Natural Steppe Research Articles

Enhancement of nutrient resorption efficiency increases plant production and helps maintain soil nutrients under summer grazing in a semi-arid steppe

Grazing regime is the most important factor that alters nutrient cycling in grassland ecosystems. Grazing exclusion has been used for restoration of degraded natural grasslands in Northern China during past two decades, while we propose that 'summer grazing' could be a better management than grazing exclusion for this purpose. Summer grazing allows plants to resorb more nutrients in autumn, thus preventing grazing-induced grassland degradation while keeping grassland in production. However, our understanding of grazing effects on nutrient resorption remains limited. In the present study, we examined plant nitrogen (N) and phosphorous (P) resorption at plant species and community levels in a natural steppe grassland that had experienced contrasting 'summer grazing' versus no-grazing treatments over a 6-year period in central Inner Mongolia. Plant community nutrient resorption efficiency (RE) and resorption fluxes were estimated, along with nutrient return fluxes via animal excreta and litter deposition. We found that (1) Summer grazing at moderate intensity increased plant production, but did not alter soil quality indicators such as soil organic carbon, total nitrogen, and total and plant available phosphorous. (2) Summer grazing increased plant community nutrient RE as the post-grazing plant re-growth with elevated nutrient concentration compensated for the nutrient removal by defoliation. Summer grazing increased nitrogen RE in Leymus chinensis and Cleistogenes squarrosa, but not in Stipa krylovii; and increased phosphorous RE in L. chinensis, but decreased that in S. krylovii and C. squarrosa. (3) Summer grazing accelerated nutrient cycling via animal excreta and litter deposition, but did not reduce plant nutrient resorption fluxes in autumn, which is a major mechanism for plant production enhancement and soil nutrient maintenance under the grazing regime. Our findings provide the key evidence to support moderate-intensity summer grazing as a sustainable grassland management regime to improve plant production while maintaining soil nutrients.

Changes in the Fractional Composition of Organic Matter in the Soils of the Forest–Steppe Zone during Their Postagrogenic Evolution

The postagrogenic dynamics of organic carbon (Corg), total nitrogen (Ntot), and density fractions of organic matter (OM) in the dark gray soil (Haplic Phaeozem, Belgorod oblast, Les na Vorskle (Forest on Vorskla) Reserve) and migrational–mycellary Chernozem (Haplic Chernozem, Kursk oblast, Streletskaya Steppe Reserve) were examined. The most significant postagrogenic changes in all the studied soil properties were observed in the top 0–5 cm layer. The contents of Corg and Ntot in this layer of the Phaeozem chronosequence increased by 1.2–1.3 times over 45 years after cessation of farming. The contents of Corg and Ntot in the top 0–5 cm layer of Chernozem chronosequence increased by 1.9–2.0 times over 60 years of the postagrogenic development. The accumulation of Corg took place in all density fractions. In both chronosequences, the free fraction of organic matter (density <1.6 g cm–3) increased, while the occluded fraction (density <2.0 g cm–3) virtually did not change. In 60 years after the cessation of farming on Chernozem, all the studied parameters became close to those in the Chernozem under natural steppe. In the Phaeozem, these parameters recovered by no more than 60% of the level typical for the natural soil over 45 years after the cessation of farming. Thus, the postagrogenic restoration of organic matter and all its fractions in the forest-steppe zone was much faster in the Chernozem in comparison with the Phaeozem.

Монгольский хаган как сын Бога

Extensive Mongol conquests in the 13th century led to a clash of different cultures and necessitated the translation of concepts from one culture to another. One of them discussed in this article was the concept of Son of God, which most likely goes back to the Chinese Son of Heaven. The Mongols practically did not use Chinese political and philosophical terminology, but it seems to have existed in their Empire thanks to Kitan advisers along with the native steppe notions. In communications with Christians, the Mongols used the phrase Son of God in relation to their khagans, especially Genghis Khan, which, of course, was perceived by Christians very negatively, since in their culture this epithet could only belong to Jesus Christ. The article attempts to trace the use of this concept in Mongolian diplomacy in the middle of the XIII century — the period of the highest power of the Mongol Empire. The author concludes that, despite the legend of the heavenly origin of their ancestors, neither Genghis Khan nor the other great khans had this title officially. It appears sporadically in diplomatic correspondence and chronicles, and only in late medieval Mongol historiography does it become a permanent epithet of deified Genghis Khan.

