Species Composition Of Vegetation Research Articles

Less hay collected at more dates: toward successful restoration of subtropical grasslands by hay transfer

Hay transfer is a promising method to restore temperate and subtropical grasslands, but its efficiency may depend on the harvesting timing and amount of hay used. We evaluated effects of harvest date (mid‐spring/November, early summer/December, and mid‐summer/February) and hay quantity (500 and 1000 g/m2) on vegetation cover, species richness, and species composition in an experimental study in subtropical southern Brazil for a period of 2 years. We transfer undried hay from a well‐conserved reference area onto a former grassland site degraded by pine plantations. Hay harvested during mid‐spring and early summer led to higher soil cover and species richness compared to the mid‐summer hay treatment in the first year of the experiment. A drought spell decreased vegetation cover in the second year following the hay transfer, with the mid‐spring hay treatment being the least affected. C3 grasses were more effectively introduced by mid‐spring and early summer hay, in contrast to C4 grasses that were better introduced by mid‐summer hay. Lower quantities of hay tended to lead to higher cover and species richness for all harvest dates. Freshly cut undried hay can be an effective way to reintroduce native species in degraded subtropical grasslands. We conclude that timing of hay collection and the amount of hay used influence vegetation cover and species composition at the restoration site and that multiple harvest dates increase restoration success. The drought in the second year of the experiment illustrates the need to consider the possibility of adverse climatic conditions in restoration planning.

Grazing intensity by sheep affects spatial diversity in botanical composition of Inner Mongolian grassland

Overgrazing by sheep causes degradation of grasslands in the Inner Mongolian steppe, yet our understanding of its impact on grassland plant communities is limited by lack of observations at high spatial resolution. Employing a nested experimental design in a long-term grazing experiment provides insights into effects of increasing sheep grazing intensity on community composition, diversity, and spatial patterns in the grassland vegetation. Effects of observed changes in the plant community are discussed based on monthly weight gain of sheep during grazing. The design of the long-term experiment included four triplicated grazing intensities applied during an 8-year period. At the end of that period, we evaluated vegetation coverage, categorized plant species by functional groups, and analyzed the data using a mixed linear model. Moreover, spatial autocorrelation methods were employed to investigate spatial patterns, visualized via a kriging model. We found that the plant community composition differed among grazing treatments, with high grazing intensity showing higher plant species richness and stronger clustering of plants at our fine scale of observation. These fine-grained spatial scale observations are usually not recorded in larger spatial scale analyses of grassland responses to overgrazing. While the grazing intensities used in our study did not influence individual sheep weight gain, total sheep weight gain per hectare increased with an increase in grazing intensity. Our study shows that in a sheep grazing intensity experiment in Inner Mongolia grasslands total sheep weight gain may increase at the expense of fine-scale species composition and spatial dynamics of the grassland vegetation. These insights may be used for determining trade-offs of sheep meat production with original composition and structure of grassland plant communities. Effects on other ecosystem properties and functions, such as on belowground biodiversity, remain to be assessed.

Species composition of weeds in various crop rotations of the Mari El Republic

The article presents the results of long-term experiments to determine the species composition of weed vegetation, the dynamics of weeds on crops in various crop rotations is established. In order to develop rational measures to control weeds, their species and quantitative composition were studied. The experiment was carried out on the field of the Mari Research Institute of Agricultural Sciences, a branch of the Federal State Budgetary Educational Institution of the North–East, founded in 1996 and 1998. The duration is four rotations of six–field crop rotations. The soil is sod–podzolic medium loamy. The purpose of the work is to determine the species composition of weeds in crop rotations, to identify the influence of crop rotations, to trace the dynamics of crop contamination. The share of juvenile weeds accounts for 26 species, perennial – 10. The minimum amount of weed vegetation was noted in the III fruit–bearing crop rotation (average over the years – 49.55 pcs/m2), the maximum – in the grassy (61.15 pcs/m2). According to factor B, in all years of research on juvenile weeds, the lowest

