Meadow Vegetation Research Articles

Анализ динамики состояния лесных растительных сообществ в заказнике «Mакаровский» (Cахалин) по данным дистанционного зондирования земли

The results of the analysis of changes in the state of forest plant communities in the “Makarovsky” Nature Sanctuary in the period from 1980 to 2020 are presented in the article. In the process of our work there was created a model of the vegetation cover of the “Makarovsky” Sanctuary, which made it possible to determine the difference between plant communities and their condition. The data for the construction of the cartographic model were formalized spectral characteristics of the surface of plant communities recorded on Landsat-1–7 and Sentinel-2 images. In a specially protected natural area, 7 classes of objects have been identified when conducting uncontrolled classification using ArcGIS according by their spectral characteristics. The division of dark coniferous and deciduous forests, the identification of the boundaries of plots with different species composition of forest stands and the allocation of felling sites was performed on the basis of the normalized vegetation index (NDVI). The accuracy of determining the composition of forest stands based on the results of interpretation was checked by data of geobotanical research data on the territory of the “Makarovsky” Nature Sanctuary. As part of the vegetation cover of the “Makarovsky” Nature Sanctuary, 8 forest communities were identified—spruce-fir, stone-birch forests, cedar elfin formation, valley deciduous, birch, birch-spruce forests, woodlands, sometimes larch forests, and 2 non-forest communities—Kuril bamboo formation and meadow vegetation. Forest communities occupy 95 % of the territory of the “Makarovsky” Sanctuary. The landscape and climatic conditions of the area are optimal for the growth of spruce-fir forests, which cover 44 % of the total area of the “Makarovsky” Nature Sanctuary. Birch and stone-birch forests (39 %) are widespread on logged land in Sanctuary. There is a wide distribution of secondary succession in the territory of the “Makarovsky” Nature Sanctuary. The composition of forest stands in Sanctuary has changed significantly over the research period in favor of young coniferous trees. Vegetation in the “Makarovsky” Nature Sanctuary has preserved its natural pristine appearance and reflects both altitude differentiation and landscape-zonal features of the middle taiga subzone of Sakhalin. The use of satellite images of medium spatial resolution made it possible to accurately analyze the state of forests of the “Makarovsky” Sanctuary. More detailed researches require the use of unmanned aerial vehicles.

Restoration of Western Siberia meadow vegetation after fires according to Sentinel-2 data

The paper considers the dynamics of restoration of plant communities of meadows in the south of Western Siberia according to Sentinel data-2. Four subjects of the Russian Federation and nine specially protected natural territories within them were taken. Sentinel-2 data is characterized by a repetition of the survey once every five days and a spatial resolution of 10-20 m, which allows you to track the moment of the fire with high accuracy and record the state of vegetation before and after it. For quantitative evaluation, we used NDVI and NBR2 indices, which were compared for burnt and unburned areas before the fire, immediately after the fire, one year after the fire and two years after the fire. As a result of statistical analysis by the Mann-Whitney test, it was found out that both indices practically do not show the consequences of meadow fires in any way a year after the fire.

Zmiany środowiska przyrodniczego wokół wsi wołoskich na północnych stokach Karpat w XV i XVI wieku

The problem of the impact of colonization on the natural environment in the 15 th and 16 th centuries has so far not been addressed by historians. Many publications were limited to only mentioning various symptoms of this phenomenon, without making efforts to analyse this phenomenon in more detail. This article aims at supplementing these inadequacies at least partially. There was a sudden demographic growth of the local population in the 16 th century, manifested by the mass founding of new villages and the population growth in the older settlements. One of the consequences of this phenomenon was the limiting of pastoralism in favour of tillage. This activity resulted not only from the gradually shrinking grazing areas and their impoverishing, but also from the efforts of great landowners supporting the agriculture which was offering more profit. The aim of the article is to present in what way these processes influenced the local natural environment. Various historical sources from the 15 th and 16 th centuries (the nobility’s inventories and surveys, location charters, entries in court documents) were used in order to present the changes in the forestation status, to indicate diverse factors influencing its reduction, and to address the problem of species’ impoverishment of forest vegetation, wild game and degradation of natural mountain meadows. The efforts to limit the presence of some of these unfavourable phenomena were made, and the assessment of their application was made.