Formation and self-maintenance of the population Hyssopus officinalis L. in conditions of the iron ore dump of Krуvyі Rih area

We ascertained the features of formation of self-renewing and self-sustaining of the local population of the Mediterranean introducent Hyssopus officinalis L. in the extremal ecologic and edaphic conditions of an iron ore dump in Kryvyi Rih Area, seeds of which have been sown on the area of 1 ha about 30 years ago. It was found that the species, during this period after reaching the reproductive phase of development, has taken the area of the dump of about 3 ha and, in fact, it formed the isolated population. This species annually multiplied by seed, and spread on the areas of ore dump, where almost no vegetation cover, in fact, performing a pioneer function. At the site, where the initial sowing of H. officinalis seeds was carried out, the phytocoenosis forms now; this phytocoenosis, according to its floristic composition, approaches the natural steppe, but the introduced species are gradually ousted. In habitats occupied by the species due to its spontaneous distribution, successional processes are at an initial stage. Within some of the population loci of H. officinalis, we have found up to 513 adult individuals with the number of generative sprouts from 20 to 70 per a plant. Flowers are formed on these sprouts in average from 160.2 to 181.6. Average seed productivity is 60 % of theoretically possible rate, and the seeds from the parent species extend to a distance of 1–5 m. In a compact areas where H. officinalis grows, there are plants of all the age groups – from the seedlings to the subsenile. H. officinalis has naturalized in the dump conditions, and its local population is а resistant, full-grouped; it develops under the conditions where other species are not competitive. Generatively developed plants are higher than 90 cm and have good vital state. The species on the dump shows pioneering features; it is not aggressive and can be displaced by zonal vegetation; thus, it does not pose invasion risk. H. officinalis can be recommended for the revegetation of iron ore dumps, or their large decommissioned areas, without technical preconditioning, only by direct sowing of the seeds into the dump rocks, to promote its spread artificially.

К стратегии сохранения и восстановления степей и управления природопользованием на постцелинном пространстве

The program for the virgin and fallow lands’ development adopted in the USSR in 1954 is the largest megaproject of the 20th century, with unprecedented ecological and socio-economic consequences. Large areas of steppe landscapes of Russia and Kazakhstan (more than 43 mln ha) have been ploughed. “Power” methods of influencing natural steppe landscapes with the aim of agricultural production intensifying led to their degradation and destruction. The consequences of these policy are well known: processes of erosion, dust storms, soil depletion, degraded land abandonment, and subsequently steppes’ autoreduction in the vast expanses of the steppe zone have developed. The anthropogenic impacts generated by the irresponsible and insufficiently scientifically grounded land resources use led to the loss of valuable land areas that are of major, not only economic, but also biospheric and environmental importance. Ecological and socio-economic changes and consequences still affect the steppe landscapes’ structure and functioning and the entire economic activity of regions that have undergone a “total” plowing. The study of these problems is of great relevance, despite many years have passed. Establishing the effectiveness of the project raises many questions. It is necessary to rethink the system of interaction “steppe–society”. It demands of the formation of new approaches to the use and protection of steppe landscapes. The main scientific directions of the strategy for the steppe landscapes’ conservation, restoration, and management were determined: land reform improvement including formation of efficient landowners and the state fund of low-productive lands; cultural rehabilitation of degraded landscapes (creation of cultural landscapes); identifying steppe land use types according to various natural, ecological and socio-economic characteristics, taking into account environmental restrictions and prohibitions; legislative establishment of the type of steppe natural resource use; transition to nature-like technologies in the agricultural sector; declaration at the state and international levels steppes’ special role on carbon sequestration; wider plant resources use in medicine and industrial production.