Hyperspectral characterization of vegetation in hemiboreal, boreal and Arctic peatlands using a geographically extensive field dataset

Northern peatlands store up to 25% of global soil organic carbon and function as important hotspots for biodiversity. However, they are facing degradation from climate change driven by human activities as well as anthropogenic land use changes, up to the point of endangering the ecosystems' functioning and the storage of soil organic carbon entailed within them. The surface vegetation of northern peatlands is an important indicator of the ecosystem's functioning and ecohydrology, highlighting the importance of its large-scale, continuous monitoring. Approaches utilizing hyperspectral data for monitoring vegetation health and species composition can also be applied to peatland vegetation. To support the development of methods for interpreting hyperspectral satellite data from peatlands, we conducted a comprehensive in situ study of hemiboreal, boreal, sub-Arctic and Arctic peatland vegetation. We measured the reflectance spectra (350–2500 nm), soil moisture, and various vegetation-related attributes from a total of 446 vegetation plots in Estonia and Finland, from a 1500 km south-north interval. We then investigated (i) the spectral variation in surface vegetation of hemiboreal, boreal, sub-Arctic and Arctic peatlands and (ii) explored its connection to plant functional types (PFTs) and soil moisture, as well as evaluated the potential of hyperspectral data in estimating PFT cover using simple vegetation indices and partial least square (PLS) regression. Our results indicate that (i) the best spectral regions to retrieve information regarding the PFT vary greatly especially between vascular plants and bryophytes, (ii) the reflectance at an individual wavelength as well as simple vegetational index can, to some extent, predict the PFT, and that (iii) the PLS regression can predict the PFT with good accuracy. Overall, our findings demonstrate the potential of using hyperspectral data in monitoring PFTs in northern peatlands. The spectral library and the ancillary data from the peatland sites collected for this study are available as open data.

Vegetation cover is a crucial key to the success of ecological restoration in the desertified steppe of Inner Mongolia

In this study, we analyzed the environmental factors influencing the restoration process of the degraded ecosystem in the Inner Mongolian steppe, the largest steppe ecosystem in Asia, which is experiencing rapid desertification, and evaluated the effects of restoration on the damaged ecosystem in China. For this purpose, we selected degraded steppe areas left to desertification in the Hulunbuir region, four restored sites where vegetation was artificially introduced for restoration, and reference ecosystems, including a non-desertified area with the dominant Pinus sylvestris var. mongolica community and a meadow steppe area. We conducted analyses and monitoring of plant community characteristics and soil environmental factors to assess the progress of restoration. The results showed that the introduction of indigenous woody plants in the degraded areas led to a proportional increase in vegetation cover, plant biodiversity, and species abundance over time. The primary external forces driving the succession of vegetation in the restored sites were soil factors including organic matter content, temperature and total nitrogen levels, which were associated with an increase in vegetation cover. These results can be interpreted as an increase in vegetation cover leading to an increase in litter production. This in turn reduces soil temperature and evaporation, subsequently enhancing the activity of soil microorganisms. Over time, the species composition, structural diversity of communities, and ecosystem functions in the restored sites gradually became more similar to those of the reference ecosystems. This indicates that vegetation restoration in this area has been very successful. In particular, the positive change in local residents’ awareness regarding the necessity of restoration has been considered a crucial contribution to the success of restoration in the degraded areas. It has led to a decrease in perceived anthropogenic threats to the restored sites. These results indicate that the introduction of native woody plants is crucial and can increase vegetation cover and species composition complexity and local residents’ positive perception of restoration for the successful restoration of desertified drylands.

