Meadow Plots Research Articles

Assessment of determinants of high nature value (HNV) farmland at plot scale in Western Pyrenees

The concept of High Nature Value (HNV) farming hinges on the causality between agroecosystems with low intensity of management and the corresponding environmental outcomes, including high levels of biodiversity and the presence of semi-natural habitats. Although European strategies for rural development and biodiversity conservation have long recognized the importance of HNV farmlands, many of those areas are currently threatened by intensification and land abandonment. A variety of approaches have been developed for identifying HNV areas and measuring changes in their distribution and extent at landscape scales. In contrast, quantitative approaches for evaluating differences in HNV among the most basic units of management (farms and farm plots) are scarce and almost exclusively based on biodiversity indicators. This gap limits our ability to derive existing gradients of HNV at fine scale and the underlying cause conducive to HNV. Hence, we implemented an index to capture multiple facets of HNV based on expert knowledge criteria and field surveys performed at the finest scale of management (plot). First, we computed this index for hundreds of grasslands located across the Western Pyrenees. Then, we analysed the relationship between the nature value of plots and environmental, management and socio-economic variables. Our results evidence a gradient between low diversity and intensively used agricultural plots and HNV grasslands in the Western Pyrenees. Highest nature values were significantly related to the occurrence of plots in meadows located in steep areas within the Natura 2000 network, whereas lowest values were related to recently opened areas and the number of treatments per year. Importantly, this index, which could be adapted to other farming areas, provides quantitative information to support the implementation of result-based schemes, including eco-schemes and agri-environment-climate interventions of the new CAP (2023–2027).

Effects of grazing and nitrogen application on greenhouse gas emissions in alpine meadow

Overgrazing and injudicious nitrogen applications have increased emissions of greenhouse gases from grassland ecosystems. To explore the effects and potential mechanisms of grazing, nitrogen application, and their interaction with greenhouse gas (GHG) emissions, field experiments were conducted on the Qinghai-Tibet Plateau for three consecutive years. Alpine meadow plots were subjected to light (8 sheep ha−1) and heavy (16 sheep ha−1) stocking rates, with or without ammonium nitrate (NH4NO3) (90 kg N ha−1 yr−1) treatment to simulate soil nitrogen deposition. During early warm growth season (May–June), peak growth season (July–September), and early cold season (October–November), static-chamber gas chromatography was used to analyze the soil's greenhouse gas emissions (CO2, N2O, and CH4). Results indicated that light stocking rate (LG) led to an increase in cumulative CO2 and N2O emissions, while also promoting CH4 uptake. Conversely, heavy stocking rate (HG) produced contrasting outcomes. Additionally, nitrogen applications significantly increased the short-term CO2 and N2O fluxes peaks. Combined treatment of nitrogen application and light stocking rate (LG + N) resulted in increased CO2 and N2O emissions while decreased CH4 uptake, consequently leading to a significant increase in global warming potential. According to the structural equation model, we discovered that nitrogen application and grazing affected GHG fluxes both directly and indirectly through their impact on the environmental factors. Our findings suggest that in the context of increasing nitrogen deposition in the Qinghai-Tibet Plateau, a moderate increase in stocking rate is more effective than reducing grazing intensity for mitigating global warming potential in alpine meadow.

Usage of Fermental Traps for the Study of the Species Diversity of Coleoptera in Open Biotopes.