GROUNDS FOR THE DEVELOPMENT AND APPLICATION OF PRECISION TECHNOLOGIES IN ORDER TO KEEP SPECIFIC BEEF CATTLE UNDER THE CONDITIONS OF YAKUTIA

The article demonstrates the research results on climate conditions of the Republic of Sakha (Yakutia) and grounds of application of precision technologies for breeding Kalmyk beef cattle on the basis of specific natural and climate conditions of Yakutia. The history of animal breeding says that enhancement of local livestock’s producing qualities in different years contributed to the fact that the stud breeds of cattle, generally dairy and beef-dairy types, were imported. Animals of the beef productivity type, known as Kazakh Whitehead cattle, the Hereford, the Kalmyk, and the Calloway breeds, were imported in order to receive crossbred youngsters with improved feeding and beef parameters. In all the time of the development, the cattle breeding in the region had beef-dairy types. The beef breeds were imported in the last decade for targeted purebred breeding and development of the beef industry for production of the beef. Therefore, in 2012, there were imported 200 animals of the Hereford cattle; the Kalmyk breed has been imported since 2013. The experience has shown that naturalizing of purebred animals to the breeding conditions of Yakutia was extremely stressful, and was followed by the diseases, falls, and decreasing of seed stock’s reproductive indicators. Particularly negative impact was observed on the animals of the highly productive Hereford breed, and this caused gradual degeneration of the breed under conditions of Yakutia. Although, specific natural and climate conditions of Yakutia significantly differ from that in other regions with developed beef cattle breeding, the animals of the Kalmyk breed, which was bred on the basis of the native steppe cattle, were relatively well adapted to the harsh conditions of the region. The authors argue the necessity and urgency of adaptive technologies development on specialized beef cattle breeding with respect to the harsh local conditions.

Compositional and functional responses of soil microbial communities to long-term nitrogen and phosphorus addition in a calcareous grassland

Increased nitrogen (N) input into the ecosystem, which is mainly caused by anthropogenic activities, is usually not paralleled by a similar increase in phosphorus (P) input, and thus, can shift the ecosystem from N limitation to P limitation. Although the effects of N enrichment on ecosystem components have been intensively evaluated, the impacts of altered P resource availability and the interactive effects of N and P on the biomass, composition, and function of soil microbial communities are not well understood. Here, based on a 9-year field experiment, we investigated the responses of soil biotic and abiotic properties to N and P addition in a semi-arid calcareous grassland in northern China. We documented a significant increase in the relative abundance of bacteria (copiotrophic group in a broad ecological meaning) and a decrease in the relative abundance of fungi (oligotrophic) and the fungi/bacteria (F/B) ratio under N addition. The proportion of arbuscular mycorrhizal fungi (AMF) decreased under both N addition and P addition. N addition and P addition inhibited N-acquisition enzymes (protease, PRO) and P-acquisition enzymes (alkaline phosphomonoesterases, Alka PME), respectively. N fertilization inhibited most of the soil enzymatic activities by reducing soil pH and microbial biomass. P addition alleviated the negative impacts of N addition on substrate induced respiration (SIR), peroxidase (PER), and Alka PME, likely by reducing the available N content in soils, but strengthened the effects of N on the soil total carbon (TC) content, which might contribute to increased plant productivity. We also found that the overall changes in soil microbial enzyme profiles in response to nutrient addition were mainly caused by eutrophication (changes in NO3−-N and Olsen-P), whereas variations in the broad community structure were driven by soil acidification. Overall, the application of N and P in this natural steppe will cause serious environmental issues and impact ecosystem service and function through changing the compositional and functional profiles of soil microbial communities.