88 ЛЕТ ФУНДАМЕНТАЛЬНЫМ ИССЛЕДОВАНИЯМ ИНСТИТУТА КОРМОВ ПО ЛУГОВОМУ КОРМОПРОИЗВОДСТВУ

Natural fodder lands are the main base for providing animal husbandry with the necessary voluminous fodder. On their area, different types of feed are produced, including for feeding during the stall period. The article presents the current state of long-term experience, which has been going on for 88 years without changing the scheme. The scheme of the experiment included different doses of lime and fertilizer and three modes of use (blocks). The composition of vegetation during regular mowing of green mass against the background without the use of fertilizer is represented by a cereal-legume-forbs type, and against the background of fertilizer application, it is a cereal-forbs type of formations. The protected regime (block without use) against the background of small doses of lime leads to overgrowing with shrubs and forests. Only the aftereffect of high doses of lime, which leads to a weak acidity of the soil, contributes to the preservation of meadow vegetation.

Dynamics of the aboveground phytomass of the Ob floodplain meadows in the area of the Tomsk carbon polygon (Kaibasovo)

At the Kaibasovo site (Tomsk carbon polygon), during 2017-2021, studies of multi-year changes in the vegetation of the floodplain meadows of the Ob river were carried out on 4 permanent sample plots to determine the effect of weather conditions and floods on the formation of aboveground phytomass.
 The research area is located within the southern taiga subzone of the forest zone and belongs to the northern part of the Shegarsky section of the floodplain. Permanent sample plots were laid out on relief elements of different flooding conditions - high ridges, their slopes, and depressions. Grass, forb and sedge phytocenoses were studied. In the phase of maximum development of the herbage, geobotanical descriptions and sampling of aboveground phytomass (including litter and rags) were carried out. Descriptions were made on an area of 100 m2, the herbage was mowed from squares of 0.25 m2 four times. Under field conditions, the mowing was sorted by types, dried and weighed. The productivity of the herbage was determined by summing up the masses of particular types. Further, the average indicators of phytocenosis such as the composition of dominant species, the total number of species, the composition and ratio of various fractions (agrobiological and ecological groups) were determined in terms of 1 m2 of aboveground mass.
 Weather conditions and meadow flooding regime for the growing seasons of 2017-2021 were characterized on the basis of data from the Molchanovo meteorological station and the Nikolskoe gauging station. We took into account the average ten-day and monthly values of temperature and precipitation as well as HTC for the entire growing season. This provided the possibility to select wet and dry, warm and relatively cold seasons as a basis for analyzing the phytomass dynamics. Based on the results of a general evaluation of hydroclimatic conditions, 2017-2018 have been assessed as warm, humid, mid-water, 2019 - extremely dry and hot, when the floodplain was not flooded, 2020 - slightly dry mid-water, 2021 - cold and dry with a relatively high flood.
 It was found that the dynamics of the meadow vegetation of the Kaibasovskiy section of the Ob floodplain is determined by the influence of the weather conditions of the current and previous years, the nature of the flood, and characterized by changes in the above-ground mass, the ratio of dominant species, the composition of ecological and biological groups of species in the herbage.
 The change in the state of the cereal community, developed on a high ridge, was due to the dynamics of weather conditions. The range of productivity changes over the years was the smallest. This was due to the good adaptability of the phytocenosis provided by a variety of vegetatively mobile long-rhizome grasses from the ecological groups of xeromesophytes, mesophytes and eumesophytes. The state of the other three communities studied was determined not only by weather conditions, but also by a more important factor such as flooding of meadows during seasonal floods. Their productivity turned out to be generally higher and the range of fluctuations in the amount of aboveground phytomass over the years was wider (on average, twice).
 The study of the relationship between the productivity of the herbage and the destruction of the aboveground part of the mortmass and hydroclimatic conditions showed that at all altitudinal levels of the floodplain in arid conditions, there is a decrease in the mass of the herbage of meadows and the accumulation of dead plant residues. The aboveground phytomass of the communities of the upper and middle altitude levels increases with the increase in environmental humidity, while the total aboveground mass increases, but the proportion of dead plant matter decreases.
 The increase of aboveground phytomass of sedge phytocenoses of medium-low and low levels occurs in humid, warm, mid-water years, while an increase in the abundance of moisture-loving grasses and sedges in the herbage is observed. The accumulation of the amount of dead plant matter is also observed in years with prolonged stagnation of water. The decomposition of litter and rags is most active in humid and warm spring.