Usage of a variety of non-trivial ways to study Coleoptera gives unexpected and original results. The studies were conducted using simple traps with fermenting baits in the central part of European Russia. There were 286 trap exposures, and 7906 Coleoptera specimens (208 species from 35 families) were collected. The largest number of species belonged to the families Cerambycidae (35 species), Curculionidae (26 species), and Elateridae (25 species). One species each was noted in 12 families. Traps were applied in five open habitats (dry meadow, shore, floodplain meadow, cuttings under power lines, and glade in woods). Only 13 species were common to all habitats: Cetonia aurata, Protaetia marmorata, Dasytes niger, Cryptarcha strigata, Glischrochilus grandis, Glischrochilus hortensis, Glischrochilus quadrisignatus, Soronia grisea, Notoxus monoceros, Aromia moschata, Leptura quadrifasciata, Rhagium mordax, Anisandrus dispar. Dry meadows were dominated by C. aurata, A. murinus, and P. cuprea volhyniensis. A shore was dominated by C. strigata, G. grandis, G. hortensis, S. grisea, and A. dispar. The dominant species in floodplain meadows were G. hortensis, S. grisea, and A. dispar. On cuttings under power lines, the most numerous were C. aurata, P. cuprea volhyniensis, and C. viridissima. In forest glades, the maximum abundance data were obtained for G. grandis, C. strigata, and A. dispar. The Shannon index was greatest in meadow habitats of varying degrees of moisture, while it was minimal on the shore. The increase in the Simpson index was also characteristic of the shore. These data indicate reduced species diversity combined with the dominance of several species in this biotope. The maximum species diversity with the highest level of species alignment was characteristic of meadow plots, while lower values were obtained under power lines and in forest glades. We recommend the usage of fermental traps with beer for ecological studies of the Coleoptera fauna in open biotopes.

Impact of plateau pika burrowing activity on the grass/sedge ratio in alpine sedge meadows in China.

Burrowing activities of plateau pikas cause widespread bare patches in alpine meadows on the Qinghai-Tibet Plateau, affecting the plant community composition and forage production. However, it is not clear how these bare patches influence the main forage composition in alpine meadows. Therefore, we investigated the plant communities in bare patches (BP) and neighboring control plots (CK) in alpine meadows in Maqu county in the Gannan region of China. Our results showed that plant communities in the CK plots differed from those in the BP plots. The sedge cover, number of sedge species and number of grass species were all significantly higher in the CK plots compared to the BP plots. However, grass cover and its dry weight were significantly higher in the BP plots. Grass cover and the grass dry weight in the BP plots were 1.859 times and 1.802 times higher than that in the CK plots across the five sites, respectively. Grasses also had a significantly higher cover and dry weight than sedge in the BP plots, grass cover was 66.5 times higher than the sedge cover, and the grass dry weight was 68.242 times that of the sedge dry weight. Therefore, bare patches resulting from plateau pika burrowing activity significantly increase the grass/sedge ratio in alpine meadows. A potential explanation is that grasses have a stronger reproductive potential than sedges in bare soil. This has implications for pasture yields since grasses have a higher biomass per unit area compared to sedges in alpine meadows.

Historical aspect of environmental thinking and steppe forestry

Historical aspect of environmental thinking and steppe forestry

Meadow-ploughing timing as an integrated pest management tactic to prevent soil-pest damage to maize

Abstract The management of soil-pests still largely relies on conventional chemical insecticides despite the provisions of Integrated Pest Management (IPM). Long-term research was carried out in north-eastern Italy to assess the potential of meadow ploughing just before maize sowing to prevent wireworm damage. The research was based on the observation that no serious wireworm damage occurred in 20 years when meadows were ploughed just before maize sowing. The research hypothesis was that soil-incorporated fresh meadow turf would be a more attractive wireworm food source than seeds, emerging seedlings and young plants. Meadow plots with a sufficiently homogeneous wireworm density were alternately ploughed the previous autumn and a few days before maize sowing. The same conditions were simulated in pots into which known numbers of cage-reared wireworms had been introduced. Results showed very consistently that plant damage in plots ploughed just before maize sowing was much lower than the damage in plots ploughed in autumn-winter, and always below the economic risk threshold (15% of damaged plants). In controlled conditions, plant damage in pots with soil-incorporated fresh meadow turf was significantly lower than that observed in pots without. In both field and controlled conditions, this major effect on plant protection is likely to be caused by the incorporation of meadow turf living plant parts into the soil. Therefore, the ploughing timing of meadows in rotation may be a viable alternative to chemical insecticides when rotation includes meadow.