Микробиологическая оценка состояния почвенного покрова агролесомелиоративных ландшафтов Каменной Степи

The microbial biomass content is the most informative indicator for early detection of soil condition. Soil microorganisms support the homeostasis of forest ecosystems due to theunique ability of rapid adaptation to changing environmental conditions. The article presents the results of soil microbiological assessment carried out within the framework of comprehensive monitoring studies of the forest ecosystems of the Kamennaya Steppe. The following objects of the agroforestry permanent study area served as options: a mowing fallow of 1882; forest belt no. 40 of 1903 laying out, located on the watershed area; forest belt no. 133 of 1950 planting; and forest belt no. 131 of 1959 planting. Additionally, arable lands adjacent to forest belts no. 40 and 133 (watershed, slope) were included in the research scheme. The research purpose was to determine the biological activity of soils of the Kamennaya Steppe, as wellas the direction and intensity of soil and biological processes in agroforestry arrangement of the territory. The total number and structure of ecological and trophic groups of the microbial community were determined by the method of E.Z. Tepper by seeding on solid nutrient media. It is shown that the soil cover under the tree plantation is defined by a higher contentof ammonifiers and actinomycetes. Intensive agricultural land use significantly reduces the intensity of microbiological processes. The undertaken studies allow stating that the optimumconditions for the development of micromycetes are formed in soils under woody and native steppe vegetation. The involvement of chernozems in active agricultural production leads toa decrease in the number of fungal flora. A high concentration of nitrifiers was revealed in arable lands. The lands with woody vegetation and steppe cenoses had lower indices and weresomewhat inferior to agrogenic soils. Annual soil cultivation is crucial and drives up the activity of bacterial colonies (genus Azotobacter) on arable lands. The activity is much lowerunder the tree crops and steppe vegetation in most cases. Mineralization coefficients are calculated for the studied soils. Due to the fact that these coefficients in all the studied objects are above one (except the field under winter wheat and bordering the forest belt no. 133), it follows that the mineralization processes of soil organic matter prevail over the decomposition of organic residues.For citation: Sautkina M.Yu., Cheverdin Yu.I. Microbiological Analysis of the Soil Cover of the Kamennaya Steppe Agroforestry Landscapes. Lesnoy Zhurnal [Russian Forestry Journal],2019, no. 6, pp. 62–78. DOI: 10.17238/issn0536-1036.2019.6.62Funding: The research was carried out within the framework of the state assignment of the All-Russian Research Institute of Forest Genetics, Breeding and Biotechnology.

Root-Colonizing Endophytic Fungi of the Dominant Grass Stipa krylovii From a Mongolian Steppe Grassland.

In several terrestrial ecosystems such as grasslands, plants live together with various root-colonizing dark septate endophytes (DSEs), fungi that are relatively frequent colonizers of healthy belowground tissues of plants in these environments. They are important members of the plant microbiota and may have various effects on plant survival under different stress conditions; however, their general functions in relation to plants and the greater ecosystem remain elusive. Although an increasing number of studies has been published focusing on DSEs in Asian grasslands, our knowledge is limited. Especially in Mongolia, where the steppe region represents a significant area, information is not available on these root colonizers. In this study, we aimed to characterize DSEs of a common dominant gramineous plant species, Stipa krylovii in a semiarid grassland of Mongolia. Root samples were collected in a natural steppe and were processed for isolation of fungal endophytes. For molecular identification of the isolates, the internal transcribed spacer (ITS) region of the nrDNA was obtained for all the isolates investigated; furthermore, the partial translation elongation factor 1-α (TEF) gene and large subunit (LSU) and small subunit (SSU) of rDNA were also amplified and sequenced in case of representative isolates. In vitro tests were used to examine the rough symbiotic nature of the fungi, and root colonization was visualized. A majority of the 135 isolates examined in detail was found to belong to several orders of Ascomycota (110 isolates) and some to Basidiomycota (25 isolates). A significant number of the isolates represented presumably novel taxa, and dominant similarities of the lineages have been found with relatively frequent and known grass root endophytes of semiarid areas in other geographic regions. These endophytes included Periconia macrospinosa, Microdochium bolley, and Darksidea, the genus of which comprised one fourth of the isolates. We found numerous lineages, which have been detected not only from Asian steppe ecosystems, but also from prairies in North America and sandy grasslands in Europe. Therefore, our results strengthen the hypothesized worldwide presence of a common and dominant core group of a DSE community in arid and semiarid grasslands.

