Meadow Plant Research Articles

The water retention capabilities of growing media for green roofs

Green roofs can help reduce the risk of peak water flow and flooding in urban areas by reducing the amount impermeable surfaces on built land. This paper examines the contribution of growing media composition and depth to the water retention capabilities of green roof systems. Green roof simulation decks (decks) 1m×1m were filled to a depth of 75mm with growing media made with coarse crushed brick, coarse crushed tile or Lytag® amended with 10% (v/v) or 20% (v/v) composted green waste and planted with sedums (sedum decks); or to a depth of 150mm with growing media made with fine crushed brick, fine crushed tile or Lytag® amended with 20% (v/v) or 30% (v/v) composted green waste and planted with flowering meadow plants (meadow decks). Growing media composition affected water holding capacity which in turn influenced water retention on the decks. The results indicated that both intra-particle pore spaces and inter-particle pore space distribution which was determined by particle size distribution were important determining factors of both water holding capacity and rainwater retention.

Cellvibrio diazotrophicus sp. nov., a nitrogen-fixing bacteria isolated from the rhizosphere of salt meadow plants and emended description of the genus Cellvibrio

Two Gram-reaction-negative, aerobic, nitrogen-fixing, rod-shaped bacteria, designated strains E20 and E50(T), were isolated from the rhizosphere of salt meadow plants Plantago winteri and Hordeum secalinum, respectively, near Münzenberg, Germany. Based on the 16S rRNA gene sequence analysis both strains E20 and E50(T) are affiliated with the genus Cellvibrio, sharing the highest similarity with Cellvibrio gandavensis LMG 18551(T) (96.4%) and (97.1%), respectively. Strains E20 and E50(T) were oxidase and catalase-positive, grew at a temperature range between 16 and 37 °C and in the presence of 0-5% NaCl (w/v). The DNA G+C contents were 52.1 mol% (E20) and 51.6 mol% (E50(T)). Major fatty acids of strains E20 and E50(T) were summed feature 3 (C16 : 1ω7c and/or iso-C(15 : 0) 2-OH), C(16 : 0), C(18 : 1)ω7c, C(12 : 0), C(18 : 0) and C(12 : 0) 3-OH. The DNA-DNA relatedness of the strains to Cellvibrio gandavensis LMG 18551(T) was 39% for strain E20 and 58% for strain E50(T). The nitrogen fixation capability of strains E20 and E50(T) was confirmed by the acetylene reduction assay. On the basis of our polyphasic taxonomic study, strains E20 and E50(T) represent a novel species of the genus Cellvibrio, for which the name Cellvibrio diazotrophicus is proposed. The type strain of Cellvibrio diazotrophicus is E50(T) ( = LMG 27267(T) = KACC 17069(T)). An emended description of the genus Cellvibrio is proposed based on the capability of fixing nitrogen and growth in presence of up to 5% NaCl (w/v).

Diet selection in overwinter caches of plateau zokor (Eospalax baileyi)

Subterranean herbivores affect the plant community by plant consumption and burrowing activities. However, diet selection of subterranean herbivores has not been studied in detail in complex natural fields, mainly for lack of an accurate method to determine diet species, frequency, and biomass. Plateau zokors' (Eospalax baileyi) caching habit for the long inclement winter makes it possible to solve this problem. We studied the diet composition and biomass in caches and vicinity of plateau zokors' burrow systems. We found that plateau zokors are dietary generalist but show a significant selection among the available food items, plant parts, functional groups, organ types, and habitats. These results suggested that plateau zokors strictly selected their diet and were able to adjust their foraging strategy according to the different conditions of food abundance and quality. Plateau zokors' selective foraging can directly reduce the proportion of toxicity forbs; plateau zokors can be recognized as an important element to influence the alpine meadow plant community and cattle husbandry.