Factors driving plant diversity in the spontaneous vegetation of the novel ecosystem of post-coal mining spoil heaps and their relationship with soil respiration

The subject of the paper is the analysis of the relationship between spontaneous vegetation diversity and soil respiration in novel post-coal mine ecosystem. In the natural and semi-natural ecosystems, soil respiration process (Rs) is a crucial ecosystem function regulating terrestrial ecosystems’ carbon cycle. Soil respiration depends on the quality and quantity of the soil organic matter (SOM), the soil microbes’ activity, and root metabolism. The listed factors are directly related to the composition diversity of vegetation plant species (biochemistry). For many years, soil respiration parameters have been studied in natural and seminatural vegetation communities and ecosystems. However, there still need to be a greater understanding of the relationship between vegetation plant species diversity and soil respiration as a crucial ecosystem function. Plant species diversity has to be analysed through both the taxonomic diversity and the functional diversity. These approaches reflect the composition, structure, and function of plant species communities. We hypothesise that the diversity of the spontaneous vegetation species composition shapes the amount of soil respiration in a post-coal mine novel ecosystem. The soil respiration differs significantly along the vegetational types driven by habitat gradients and is significantly higher in highly functional richness and dispersion vegetation patches. Contrary to our expectation, soil respiration was the highest in the less diverse vegetation types – both taxonomical and functional evenness were non-significant factors. Only functional dispersion is weakly negative correlated with soil respiration level (SRL).

Conservation Management Practices for Biodiversity Preservation in Urban Informal Green Spaces: Lessons from Central European City

Urban informal green spaces (IGS) represent valuable reservoirs of biodiversity within urban areas and are increasingly recognized as integral components of green infrastructure. They are perceived as temporary ecosystems, and the management of their vegetation is relatively understudied. The development time of spontaneous vegetation on transformed lands is considered to be in the range of decades, which makes it even more necessary to provide managers with better guidelines for such a long period. Two suggested management approaches for these areas involve: (1) retaining vegetation at various stages of succession (non-forest IGS) and (2) protecting advanced developmental stages (forest IGS), with options for balanced intervention or complete non-intervention. However, the differences in biodiversity between these two types in cities across Central Europe remain unknown, as well as whether the predictors of biodiversity at both local and landscape scales are consistent for non-forest and forest IGS. We examined factors such as habitat continuity, landscape structure, soil quality, and human impact to shed light on pathways for enhancing urban floristic diversity. Conducting extensive botanical surveys in existing informal green spaces (IGS) in Warsaw, we derived various parameters, including the total number of species, Shannon-Wiener biodiversity index, hemeroby, urbanity, share of species from distinct ecological groups, and the number of rare and ancient forest plant species. Tracing habitat continuity from the early 20th century using digitized aerial imagery provided a unique long-term perspective on IGS development. We revealed that no management is pivotal for the conservation of select rare and ancient forest species. On the other hand, partial abandonment with occasional maintenance may enrich species diversity across different successional phases. We uncovered the significant influence of landscape structure and human activity on vegetation species composition within IGS. Notably, IGS proximate to extensive forest landscapes displayed a marked abundance of forest species, alongside a greater prevalence of rare species. However, the presence of other vegetation types in the vicinity did not yield similar effects. Our findings indicate that IGS, when left untouched for decades near forested areas, are valuable for urban biodiversity. As cities across the globe seek sustainable paths, this research underscores the importance of properly understanding and integrating IGS into urban ecological planning.

Оценка ежемесячной динамики площадей открытых песков на востоке Ставропольского края в 2023 г.

The author examines the open sands’ spatial position dynamics in the east of the Stavropol Krai (Levokumsky, Neftekumsky, Stepnovsky and Kursk rayon) in the context of the months of 2023. The current year differs from a number of previous ones (2017–2022) in terms of meteorological conditions, in connection with which the changes assessment will clarify the dust storms impact degree on the sandy areas acreage. Mapping of open sands was carried out using satellite survey data (Sentinel-2) for each month for the March-October period 2023. At the beginning of the term, the area of open sands was 51 thousand ha, due to gradual decrease in October, 17.2 thousand ha were identified. Monthly dynamics for 9.6 thousand objects was estimated, considering differentiation into parts caused by the proliferation of annual psammophytes. The results of determining the species composition of vegetation on the sands during field research are presented. The accuracy of decryption exceeded 98 %

Yak and Tibetan sheep dung increase the proportional biomass of grasses and alleviate soil nitrogen limitation in degraded Tibetan alpine grassland

