Monodominant Communities Research Articles

ВОДНІ, ПРИБЕРЕЖНО-ВОДНІ ТА ЗАПЛАВНІ БІОТОПИ ТЕРИТОРІЇ РЛП «ЯЛІВЩИНА», ЇХ ВИДОВА РІЗНОМАНІТНІСТЬ ТА ЕКОЛОГО-ЦЕНОТИЧНІ ОСОБЛИВОСТІ

The article is devoted to the study of aquatic, coastal, and floodplain habitats within the territory of the RLP “Yalivshchyna”. It analyzes the species diversity of these habitats and provides data on the classification of biotopes in the RLP “Yalivshchyna”. A preliminary classification scheme, based on the results of original research and some bibliographic data, is presented. The analysis has revealed a significant diversity of aquatic ecosystems in the RLP “Yalivshchyna”, indicating the ecological stability and azonality of these systems within the park. The aquatic, coastal, and floodplain habitats within the study area are characterized by seven main categories (types), which exhibit significant floristic diversity, including 130 species of vascular plants belonging to 78 genera and 41 families. A notable feature of the studied habitats is the presence of a wide-ranging flora of most species due to their influence on water and floodplain systems. This results in the predominance of species characteristic of the Holarctic and Euro-Asian regions. From an ecological perspective, the biotopes of the Stryzhen River within the territory of the RLP “Yalivshchyna” are significantly represented by vascular plant species from limnophytic groups, and marsh and hygrophilic florogenetic complexes. This diversity is influenced by the overregulation of the Stryzhen riverbed, slow flow, and the formation of bottom sediments of varying thicknesses. The aquatic, coastal, and floodplain vegetation of the Stryzhen River is characterized by the presence of monodominant communities typical for this region, which exhibit limited species diversity, similar composition and structure of coenoses, and the influence of adventive species. An inventory of habitats in the channel and floodplain parts of the Stryzhen River was carried out, allowing for an assessment of the natural environment in accordance with modern approaches. The data obtained on these habitats allows for the determination of their hierarchical structure and identification of the stability level of each habitat. This, in turn, will facilitate the development of appropriate conservation strategies for these habitats in the future and can be used to maintain and preserve aquatic ecosystems, ensure the balanced use of natural resources, and support the sustainable development of the RLP “Yalivshchyna”.

THE RATIO OF THE FREQUENCY OF OCCURRENCE OF MONO- AND POLYDOMINANT COMMUNITIES IN SYNANTHROPIC VEGETATION WITH DIFFERENT PARTICIPATION OF ALIEN SPECIES

If the invasion of alien species into the vegetation cover leads to an increase in the area of monodominant communities, then this may have negative consequences for native plant species in the long term. We compared the frequency of occurrence of communities with the dominance of alien species, with the dominance of native species, as well as polydominant communities, in 71 sites of synanthropic vegetation in the vicinity of the settlements of the Republic of Adygea and the Krasnodar Territory (Russia). The results showed that sites with a higher frequency of alien species dominance are characterized by a predominantly lower frequency of native species dominance, as well as a lower occurrence of polydominant communities, and, accordingly, a higher occurrence of monodominant communities in general. At the same time, the peculiarities of the biology of alien plant species reaching a high coverage in the studied areas suggest that this is due, rather, to the ability of alien species to quickly populate disturbed (open) habitats than to displace native species from closed grass stands. Therefore, the influence of the factor assessed by us on the floristic richness of synanthropic vegetation in the study area can be considered as limited. However, in other regions of the world, as follows from the publications known to us, it can be significant.

Phylogeny and Flow Cytometry of the Genus Kalidium Moq. (Amaranthaceae s.l.) in Kazakhstan.