Taxonomic, phylogenetic and functional homogenization of bird communities due to land use change

Biotic homogenization, the increasing similarity of biotas over time, is an important topic in biodiversity conservation and has been widely linked to anthropogenic factors, e.g., land use change and climate change. However, so far few studies have simultaneously tested the taxonomic, phylogenetic and functional homogenization caused by human activities. Here, we analyzed the effects of land use change on biotic homogenization of bird communities in these three biodiversity dimensions in the steppe region in Inner Mongolia, China. The results showed that taxonomic, phylogenetic and functional similarities were significantly lower in relatively natural grassland than in the other disturbed habitats, i.e., planted woodland, farmland and village. In addition, there were also higher associations between bird community similarities and climate distances in natural grassland than in the other disturbed habitats. These results suggest that more intense land use types result in consistent taxonomic, phylogenetic and functional homogenization of bird communities, while at the same time diminish community turnover across climate gradients. These findings indicate that anthropogenic activities in this steppe region may not only cause biodiversity loss in taxonomic level, but also in other biodiversity dimensions, highlighting the important role of natural steppe in biodiversity conservation.

CURRENT STATE AND PROBLEMS OF MODERNIZATION OF ECOLOGICAL FRAMEWORK OF REGIONS OF THE STEPPE ZONE OF EUROPEAN RUSSIA

Aim. The aim of the study is to assess the current state of the elements of the naturalecological framework of the steppe regions of European Russia and the peculiarities of its spatial distribution. Discussion . The most important component of the environmental framework of the steppe regions of European Russia is the system of relatively large zonal landscape areas of the nature reserve fund which contribute to the preservation of biodiversity, the functional integrity of landscapes and the development of ecological networks. As of January 1, 2018, the natural reserve fund of the federal level in the territory of the considered mezoregion is represented by 22 specially protected natural territories (10 reserves, 5 national parks and 7 wildlife sanctuaries) with a total area of 16.1 thousand km2. The share of the area of specially protected natural reservation is about 2% of the area of the considered mezoregion. Practically for all the regions under consideration, there is a situation where numerous natural territories with “prospective” status are considered for integration into the nature reserve fund; however, the efforts of the scientific community, environmental services and relevant ministries are not very active in implementing projects to give them corresponding status. Conclusion. For the territory stretching from the northern border of the Saratov region to the central part of the Krasnodar Territory, the problem of the absence of cores and key elements constituting the framework of the nature reserve fund is most acute. In six territorial subjects of the Mesoregion, there are no specially protected natural steppe reservations of the federal level. The analysis of modern territorial planning schemes of the steppe regions indicates that the environmental framework of European Russia has not yet become the basis for the adoption of urban planning decisions. At the same time, its structural elements (preserved zonal landscapes, natural and derived landscape complexes), along with autonomously functioning nature-like territorial complexes, will help create a favorable environment for the population.

Differences in main processes to transform phosphorus influenced by ammonium nitrogen in flooded intensive agricultural and steppe soils

Exogenous ammonium nitrogen (AN) fertilization/deposition and the subsequently induced soil acidification, might exacerbate soil phosphorus (P) transformation and mobility, whereas poor understanding in abiotic and biotic processes still existed between intensively cultivated soil with high proportion of legacy inorganic P (Pi) in comparison to natural steppe soil with high proportion of organic P (Po). Column batch flooded experiment using vegetable (VEG) and steppe (STE) soils was conducted to investigate the P transformation and mobility influenced by 60-day intermittent elution with an (1500 mg N kg−1) solution or an acid sulfate (107 mmol H+ kg−1) solution. The results showed that AN elution significantly decreased the contents of all Pi fractions and strengthened Pi leaching, whereas acid elution increased the contents of Al-Pi, Fe-Pi, and reductant-soluble Pi and reduced P leaching in VEG soil. In contrast, AN elution increased the contents of soluble-Po and Al-(Pi + Po) and decreased Ca-P and Fe-Pi, no effects on P leaching, whereas acid elution increased the contents of soluble-(Pi + Po), Al-(Pi + Po), Fe-(Pi + Po) and reduced P leaching in STE soil. Variances analysis showed that pH and microbial biomass carbon were the most important factors to predict the P composition of the VEG and the STE soil, respectively. This indicated that AN elution released the soil mineral-bound phosphate with ammonia oxidation coupled with Fe(III) reduction, besides the same chemical influences on Fe/Al oxides as acid elution in VEG soil; while predominantly affected biochemical/biological processes of soil P by changing microbial biomass and enzyme activities in STE soil.