Effects of historical management on the vegetation and habitat properties of wet meadows in Germany

Wet meadows in Germany are of high conservational value with a strong decline over the last centuries. Occasionally, new meadows developed, providing us with the opportunity to compare vegetation and habitat properties of wet meadows with currently similar, but different historical management. We categorized the areas as ancient, old or young, according to the point of establishment and grassland continuity in the last two centuries. Several trends derived from other grassland types proved also to be true for wet meadows like a high diversity of vascular plants and Red List species in long‐term managed grasslands. Old grasslands, established one to two centuries ago, exhibited the highest diversity of vascular plants and bryophytes, indicating additional plants arrived by seeding. We investigated species composition using ordination and indicator species. Ancient grasslands were characterized by plants adapted to wet meadows (Molinietalia) such as Rhinanthus serotinus. Young meadows were marked by plants revealing succession like Carex brizoides or a high productivity. A trend, contrary to other grassland types, was that most habitat properties exhibited no temporal pattern except habitat area and few soil attributes. Altogether, a stepwise intensification from ancient to young meadows was detected that reflects the fast development from traditional to modern agriculture. Including the grassland's history in conservation approaches and adapting the management accordingly will improve restoration attempts. Ancient and old grasslands provided more appropriate species for future wet meadows, whereas young grasslands often need a more intensive land use and would benefit from seeding to develop to species‐rich meadows.

Vegetación de la Sierra Madre Occidental, México: una síntesis

La Sierra Madre Occidental (SMO) es el complejo montañoso más grande de México, extendiéndose por casi 1200 km desde el noreste de Sonora (30°35' N) hasta el norte de Jalisco (21°00' N). A pesar de su gran importancia ambiental y económica, es todavía deficientemente conocida. Se presenta una sinopsis de los tipos de vegetación, con datos sobre la superficie que ocupan las comunidades reconocidas, intervalos de elevación y climas donde se localizan, así como un mapa. En la zona confluyen tres regiones, albergando ecosistemas templados y semifríos (región Madrense), semiáridos (Madrense-Xerófila) y cálido-secos (Tropical), respectivamente. La región Madrense, en el macizo de la sierra, incluye bosque de pino, bosque mixto de coníferas, bosque de pino-encino, bosque de encino y manchones de bosque mesófilo de montaña, además de comunidades como chaparral (primario y secundario) y vegetación de claros de bosque. La región Madrense-Xerófila, en el piedemonte norte y oriental y estribaciones al oriente de la sierra, presenta bosque bajo abierto (de encino o de pino-encino), matorral perennifolio y zonas de ecotonía hacia pastizal y matorral xerófilo, además de ecotonías con matorral subtropical hacia el sur del Archipiélago Madrense. En la región Tropical, a lo largo de la base occidental de la sierra e ingresando a esta a través de las barrancas y quebradas, predomina bosque tropical caducifolio y matorral subtropical, con pequeñas áreas de bosque tropical subcaducifolio. La alta diversidad de la SMO se ejemplifica con los tres géneros dominantes fisonómicamente en la vegetación: 24 especies de Pinus (46% del total nacional), 54 de Quercus (34%) y 7 de Arbutus (100%).

The dynamics of the perennial grass crops communities on the restoration succession gradient