The dung of Tibetan livestock serves as a natural fertilizer that plays a crucial role in maintaining plant productivity and restoration of degraded alpine grasslands. However, research on how livestock dung affects vegetation composition and soil quality in Tibetan alpine grassland on the time scale remains uncertain. We established three types of nutrients (yak dung, Tibetan sheep dung and urea) and control on a Tibetan alpine grassland in 2017, and measured the vegetation (species composition, aboveground biomass, composition of functional group biomass, and species diversity) and soil characteristics (soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP)), and calculated the SOC/TN, SOC/TP and TN/TP ratios) at the end of August 2017, 2018, and 2019. The study aimed to compare the effect organic fertilizers (two Tibetan livestock dungs) and inorganic nitrogen fertilizer (urea) on vegetation characteristics and soil chemical properties, and to assess whether the livestock dung can improve soil nutrient availability level in degraded Tibetan alpine grassland. Our results showed that: (1) Tibetan sheep dung delayed the increase of aboveground biomass, and urea increased the aboveground biomass in 2017 and 2018; (2) yak and Tibetan sheep dungs and urea increased proportional biomass of aboveground grasses and plant species richness index in the three years; and (3) livestock dungs increased SOC, TN, the ratios of SOC/TP and TN/TP in 2018. Our study implies that yak and Tibetan sheep dung stimulated plant growth and altered soil nutrients, while alleviating soil nitrogen limitation in degraded alpine grasslands. The return of livestock dung to soil may be a sustainable alternative to chemical fertilizers in near-natural recovery of degraded Tibetan alpine grasslands.

The influence of herbicide protection on the yield of annual sunflower (Helianthus annuus L.) in the conditions of Western Forest Steppe

Methods. Field, quantitative to determine weediness of crops, mathematical and statistical to assess the reliability of the data obtained.
 Results. It was established that the species composition of the dicot segetal vegetation in the sunflower agrocenosis was mainly represented by white quinoa (Chenopodium album L.), common bittersweet (Amaranthus retroflexus L.), birch mustard (Polygonum convolvulus L.), field mustard (Sinapis arvensis L.). Among the variants of the experiment, the highest number of weeds was noted in the control without herbicides — 31.2 weeds/ m2. The introduction of soil and insurance herbicides contributed to the reduction of weediness of sunflower crops. The negative influence of segetal vegetation on the formation of the yield of the studied crop has been proven, which manifested itself in a decrease of its seed productivity with an increase in the number of weeds in the crops. Thus, in the control variant without the use of herbicides the yield of sunflower was the lowest and amounted to 1.55 t/ ha due to strong weediness of the crops. The highest yield of sunflower (4.13 t/ ha) was noted for the variant in which the herbicide Oscar Premium, s.e. was applied to the seedlings. at the rate of 3.75 l/ ha and post-emergence spraying of crops with a tank mixture of herbicides Challenge, s.c., 1.0 l/ ha and Heliantex, s.c., 0.045 l/ ha with the addition of Vivolt surfactant 0.25 l/ ha.
 Conclusions. The lowest weediness of sunflower agrocenoses (1.5 units/ m2) at the time of harvesting was noted on the variant with the use of ground (Oscar Premium, s.e. 3.75 l/ ha) and tank mixture of insurance herbicides (Challenge, s.c., 1.0 l/ ha + Heliantex, s.c., 0.045 l/ ha + Vivolt surfactant 0.25 l/ ha) in the phase of BBCH 14. The highest yield of the researched crop was also noted on the specified version of the experiment — 4.13 t/ ha, which is 2.58 t/ ha more than the control version.