The Melliferous Potential of Forest and Meadow Plant Communities on Mount Tara (Serbia)

The apiflora of 34 forest and meadow plant communities in Tara National Park was studied with the aim of assessing their melliferous potential and their contribution to bee pasture during the vegetation period. The melliferous plants were analyzed individually from the aspect of their flowering phenology, abundance, and the intensity of nectar and pollen production, as well as the production of honeydew. The melliferous potential of each investigated plant community was theoretically assessed on the basis of the coenotic coefficient of melliferousness incorporating a phytocoenotic analysis, the coenotic coefficients of nectar and pollen production, and the percentage of melliferous species in relation to the total number of species that characterize the association. The highest percentage of the melliferous species was noted in the meadow association Petasitetum hybridi (70%) and the forest association Piceetum-Abietis serpentinicum (63.6%). The highest values of the coenotic coefficient of melliferousness were established for the forest association Querco-Carpinetum iliricum, and the meadow association Rhinantho-Cynosuretum cristati. Trees notable for their honeydew production in good quantities were Pinus nigra Arnold, Picea sp. Fagus sylvatica Linnaeus, Populus tremula Linnaeus, and Quercus cerris Linnaeus. Because, the vegetation in the study area is forest dominated, forest bee pasture including early flowering herbaceous and woody plants, is of the greatest significance for the honey bee, both in the early spring because of pollen and nectar production, and in the autumn as a source of honeydew.

Floristic quality assessment for marshes in Alberta's northern prairie and boreal regions

Floristic quality indices are used to monitor and assess wetland condition by measuring a plant community's tolerance to environmental stress. The aim of our research was to evaluate whether stormwater and reclamation marshes supported wet meadow plant communities that were similar in floristic quality to reference wetlands. Coefficients of conservatism were assigned to a comprehensive list of marsh plant species by nine expert botanists. Various metrics such as the floristic quality index (FQI) were tested for a linear relationship to regional environmental stress gradients in 78 sites in the northern prairies (Aspen Parkland) and 66 sites in the Boreal Plains ecoregions in Alberta, Canada. Sensitivity of floristic quality metrics to the stress gradients was higher when rare species were excluded (species with <5% site-level cover). An adjusted FQI that eliminated bias towards sites with higher species richness yielded the strongest relationship to the stress gradient in both ecoregions (r2 = 0.55 in northern prairies; r2 = 0.46 in Boreal Plains). The adjusted FQI also yielded more consistent scores than richness-weighted metrics in a subset of 47 sites where sampling was replicated in dry and wet years (r = 0.75). Including exotic species in floristic quality metrics was not beneficial in the northern prairies where reference sites were located near areas of high urban and agricultural development. This study demonstrates that floristic quality assessments are reasonably good predictors of plant community condition in relation to environmental stress. Results of this study also highlight that existing stormwater ponds and reclamation marshes are not successfully restoring plant community habitat.

Comparison of soil seed banks of habitats distributed along an altitudinal gradient in northern Iran

In this study we investigated the variations in soil seed banks along an altitudinal gradient in the Alborz mountains, Iran, covering three habitats from lower to upper altitudes: forest, forest-subalpine grassland ecotone and subalpine meadow. In each habitat from 1850 to 2400m, 20 quadrats were established along four transects, and the above-ground vegetation and the germinable seed banks were determined. Results show that the similarity between seed bank and vegetation was lowest in the ecotone located at intermediate altitudes. Together with the contrasting highest density and species diversity of seeds at these altitudes, the ecotonal role of this habitat was confirmed.We found evidence that lower altitudes could act as storage for seeds of some species growing at higher altitudes; the role of the ecotone was more prominent as a reserve for the meadow plant seeds than the role of the forest as a reserve for seeds of the meadow and ecotone habitats. Soil seed banks, particularly from the ecotone, can be used for restoring vegetation in some degraded sites.

Downfall of meadow plants communities on the Left Bank Forest-Steppe Boundary in Ukraine