The trends of the coenoflora structure dynamics of the perennial grass crops communities were characterized on the gradient of restorative succession in the conditions of the steppe and forest-steppe zones of the Southern Urals. Using an agglomerative cluster analysis, four community groups have been identified, which corresponds to the stages of succession and reflecting the age of the communities (from 1 to 16 years or more). It is demonstrated that the succession gradient complicates the species composition, the species richness of the communities increases by almost 2 times. An analysis of the activity index change for the coenoflora core species at each stage has been carried out. It has been revealed that the activity of sown herbs species decreases, while the total activity of well-eaten species as well as the feed value of the whole phytocoenoses increases with the age of communities. A community of each stage of succession is marked by a group of highly active species, the functional composition and coenotic affinity of which changes. The activity of apophyte species increases while the activity of synanthropic ones decreases. There is a natural complication of the phytosociological spectrum from species of affine to classes of synanthropic vegetation Sisymbrietea and Artemisietea to species of classes of natural vegetation meadows (Molinio-Arrhenatheretea) and steppes (Festuco-Brometea). At the same time, the most active substitution of synanthropic species for natural ones occurs after the second stage of succession, i.e. its significant acceleration is observed after the age of 11 years. According to the results of the ordination analysis (DCA-ordination) with an additional assessment of the contribution of environmental variables, the leading in the differentiation of the species composition of communities is the factor of the age of communities, the factor of humidification of habitats makes a smaller contribution. According to the results of the comparison of the studied phytocoenoses with the data of weed, meadow and steppe communities from the database of non-forest vegetation of the Southern Urals (1660 releves), the central position of perennial grass crop communities on the gradient of restorative succession from disturbed arable land vegetation to natural (steppes) (steppes) and quasi-natural (meadows) vegetation types is demonstrated. Thus, a high importance of perennial grass crops for the creation of stable phytocoenoses of high forage value, which can be used for the restoration of biodiversity in the forest-steppe and steppe regions, is revealed.

Voldstedet Sallingholm

The Sallingholm castle mound – process, results and methodological considerationsThe investigations at Sallingholm castle mound were carried out as part of a study of four test localities in a pilot project called Middelalderborge i Region Midtjylland (Medieval Castles in Central Denmark Region). A joint project established for the region’s archaeologists, carried out in 2014-15.Prior to the archaeological survey executed in 2014, the Sallingholm castle mound lay relatively unnoticed in the Hinnerup river valley. Its banks were barely noticeable under the meadow vegetation, especially when compared with the impressive Skansehøj castle mound just 200 m to the east of Sallingholm, with its steep banks towering above the edge of the river valley. A causeway provided the only access to Sallingholm, and Skansehøj is located precisely at the point where the road from the castle mound meets the mainland. There has been speculation over time as to the connection, if any, there may have been between the two strongholds. In the study of Sallingholm, several aspects were clarified that have a bearing on an interpretation of the relationship between Sallingholm and Skansehøj.Sallingholm turned out to be a much larger structure than foreseen. In earlier submissions, the structure was recorded as consisting of two oval banks, together with a causeway. The project’s initial field survey, followed up by archaeological excavations, revealed that it consists of four discrete man-made turf banks and was extraordinarily well-constructed. Given its position, Skansehøj was able to control access to Sallingholm, the castle mound in the meadow, and Sallingholm’s interpretation as a refuge seems obvious. The locality was not excavated in its entirety, and it is possible that the picture that emerged, based on a relatively small number of finds and a limited occurrence of accumulated waste layers, is not fully comprehensive. The information currently available forms the basis for an interpretation of Sallingholm as a stronghold that was not in continuous use and perhaps only occupied quite briefly: This concurs with the theory that Skansehøj was built for a siege.One aim of the study was to obtain an accurate date for Sallingholm using dendrochronology. To this end, samples of well-documented, dateable wood were collected for analysis. Of these, ten samples produced reasonably reliable dates and one was particularly precise, specifying a felling date in the spring of 1372. The remaining dates were less precise and fell into two groups: One group dated remains associated with the construction of one of the banks to about 1372, the other group, comprised of samples from a presumed timber road by another bank, gave a date approximately 20 years later.A precise date for activities at the stronghold focussed the search for relevant historical sources. The date in the spring of 1372 proved to be particularly interesting in relation to the siege/refuge hypothesis: 1372 was the year when King Valdemar IV Atterdag concluded peace with the coalition of the southern counts who had ruled the kingdom since 1368. Not everyone wanted to surrender to Valdemar voluntarily, and some of the Jutland nobility, in particular, had to be persuaded by force and siege.The results presented here suggest that the owner of Sallingholm was one of the rebellious Jutland nobles who, in 1372, needed to defend themselves against the Danish king.With this study, Sallingholm, a previously unknown castle mound, has become part of Danish history.