2011–2015年东洞庭湖洲滩典型植物群落样方调查数据集

The fixed sample plot investigation obtains the dynamic characteristics of ecosystem through long-term data accumulation and accurate space-time comparison, which provides a solid basis for long-term ecosystem research. In accordance with the unified monitoring specifications set forth by the Chinese Ecosystem Research Network (CERN), Dongting Lake Wetland Ecosystem Research Station conducts long-term positioning monitoring on the species composition and community characteristics of typical beach vegetation in the wetland ecosystem in response to the changing hydrological conditions of Dongting Lake. We processed the data of long-term monitoring sample plots of three typical wetland plant communities (Carex sp, Miscanthus lutarioriparius and Polygonum hydropiper) in Dongting Lake to obtain the dataset of sample survey of typical plant communities on East Dongting Lake beach from 2011 to 2015. This dataset covers a total of 14 indicators, including species name, Latin name, number of plants (clusters) (plants or clusters/quadrats), average height of leaf layer (cm), average height of reproductive branches (cm), coverage (%), phenological period, dominant species, number of plant species, density (plants or clusters/m2), leaf layer height (cm) of dominant species, reproductive branch height (cm) of dominant species, total coverage (%), and total dry weight of aboveground green parts (g/m2). This dataset comes with detailed background information to ensure its consistency across both spatial and temporal dimensions. Moreover, to ensure data accuracy and reliability, the dataset underwent comprehensive quality control throughout the entire process and is subject to expert review and verification. It can serve as an important source of background data for studying the process and succession trends of the beach wetland ecosystem in response to the hydrological conditions of Dongting Lake, and provide data support for vegetation remote sensing monitoring, biodiversity protection, wetland ecological restoration and adaptive management of Dongting Lake.

2011–2015年洞庭湖洲滩群落植物生态型、生活型和生长型组成数据集

Analyzing plant life-forms and ecotypes can provide deep insights into the relationship between plant community structure and environmental conditions, and plant life-forms play an important role in understanding the emergence, development, and succession laws of plant community. An investigation was made on the species life-forms and ecotypes of wetland plants in Dongting lake wetland. In accordance with the unified monitoring specifications of the Chinese Ecosystem Research Network (CERN), the Dongting Lake Wetland Ecosystem Observation and Research Station conducts long-term positioning monitoring on the species composition, species life-forms, growth forms and ecotypes of typical beach vegetation in the wetland ecosystem in response to the changing hydrological conditions of Dongting Lake. The dataset of long-term monitoring conducted on three typical plant communities (Carex sp., Miscanthus lutarioriparius and Polygonum hydropiper) in Dongting Lake wetland has been verified by experts to ensure the accuracy of the data. We then classified and processed the data to obtain the dataset of community composition of plant life-forms, growth forms and ecotypes on Dongting Lake beach (2011–2015). The dataset covers a total of 8 indicators, namely species name, Latin name, life-form, growth form, ecotype according to light intensity, ecotype according to water requirement, ecotype based on soil pH and ecotype according to responses sediment burial. This dataset comes with detailed background information to ensure its consistency across both spatial and temporal dimensions. This dataset comes with detailed background information about site information and site management records to ensure its consistency across both spatial and temporal dimensions. This dataset can provide support for the analysis of the classification of plant life forms and the composition and structure of ecotypes, and serve as valuable reference for further study of vegetation succession in Dongting Lake wetland.

How to successfully improve the biodiversity of city grasslands?

Urban grasslands (UG) are among the most common types of urban green areas. They are usually species poor, and spontaneous plant migration, which can increase biodiversity, is limited. To improve the range of ecosystem services provided by UG, various seed mixtures are applied during the establishment and restoration of UG. These mixtures vary in content, quality, and cost. High-quality seed mixtures are expensive and are usually only available in small amounts. Meanwhile, alternative methods of seed introduction (e.g., fresh hay application, seeds harvested by brush) have not been well studied in UG restoration, and inexpensive commercial mixtures could have low quality and lead to poor restoration outcomes. Here, we tested the effectiveness of different seed sources to create high-quality UG at two study sites. Based on the results, all seed addition methods increased the species richness of restored grasslands. The outcome of seed addition was satisfactory regardless of differences in residual vegetation species composition and soil properties between the sites. The species richness on plots that received a commercial mixture of flower meadow plants dedicated to pollinators decreased after overwintering. The alternative seed sources (fresh hay and seed incidentally collected during mowing) yielded grassland quality that was comparable to that on plots that received high-quality mixtures with known seed origin (a seminatural meadow mixture and a mixture with the addition of grasses).

