Dynamics of plankton biocenoses under water level fluctuations in steppe lakes

Barun-Torey and Zun-Torey lakes are located in the arid steppe zone of the Central (Inner) Asia, Eastern Siberia, Russia. The Torey lakes are characterizes unstable hydrological regime. The water level variation is explained by the periodic filling and drying of the lakes due to cyclical climatic changes in humidity and temperature. We conducted our studies various water level phases of the climatic cycle: from high water level (1999, 2003) to drying out and the initial filling phase (2007, 2011, 2014, 2016, 2018, and 2020). The aim of this paper is to present long-term research results on changes in the plankton biocenoses of the Torey lakes during a climate cycle, the drying and initial filling of basins. Succession of plankton dominant species is in the direction of: diatoms+green algae and rotifers+crustaceans → green algae and crustaceans → green algae+cyanobacteria and crustaceans → no planktonic algae and invertebrates → cyanobacteria+diatoms+green algae and rotifers+cladocerans+copepods.

The Distribution and Turnover of Bacterial Communities in the Root Zone of Seven Stipa Species Across an Arid and Semi-arid Steppe

The bacterial communities of the root-zone soil are capable of regulating vital biogeochemical cycles and the succession of plant growth. Stipa as grassland constructive species is restricted by the difference features of east–west humidity and north–south heat, which shows the population substituting distribution. The distribution, turnover, and potential driving factors and ecological significance of the root-zone bacterial community along broad spatial gradients of Stipa taxa transition remain unclear. This paper investigated seven Stipa species root-zone soils based on high-throughput sequencing combined with the measurements of multiple environmental parameters in arid and semi-arid steppe. The communities of soil bacteria in root zone had considerable turnover, and some regular variations in structure along the Stipa taxa transition are largely determined by climatic factors, vegetation coverage, and pH at a regional scale. Bacterial communities had a clear Stipa population specificity, but they were more strongly affected by the main annual precipitation, which resulted in a biogeographical distribution pattern along precipitation gradient, among which Actinobacteria, Acidobacteria, Proteobacteria, and Chloroflexi were the phyla that were most abundant. During the transformation of Stipa taxa from east to west, the trend of diversity shown by bacterial community in the root zone decreased first, and then increased sharply at S. breviflora, which was followed by continuous decreasing toward northwest afterwards. However, the richness and evenness showed an opposite trend, and α diversity had close association with altitude and pH. There would be specific and different bacterial taxa interactions in different Stipa species, in which S. krylovii had the simplest and most stable interaction network with the strongest resistance to the environment and S. breviflora had most complex and erratic. Moreover, the bacterial community was mainly affected by dispersal limitation at a certain period. These results are conducive to the prediction of sustainable ecosystem services and protection of microbial resources in a semi-arid grassland ecosystem.

Genetic Risks and Demographic History of Indigenous Goats of Mongolia Revealed by SNP Genotyping

Recent climatic disasters (dzudzs) and uncontrolled massive breeding endangered valuable ge-netic resources of Mongolian goats labored by five thousand years of evolution in extremes of Al-tai mountains and Gobi deserts. Meanwhile, Mongolian goats has never been characterized by genomic data. We used Illumina Goat SNP50 to investigate phylogenic relationships and genetic risks in 5 local Mongolian populations: Erchim (N=37) from geographically remote Darkhat Valley in the northern mountains, Ulgii Red (N=35) and Dorgon (N=28) from the western mountain region, Buural (N=34) from the western steppe and mountain areas and Gobi Gurvan Saikhan (N=33) from semi-arid steppe area in the South Gobi region. ROH analyses, estimated populations sizes and Fst values showed South Gobi and Darkhat Valley goats to be of a high risk of inbreed-ing that however appear to be of distinct origin (artificial selection vs geographical isolation). In-dices of genetic differentiations between Mongolian goats were relatively low compared to Euro-pean breeds. Meanwhile, we suggest direct comparison is not fully appropriate given that Mongo-lian breeds were not subjected to intense selection. Darkhat Valley goats were clearly differentiat-ed from other Mongolian breeds according to various types of analyses. Phylogenetic relationships within XXX breeds of the rest of the world plotted Mongolian goats between some Russian (Altai, Orenburg) and Chinese populations (Nanjiang and Qinggeli). Thus, present study (i) highlights demographic history Mongolian goats and (ii)provides unified SNP-data called for support deci-sions in conservational genetics. Finally, our work (iii) raises a question of how exactly these data should be compared to make objective choices.