Timing and mulching frequency affected the number of nests of cavity-nesting wasps that hunt for aphids in forest meadows

Mulching, cutting of the vegetation without plant biomass removal, is a common alternative to mowing. The aim of our study was to find out if the mulching of forest meadows at different time points affects cavity-nesting bees and wasps. We exposed trap nests for cavity-nesting bees and wasps at 24 forest meadows in south-western Germany over 2 years and applied four experimental mulching treatments with six replicates: (i) mulching in June, (ii) mulching in September, (iii) mulching in June and September, and (iv) no mulching as control. Nests were collected throughout the growing period. The insects were sorted and analyzed according to functional groups. Mulching in June and September reduced the nest number of all cavity-nesting insects in the second but not in the first year. The separation of insects into three functional groups (bees, herbivore-hunting wasps and carnivore-hunting wasps) showed that the number of herbivore-hunting wasp nests was reduced by mulching in September in both years and by mulching in June and September in the second year. Specifically, aphid-hunting wasps were influenced by mulching in September or mulching twice in the second year. Aphid-hunting wasps likely find their larval food in the vegetation of the forest meadows, while the other studied groups likely find their main larval food in the surrounding forests and are therefore not negatively affected.Implications for insect conservationFor maintaining the reproductive success of cavity-nesting wasps that hunt for aphids, we recommend mulching once in June rather than mulching in September or twice a year.

Фитоценотическая активность видов рода Rumex L. на пойменных и суходольных лугах в Брянской области

In the article the phytocoenotic activity of species of the genus Rumex L. in the space of 5 syntaxa of meadow vegetation in the Bryansk Region assessed. Based on geobotanical materials collected in 2018–2022 two new associations and one subassociation were established, for which high activity of Rumex acetosella and R. thyrsiflorus was revealed. The maximum activity (V3–5) of R. acetosella is characterized for the ass. Koelerio delavignei–Festucetum rubrae Rumex acetosella var., R. thyrsiflorus – the ass. Trifolio arvensis–Rumicetum thyrsiflori (V1–5) and the ass. Kadenio dubiae–Rumicetum thyrsiflori (V5). R. acetosella reaches the highest abundance-coverage on dry and poor soils, while R. thyrsiflorus naturally increases the abundance-coverage under more mesophytic conditions. High activity of R. acetosella and R. thyrsiflorus was revealed in grass plant communities in xerophytized river floodplains. This change in the moisture regime against the background of a reduction in the duration and height of floods, as well as the lack of haymaking and grazing in floodplain locations in recent decades, contributed to an increase in the activity of the studied species. In the future, if the trend towards xerophytization of the floodplains persists, we can expect the stable positions of these species to remain in meadow grass stands.

Effects of biological soil crusts on soil labile organic carbon of patchy alpine meadows in the Source Zone of the Yellow River, West China

Biological soil crusts (BSCs) play an important ecological role in the biogeochemical cycles, but there is limited knowledge about their effects on the composition of soil labile organic carbon (LOC) in the soil of patchy alpine meadow. In patchy alpine meadow with different altitudes, the different LOC compartments, vegetation, soil properties and C-hydrolase activity of active patches (with plateau pika), inactive patches (without plateau pika), restored patches, BSCs patches, and healthy alpine meadow were analyzed to assess the effects of BSCs on LOC. The key influence pathway of eco-environmental factors of LOC was determined by the structural equation model (SEM). The results showed that the BSCs at the altitude of 3570 m increased dissolved organic carbon (DOC), easily oxidized organic carbon (EOC) and microbial carbon (MBC) by 293%, 73% and 36%, respectively, compared with active patches in the 0–2 cm layer, which was significantly higher than those of inactive patches and recovered patches. There was no significant difference among DOC, EOC and MBC in different patches at the altitude of 4224 m. The MBC content of active patches decreased, but other patches and healthy alpine meadow showed a Λ- shaped change with altitude. The contents of soil total nitrogen and organic matter of BSCs patches were generally higher than those of active and inactive patches at three different altitudes. Structural equation model results showed that at the altitude of 3570 m, total nitrogen had a strong positive correlation with DOC, with a path coefficient of 0.677. There was a direct negative relationship between soil organic matter and DOC (path coefficient = −0.278) at the altitude of 4013 m. At the altitude of 4224 m, there was no direct correlation among soil nutrient, C-hydrolase activity, and soil LOC. Therefore, BSCs mainly promote the accumulation and recovery of LOC by increasing the soil total nitrogen content in different patches at different altitudes, which are beneficial to the restorations of LOC, total nitrogen and soil organic matter. Hence, they should be considered as key factors in the processes of restoring patchy alpine meadows.