INFLUENCE OF HERBICIDE TREATMENT ON YIELD SPRING RAPE IN THE FARMS OF THE MAGZHAN ZHUMABAYEV DISTRICT OF THE NORTH KAZAKHSTAN REGION

The research work is devoted to the study of the effect of herbicide treatment on the yield of spring rapeseed in the farms of the Magzhan Zhumabayev district of the North Kazakhstan region. Field experiments were conducted to study the effect of herbicides on weed vegetation and the yield of spring rapeseed oil seeds. The timing of sowing spring rapeseed is the end of May. The species composition of the weed vegetation of rapeseed agrophytocenosis was determined. The most common weeds in spring rapeseed crops are tilted schiritsa, common shepherd's bag, white mar, field osot, creeping wheatgrass. The type of clogging of crops is root-sprout-annual. The soil of the experimental field is a complex of leached and ordinary chernozems. The objects of the study were selected herbicides "Simba" and "Hacker". These drugs are aimed at combating annual and perennial weeds. They have a systemic effect, are absorbed by the leaves, transferred to the point of growth, roots and rhizomes and easily move around the plant, disrupting cell division and stopping its growth. The drug Simba has a high efficiency in the fight against monocotyledonous weeds in spring rape crops, the average efficiency for 28 days was 28.9%. Hacker herbicide is effective for controlling dicotyledonous juvenile and perennial weeds, providing an average efficiency of 40% in 28 days. Among the processing options, the most optimal from the point of view of crop quality was the treatment with Hacker preparation in compliance with the recommended consumption rate. The quality of the crop in this variant is close to the harvest with manual weeding and differs by only 3-5%.

Comparative assessment of the change in the species composition of vegetation on the territory of the western field of RSAU-MTAA

The article presents the analysis of changes in the floral composition of the western field of the Ecological Station of the Russian State Agrarian University – Moscow Timiryazev Agricultural Academy for 4 years. The research object is located in the center of the megalopolis, it is subject to high anthropogenic load, as it is surrounded on both sides by a road network, and at the same time it is part of the facies of the Forest Experimental Dacha. The site is characterized by close occurrence of groundwater, high density of upper soil horizons, heterogeneous soil structure and mesorelief, resulting of in flooding. As a result of a significant number of anthropogenic and abiotic factors, it is necessary to analyze the vegetation composition and the species richness of the area in order to assess the dynamics of variability of these conditions and to predict the potential stability of the biological diversity of the area. The changes in the species composition were analyzed by describing the vegetation and evaluating quantitative indicators: frequency of occurrence, abundance of species, degree of their dominance according to the O. Drude scale, as well as the Shannon index and indicators of species richness and saturation.The studies carried out showed a pronounced variability in vegetation cover from 2018 to 2022. During the study period, there was a change in plant families and an increase in species diversity: richness and saturation indices. In 2022, there was an increase in the number of species and an increase in the uniformity of their numbers compared to 2018.

Is spectral pixel-to-pixel variation a reliable indicator of grassland biodiversity? A systematic assessment of the spectral variation hypothesis using spatial simulation experiments

