest; they avoided hedgerows with a west-easterly orientation and an adjacent land use in the form of fields or grasslands. Forest species found and not found in hedgerows did not differ in their environmental preferences or life history traits. The number of threatened forest species in the hedgerows, however, was lower than expected with respect to their overall proportion to the total number of forest species in the region.     

The distribution of cholinesterases in plant species

The neostigmine-inhibited hydrolysis of acetylthiocholine has been found in extracts prepared from 23 species from five of the 24 families assayed: Characeae, Cruciferae, Graminae, Leguminosae, and Solanaceae but not present in 33 other species. In no case was activity found in all species tested from the five positive families. In extracts prepared from Phaseolus aureus Roxb. there was an agent which decolorizes the product formed in the calorimetric assay used for assaying cholinesterase. This decolorant is heat-inactivated and partially dialyzable.     

Non-woody life-form contribution to vascular plant species richness in a tropical American forest

We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in central Bolivia. Species richness ranged from 297 species and 22,360 individuals/ha in the dry deciduous forest to 382 species and 31,670 individuals/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich major plant groups in each plot, and Peperomia (Piperaceae), Pleurothallis (Orchidaceae) and Tillandsia (Bromeliaceae), all epiphytes, were the most species-rich genera. This dominance of a few but very diverse and/or widespread taxa contrasted with the low compositional similarity between plots. In a neotropical context, these Central Bolivian forest plots are similar in total species richness to other dry deciduous and humid montane forests, but less rich than most Amazonian forests. Nevertheless, lianas, terrestrial herbs and especially epiphytes proved to be of equal or higher species richness than most other neotropical forest inventories from which data are available. We therefore highlight the importance of non-woody life-forms (especially epiphytes and terrestrial herbs) in Andean foothill forest ecosystems in terms of species richness and numbers of individuals, representing in some cases nearly 50% of the species and more than 75% of the individuals. These figures stress the need for an increased inventory effort on non-woody plant groups in order to accurately direct conservation actions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Stand stratification and woody species diversity of a subtropical forest in limestone habitat in the northern part of Okinawa Island

Stand stratification and woody species diversity were studied in a subtropical forest in limestone habitat in the northern part of Okinawa Island, Japan. The forest stand consisted of four architectural layers. Cinnamomum japonicum Sieb. was the most dominant species as it had the highest importance value in all layers, especially in the lower three layers. Although Rhus succedanea L. was a major top-layer species, it might disappear because of its absence in the lower two layers. The lower two layers had similar floristic composition, while the composition of the top layer differed greatly from that of the lower two layers. The value of H′ in each layer increased from the bottom to the second layer and then decreased, and the value of J′ in each layer consistently increased from the bottom layer upward. The values of Shannon’s index H′ and Pielou’s index J′ were 4.27 bit and 0.74, respectively, at the stand level. The trends of H′ and J′ based on the cumulative height range from the top layer downward were, respectively, the same as those in each layer for the present forest in limestone habitat. However, these trends were opposite from those of a nearby subtropical forest in silicate habitat, where the values of H′ and J′ based on the cumulative height range decreased steadily from the bottom layer upward.     

Landscape-dependent distribution of northern forest birds in winter

We evaluated the effects of landscape structure, along a broad gradient of deforestation (forest cover 8–88%, 500-m radius), on the spatial distribution of forest birds exposed to winter climatic conditions, in Quebec, Canada. Concurrently, we conducted an experiment to determine if these effects would persist if an unlimited source of energy, provided by food-supplementation, became available. We analyzed these effects at the population level, using count data of black-capped chickadees Poecile atricapillus , but also at the community level, referring to species richness. In one of the two years of the study, before food-supplementation began (November), forest integrity (a composite of forest cover and edge density) was positively associated with chickadee abundance and species richness. Each year, forest integrity was also positively associated with chickadee abundance and species richness in landscapes that were supplemented (December–February). However, in control landscapes, during the food-supplementation period, chickadee abundance and species richness tended to decrease with an increase in forest integrity. We argue that the more forested control landscapes facilitated winter emigration of juveniles and transient birds. Conversely, our results further suggest that, in the highly deforested and fragmented control landscapes, birds became gap-locked when rigorous winter climatic conditions exacerbated already existing movement constraints.     

Diversity and dominance patterns in Amazon coast dune forest island tree communities

Aiming to better understand richness, dominance, diversity and community changes of coastal vegetation, we studied woody plant communities and soil parameters of equatorial dune forest islands. We investigated four sites isolated by mangroves (Buraco Beach, Bonifácio, Camarauaçu, Apeu-Salvador) and compared data to a paleodune forest with higher floristic and structural complexity (Salinas do Roque) for assessment of the regional species pool. We determined grain size distribution and organic matter content at Buraco Beach, Camarauaçu and Apeu-Salvador. Grain size distribution was similar among sites but upper soil layers at Camarauaçu showed low organic matter contents. We recorded trees and shrubs along several transect plots crossing forested dune ridges and surveyed areas outside of plots for additional species. Richness was lower at Camarauaçu (18 species vs. 25, 26 and 28 at Bonifácio, Apeu-Salvador and Buraco Beach, respectively). Fisher’s α ranged between 3.2 and 4.7, Pielou’s J’ between 0.70 and 0.80. Rényi profiles confirmed lower diversity for Camarauaçu, dominated by a small group of species with high importance values. Within-site beta diversity was lowest at Buraco Beach. Species were mainly wide-spread generalists. We found low richness compared to the Salinas do Roque reference site; null model tests indicated that the species pool of the dune sites was partly shaped by environmental filtering. We attribute differences in species composition and diversity/dominance patterns among the four dune sites to distance to the mainland and stochastic events with effects on non-standard long distance dispersal.     