Construction of root tip density function and root water uptake characteristics in alpine meadows.

Accurate calculation of root water uptake (RWU) is the key to improving vegetation water use efficiency and identifying water cycle evolution patterns, and root tips play an important role in RWU. However, most of the current RWU models in the alpine meadow are calculated based on the root length density (RLD) function. In this study, a large number of roots, soil hydraulic conductivity, and physicochemical property indices were obtained by continuous field prototype observation experiments for up to 2 years. It was found that the RLD and root tip density (RTD) in alpine meadows decrease by 16.2% and 14.6%, respectively, in the wilting stage compared to the regreening stage. The RTD distribution function of the alpine meadow was constructed, and the RWU model was established accordingly. The results show that the RTD function is more accurate than the RLD function to reflect the RWU pattern. Compared with RLD, the simulated RWU model constructed by using RTD as the root index that can effectively absorb water increased by 24.64% on average, and the simulated values were more consistent with the actual situation. It can be seen that there is an underestimation of RWU calculated based on the RLD function, which leads to an underestimation of the effect of climate warming on evapotranspiration. The simulation results of the RWU model based on RTD showed that the RWU rate in the regreening stage increased by 30.24% on average compared with that in the wilting stage. Meanwhile, the top 67% of the rhizosphere was responsible for 86.76% of the total RWU on average. This study contributes to the understanding of the alpine meadow water cycle system and provides theoretical support for the implementation of alpine meadow vegetation protection and restoration projects.

Differences in arthropod communities between grazed areas and grazing exclosures depend on arthropod groups and vegetation types

Livestock grazing is one of the most common management practices for grasslands and can greatly affect their biodiversity. However, arthropod diversity response patterns to grazing regimes are difficult to predict. We conducted a short-term grazing exclusion experiment in traditionally managed alkali grasslands in Hungary to investigate differences between grazed and ungrazed vegetation for different arthropod groups. The experiment was laid out in a full factorial design, with twelve 50 × 100 m short-term grazing exclosures in vegetation types with high (alkali wet meadow) and low productivity (alkali steppe). We sampled ground beetles and spiders with pitfall traps and true hoppers by sweep netting. We used vegetation type (wet meadow vs dry steppe), management (grazed vs ungrazed) and their interaction as fixed effects in mixed models. We found higher species richness and activity density of spiders and ground beetles in the more productive wet meadow vegetation, where the community structure of each arthropod group also shifted toward hygrophilous species. Significant interactions between vegetation type and management indicated a dependence of management effects on vegetation types: arthropod community structure shifted towards hygrophilous species in ungrazed meadows, but not in ungrazed steppe sites. True hopper abundance was higher in grazed meadow sites, but lower in grazed steppe sites, compared to ungrazed sites. True hopper community structure shifted toward generalist herbivores in ungrazed sites, regardless of vegetation type. We concluded that vegetation types determine arthropod communities and modulate the effects of grazing on arthropods. Our results suggest that moderate disturbance from low-intensity grazing has a positive or neutral effect in wetter, more productive vegetation, but a negative or neutral effect in drier, less productive vegetation, depending on the arthropod group. Herbivorous insects that dwell on plants are particularly affected by management because they are more susceptible to direct impacts, such as unintentional predation by grazing cattle, and because of asymmetrical competition between mammalian and insect herbivores.

Soil characteristics and response thresholds of salt meadow on lake beaches of the Ordos platform