Varied response of underground and aboveground plant matter: functional diversity of three different vegetational types after translocation to reclaimed postindustrial land

AbstractThe indicators of functional diversity are increasingly used to assess the conservation effectiveness of the most valuable habitats. However, little is known about the response of functional traits, their diversity, and divergence in plant communities after translocation. To assess how functional diversity changes on dry heath, meadow, and fen after translocation of entire turfs of vegetation from an airport area to the Botanical Garden in Radzionków, we used leaf–height–seed (LHS) traits (specific leaf area, height, and seed mass) and vegetative traits (bud bank size, bud bank depth, and lateral spread). We also measured community weighted means and multifunctional diversity metrics (functional richness, evenness, and divergence) for all the traits and for LHS and vegetative traits separately. On the basis of our results, we found that the most sensitive type of vegetation to changes in functional diversity is meadow, where an increase in functional evenness and divergence were observed. The functional richness increased also for the LHS traits set in meadow plots. The response to the translocation on dry heath was a decline in functional richness and an upswell of functional evenness and divergence of vegetative reproduction traits. Additionally, we observed changes in community weighted means on meadow and dry heath. Fen was the most resistant to alterations in functional diversity after translocation. Despite the changes in functional diversity and community weighted means being significant, the shift in values of particular indices was not considerable. Our results may provide a better insight into function changes in translocated vegetation plots.

Elytrigia repens co-occurs with glycophytes rather than characteristic halophytes in low-growing salt meadows on the southern Baltic Sea coast

Baltic salt meadows of the supralittoral are recognizable by a low vegetation structure of perennial plants, distinct zonation, and the presence of characteristic species of high ecological value. This semi-natural, grazing-dependent vegetation is declining in overall distribution and habitat quality. Abiotic and biotic habitat changes as well as the loss of characteristic species and a simultaneous increase of Elytrigia repens are particularly concerning. We hypothesize that, if E. repens increases due to abandonment or other causes, characteristic salt-meadow species will be affected adversely. To investigate the floristic changes and salt meadow species loss over a wide area, we used a dataset of salt meadow plots from along the southern Baltic Sea coast, partitioned by different cover ranges of E. repens. Between these groups, we compared the abundance and frequency of characteristic salt meadow species. We additionally tested (Mann-Whitney-U test) relevant structural factors, plot-based indicator values and strategy types. E. repens indicated low incidence of characteristic salt-meadow species. Soil moisture, salinity and light availability were lower where E. repens occurred; mean vegetation height was increased. Five species co-occurred with Elytrigia repens (Achillea millefolium, Holcus lanatus, Poa pratensis, Schedonorus arundinaceus, Trifolium repens), showing simultaneously a low relative abundance in the remaining dataset. We discuss our findings in terms of frequently observed vegetation changes in the light of salt meadow abandonment. In conclusion, we draw up an easy-to-use method for monitoring salt-meadow medium-term dynamics for applied nature conservation purposes.

Translocation of meadow, heath and fen to the Habitat Garden: The first insights after 4 years of the experiment

AbstractQuestionsHow does species composition of different vegetation types respond to translocation? How do they respond to encroachment of expansive native or alien species?LocationMeadow, heath and fen plots in Radzionków Habitat Botanical Garden, Poland.MethodsIn 2013, between June and October, 16,500 pieces of turf blocks from three communities, each 80 × 120 cm in size and 40–50 cm deep, were transferred from a donor site to newly constructed artificial basins. Temporal changes of species composition were observed in 163 permanent plots 2 × 2 m from 2013 to 2016. To analyse compositional changes, we carried out constrained ordination with time as explanatory variable. For changes in species richness, diversity, herb and shrub layers, contribution of woody species, diagnostic taxa, archaeophytes, neophytes, native expansive taxa and ruderal plants, a one‐way ANOVA was applied.ResultsWe found that only 35%–39% of species had a positive correlation with time. The total number of species significantly decreased only within the meadow plots. The fen and heath only experienced a slight decrease in species number. Significant changes in abundance of diagnostic species were observed in all plant communities. The abundances of diagnostic taxa were maintained during the first 2 year, then dropped considerably. The highest decrease was noted in the heathland community.ConclusionsTurf translocation appeared to be only partially effective as a compensatory measure. Four years after the translocation, the three different habitats still maintained their specific structural features, however the number of diagnostic taxa considerably decreased, particularly in the heathland and the wet meadow. Given the high financial and logistical effort required, translocation measures are questionable and should only be applied as an exceptional last resort method.