Covering 30%–40% of the terrestrial surface, grasslands are important hosts of biodiversity, crucial for nutrient cycles and carbon sequestration. However, these ecosystems face a pressing threat in the form of biodiversity loss, which can disrupt their functioning and resilience. Addressing this challenge requires effective monitoring of biodiversity changes on large scales. Remote sensing emerges as a valuable tool in this endeavour, enabling the assessment of grassland biodiversity through the analysis of vegetation patterns, species composition, and ecosystem health over extensive areas.According to the spectral variation hypothesis (SVH), the link between pixel-to-pixel spectral variation and species diversity in remote sensing images can be used to retrieve plant diversity based on spectral data. Nevertheless, the transferability of the proposed relation across ecosystem types, seasons and spatial resolutions remains unclear. The absence of comprehensive data has hindered systematic assessments of the SVH so far, which would ideally incorporate coherent sets of diversity estimates from remote sensing data and in-situ plant diversity measurements.With this study, we present a combined approach that brings together trait data from field measurements, simulations of spatial species distributions and radiative transfer models for a systematic and in-depth analysis of the SVH in temperate grasslands. Based on simulated grassland communities with different diversity levels, we assessed the spectral-to-species diversity relationship across (1) three temperate grassland types, (2) three seasons and, (3) five spatial resolutions (from 10 m to 0.2 m pixel size). We used the mean Euclidean distance and Rao’s Q as measures for spectral diversity and different biodiversity indices to describe the species and trait diversity of the simulated grassland communities.Based on 45000 simulated grassland communities in five different spatial resolutions, we found that the spectral-to-species diversity relationship is not stable across grassland types and seasons, despite the spectral diversity metric used. Correlations with spectral diversity were inconsistent for the different applied diversity indices and no single index outperformed the others. Spectral diversity was mainly driven by the spatial resolution (i.e. pixel size) of the image and not by species richness (SR) or functional trait diversity (FD) per se. Our results further underline that the link between SR and FD is not always prominent in plant communities and the basic assumption of the SVH is fulfilled only under certain conditions. Consequently, we argue that FD, which is an important driver of the spectral signature of a plant community, is not inevitably linked to the number of present species in an image. We conclude that the interplay of SR and FD is crucial for the expression of the spectral-to-species diversity relationship. This study clearly underlines the context-dependency of the SVH and we point out that, although of promising value for distinct ecosystems, it is not universally applicable in grasslands.

МЕРЫ БОРЬБЫ С СОРНОЙ РАСТИТЕЛЬНОСТЬЮ НА ПОСЕВАХ СОИ

In the forest-steppe zone of the Republic of North Ossetia-Alania on soybean crops (Iriston varieties), the effect of the soil herbicide Harness and insurance herbicides Galaxy Top, Illoxan, Frontier was studied. The aim of the research was to study the effect of various herbicides on the contamination of crops and the species composition of weed vegetation of promising soybean varieties in the conditions of the forest-steppe zone of the Russian Federation. Scientific novelty of research. The influence of various herbicides on the growth, development and productivity of promising soybean varieties has been studied; the effect of herbicides on the contamination of crops has been shown; The removal of basic nutrients by individual species of weeds has been established. Every year, more and more new herbicides appear on the market, so studying the properties of herbicides and their effect on weeds is an urgent task. The methodology. On the leached chernozems of the forest-steppe zone of the Russian Federation-Alania in 2020-2022, on the experimental fields of the SCNIIGPSH VNC RAS. The sowing method is wide–row (row spacing – 45 cm), with a seeding rate of 400 thousand germinating seeds per 1 hectare. The research area is hot, mostly well-humidified. The sum of temperatures is 3000-3200 °C. The climate of the described territory is continental, the absolute annual amplitude of air temperature fluctuations is 64 ° C. On the territory of the experiment, the soil is represented by medium-sized, heavy-loamy leached chernozem, underlain by pebbles. The soil is mechanically loamy, with a depth that turns into light and medium loamy- rocky. The authors found that chemical protection of crops from weeds in the forest-steppe zone should be carried out with combinations of herbicides Pivot 0.9 + Bazagran 1.1. At the same time, weed death reaches from 79.4 to 92.9%. After harvesting soybeans, the soil is quite suitable for the cultivation of any agricultural crop, since (in specified doses) herbicides do not accumulate in products and are safe for the environment.