EFFECTIVENESS OF SOWING APPLICATION OF DIFFERENT DOSES OF UREA-AMMONIA LIQUORKAS-32, AMMONIUM SULFATE AND COMPOUND NPK FERTILIZER DIAMMOPHOSKA IN LINSEED FLAX CULTIVATION IN TEMPERATELY ARID FOREST-OUTLIER STEPPE

The farming enterprise AO Orbita annually cultivates linseed flax on an area of more than 8 thousand hectares. The areas under crop are located in the zone of temperate-ly arid steppe where resource-saving cropping technolo-gies with direct sowing and fertilization are used. The pre-vailing soils of the arable lands are leached chernozems with low nitrogen supply, increased phosphorus and high exchange potassium. To obtain a seed yield of 2.0 t ha or more, it is necessary to optimize flax nutrition during the first month of its growth. The best fertilizers for small-seeded flax are liquid nitrogen fertilizers and, first of all, urea-ammonia liquor KAS-32containing three forms of nitrogen. However, such experiments are rare in the Re-gion. This paper presents the results of the action of at sowing application of different KAS-32rates with ammoni-um sulfate dissolved init and compound NPK fertilizerDi-ammophoska by using a converted seeder. It was found that under arid conditions (the hydrothermal index over the growing season varied from 0 to 0.6 at 0.74-0.91 normal), fertilizer application contributed to greater crop density, boll formation and the formation of seed yield by 0.06-0.8 t ha above the control. The increase made 4.2-55.9%, the pro-tein content increased to 17.04-20.16% with a protein yield of 0.257-0.412 t ha as compared to 0.24 in the control; the oil content increased to 50.2-52.2% and oil yield –to 0.784-1.128 t ha as compared to 0.736 in the control. The highest indices of yield and seed quality were obtained when 50 kg ha of KAS-32 and ammonium sulfate were applied with 80 kg ha of Diammophoska compound NPK fertilizer.

Legacy Effects of Nitrogen Deposition and Increased Precipitation on Plant Productivity in a Semi-Arid Grassland

Nitrogen (N) deposition and increased precipitation induced by anthropogenic activities were widely reported to promote plant productivity in terrestrial ecosystems. However, few studies have explored the effects of historical resource supplement on plant communities although N deposition was predicted to decrease in the near future and the directional change of precipitation would shift among years. Here, we examined the legacy effects of N deposition and increased precipitation on plant productivity in a semi-arid steppe after cessation of a 13-year N and water addition experiment. We found historical N and water addition generally had positive effects on plant productivity even after the treatments were ceased. However, such legacy effects showed strong inter-annual variation, and the positive effect of N and water addition on productivity were stronger in a wet year (i.e., 2019) than an extremely drought year (i.e., 2018). Although N and water availability decreased rapidly, the independently positive effects of historical N and water input persisted after 2 years of cessation largely due to the stable community composition. The increased plant stature of dominant functional groups largely contributed to the increased current productivity after the historical N and water addition. Together, these findings will facilitate the projection of the primary productivity and carbon cycling under the scenarios of predicted reduce in N deposition and changeable precipitation.

Productivity of the crop rotation link depending on the technology of development of fallow lands in the south of Central Siberia

Relevance. According to the conducted studies, it was found that the disadvantages of steppe nature management include water erosion, deflation and other adverse phenomena. Similar processes are taking place in Siberia. At present, the redevelopment of deposits is beginning and soil degradation is again manifested in the steppe regions of Khakassia. For the rational and efficient use of land resources, it is necessary to develop a technology for processing soil deposits in the arid steppe zone of the south of Central Siberia.Methods. The study of the efficiency of soil cultivation technologies for the erosional agroecological group of fallow lands was carried out in the arid steppe agrolandscape region of the Republic of Khakassia, located in the south of Central Siberia. Research for four years was carried out in the link of fodder crop rotation: a long-term (20–25 years) cereal-forb fallow — oats (corn) for green mass by the method of B.A. Dospekhov. When performing the work, statistical and graphical methods were used.Results. It is established that malicious perennial grasses and juvenile weeds grow on long-term fallow lands (20–25 years). High efficiency of complex application of herbicides of continuous action (Tornado 500, Octopus Extra) and intensive tillage was revealed. Tillage of a long-term deposit to a depth of 18–20 cm, disking, fine flatcutting treatment and spraying with herbicide reduces the number of perennial weeds by 2 times more compared to technologies, that include small treatments and herbicide application. In the arid steppe zone, the technology with tillage of a long-term deposit to a depth of 18–20 cm increases the productivity of the feed crop rotation link by an average of 25.3–33.7% compared to technological operations involving small-scale processing (12–14 cm and 14–16 cm).