The research was carried out on the different types of grassland plant communities on the left-bank forest boundary in Ukraine. It was established that the supplies of downfall on the floodplaine meadows were within 37,3–1973,7 g/m2, upland medows – 21,8–627,3 g/m2, lowland medows – 70,0–1363,0 g/m2. The results of the research made it possible to identify three groups of indicators on the amount of downfalls. The first group consists of the areas with such amount of dawnfall as – 80.0 g/m2, the second one – 80,0–160,0 g/m2, and the third one – more than 160.0 g/m2. The change rate which depends on the part of the floodplain medows was considered. In the riverine area it was defined in the range of 31,8–663,6 g/m2, in the central area – 41,8–1973,7 g/m2, in the pre-terrace area – 37,3–1654,6 g/m2. The difference among minimal parameters is small but among maximum is significant. It is generally accepted that the results of the research are mainly supported by specific differences of floristic composition. The larger number of indicators (within the second group) are in the central parts of the investigated floodplains and rivers. In the central areas in general, there was a higher level of dry matter content. Combined with the increasing amount of downfall, to some extent, it is considered to be an indicator of higher crop level in this area. It was figured out that in some areas the upland meadows have got different number of the investigated indicators. The most important factors for this issue are the lower parts of the area but the minimum are the tops of the slopes. The difference can be quite significant. The comparison between the formation of downfall in the upland grasslands and the steppe area showed a certain regularity. In steppe areas the accumulation of the indicator was nearly one third less than the average one in the investigated meadows. The number of dry matter varied in the range of 31,8–95,7 %. The lower indicators as well as the upper ones differed in general not more than 10,0 %. In general the amount of dry matter content was the highest on the top of the slopes ant the lowest amount was on the bottom. In the overwhelming majority of surveyed lowland there was an increasing level of accumulation in the second and third groups.The comparison of the results about the accumulation of the downfall in the lowland meadows in the studied forest-steppe and steppe regions of Ukraine, which borders on the South, showed that its accumulation in the steppe regions was much less comparatively to the surveyed regions. Dry matter content of the downfall of this grassland areas was in the range of 31,9–94,4 %. We found that the energy storage of downfall meadow plant communities of the region is in the range of 0,4 × 106–37,1 × 106 Dzh/m2. Each type of medows has its own specific characteristics of the index and indicators. Thus, energy storage on the floodplaine was within 0,6 × 106–37,1 × 106 Dzh/m2, upland 0,4 × 106–12,1 × 106 Dzh/m2, lowland meadows – 1,3 × 106–25,7 × 106 Dzh/m2. Indicators of lowland meadows occupy an intermediate position between floodplain and upland areas. The comparison of borderline indicators allows us to see that they vary greatly both upper and lower. Minimal indicators are differe for 0,2 × 106–0,7 × 106 Dzh/m2 and maximum 7,3 × 106–16,1 × 106 Dzh /m2. The reduction of economic activity, in particular, the implementation of conservation as for all investigated meadow plant communities of the region leads to increasing amount of downfall in average. Weather conditions influences greatly the accumulation of the downfall. The analysis of climat map which was presented, shows us more favourable weather conditions during particular years. That is why the maximum storage of downfall was observed during this period.

Effects of nitrogen fertilization on β-caroten content in meadow plants

β-caroten content was estimated in the leaves of <em>Alopecurus pratensis, Festuca rubra, Festuca pratensis, Holcus lanatus, Poa pratensis, Carex hirta, Carex Hudsonii</em> <em>and Plantago lanceolata</em> from two different meadows on which different nitrogen fertilization and uniform phosphorus and potassium fertilization were applied. Nitrogen fertilization was found to affect the accumulation of β-caroten in plants.

Effects of some physical properties of the soil and of accompanying species on the β-caroten content in meadow plants

β-caroten content was estimated in the leaves of 8 selected species of meadow plants from two meadows on which rolling was done once or twice. The percent content of accompanying plants occurring on the examined meadows was estimated on the basis of the biomass of these species. The volume weight and the water relationships were estimated in the soil. The accumulation of β-caroten in the examined plants was found to depend on the physical properties of the soil which change as a result of rolling. Moreover, various species of accompanying plants (symptoms of allelopathy) affect the accumulation of β-caroten in plants.

Determination of Insecticide Application Time in Alfalfa Crops AgainstSitona Humeralis Stephens, Based on its Biology and Ethology

ABSTRACTSitona humeralis (S.) is the most dangerous insect in the Mediterranean region, which infests Medicago sativa, causing a considerable loss of the final produce. In the last years, surveillance of S. humeralis adults took place by means of scanning sampling in alfalfa fields and probable aestivation sites in Northern, Central and Northwestern Greece. The insect was found to aestivate either in mountainous regions or in regions situated near lakes, rivers or the sea, where the temperatures are lower than those in the fields, attacking mainly natural meadow plants. The insect's migration is due to the need of this period in order to give the eggs the time necessary to mature inside the ovarian tubes. In the alfalfa fields, the greatest number of adults collected was recorded from March to June and in September up to November when the adults mated and oviposited, with a peak in October; in the aestivation sites this happened during the hot months July and August. The findings of the present work permit us to define the timing for the application of control measures against S. humeralis in the alfalfa fields.