Perceived species-richness in urban green spaces: Cues, accuracy and well-being impacts

Evidence that urban green-space promotes health and well-being of urban residents is increasing. The role of biodiversity is unclear: perceived biodiversity may be important, but how accurately it is perceived and the factors influencing this accuracy are poorly understood. We use experimental perennial urban meadows in southern England to investigate the impact of creating biodiverse habitats on green-space users’ i) physical and mental health, psychological well-being, ii) factors moderating health and well-being outcomes (site satisfaction and nature connectedness), and iii) perceived biodiversity. We explore whether ‘nature dose’ (time spent at a site) influences these relationships. We then assess whether green-space users can estimate botanical diversity accurately across meadow treatments differing in plant species richness and vegetation structure, and determine the environmental cues and personal characteristics associated with these estimates. Sites with experimental meadows did not increase respondents’ perceptions of site level biodiversity, their self-rated physical and mental health or psychological well-being relative to control sites lacking meadows. However, there were significant associations between perceived site level biodiversity per se, and site satisfaction and feeling connected to nature. Moreover, we observed a positive association between nature dose and self-estimated mental health. We found that actual and perceived botanical richness in individual meadow plots were strongly positively correlated. Perceived richness was positively associated with vegetation height, evenness, and colourfulness suggesting that these are cues for estimating species richness. The accuracy of estimates varied, but respondents with higher levels of eco-centricity were more accurate than people who were less connected to nature.

Harvesting and Recolonization of Wild Populations of Oshá (Ligusticum porteri) in Southern Colorado

Land managers face the challenge of conserving medicinal plants that may be threatened by harvest pressure, often with limited biological information available to inform management decisions. Osha (Ligusticum porteri) is an important medicinal plant whose roots are harvested as an herbal remedy for flu, sore throat, and other illnesses. However, little is known about population structure, root production, or the capacity of osha to recover from harvest in different environmental contexts. We compared osha population structure and root production within a gradient of canopy cover from meadow to forested habitat. We experimentally harvested roots of mature osha plants and recorded osha recolonization of pits created by root harvest. Prior to harvest, the number and percent cover of reproductive plants and the number of flowering stems per plot were higher in the meadow than in forested habitat. Canopy cover had a significant negative relationship to these variables, suggesting that osha populations benefit from increased light availability. Average root weight per plant in meadow plots was three times higher than in forested plots. One year after harvest, the majority of all harvest pits across the canopy cover gradient were recolonized by osha. Our results suggest that osha population structure and root production are significantly influenced by canopy cover, but that plants have a high capacity for post-harvest recolonization under variable light conditions. These results demonstrate the need to account for environmental factors that influence population structure when addressing concerns about the overharvest of wild medicinal plants.

Alpine meadow restorations by non-dominant species increased soil nitrogen transformation rates but decreased their sensitivity to warming

Alpine meadow soils are large carbon (C) and nitrogen (N) pools correlated significantly with global C and N cycling. Soil N transformations, including nitrification and N mineralization, are key processes controlling N availability. Alpine meadow degradations are common worldwide, and vegetation restorations have been widely implemented. However, grass species used for restorations may alter soil N transformations or their response to warming and N deposition due to divergent plant traits and their different effects on soil characteristic. To understand the effects of meadow restorations by non-historically dominant species on N transformations, we measured N transformation rates in restored soils and control soils under the context of warming and N deposition. We collected soils from plots restored by dominant (Miscanthus floridulus) and non-dominant species (including Carex chinensis and Fimbristylis dichotoma) and non-restored plots in alpine meadows of Wugong Mountain, China. We measured nitrification and N mineralization rates when soils were incubated at different temperature (15 or 25 °C) and N additions (control vs. 4 g m−2) to examine their responses to restoration species, warming, and N. Vegetation restored soils differed substantially from non-restored bare soils. Total N, total organic C, pH, and dissolved organic C contributed the most to the separation. Restoration altered soil N transformations substantially, even though the effects varied among restoration species. Specifically, non-historically dominant species accelerated N transformations, while the originally dominant species decreased N transformations. In addition, sensitivity of nitrification to warming in restored soils was decreased by restorations. Soils restored by originally dominant species were higher in sensitivity of N transformations to warming than those restored by the other two species. Warming increased nitrification rates by 45.5 and 17.4 % in bare soils and restored soils, respectively. Meanwhile, N mineralization rates were increased by 52.8 and 21.9 %, respectively. Vegetation restoration of the degraded meadows impacted N transformations and their sensitivity to warming. The effects varied with identity of the restoration species, suggesting that grass species should be considered in future restorations of degraded meadows in terms of their divergent effects on N transformations and sensitivity to warming.