The article presents data on phylogeny, genome size, and ploidy of species of the genus Kalidium Moq. in the flora of Kazakhstan. Genus Kalidium belongs to the tribe Salicornieae of the subfamily Salicornioideae of the family Chenopodiaceae and unites eight species, the main range of which covers the Iranian-Turanian and Central Asian deserts. There are four species in the flora of Kazakhstan: K. foliatum, K. caspicum, K. schrenkianum, and the recently described K. juniperinum. Populations of species of the genus Kalidium in the saline deserts of Kazakhstan occupy large areas, often forming monodominant communities. Sometimes there is a joint growth of two and very rarely three species of the genus. During the period of fieldwork (2021-2022), populations were identified in which these species grew together with a predominance, in most cases, of K. caspicum. Samples of representatives from 15 populations were collected for research. Selected plant samples were studied by flow cytometry to determine plant ploidy. Sequencing of nrITS and two chloroplast fragments were used to build a phylogenetic tree, including sequences from the NCBI database., A phylogenetic tree of species of the genus Kalidium was compiled, which takes previously published data into consideration. In the valley of the middle reaches of the Syrdarya River, tetraploid populations of K. caspicum were found. A hybrid between K. foliatum and K. caspicum was found in the Ili River valley (Almaty region, Uigur district). To identify phylogenetic processes at the intraspecific level, the SCoT (Start codon targeted) fingerprinting method was used.

Macrozoobenthos of the Pechora Bay in 2020–2021 indicates a likely change of common bivalve molluscs in the Arctic estuary

The Pechora Bay is a hydrologically and ecologically important area of the Barents Sea but there are still gaps in our knowledge of biodiversity of the area, including macrozoobenthos. In the first half of the twentieth century, the Pechora Bay was noted as a type locality for the bivalve mollusc Portlandia aestuariorum. Only a few surveys of macrozoobenthos have been conducted since and the last work from this area indicated the absence of P. aestuariorum. In this paper, we described macrozoobenthos and hydrological conditions of the bay based on the data collected in field campaigns in 2020–2021. All estuarine stations corresponded to a monodominant community of Macoma balthica poor in biomass (27.29 ± 20.82 g m−2) and species richness (33 species of macrozoobenthos recorded from 10 stations). The seaward most station was occupied by a marine assemblage of macrozoobenthos dominated by polychaetes Nephtys longosetosa and Cistenides hyperborea. Macrozoobenthos of the bay forms an ecocline from estuarine to marine species along the gradient of salinity. No significant differences in macrobenthic abundance, biomass and species richness were found between the 2 years of sampling and described fauna corresponds well to communities sampled in 1990s. Portlandia aestuariorum was absent in all our samples, which supports the hypothesis of disappearance of this previously common bivalve mollusc from the area, but the question of the driver of the change in macrozoobenthos remains open and requires further investigation.

Polyploidization-enhanced effective clonal reproduction endows the successful invasion of Solidago canadensis.

Clonality and ploidy levels are positively associated with plant invasiveness. However, there is still no consensus on whether polyploidization can promote the invasion of alien plants by enhancing clonality. Our recent long-term community succession study found that the more vigorous clone of introduced polyploid Solidago canadensis succeeded into mono-dominant community, which seems to be a positive correlationship between polyploidization and clonal reproduction. However, the formation process of clonal ramet and how polyploidization improves the clonal reproduction of S. canadensis remains unknown. Here, we compared clonal growth ability among diploids and polyploids of S. canadensis from native and introduced ranges in a common garden. Results showed that the rhizomes of S. canadensis originated from axillary buds of dense nodes at the basal stem of seedling and then produced into clonal ramets from the rhizomes. Diploids had denser nodes and more buds, developed more rhizomes per unit mass and produced more clonal propagules at the early growth stage compared with polyploids. However, the number of juvenile and secondary rhizomes, as well as the diameter and length of rhizomes in polyploid populations was significantly higher or greater than those of diploids, and those clonal traits in introduced polyploids were significantly higher than in native polyploids. Moreover, a phalanx growth form was observed in native and introduced diploid populations, which allocated about 3% and 5% of the total biomass to rhizomes, respectively, resulting in short and weak rhizomes. However, native and introduced polyploids allocated about 35% and 40%, respectively, of the total biomass to rhizomes, resulting in long and strong rhizomes, which were guerrilla growth forms. This study firstly shows that polyploidization enhanced the effective clonal reproduction of S. canadensis through pre-adaptation and rapid post-adaptation evolution, and consequently contributed to its successful invasion.