Alpine Moist Meadow Response to Nitrogen Deposition in the Greater Yellowstone Ecosystem

The deposition of anthropogenic reactive nitrogen (N) in alpine ecosystems can have multiple deleterious effects on plants, soils and hydrology in both the alpine and areas downstream through leaching and export. Thresholds for ecological responses to N deposition have been established for lakes, soils and changes in plant community composition in some areas of the Rocky Mountains. These thresholds offer a target for land and air resource managers to prevent significant changes in ecosystem function, however the underlying feedbacks controlling ecosystem response have not been fully examined. Research originally proposed in association with our UW NPS Small Grant aimed to examine plant to ecosystem interactions within alpine moist meadows between two sites receiving different levels of N deposition. This focus has been modified, in response to site limitations, to examine the mediation of the N cycle by the alpine moist meadow plant community.

基于PCA的滇西北高原纳帕海湿地退化过程分析及其评价

PDF HTML阅读 XML下载 导出引用 引用提醒 基于PCA的滇西北高原纳帕海湿地退化过程分析及其评价 DOI: 10.5846/stxb201205060653 作者: 作者单位: 同济大学环境科学与工程学院污染控制与资源化国家重点实验室，长江水环境教育部重点实验室，上海,同济大学环境科学与工程学院污染控制与资源化国家重点实验室，长江水环境教育部重点实验室，上海,同济大学环境科学与工程学院污染控制与资源化国家重点实验室，长江水环境教育部重点实验室，上海 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目(41171074, U0933601, 40771013) Process analysis and evaluation of wetlands degradation based on PCA in the lakeside of Napahai, Northwest Yunnan Plateau Author: Affiliation: Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China,Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China,Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以滇西北高原纳帕海湖滨过度放牧、水文改变协同胁迫(简称GAD)和过度放牧单独胁迫(简称GD)退化湿地为研究对象,将其划分为4个梯度:原生湿地、轻度退化、中度退化、重度退化,采用聚类分析和主成分分析(PCA)在"植物-水体-土壤"系统上进行湿地退化过程、机制探讨及定量评价。沿退化梯度,植物群落演替规律为"水生植物群落→沼泽植物群落→沼泽化草甸植物群落→草甸植物群落",群落结构趋于复杂,向中生植物群落演替;矿化度、总硬度、总碱度、氮、磷等水质指标在GD梯度上升,在GAD梯度下降,水文改变对水质影响显著;土壤有机质、全氮、速效氮含量降低,全磷、全钾有所增加,速效磷和速效钾含量无明显变化规律。基于PCA建立了纳帕海湖滨湿地退化模型,并给出不同程度退化湿地的阈值。 Abstract:Napahai wetland is a unique and seasonal marsh wetland located in the middle of Hengduan Mountains, northwestern Yunnan Plateau. In the recent decades, it has been seriously degraded under human disturbances, mainly including drainage and overgrazing. In the present paper, two kinds of typical degradation transects were established to evaluate the synergistic impacts of overgrazing stress and water regime and the single impacts of overgrazing stress in the lakeside of Napahai. The two transects were further classified into four degradation gradients, including primary wetland(PW), lightly degraded wetland (LW), moderately degraded wetland (MW) and severely degraded wetland (SW). Cluster analysis and principal component analysis (PCA) were conducted to explore the process and mechanism of wetland degradation as well as to evaluate the degree of wetland degradation quantitatively at system level of "vegetation-water-soil". The results were as follows: the numbers of plant families, genera and species as well as species diversity and richness all increased gradually from PW to SW, whereas species evenness remained stable. The plant community succession is in the direction of aquatic plant community→swamp plant community→swamp meadow plant community →meadow plant community. Correspondingly, the community changed towards more complicated structure characterized by the decreasing of helophyte and increasing of hygrophyte and mesophyte. Overgrazing stress changed the inherent mode of plant community succession and accelerated the degraded stage of "swamp meadow community" to some extent, although the direction of succession had not changed. The degradation characteristics of water properties varied in different disturbance type, the water indices of salinity, total alkalinity, total hardness, total nitrogen, ammonia nitrogen, nitrate nitrogen and total phosphorus all increased along the GD gradients, whereas decreased along the GAD gradients, depending on the water regime. Therefore, hydrologic alteration had a significant effect on wetland water properties. The changes of wetland soil properties were similar in the two disturbances. Among them, the contents of organic matter, total nitrogen and available nitrogen decreased, total phosphorous and total potassium (K) increased, whereas the available phosphorous and available potassium (K) showed no obvious changes. The vertical distribution for each nutrient content in the soil profiles of degraded wetlands varied greatly. Soil total phosphorous, available phosphorous and available potassium (K) decreased along the soil depth gradients. It showed that soil nitrogen content was the most obvious characteristics of wetlands degradation. In order to identify the driven factors of wetlands degradation under the multi-factorial stresses, PCA was employed to synthesize the degradation information from multiple aspects as discussed in this paper. Thirty indices based on vegetation, water and soil were simplified into three principal components by PCA, explained 54.8%, 29.1% and 15.9% of the total variance, respectively. PCA results indicated that plant community was the most representative of wetlands degradation, and the soil structures and nutrient contents changed significantly along the degradation gradients of lakeside wetlands, Napahai. By contrast, the contributions made by water nutritional contents were lowest compared with vegetation and soil for wetlands degradation. Based on the three principle components derived from PCA, a multiple linear regression model, PC=0.548×PC1+0.291×PC2+0.159×PC3, was conducted to calculate the scores for each degradation stage, which could be taken to evaluate the wetlands degradation. 参考文献 相似文献 引证文献

