Multi-Annual Structure of Cenopopulations of Dracocephalum peregrinum L. in the Steppe Communities of Siberia (Russia)

Semi-arid shrub steppe occupies a vast geographic range that is characterized in part by distinct seasonal patterns in precipitation. Few studies have evaluated how variability in both the amount and timing of precipitation affect the structure and physiology of shrubs in these systems. We quantified changes in foliar crown parameters, xylem anatomy, gas exchange, and hydraulic transport capacity in deep-rooted Artemisia tridentata shrubs following 20 years of experimental manipulations in amount and seasonal timing of precipitation. We hypothesized that shrub growth (total leaf area per shrub and cover of shrub community), hydraulic transport efficiency, and gas exchange would increase in shrubs in irrigated plots compared to non-irrigated control plots, especially for irrigation applied in winter rather than summer. We also predicted similar changes in xylem anatomy (ring width, vessel size and frequency). Most treatment responses entailed changes in plant structure, and were generally consistent with our hypotheses: total-shrub leaf area, shrub basal area, canopy cover, and maximum sapwood-specific branch hydraulic conductivity were more than 2× greater in shrubs in winter-irrigated compared to control plots, while summer irrigation had few effects on these variables. Irrigation in either season did not affect xylem vessel size, but did increase xylem ring width by ~ 2 × and decreased xylem vessel frequency by about half. Anatomical, morphological, and stand-level abundance of A. tridentata appeared much more responsive to irrigation than state changes in gas exchange, particularly when the extra water is received during winter. Thus, it appears for sagebrush that seasonal timing is at least as important as the amount of precipitation, and that responses to changes in precipitation timing occur through changes in carbon allocation more so than changes in leaf-level carbon gain.

Winter precipitation - not summer temperature - is still the main driver for Alpine shrub growth

We studied variation of morphological characters, ontogenetic structure and vitality of 10 cenopopulations of Traunsteinera sphaerica (M. Bieb.) Schltr. within the Kabardino-Balkar Republic. The studies were conducted in the meadow plant communities under different conditions of anthropogenic load (recreation and grazing). The species presents medium phytocoenotic plasticity of morphological characters (I p =0,51%) and high variation of morphological characters (CV х ¯ ср =20,08-42,66%). The maximum increase of the cenopopulation vitality with the stable seed reproduction is observed in the composition of undisturbed meadows; the portion of generative individuals is increased in ontogenetic spectra (55,9-65,3%). Under the intensification of the anthropogenic load, vitality of cenopopulations and the density of individuals (0,64 ind./m 2 ) are decreased; the portion of virginal individuals is increased in ontogenetic spectra. The rate of the seed reproduction of cenopopulations, in which the density of individuals accounts for 18,24-23,17 ind./m 2 , is high on the rubbly substrata with low total projective cover (75-80%).

Under the background of global warming, the studies of quantitative water vapor transport characteristics in arid and semi-arid Central Asia are rare. We examine the spatiotemporal variation of precipitation in Central Asia from 1979 to 2017 based on Global Precipitation Climatology Project (GPCP) and circulation reanalysis data. We simulate the sources and transport of water vapor in different regions of Central Asia in winter and summer using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. The seasonal variation in precipitation over the whole region of Central Asia shows a single minimum in September, with little change in the amount of precipitation in other months; however, there are clear regional and seasonal differences in precipitation in western (region I) and eastern (region II) Central Asia. In region I, the maximum and minimum amounts of precipitation are observed in winter and summer, respectively, whereas in region II, the maximum amount of precipitation occurs in summer and the minimum in winter. The amount of precipitation in winter increased significantly more than the amount of precipitation in summer in both regions I and II from 1979 to 2017. Quantitative calculations of water vapor transport show that Europe and the North Atlantic Ocean are the largest sources of water vapor for regions I and II and contribute >50% of the transport of water vapor in both winter and summer. The contribution of water vapor from other sources varies greatly in different seasons. For region I, the second highest contribution to water vapor in winter is transport from the South Atlantic Ocean, while in summer is from the Arctic Ocean and northern Asia. For region II, water vapor from the local area (Xinjiang) makes an important contribution in summer. In summer, the northerly currents from the Arctic Ocean are strong due to the anticyclonic circulation maintained in Central Asia. The water vapor flux budget across each border and the net budget in region I are higher than those in region II in winter. The response of water vapor transport to global warming in Central Asia shows a north shift during past 40 years.