Salt meadow on lake beaches is the most dynamic plant community. Studying its soil characteristics and response threshold allows us to understand the external driving forces of vegetation stable-state maintenance and dynamic changes, and provide a theoretical basis for the utilization and ecological restoration of lake beach wetland resources. In this study, the community diversity, physical and chemical properties of soil, and ecological response thresholds of key soil indexes of four groups of meadows are discussed: (I) succulent salt-tolerant plant meadow, (II) Carex meadow, (III) grass meadow, and (IV) weed grass meadow. The major findings are as follows. First, Group I is easy to form a single-optimal community in the inland salt marsh beach, with patchy distribution. Group II has a lot of associated species, and most of them grew in clusters. Group III often has obvious dominant species, and the populations and individuals are evenly distributed in the community. The dominant species of Group IV are diverse, and the distribution is the most uniform. Second, there are significant differences in water content, salinity, nutrient and particle size composition of the four types of salt meadows. For Groups I-IV, the soil water content (WC) follows I > II > IV > III; the total salt content (TS) of soil follows I > III > II > IV; the pH value follows III > II > IV > I. Third, the diversity of salt meadow plants in lake beaches is closely related to the contents of WC, TS, Na+, HCO3−, particle size, available potassium (AK), alkali hydrolyzable nitrogen (AN) and available phosphorus (AP) in soil. The vegetation of the four formation groups shows different ecological response threshold intervals. Fourth, the response thresholds of salt meadow vegetation to water content, salt content and sand content of soil are inherently related (but the response threshold to nutrients in soil is unclear).

Different grassland managements significantly change carbon fluxes in an alpine meadow.

Alpine meadow plays vital roles in regional animal husbandry and the ecological environment. However, different grassland managements affect the structure and function of the alpine meadow. In this study, we selected three typical grassland managements including free grazing, enclosure, and artificial grass planting and conducted a field survey to study the effects of grassland managements on carbon fluxes in an alpine meadow. The carbon fluxes were observed by static chamber and environmental factors including vegetation and soil characteristics were measured simultaneously. Our results show that the alpine meadow was a CO2 and CH4 sink, and grassland managements had a significant effect on all CO2 fluxes, including gross ecosystem production (GEP, P< 0.001), net ecosystem production (NEP, P< 0.001) and ecosystem respiration (ER, P< 0.001) but had no significant effect on CH4 fluxes (P > 0.05). The ranking of GEP under the different grassland managements was enclosure > free grazing > artificial grass planting. Furthermore, NEP and ER at enclosure plots were significantly higher than those of the free grazing and artificial grass planting plots. In addition, different grassland managements also affected the vegetation and soil characteristics of the alpine meadow. The aboveground biomass of artificial grass planting was significantly higher than that of the free grazing and enclosure plots. The vegetation coverage under three different grassland managements was ranked in the order of enclosure > artificial grass planting > free grazing and significant differences were observed among them. Moreover, significant differences in the number of species (P< 0.01) and the Margalef richness index (P< 0.05) were detected under three different grassland managements. Further analysis of the relationship between environmental factors and carbon fluxes revealed that GEP and NEP of the alpine meadow were positively correlated with vegetation coverage, the number of species, and the Margalef richness index. Therefore, grassland restoration should be configured with multiple species, which could improve carbon sink capacity while considering the functions of grassland restoration and production.

Изучение пойменных лугов, как кормовой базы для сельскохозяйственных животных

The reduction in the number of livestock in the private sector and small-scale farms has led to a lack of haymaking and insufficient pasture load, which gradually leads to the degradation and disappearance of floodplain meadows due to the formation of trees and shrubs (Salicaceae) on them. We have studied the vegetation of the floodplain meadows of the Tobol River (the forest-steppe part of the current). In the course of the research, 19 plant associations were identified, which occupy habitats in a clear dependence on the meso- and macrorelief and growing conditions. The leading families with the highest species diversity include 8: Poaceae, Fabaceae, Asteraceae or Compositae, Plantaginaceae, Cyperaceae, Rubiaceae, Rosaceae, Poligonaceae. With high fodder qualities, such plant associations as meadow-foxtail, campfire and sedge-grass are noted. The assessment of the condition of the meadows made it possible to give some recommendations for their maintenance and improvement. Keywords: FLOODPLAIN MEADOWS, FODDER, FABACEAE, POACEAE, PLANT ASSOCIATIONS

Grazing rest during spring regreening period promotes the ecological restoration of degraded alpine meadow vegetation through enhanced plant photosynthesis and respiration.