The consequences of multiple resource shifts on the productivity and composition of alpine tundra communities: inferences from a long-term snow and nutrient manipulation experiment

Background: Gradients in the amounts and duration of snowpack and resulting soil moisture gradients have been associated with different plant communities across alpine landscapes.Aims: The extent to which snow additions could alter plant community structure, both alone and in combination with nitrogen (N) and phosphorus (P) additions, provided an empirical assessment of the strength of these variables on structuring the plant communities of the alpine tundra at Niwot Ridge, Colorado Front Range.Methods: A long-term snow fence was used to study vegetation changes in responses to snowpack, both alone and in conjunction with nutrient amendments, in plots established in dry and moist meadow communities in the alpine belt. Species richness, diversity, evenness and dissimilarity were evaluated after 20 years of treatments.Results: Snow additions, alone, reduced species richness and altered species composition in dry meadow plots, but not in moist meadow; more plant species were found in the snow-impacted areas than in nearby controls. Changes in plant community structure to N and N + P additions were influenced by snow additions. Above-ground plant productivity in plots not naturally affected by snow accumulation was not increased, and the positive responses of plant species to nutrient additions were reduced by snow addition. Plant species showed individualistic responses to changes in snow and nutrients, and indirect evidence suggested that competitive interactions mediated responses. A Permanova analysis demonstrated that community dissimilarity was affected by snow, N, and P additions, but with these responses differing by community type for snow and N. Snow influenced community patterns generated by N, and finally, the communities impacted by N + P were significantly different than those affected by the individual nutrients.Conclusions: These results show that changes in snow cover over a 20-year interval produce measureable changes in community composition that concurrently influence and are influenced by soil nutrient availability. Dry meadow communities exhibit more sensitivity to increases in snow cover whereas moist meadow communities appear more sensitive to N enrichment. This study shows that the dynamics of multiple limiting resources influence both the productivity and composition of alpine plant communities, with, species, life form, and functional traits mediating these responses.

Importance of molehill disturbances for invasion by Bunias orientalis in meadows and pastures

Small-scale soil disturbances by fossorial animals can change physical and biotic conditions in disturbed patches and influence spatial and temporal dynamics, and the composition of plant communities. They create regeneration niches and colonization openings for native plants and, according to the intermediate disturbance hypothesis, they are expected to increase plant community diversity. However, it also has been reported that increased disturbance resource availability and decreased competition with native species may result in the invasion of communities by alien plant species, as predicted by the fluctuating resources theory of invasibility. In this study, we investigated the importance of European mole disturbances for the invasion of semi-natural fresh meadows and pastures by the alien plant, Bunias orientalis, which has mainly spread throughout Central Europe on anthropogenically disturbed sites. We hypothesized that the invader, being particularly well adapted to anthropogenic disturbances, enters into dense vegetation of meadows and pastures mainly on mole mounds. To assess the seedling recruitment of B. orientalis in relation to disturbance, we counted the number of seedlings that emerged on molehills and control plots in meadows and pastures. The establishment of juvenile (0–1 year) rosette plants on and off molehills was surveyed on 5 × 5 m plots. In accordance with our hypothesis, mole disturbances were found to serve as a gateway for B. orientalis by which the invader may colonize semi-natural grasslands. The seedlings of the species emerged almost solely on molehills and the young rosettes were established predominantly on mole mounds. Although the seedling density did not differ significantly between the meadows and pastures, the number of established plants in the pastures was considerably higher. We suggest that the invasion by B. orientalis in pastures may be facilitated by vegetative regeneration following root fragmentation by sheep pasturing.