Blackfly (Diptera, Simuliidae) communities and species richness estimation in Carpathian montane streams

The present work gives the result of blackfly fauna research of the Slovenský raj (West Carpathians, Slovakia). Our aim was to describe the composition of blackfly communities, find indicator species for communities, describe environmental factors affecting communities and determine the potential changes in species richness. Research was carried out in 2007 and 2008. The presence of 22 species of blackflies was confirmed at 20 sites in the area of Slovenský raj. 12 species were recorded for the first time in this area. The potential for further increase in diversity was calculated by a nonparametric estimation of species richness. Two main groups of sites with their typical blackflies communities were indentified using a TWINSPAN analysis. The presence of Simulium ornatum, S. variegatum and S. argyreatum was typical in larger streams in broad valleys. The absence or low abundance of these species was typical for smaller streams in canyons. Based on the species composition of blackflies communities, we identified 6 groups of sites: 1. anthropogenically disturbed submountain rivers (typical species: Simulium ornatum, S. reptans, S. equinum), 2. undisturbed metarhithral (typical species: Simulium bertrandi, S. codreanui, S. costatum, S. vernum, S. argenteostriatum, S. degrangei, S. argyreatum, S. variegatum), 3. undisturbed hyporhithral (typical species: Simulium trifasciatum, S. tuberosum), 4. undisturbed epirhithral (typical species: Prosimulium hirtipes, P. rufipes), 5. hypocrenal (typical species: Simulium cryophilum, S. monticola) and 6. anthropogenically disturbed epirhithral (typical species: Simulium brevidens, S. maximum). The most important environmental factors explaining differences in species composition like altitude, flow speed, pH, conductivity, oxygen saturation, sulphates concentration and presence of riparian vegetation were identified by the CCA analysis.     

The role of introduced species in shaping the distribution and abundance of island reptiles

Summary Species interactions, as revealed by historical introductions of predators and competitors, affect population densities and sometimes result in extinctions of island reptiles. Mongoose introductions to Pacific islands have diminished the abundance of diurnal lizards and in some cases have led to extinctions. Through these population level effects, biogeographic patterns are produced, such as the reciprocal co-occurrence pattern seen with the tuatara and its predator, the Polynesian rat, and with the tropical gecko competitorsHemidactylus frenatus andLepidodactylus lugubris in urban habitats in the Pacific. Although competition has led to changes in abundance and has caused habitat displacement and reduced colonization success, extinctions of established reptile populations usually occur only as a result of predation.These introductions, along with many manipulative experiments, demonstrate that present day competition and predation are potent forces shaping community structure and geographic distributions. The human introduction of species to islands can be viewed as an acceleration of the natural processes of range expansion and colonization. The immediate biotic consequences of these natural processes should be of the same intensity as those of the human introductions. Coevolution may subsequently act to ameliorate these interactions and reduce the dynamical response of one species to the other. The role played by coevolution in mediating interactions between competitors and predator and prey is highlighted by the susceptibility of predator-naive endemic species to introduced predators and the invalidity of species-poor communities.     

天山北麓中段拟南芥生存群落主要种群种间联结性

运用种间联结测定方法研究了天山北麓中段拟南芥(Arabidopsis thaliana)生存群落24个主要种群的种间联结特征.结果表明:群落内物种总体联结方差比率(VR)为1.55,表现为显著正联结.24个物种组成的276个种对中,有123对表现出正关联(V>0),150对为负关联,3对无关联.χ2检验有61对表现显著或极显著正关联,有24对表现显著或极显著负关联.有232个种对00.6,另有32个种对OI=0,表明多数物种间联结性较弱或无联结.DCA分析显示,排序图中的种间距离较好地表示了种间联结的强弱.拟南芥与新疆绢蒿(Seriphidium kaschgaricum)、猪毛菜(Salsola collina)等耐旱植物关系密切,对它们依赖性较强,表明拟南芥具有较强的抗旱特性.拟南芥与邻近种庭芥(Alyssum desertorum)呈极显著正关联,与丝叶芥(Leptaleum filifolium)和舟果芥(Tauscheria lasiocarpa)显著正关联,表明它们生态需求相似,生境趋同.拟南芥与邻近种小拟南芥(A.pumila)等联结性较弱,生境趋异.多数十字花科短命植物之间以及它们与群落优势物种之间具有较强的关联性,体现了该科物种在干旱区分布的特点.