Grazing rest during the spring regreening period is the most economical and feasible measure for the ecological restoration of degraded alpine meadows and has been widely popularized and applied in China. The aim of the present study was to undertake a comparative analysis of the effects of grazing rest on the ecological restoration of degraded alpine meadows by plant photosynthesis and respiration. Coverage, height, ground biomass, belowground biomass of degraded alpine meadow vegetation, net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO2 concentration, chlorophyll fluorescence parameters, relative chlorophyll content, respiration rate, metabolite content, leaf relative water content, and related mineral element content of the dominant grass Elymus nutans Griseb. were measured in degraded alpine grassland with different grazing rest years. The results show that grazing rest during the spring regreening period promoted the ecological restoration of degraded alpine meadows by enhancing the photosynthesis and respiration of the dominant grass E. nutans Griseb. Grazing rest enhanced photosynthesis in dominant grass by increasing metabolites related to the Calvin cycle, chlorophyll content, leaf relative water content, and related mineral element content. Grazing at rest enhanced the respiration of dominant grass by increasing metabolites related to the TCA cycle, leaf relative water content, and related mineral element content. This positive effect gradually became stable with increasing years of grazing rest. Our results provide a fundamental basis for the popularization and application of grazing rest during the spring regreening period on degraded Tibetan Plateau grasslands.

Climate‐Driven Variations in Nitrogen Retention From a Riverine Submerged Aquatic Vegetation Meadow

AbstractLarge rivers can retain a substantial amount of nitrogen (N), particularly in submerged aquatic vegetation (SAV) meadows that may act as disproportionate control points for N retention. However, the temporal variation of N retention in large rivers remains unknown since past measurements were snapshots in time. Using high‐frequency plants and NO3− measurements over the summers 2012–2017, we investigated how the climate variation influenced N retention in a SAV meadow (∼10 km2) at the confluence zone of two agricultural tributaries entering the St. Lawrence River. Distinctive combinations of water temperature and level were recorded between years, ranging from extreme hot‐low (2012) and cold‐high (2017) summers (2°C and 1.4 m interannual range). Using an indicator of SAV biomass, we found that these extreme hot‐low and cold‐high years had reduced biomass compared to hot summers with intermediate levels. In addition, changes in main stem water levels were asynchronous with the tributary discharges that controlled NO3− inputs at the confluence. We estimated daily N uptake rates from a moored NO3− sensor and partitioned these into assimilatory and dissimilatory pathways. Measured rates were variable but among the highest reported in rivers (median 576 mg N m−2 d−1, range 60–3,893 mg N m−2 d−1) and SAV biomass promoted greater proportional retention and permanent N loss through denitrification. We estimated that the SAV meadow could retain up to 0.8 kt N per year and 87% of N inputs, but this valuable ecosystem service is contingent on how climate variations modulate both N loads and SAV biomass.

Bedrock meadows: A distinct vegetation type in northwestern North America

AbstractAimsIn northwestern North America, montane meadows fed by vernal ground‐flow seepage occur scattered throughout an otherwise forested landscape on shallow soils over bedrock. Although their significance for biodiversity has been known, they have never been subject to systematic scientific research and thus, are not included in regional or national vegetation classification schemes. We provide the first vegetation survey of bedrock meadows and compare them to other major non‐forest vegetation types in the region.Study areaNorthwestern North America (United States, Canada).MethodsWe surveyed 110 plots of bedrock meadow vegetation in Montana, Idaho, and British Columbia and compared them with data from 1052 plots from six studies of other open vegetation in the region: prairie and foothill grasslands, maritime mountain, alpine, and timberline meadows. We used cluster analysis to identify groups based on vascular plant composition, related abiotic and structural characteristics to clusters using non‐metric multidimensional scaling (NMDS), and compared proportions of plant growth forms and life spans.ResultsCluster analysis identified five groups, with bedrock meadows forming a distinct community. According to the NMDS, bedrock meadows had a high cover of vascular plants, bryophytes, and lichens and a low cover of litter. Their climate was intermediate between maritime mountain and interior timberline meadows. A distinct functional feature of bedrock meadows was their high proportions of annual plants (therophytes) and plants regenerating from bulbs and corms (geophytes)—a functional composition they shared with maritime mountain meadows.ConclusionBedrock meadows have distinct floristic, functional, and environmental features, are important hotspots for biodiversity, and host several rare plant species. They are an important habitat for conservation and environmental impact assessment and should be incorporated into regional and national classification schemes. Future research priority should be given to understanding their spatial extent, ecological functioning, and drivers of non‐vascular and vascular species richness.