Barrier functions of spoils of natural and technogenic steppe landscapes.

Barrier functions of spoils of natural and technogenic steppe landscapes.

The current state and protection of steppe landscapes in the Volgograd region of Russia

The anthropogenic activity creates a significant negative impact on the steppe biome of the Earth. Eurasian steppe is one of the most altered by human economic activity, particularly in Russia. These changes are especially vividly manifested in the Russian Plain, the old-developed territory of Russia. The most substantial damage on steppe landscapes of the Russian Plain was caused by the extensive agricultural use of natural grasslands, especially in the second half of the 20th century. The overwhelming majority of natural steppe landscapes are replaced here by agricultural landscapes which threaten the preservation of the unique soil, biological and landscape diversity of steppes. The main goal of the article is to analyze the current geoecological situation in the steppe zone of the Russian Plain from the regional aspect: by the example of its south-eastern part attributed to the Volgograd region. The described territory is characterized by the extraordinary landscape diversity and located within forest-steppe, steppe and semi-desert natural zones. The article deals with the analysis of the current agricultural structure in the south-east of the Russian Plain within Volgograd Region, of major geoecological consequences of economic activity typical of different types of agricultural lands, and also of pressing problems related to the preservation of the landscape, and of the biodiversity of steppe landscape. The results of this research are necessary to make decisions aimed at optimizing agriculture, at raising the quality of steppe landscape preservation, and at organizing ecologically-conscious recreational activity to preserve the unique variety of steppe landscapes.

Forage Resources, Nutrition, and Food Supply of Free-Grazing Camels (Сamelus bactrianus) in a Pasture within the Natural Steppe Zone

Abstract—This paper reports the results of investigation on the food of free-grazing Bactrian camels in a forb–grass steppe pasture, including anthropogenically disturbed areas with dominance of ruderal annuals. We identified the composition of consumed plants using a microhistological analysis of the feces; the digestibility coefficient based on inert (indigestible) silicon contained both in the diet and feces; the quantity of the forage consumed based on the mass of the feces and the digestibility coefficient; and the energy balance based on interrelations between the actual consumption and the existing requirement norms of camels and wild ungulates in energy. In spring, camels mainly consume graminoids (Stipa sp. and Festuca valesiaca), switching to forbs, largely ruderal annuals, in summer and autumn. The forage digestibility is low in spring (56%), increasing to 69–70% in summer and autumn. Low daily consumption rates of dry forage mass in winter and spring (8–9 kg) are changed to high in summer and autumn (20–26 kg), this reflecting the animals’ winter hypophagy. The amount of energy received during the warm season (1.2–1.8 MJ/kg W 0.75) considerably exceeds the requirements, thus explaining the ability of camels to accumulate a safety store of fat in the humps.

PHYTODIVERSITY OF PRESENT LANDSCAPES OF UKRAINIAN FOREST-STEPPE ZONE (BY THE EXAMPLE OF APART AREAS OF HAISYN DISTRIC T, VINNYTSIA REGION)