Conifer reinvasion of montane meadows following experimental tree removal and prescribed burning

Tree invasion of mountain grasslands and meadows, pervasive throughout western North America, has become a management concern. Restoration of these systems requires tree removal and possibly prescribed burning; however, subsequent reinvasion by trees may compromise these efforts. In this study, we assess patterns of tree seedling establishment 8years after tree removal (with and without burning) from 1-ha experimental plots in conifer-invaded meadows in the Oregon Cascades. We quantify variation in the timing, spatial distribution, and density of establishment of species with differing seral roles; compare effects of burning; and explore relationships with distance to and characteristics of adjacent, residual forests. Seedlings established continuously after tree removal, dominated by late-seral Abies grandis (cumulative plot densities of 116–460/ha). Early-seral Pinus contorta and Pseudotsuga menziesii were much less abundant (0–25 and 1–52/ha, respectively). Frequency (percentage of 5×5m subplots) and density of seedlings did not differ between treatments (burned vs. unburned), nor did seedling growth rates (inferred from height-age relationships). Seedling spatial distributions and relationships with distance to adjacent forest varied both within and among plots. On average, however, seedlings were concentrated along edges. In the 5-m outer band of subplots, frequency averaged 37% and density, 682/ha, compared to 18% and 140/ha in the remaining cores of the plots. Density of Abies was significantly greater along more shaded southern edges (north-facing) than along more exposed northern edges (south-facing), but it declined steeply with distance from edge, especially for southern edges. Plot-level density of Abies seedlings was also correlated with basal area of Abies in the adjacent forest (but not with tree density or summed height). Strong relationships of seedlings with distance, exposure, and characteristics of adjacent forests suggest that conifer reinvasion can be minimized by targeting tree removal to maximize distances to residual trees. However, absence of a treatment effect suggests that burning—critical for reducing woody residues—does not increase the probability of seedling establishment, particularly in systems in which late-seral species are the principal colonists.

芦芽山亚高山草甸、云杉林土壤有机碳、全氮含量的小尺度空间异质性研究

PDF HTML阅读 XML下载 导出引用 引用提醒 芦芽山亚高山草甸、云杉林土壤有机碳、全氮含量的小尺度空间异质性 DOI: 10.5846/stxb201210231466 作者: 作者单位: 山西农业大学林学院,山西农业大学林学院,山西农业大学林学院,山西农业大学林学院 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（30970480）；山西省自然基金资助项目（2010021027-4，2010021028-6）；山西农业大学博士科研启动资助项目；山西农业大学“学术骨干”资助项目 Spatial heterogeneity of soil organic carbon and total nitrogen at small scale in subalpine meadow and Picea meyeri forest in Luya Mountain Author: Affiliation: Forestry College of Shanxi Agriculture University,Taigu,Forestry College of Shanxi Agriculture University,Taigu,Forestry College of Shanxi Agriculture University,Taigu,Forestry College of Shanxi Agriculture University,Taigu 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:分析比较了山西芦芽山不同海拔处分布的亚高山草甸（样地A，海拔2756.3 m；样地B，海拔2542.3 m）和云杉林（样地C，海拔2656.8 m；样地D，海拔2387.2 m）土壤有机碳和全氮的小尺度空间异质性特征。结果表明：相同植被类型下海拔较高的样地有机碳含量较高（A：49.84 g/kg，B：38.33 g/kg，C：47.06 g/kg，D：40.67 g/kg），而较低海拔的样地土壤有机碳含量的异质性较高；除样地A以外的其他3个样地均表现为高度空间依赖性。亚高山草甸土壤全氮含量的异质性远远高于云杉纯林，四个样地中均表现出强的空间自相关性。亚高山草甸样地土壤有机碳和全氮含量均在较大尺度上空间自相关，云杉纯林样地则表现为较小尺度的空间自相关变异。 Abstract:The patterns and controls of soil organic carbon(SOC) and total nitrogen are critical for our understanding of recycling of nutrients. Spatial heterogeneity causes uneven soil resource distribution. Quantification of the spatial variability is essential for evaluating attributes at unsampled locations. This study was conducted in Luya Mountain, Shanxi Province, China. Four sample plots (30m×30m) were placed, two subalpine meadow plots (Plot A, 2756.3 m; Plot B, 2542.3 m) and two Picea meyeri forest plots (Plot C, 2656.8 m;Plot D, 2387.2 m), The spatial heterogeneity of soil organic carbon(SOC) and total nitrogen(TN) was analyzed based on theory and methodology of spatial pattern analysis in geostatistics.. Soil samples (n=119) were collected from each of the plots in the summer of 2010. We calculated the isotropic semivariograms of SOC and TN. Then spherical models were used to test the semi-variances of SOC and TN for spatial dependence. The experiment results indicated that the SOC of four plots were 49.84 g/kg (A), 38.33 g/kg (B), 47.06 g/kg (C), and 40.67 g/kg (D), respectively. The SOC contents appeared to be higher in the plots with higher elevation. Rather, the spatially variance showed more intensively in the plots with lower altitude. In contrast to the random variation of SOC in plot A, there were high spatial dependences in the spatial distribution of SOC in the others. The spatial heterogeneity of TN in Picea meyeri forest plots were higher than those in subalpine meadow plots,and spatial autocorrelation were high in all the plots. The ranges of spatial autocorrelation variation (the distances within which parameters are spatially dependent) for SOC and TN were larger for subalpine meadow plots, but smaller for Picea meyeri forest plots. 参考文献 相似文献 引证文献