The biodiversity and stability of alpine meadow plant communities in relation to altitude gradient in three headwater resource regions

Kobresia pygmaea meadow community diversities in relation to altitude gradients (4200, 4300, 4400, 4450) on free grazing grassland was studied in the range of Chenduo county, Yushu prefecture, Qinghai province. Species richness and diversity index of vegetations in the four altitudes were comparatively analyzed. The results showed that the shape of species richness responsive curves to altitude gradient is “Bell-shape”. There were the same 11 common species in the four communities. The relative abundance of K. pygmaea decreased along increasing altitude. Moreover, the fuzzy membership functions were used to calculate the degree of stability, showing medium altitude > high altitude > low altitude, which suggested that grass land vegetation in low altitude of the sampling site had lower diversity, and the grade of species vulnerability risks may be decided with the help of the degree of stability. Key words : Alpine meadow, Yangtze, Yellow and Yalu Tsangpo river source region, altitude gradient, species diversity, membership functions.

Does soil nitrogen availability mediate the response of grassland composition to water regime?

AbstractQuestionsHow is the composition of wet meadow plant communities influenced by water regime? What controls soil nitrogen (N) availability along a gentle soil water regime gradient? Is vegetation response to subtle changes in soil water regime mediated by N availability?LocationCricklade, Wiltshire, southwest England.MethodsA field survey of community composition and soil N availability was conducted along a gentle gradient of water table depth (mean water table depth between 25 and 70 cm) at a species‐rich hay meadow in southwest England. This study was complemented by a controlled mescosm study undertaken at water table depths between 5 and 45 cm, and a controlled laboratory N mineralization study with water tension varying between 0 and 100 cm (0–10 kPa), the latter augmented with a microbial community study.ResultsThe field, mesocosm and laboratory studies showed that the soil N mineralization rate and N availability responded to water regime. In particular, the N mineralization rate strongly declined when the soil air‐filled pore space dropped below 10% of total soil volume. In the field, plant cover distribution (individual species as well as functional groups) correlated with increase in soil water table depth (r = −0.86 and r = 0.89 for graminoids and forbs, respectively) and soil N availability (r = 0.77 and r = −0.85, respectively). A switch in dominance between forbs and graminoids occurred at a mean water table depth of 55 cm and mean soil inorganic N of 20 mg·kg−1). Study of the soil microbial community composition in the mesocosms, using phospholipid fatty acid (PLFA) signatures, showed that microbial community composition was also significantly influenced by soil water status.ConclusionsWe show that soil moisture content and soil aeration control the availability of N, a limiting nutrient, in species‐rich wet meadows. The mechanism is linked to changes in suitability of the soil water regime for microbially mediated N mineralization. Maintaining the water regime is therefore critical because adjustment of the hydrological niche also conditions species' responses along the N availability gradient. This could subsequently prove a useful tool for conservation managers trying to sustain a target vegetation type.