Problem Statement and Purpose. Biological diversity is one of the fundamental property of natural complexes, which provides their firmness and shows up on the different levels of their hierarchy. Within the biodiversity researchers mark out phytodiversity which is an account of plant species of the complex.The main purpose of the research is assessment of phytodiversity of relatively natural territorial systems of forest-steppe zone in the conditions of powerful anthropogenic influence. Relatively natural landscapes are the systems which have not been used in human activity for 10 years and more. Present days there are not a lot of such areas because new type of landscapes - agroindustrial complexes - covers large territories. So it is important to know if remaining relatively natural complexes are sustainable. Data iC Methods. The field research of phytodiversity was done in summer 2017. The subjects of research were the areas of steppe and woods on slopes of PivdennyiBug’s and Sob’s valleys (Haisyn district, Vinnytsia region). Standard methods of field describing and assessment of phytodiversity were used.One of basic parameters of phytocenosis firmness is the species composition like an amount of all plants species of phytocenosis in set geographical conditions. The coefficient of germination shows the deviation from the norm of species composition. The index of adventitious species and weed is a value for description of species composition and its transformation under anthropogenic pressure. Also one of the impotent characteristics of species variety is the spectrum of life forms which describes the stability of natural zone.Results. Due to research and calculations it is got that the coefficient of germination was about 55% for steppe areas and only 38% for woods. The index of adventitious species and weed is highly for wooden territories. It means that forests are less steady than steppes.At present days the relatively natural steppe systems (by the example of Haysin district, Vinnytsya region) are characterized with a high germination and monotony regardless of their location. The amount of species is more than 30 for each area. Such complexes might be steady for a long tune. But the wood complexes are unsteady enough and feel the substantial changes in species composition at the increase of the anthropogenic loading. Although their spectrum of life forms corresponds with forest-steppe natural zone.

Wind erosion enhanced by land use changes significantly reduces ecosystem carbon storage and carbon sequestration potentials in semiarid grasslands

AbstractWind erosion exerts a fundamental influence on the biotic and abiotic processes associated with ecosystem carbon (C) cycle. However, how wind erosion under different land use scenarios will affect ecosystem C balance and its capacity for future C sequestration is poorly quantified. Here, we simulated different intensities of land uses in Inner Mongolia: control, 50% of vegetation mowed (50 M), 100% vegetation mowed (100 M), and tillage (TI). We monitored abiotic C flux caused by wind erosion, net ecosystem exchange (NEE), and soil characteristics from 2013 to 2016. We found that the frequency of heavy wind exerts a fundamental control over the severity of soil erosion, and its interaction with precipitation and vegetation characteristics explained 69% of the variation in erosion intensity. With increases in land use intensity, the abiotic C flux induced by wind erosion increased rapidly, equivalent to 33%, 86%, 111%, and 183% of the NEE of natural steppe in the control, 50 M, 100 M, and TI sites, respectively. The erosion‐induced decrease in fine fraction soils led to 31%, 43%, and 85% permanent losses of C sequestration potential in the surface soil for 50 M, 100 M, and TI sites. Overall, our study demonstrates that the abiotic C flux associated with wind erosion is too large to be ignored. The loss of C‐enriched fine particles not only reduces the current ecosystem C content but also results in an irreversible loss of future soil C sequestration potential. These dynamic soil characteristics need to be considered when projecting future ecosystem C balance in aeolian landscapes.

БОТАНІЧНА МЕЖА МІЖ ЛІСОСТЕПОМ І КАРПАТАМИ ТА ЇЇ ВПЛИВ НА ФОРМУВАННЯ ЛІСОВОЇ РОСЛИННОСТІ ДРОГОБИЦЬКОЇ ВИСОЧИНИ

Наведено результати досліджень лісової рослинності Дрогобицької височини та зроблено спробу виокремити асоціації лісової рослинності, які розмежовують природну зону Лісостепу та гірську країну Українських Карпат. На прикладі лісів урочища Воля Якубова встановлено, що ознаки фізико-географічних зон проявляються у характерних рисах рослинних асоціацій. Застосовані різні методики досліджень лісової рослинності показали подібні результати. За домінантною класифікацією Лісостеп репрезентують асоціації Quercetum roboris caricosum brizoidi, Quercetum roboris caricosum remotae, Quercetum roboris filipendulosum, Carpineto-Quercetum roboris caricosum pilosae, Carpineto-Quercetum roboris caricosum brizoidi, а Українські Карпати – Abieto-Querceta roboris caricosum brizoidi. За класифікацією типів лісу Лісостеп представляють грабові, а Карпати – ялицеві діброви і судіброви. За еколого-флористичною класифікацією, окрім асоціацій широколистяних мезофільних лісів, розмежування природних зон добре репрезентують вільхові ліси з різних синтаксономічних класів – Stellario nemorum-Alnetum glutinosae (клас QUERCO-FAGETEA) є характерним для Українських Карпат, натомість Ribeso nigri-Alnetum (клас ALNETEA GLUTINOSAE) – для Лісостепу. Отже, на прикладі лісового урочища поблизу села Воля Якубова вдалося простежити закономірності зміни лісостепових фітоценозів на гірські.