The application of the concept of population organization of ecosystems is an integral part in assessing the state of plant populations, as well as in modeling the response of vegetation to climate change. In this regard, it is especially important to focus on the plant species which are widespread in different habitat conditions, the study of their populations will reveal the range of adaptive capabilities of the species at different levels of organization (organismic, populational). One of such species is Thymus mongolicus (Ronn.) Ronn., an implicitly polycentric dwarf shrub, widely distributed in different environmental conditions of Tuva. The aim of the work is to study the features of the development and ontogenetic structure of T. mongolicus coenopopulations in different environmental conditions of Tuva.Three coenopopulations (CP) were studied: in a sandy steppe on a plain (51°34'55.6"N, 94°21'25.5"E), in a steppified meadow along the river bank (51°18'26.4"N, 95°50'45.7"E), in a petrophytic high-altitude steppe on a talus slope (50°31'55.6"N, 91°07'25.5"E). The polyvariance of individual development, the ontogenetic structure of CP, the type of the ontogenetic spectrum of CP, the type of CP, the ecological and average density of CP, demographic parameters (recovery index, aging index, efficiency and age indexes, the rate of population development) were analyzed (Uranov, 1975; Tsenopopulatsii…, 1976, 1988; Zhukova, 1995; Zhivotovsky, 2001). The variability of population traits in different years of the study (2012 and 2021) was analyzed in the CP in the sandy steppe. Spearman’s correlogram was used to study the interrelationships between the traits of coenopopulations and environmental conditions.In this research we revealed that a bimodal type of the ontogenetic spectrum with an absolute maximum on individuals of the young generative state (44.1%) is formed in the CP located in the sandy steppe. According to the peculiarities of the T. mongolicus development in the conditions of sandy steppes, the accumulation of individuals of a young generative state is associated with intensive vegetative reproduction. It was also revealed that their number increases with an increase in the amount of precipitation during the growing season, the height of the snow cover and the projective cover of the herbage. Due to increased competition for environmental resources, later on there is a rapid transition of young generative individuals to the old generative state, a second maximum is formed in the right part of the spectrum. The bimodal type of the ontogenetic spectrum is also formed in the CP located in the conditions of a petrophytic community on a steep slope (angle 40°) with a mobile rocky substrate. Virginal and young generative individuals accumulate in almost equal numbers (26.3% and 25.4%, respectively). Statistical analysis shows a relationship between the slope steepness and a high proportion of individuals of vegetative origin, and on the contrary, the number of individuals of seed origin is in inverse relation to the slope steepness. Ramets are characterized by low viability, they quickly pass into a subsenile state. In the CP in the conditions of a steppified meadow community, a left-sided type of the ontogenetic spectrum is formed. The maximum in the spectrum is accounted for young generative individuals. A strong positive relationship was revealed between the number of young individuals and such factors as the amount of precipitation during the growing season, leveled relief, static soil substrate, snow cover height, total projective cover of the herbage.It is established that fluctuations occurring in different years in the CP located in the sandy steppe are expressed in the alternation of the processes of aging (in 2012) and rejuvenation (in 2021). The rejuvenation of the CP in 2021 occurs due to intensive particulation in young and mature generative states and coincides with a more favorable humidification regime. In addition, there is a decrease in ecological and average density due to a decrease in the proportion of old individuals over the past 10 years.The revealed changes in the characteristics of coenopopulations due to the peculiarities of the development of individuals in specific habitat conditions should be considered as organismic and populational adaptation mechanisms that support the stable state of T. mongolicus coenopopulations in Tuva.

The paper presents the results of studying the population structure of rare species Hedysarum argyrophyllum Ledeb., H. cretaceum Fisch., H. gmelinii Ledeb., H. grandiflorum Pall. and H. razoumowianum Fisch. et Helm in the Volga and Ural regions. The study area covers Volgograd, Samara, Saratov, the southern part of the Ulyanovsk and the western part of the Orenburg Regions and the Republic of Bashkortostan. 10 coenopopulations of Hedysarum argyrophyllum, 18 coenopopulations of H. cretaceum, 410 coenopopulations of H. gmelinii, 1800 coenopopulations of H. grandiflorum, 1400 coenopopulations of H. razoumowianum were examined. The work was carried out in 20002021 using population-ontogenetic methods. The studied representatives are rare, their population characteristics are subject to changes under the influence of anthropogenic factors. Species have sufficient potential for self-recovery of natural populations. The ontogenetic spectra of populations are similar in their parameters; the dominant fraction of individuals is the generative one. Common features are the fluctuation type of population dynamics and ontogenetic structure of model representatives, relatively low demographic characteristics, weak ability for self-maintenance and self-recovery of populations under anthropogenic load. Anthropogenic load leads to a decrease in the number of individuals, their density and the gradual aging of populations.

This research examines the impact of population over-coverage on socio-demographic indicators for international migrants in Sweden. Over-coverage occurs when emigrants or deceased individuals remain in population registers, leading to overestimation of the resident population. This particularly affects migrants due to the increasing prevalence of return, onward, and circular migration. As register-based data collection becomes prevalent, addressing over-coverage bias is critical. Using multiple systems estimation models, we adjust for over-coverage in Swedish population registers and calculate accurate demographic and socio-economic rates. We use administrative data for 2003–16 to compute age-specific fertility rates, mortality rates, employment/unemployment rates, Total Fertility Rates, and life expectancy for migrants. Results demonstrate that over-coverage substantially affects demographic and economic indicators, particularly at typical migration ages, with mortality rates showing the largest bias at older ages. Findings highlight the importance of addressing over-coverage to improve the reliability of socio-demographic insights from register-based population systems.