Stochastic and deterministic processes together determine alpine meadow plant community composition on the Tibetan Plateau

To predict the consequences of environmental change on the structure and composition of communities, it is necessary to also understand the regional drivers underlying the structuring of these communities. Here, we have taken a hypothesis-based approach to test the relative importance of niche versus neutral processes using niche overlap, species traits and population asynchrony in two crossed treatments of fertilization and grazing in an alpine meadow community. Our results suggested that the observed species biomass overlap was not significantly different between treatments of grazing, grazing × fertilization and grazer exclusion. In contrast, the species biomass overlap was higher than expected in fertilization treatments when grazers were excluded. On the one hand, we found no relationship between species traits and relative abundance in grazing, grazing × fertilization and grazer-exclusion treatments; on the other hand, mechanistic trait-based theory could be used to predict species relative abundance patterns in fertilization treatments when grazers were excluded. From grazing to fertilization, when grazers were excluded, there was a slight increase in species synchrony, which indicated that the complementary dynamic of species gradually changed from complete independence into synchronously fluctuating with increasing fertilization. Based on the above results, we concluded that stochastic and deterministic processes formed ends of a continuum from grazing to fertilization when grazers were excluded in an alpine meadow plant community, and the importance of niche differences between species in structuring grassland communities increased with increasing fertilization and decreased with grazing.

The content of selenium in some species of meadow plants

The aim of the investigation carried out in 2006-2007 was to assess differences between 5 grass species and 5 species of plants belonging to meadow herbs in their ability to accumulate selenium. According to the results, among the grass species, the samples of Arrhenatherum elatuis L. had the highest average Se content (46 µg Se⋅kg -1 d.m.), and the lowest average Se amount was found in Holcus lanatus L. (24 µg Se⋅kg -1 d.m.). The content of Se in meadow weeds (70 µg Se⋅kg -1 d.m.) was approximately twice as high as in grasses (32 µg Se⋅kg-1 dm.). Among this group of plants, the highest Se accumulation occurred in Equisetum arvense L. (103 µg Se⋅kg-1 dm.) and the lowest – in Taraxacum officinale (59 µg Se⋅kg -1 dm.). Both in grasses and in meadow weeds, the Se content significantly depended on the amount of this element in soils. In the following species: Dactylis glomerata L., Arrhenatherum elatius L., Poa pratensis L. and Taraxacum officinale, the amount of accumulated Se was also conditioned by the soil’s abundance in organic and total C.

Influence of local and landscape factors on bumblebees in semi-natural meadows: a multiple-scale study in a forested landscape

Understanding the effects of local and landscape factors on bumblebees is relevant for the conservation of this group of pollinators. Bumblebees have been well-studied in agricultural landscapes of Western Europe, Asia and North America, but few studies have been developed on bumblebees in forest-dominated landscapes of Eastern Europe. We developed this study in 22 semi-natural meadows located in a patchy forested landscape of Estonia. We investigated the influence of habitat characteristics and landscape factors (calculated at four spatial scales: 250, 500, 1,000 and 2,000 m radius) on the total species richness and abundance of bumblebees. Correlation analysis, partial least squares (PLS) and stepwise forward-selection multiple regression analysis were applied in this study. The presence of a high diversity of flowering plants in semi-natural meadows may benefit the abundance of bumblebees. At the local level, patch area and shape seem to have positive and negative influences, respectively, on bumblebee species richness. At the landscape level, human settlements with the presence of gardens may favour bumblebee richness and abundance. Also, bumblebee species may increase with a high presence of meadows in the landscape, and may decrease with high percentages of forest and young forest. Overall, forested landscapes with a strong presence of edges and a diverse matrix may support a higher species richness and abundance of bumblebees. Both local and landscape factors should be considered when designing conservation strategies and agri-environmental measures.