ВОДНЫЕ РАСТЕНИЯ ПРИБРЕЖНОЙ ЗОНЫ КАСПИЙСКОГО МОРЯ И ИХ ПРАКТИЧЕСКОЕ ПРИМЕНЕНИЕ

Seagrasses of the Zosteraseae family are a valuable biological resource and raw material used for the production of zosterol, a polysaccharide of pectic nature, since the early 40-s of the XX century. Currently, the volumes of Zostera reserves in the Caspian Sea have not been sufficiently studied. The places of mass growth of Zostera, as well as the places of mass accumulation of storm emissions of Zostera formed after seasonal storm winds, remain unknown. The presented research results are devoted to determining the species composition of aquatic vegetation in the coastal zone of the Caspian Sea, as well as the problem of collecting and storing storm emissions of the sea grass Nanozostera noltei. The coast of the Caspian Sea with a length of about 150 km from the Agrakhan Bay to the city of Izberbash was explored. Dominant species of aquatic plants were found: Ruppia maritima, Ceratophyllum demersum, Laurencia caspica, Cladophora, storm surges of N. noltei. Technological instructions for the collection and preparation of dried sea grass of the Zosteraseae family have been developed. It was revealed that Nanozostera and Laurencia are of particular practical interest.

Landscaping of settlements in the Aral Sea disaster zone (Kazakhstan)

The role of landscaping in ameliorating the environmental conditions within settlements surrounding the Aral Sea is paramount. The primary natural constraints affecting the proliferation of plant species in the green spaces of Aralsk include low winter temperatures, elevated summer temperatures, meager precipitation, and susceptibility to windstorms. An evaluation of the species composition of tree and shrub vegetation was conducted in landscaped areas belonging to social and cultural facilities, as well on private residential property, within the municipal boundaries of Aralsk. Plantings surveyed encompassed an area of approximately 34,000 m2. 89.5% of the flora is comprised of five predominant taxa: Ulmus pumila, Populus x canadensis, Haloxylon ammodendron, Platycladus orientalis, and Acer negundo. These species demonstrate resilience to both high and low temperatures throughout the growing season, and their availability as planting material in the region further enhances their suitability. Presently, the city incorporates 31 taxa of tree and shrub species in its green spaces. Notably, Ulmus glabra, Catalpa ovata, Platanus orientalis, Hibiscus syriacus, and Prunus padus have been introduced and were not previously observed in the city. Analysis of the age distribution reveals 68.7% of young trees, underscoring ongoing landscaping efforts within the city even amid a shortage of irrigation water.

Impact of Phytophthora dieback on a key heathland species Xanthorrhoea australis (Asphodelaceae) (austral grasstree) and floristic composition in the eastern Otways, Victoria

Context The plant pathogen Phytophthora cinnamomi causes severe declines in susceptible vegetation, including loss of plant species, vegetation structure and fauna abundance. Grasstrees (Xanthorrhoea spp.) are keystone species that provide optimal habitat for vertebrates and invertebrates and are highly susceptible to the pathogen. Although effects in the Otway Ranges have been assessed at specific sites, there is less knowledge across the landscape on the extent of loss of Xanthorrhoea australis (austral grasstree). Aims The aims were thus to assess impacts at three Heathy Woodland sites and to determine the magnitude of loss of X. australis and susceptible species losses. Methods Floristic composition, species cover or abundance, and basal area of X. australis were recorded in quadrats within treatments (uninfested, infested, post-infested vegetation). Analyses included floristics (PRIMER v7), significant effects (ANOSIM), species contribution to similarity/dissimilarity (SIMPER). Species richness and susceptible species cover were analysed using two-way crossed ANOVAs to detect the influence of site, treatment, and interactions. Key results Species composition of uninfested vegetation was significantly different to infested and post-infested vegetation, with susceptible species more abundant in uninfested areas. Post-infested vegetation had the lowest percentage cover of susceptible species. The mean percentage cover of X. australis in uninfested vegetation (43%) was 10-fold greater than in infested areas (4.3%) and extremely low in post-infested vegetation (0.9%). Conclusions Susceptible species were subject to density declines and extirpation, and the loss of X. australis resulted in major structural vegetation changes. Implications These results have severe implications for heathy woodland communities and reliant fauna. Limiting the spread of P. cinnamomi and protecting grasstrees is critical for their security.