Hyperspectral luminescence imaging adds high-resolution spectral data to electroluminescence and photoluminescence images of photovoltaic materials and devices. This enables absolute calibration across a range of spectra, and subsequently enhances the information that can be gained from such measurements. We present a temperature-dependent luminescence hyperspectral imaging study of dilute InGaAs solar cells. We are able to identify the cause of dark spots on the device as local areas with increased defect-related recombination and identify a likely candidate for the type of defect. Hyperspectral images also reveal a device-wide pattern in low-energy-tail luminescence and In alloy fraction, which corresponds with increased nonradiative recombination. This pattern would not be identifiable with conventional imaging methods. Detailed information on such features is useful as, paired with knowledge of fabrication processes and device design features, it can help identify ways to reduce associated non-radiative recombination and improve device performance.

The importance of dog population control relies on its implications in the transmission of zoonotic diseases, environmental pollution and possible injuries or attacks to humans. The aim of this work was to assess the impact of surgical neutering on the dog population in the city of Buenos Aires and Gran Buenos Aires area, Argentine through demographic rate indexes and tenancy behaviors. Data was obtained in a survey conducted in 2008 and 2009 in 136 households in the areas of Villa del Parque (CABA) and 143 of Villa Ballester (MGSM). A probabilistic model to calculate the annual growth rate of the dog population was developed. No differences were observed in the proportion of households keeping animals and those keeping dogs. However, MGSM presented an average rate of dogs per household higher than CABA. Population control indicators for surgical neutering were significantly higher whilst the average age of neutering was significantly lower in MGSM (p<0.01). No significant differences were observed in the growth rate estimation. The results suggest that with a female neutering level near 13%, the CABA canine population would grow an annual average of 13%, while considering a neutering level near 45% the MGSM dog population would grow an annual average of 8%. It is suggested that the growth of dog populations is linked to decisions and behaviors of the human population.

The quantitative assessment of ecosystem diversity is a basic tool for the evaluation of its resilience to anthropogenic loads and climatic changes. Our work is devoted to the large-scale predictive ecosystem mapping of hard-to-reach West Altai Mountain areas as well as vegetation, soil, and ecosystem quantitative diversity assessment (basing on Shannon and Simpson indices). The key site (7x4.5 km area) located in the Tigirek State Natural Reserve in the humid climate of the windward part of Altai. The predominance of shrub meadow communities and forb meadows on Gleyic Chernozems and Gleyic Chernic Phaeozems, Gleyic Cambisols, as well as the development of larch forests on the slopes of shady exposures on Greyzemic Chernozems are the regional specificities of the forest-steppe Altai ecosystem. Steppe communities (located on the Haplic Chernozems, Cambisols, and Leptosols), occupy less than 2% of the key site. The studied mountain forest-steppe ecosystem of West Altai is characterized by an extremely high level of spatial diversity: the Shannon index is 3.28, the Simpson is 0.95; an increase in soil diversity leads to a linear increase in vegetation diversity.

The potentialities of the physically-based model ECOMAG-HM for the study of zinc content formation regularities in the Nizhnekamskoe Reservoir basin have been demonstrated. The basin is characterized by high concentrations of heavy metals in natural waters due to the significant content of ore-forming elements in rocks and a high level of economic development. The daily zinc concentrations have been calculated, and the maps of mean annual zinc concentrations in the river network have been compiled. Local areas of the catchment not covered by hydrochemical observations and showing a significant level of river water contamination by zinc have been identified. The fields of the genetic components of zinc hydrochemical runoff have been calculated. The contribution of anthropogenic sources to the zinc runoff formation has been estimated, and it has been established that, with the current level of anthropogenic load, the contribution of wastewater point discharges does not exceed 4%. The scenarios and consequences of increasing the amount of zinc discharged as part of wastewater are considered. The time scale of the catchment self-purification from zinc has been evaluated. The results show that, in the absence of external impacts on the catchment area, a decrease in zinc content in river waters over a 400-year period will be about as little as 8%.

Three local cenopopulations of Adonis apennina L. were studied in the south of the Tomsk region (environment of the village of Kolarovo, Tomsk region), where the species occurs among meadow-forest herbs. The density of individuals in the studied local areas is low – from 0.7 individuals/m2 to 2.8 individuals/m2. The age composition is characterized by incompleteness: there are no individuals of the pregenerative period or the aging fraction. The reproductive potential has been poorly realized; the seed productivity of an individual shoot is relatively low. In anthropogenically disturbed communities, the productivity of individuals is reduced by more than half. Renewal and maintenance of the number of individuals in natural conditions is carried out exclusively by seed. A comparative analysis of the morphological characteristics of A. apennina in various ecological and cenotic conditions showed that the largest individuals develop in undisturbed communities or those experiencing weak anthropogenic impact. Located in the vicinity. With. Kolarovo has two specially protected natural areas – the landscape natural monument “Kolarovo wetlands” and the botanical natural monument “Slope with relict vegetation near the village. Kolarovo” occupy relatively small areas and are not able to cover all locations of rare species. Based on the research, recommendations were given for the protection of Adonis apennine in the Tomsk region.