Dynamics of seasonal plant growth in halophytic meadows taking into account the temperature factor and soil salinity level

A mathematical model has been constructed to describe the growth dynamics of various plant communities of halophytic meadows depending on the temperature factor and degree of soil salinity. Field investigation of the yields of halophytic meadow plant communities were performed in the coastal area of Kurinka Lake in the Altaiskii district of the Republic of Khakasia in 2004 and 2006. The results of field investigations and model studies show that there is a correlation between plant growth and air temperature for plant communities growing on soils with the lowest and medium salinity levels. It was proven in model studies that for the plant communities that grow on highly saline (3.58%) soils, not only air temperature but also the salinity level of the soil should be taken into account.

Reinforced Traditional Management is Needed to Save a Declining Meadow Species. A Demographic Analysis

The changes in agricultural practices during the last century have led to a drastic decrease in the number of traditionally managed hay meadows. Also, traditional management practices are often applied more cursorily in the remaining meadows. In combination with an increase in aerial anthropogenic nitrogen deposition, this has led to a loss of biodiversity. To investigate whether the current management is sufficient for maintaining viable populations of a typical meadow plant, Succisa pratensis, we experimentally reinforced the raking and mowing parts of the traditional management over four years in a two-by-two factorial experiment in three traditionally managed wooded hay meadows on the Baltic island of Gotland, Sweden. We found decreased litter and hay production in two of the three studied meadows as a result of our treatments. Plant sizes and asymptotic population growth rates (λ) of S. pratensis increased, particularly in plots receiving the combined raking and mowing treatment. Stochastic long-term population growth rates (λs) increased under the reinforced management: projected population sizes 50 years into the future showed a three-fold increase in raked plots and a 17-fold increase in plots that were both raked and mown. Because we found positive responses even in these seemingly well-managed meadows we conclude that it is essential that management is carried out more thoroughly to ensure viable population sizes. Our conclusion applies to most semi-natural grasslands receiving anthropogenic nitrogen, or where traditional management practices are less rigorously applied. We also suggest using biomass estimation instead of vegetation height as a measure of management strength.

Late Quaternary pedogenesis in periglacial zone of northeastern Europe near ice margins since MIS 3: Timing, processes, and linkages to landscape evolution

Two paleosol-sedimentary sequences Koskovo and Puzbol developed within the nearest periglacial zone of Valday glaciation of the East European Plain (56.7°–58.5° N, the Upper Volga River basin) were studied to reconstruct soil mantle and landscape evolution since Marine Isotope Stage (MIS) 3. The sequences are formed on terraces at 130–141 and 172m a.s.l., constituted by ancient (Early Valday (Würm) or Late Moscow (RissII)) lake clayey sediments. The buried paleosols are represented by system of horizons Hb–G3b (Histosol), Agb–G3b and AGb horizon (Umbric Gleysol). The 14C age of the paleosol humus and peat varied between 50,300–39,700 cal. BP. These paleosols were developed under forest-tundra and pine-spruce forests with the meadow plant communities and the areas of swampy vegetation according to palynological data from Puzbol. They represent the northernmost occurrence of the MIS3 fossil soil in Europe dominated by the features of gleyzation, cryogenic aggregation, cracking, and humus and peat formation. Clay coatings in the Middle Valday paleosols and pedosediments are products of Holocene pedogenesis.The upper lithological layers covering the MIS3 paleosols are loess-like (mantle) loams underlain by clayey Late Pleistocene lake deposits. They mark the presence of wide extraglacial lakes with existed within the Upper Volga basin during the maximum advance of the Valday glaciation (MIS2). Based on the stratigraphy of the studied sections, the highstands of these Late Quaternary lakes might exceed ≈170m a.s.l.For the first time it was possible to date the age of humus-clay coatings developed in the Bthk3 horizon (c.1.6–2.0m) of Puzbol where in the upper part of the section the Cutanic Albeluvisol formed. The Early Middle Holocene age of humic acid of humus-clay coatings (≈10,900 cal. BP) and carbonate nodules 7500–8180 cal. BP refer to the first stage of pedogenesis of this polygenetic soil, which occurred from pre-Boreal to the Atlantic period, and was characterized by dark humus accumulation and carbonate precipitation in a poorly drained landscape. The 14C age of the fulvic acids of these coatings (≈6130 cal. BP) is indicative of the beginning of the second stage, dominated by clay illuviation under a better drained, leaching environment.