Eсomorphic structure of the soil macrofauna communities of technosols of the Nikopol Manganese Ore Basin

This study established features of the animal population of artificial soil-like bodies – technosols in terms of ecomorphic analysis. The survey was conducted at the research station of the Dnipro State Agricultural University in the city Pokrov in 2012–2014. The experimental polygons were laid within four technosol types: pedozems, sod loess-like lithogenic soils on loam, grey-green clay and red-brown clay. The polygon consisted of 15 transects and each transect was composed of seven test sites. The distance between rows in the polygon was 3 m. Each test site was a square with size 3 × 3 m. The manual sorting of the soil-zoological samples was conducted within each site for areas 0.25 × 0.25 m to the depth where animals were found. Samples were taken in late April or early May. In general, for each period of counting for each polygon 105 soil-zoological samples were taken 123 species of invertebrates were found in the soil macrofauna community of the technosols. These communities are a steppe monoceonosis with a tendency to transformations into pseudoomonoceonosis on account of increased share of pratants. The soil macrofauna of sod lithogenic soils on grey-green clay and loam on loes-like clays is most adapted to xerophilous condition. Animal communities in pedozems and sod-lithogenic soils or on red-brown clay have a more mesophilic character. The trophoceonomorphic structure of the soil macrofauna community indicates a significant potential of the fertility of artificial soil. The aeromorphs’ structure reveals a significant ability of technosols to create cracks and pores, which can lead to hyperaeration. The dominant part of the of soil macrofauna community was hypercarbonatophils. Against the background of the steppe character, the soil macrofauna community had a topomorphic structure that is unusual for natural steppe black soil biogeocenoses on loess-like loam. The trophomorph structure was greatly dominated by phytophages, which indicates the prevalence of processes of mineralization of plant residues under the humification process. The phoromorphic spectrum of soil animal communities was dominated by ecological groups which move without the active construction of tunnels.

Grazing exclusion-induced shifts, the relative importance of environmental filtering, biotic interactions and dispersal limitation in shaping desert steppe communities, northern China

Grazing exclusion is one of the most efficient approaches to restore degraded grassland but may negatively affects the recovery of species diversity. Changes in plant species diversity should be a consequence of the ecological assembly process. Local community assembly is influenced by environmental filtering, biotic interactions, and dispersal. However, how these factors potentially contribute to changes to species diversity is poorly understood, especially in harsh environments. In this study, two management sites within a Stipa breviflora desert steppe community (typical natural steppe) were selected in northern China. In one of the two management sites, grazing has been excluded since 2010 and in the other with open grazing by sheep. In August 2016, three plots were established and 100 sampling units were created within each plot in a 5 m×5 m area at the two management sites. To assess the effects of grazing exclusion on S. breviflora steppe, we analyzed the vegetation biomass, species diversity, soil organic carbon, and soil particle size distribution using paired T-tests. In addition, variation partitioning was applied to determine the relative importance of environmental filtering and dispersal limitation. Null mode analysis was used to quantify the influence of biotic interactions in conjunction with EcoSim niche overlap and co-occurrence values. Our results demonstrated that (1) species diversity significantly decreased and the main improvements in soil quality occurred in the topsoil 0–10 cm after the grazing exclusion; (2) environmental filtering was important for community assembly between grazed and fenced grassland and this appears particularly true for soil particle size distribution, which may be well correlated with soil hydrological processes; and (3) however, competitive exclusion may play a significant role within the exclusion. The multiple pathways of assembly may collectively determine negative effects on the restoration of species diversity. Therefore, designers should be aware of the risk of reducing grazing exclusion-induced species diversity and account for manipulating processes. This in turn will reduce dominant species and promote environmental heterogeneity to maximize species diversity in semi-arid regions.