Annual Glyphosate Treatments Alter Growth of Unaffected Bentgrass (Agrostis) Weeds and Plant Community Composition

Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.

Variation of Snail Assemblages in Hay Meadows: Disentangling the Predictive Power of Abiotic Environment and Vegetation

ABSTRACT We studied snail assemblages at 39 plots in hay meadows of the White Carpathians, Czech Republic. We recorded snails quantitatively in 1 m2 quadrats, along with vegetation and several measured variables in the same plots in order to investigate the influence of selected environmental factors on meadow snail species composition and richness. The study aimed to determine the extent to which it is possible to use vegetation as a predictor of land snail composition by comparing the predictive power of three groups of variables: (i) measured variables and climatic factors, (ii) vegetation, and (iii) Ellenberg indicator values for plants estimated from plant composition. Detrended correspondence analysis revealed that both snail and plant assemblages were strongly affected by the main environmental gradient running from calcium-poor, wet and cool upland sites to calcium-rich, dry and warm lowland sites. The main changes of vegetation and snail species composition were highly correlated (rs = 0.77, p < ...

Uncut grass refuges mitigate the impact of mechanical meadow harvesting on orthopterans

Semi-natural grasslands require regular harvesting (cutting) or grazing to avoid vegetation succession, and this is well known to promote plant diversity. However, recent studies have shown that meadow harvesting has a severe direct negative impact on orthopterans and other grassland invertebrates. In view of this, leaving areas of uncut grass as refuges has often been recommended as a mitigation measure. Yet to date no studies have tested this hypothesis. We experimentally investigated the direct influence of leaving a 10% uncut grass refuge in the centre of 50m diameter meadow plots on orthopteran population. During harvest, orthopteran densities dramatically declined within mown areas and doubled within refuges, showing that during the mowing stage some individuals actively moved to uncut areas, safe from the impact of post-mowing stages. After baling, final orthopteran population sizes were on average 53% higher in plots with an uncut refuge, compared to plots without. To maximise the benefit of refuges, we recommend mowing towards the refuge, as this is likely to drive field invertebrates into the refuge.

Wild red deer [Cervus elaphus L.) grazing may seriously reduce forage production in mountain meadows

This study aimed at estimating the impact of red deer grazing on the productivity of meadows located in Pian Cansiglio, north-eastern Italian Pre-Alps. These meadows (185 ha; average elevation 1000 m asl are managed for hay/silage production (1–2 cuts per season) and are included in a protected area that hosts a high density of deer (around 30 heads/100 ha). In 2008 and 2010, dry matter (DM) production and loss due to deer grazing were estimated with exclusion cages (1 m2; 48 exclusion cages in 2008 and 52 in 2010). Night counts with spotlights were conducted to index deer use of meadows plots. DM production inside the cages was fairly good for the area (first-second cut: 4963-2297 kg DM/ha in 2008, and 4145-2475 kg DM/ha in 2010). DM production outside the cages was significantly lower (first-second cut in 2008: 4199-1378 kg DM/ha, and in 2010: 3376-2052 Kg DM/ha). Therefore, the magnitude of losses was of 15–20% at the first and 25–40% at the second cut. DM losses in the different meadow plots were positively correlated with index of deer use, which in some plots was as high as 7–8 heads/ha. Deer grazing reduced also crude protein (CP) content of forage (15.6±4.4% DM inside exclusion cages and 13.8±3.5% DM outside), with losses being greater where CP content was higher. This study demonstrates that high densities of grazing deer may seriously impact on forage production and quality.