Distribution, ecology and biology of Sparganium hyperboreum (Typhaceae) in Western Siberia

Geographical analysis has shown that Sparganium hyperboreum is most widespread in the forest-tundra and in the subarctic tundra subzone. In Western Siberia, this species grows in low and slightly mineralized and slightly acidic/neutral/slightly alkaline cool waters with fluctuating water level. It forms both monodominant communities (Sparganietum hyperborei purum association), and communities in which it is an edificator. In the southern tundra, S. hyperboreum is often found in anthropogenically transformed water bodies and man-made reservoirs. The species is characterized by high vegetative mobility and ecological plasticity with four ecological forms, depending on the depth of growth. Along with this, S. hyperboreum is characterized by only one life form.

Leaf litter decomposition characteristics and controlling factors across two contrasting forest types

Abstract Plant leaf litter decomposition provides a source of energy and nutrients in forest ecosystems. In addition to traditional environmental factors, the degradation process of litter is also affected by plant functional traits and litter quality. However, at the community level, it is still unclear whether the relative importance of plant traits and litter quality on the litter decomposition rate is consistent. A year-long mixed leaf litter decomposition experiment in a similar environment was implemented by using the litterbag method in seven typical forest types in Dongling Mountain, Beijing, North China, including six monodominant communities dominated by Juglans mandshurica, Populus cathayana, Betula dahurica, Betula platyphylla, Pinus tabuliformis and Larix gmelinii var. principis-rupprechtii and one codominant community dominated by Fraxinus rhynchophylla, Quercus mongolica and Tilia mongolica. The results showed that there were considerable differences in the litter decomposition rate (k-rate) among the different forest types. The community weighted mean (CWM) traits of green leaves and litter quality explained 35.60% and 9.05% of the k-rate variations, respectively, and the interpretation rate of their interaction was 23.37%, indicating that the CWM traits and their interaction with litter quality are the main factors affecting the k-rate variations. In the recommended daily allowance, leaf nitrogen content, leaf dry matter content, leaf tannin content and specific leaf area were the main factors affecting the k-rate variations. Therefore, we suggest that future studies should focus on the effects of the CWM traits of green leaves on litter decomposition at the community level.

三峡水库秭归段消落带植物群落特征及其与环境因子的关系

消落带植被群落特征及物种多样性的研究一直是植物生态学和恢复生态学研究的热点。三峡水库的运行对消落带生态系统造成了极大的影响, 如引起绝大部分河岸带土著植物消失、生物多样性降低以及土壤侵蚀严重等一系列生态学问题。研究消落带植物群落特征及其影响机制, 旨在丰富消落带新生湿地生态学研究内容, 为消落带植被的恢复、湿地保护和管理提供科学依据。通过对三峡水库秭归段香溪河与童庄河陡坡消落带植物群落及其环境因子的实地调查, 并结合双向聚类分析及典范对应分析(CCA), 研究了三峡水库消落带植物群落特征、物种多样性及其与环境因子之间的关系。结果表明：(1)在三峡水库秭归段消落带共发现维管植物34种, 隶属于15科32属, 其中菊科(Compositae)和禾本科(Gramineae)种类数较多, 为优势物种, 植物群落组成以草本植物为主, 一年生和多年生草本植物为23种和11种, 分别占67.65% 和32.35%, 一年生植物占绝对优势；(2)随海拔升高, 物种数、Shannon多样性指数、Pielou均匀度从低海拔到高海拔随着海拔的增加而升高, 而Simpson优势度指数指数从低海拔到高海拔呈下降趋势；(3)双向聚类显示消落带主要包括3种植物群落：狗牙根群落、狗尾草+马唐群落以及鬼针草群落, 中低海拔以狗牙根单优群落为主, 高海拔为狗尾草、马唐、鬼针草及苍耳等为主的共优群落。CCA结果表明海拔与水淹时间是影响消落带植被群落物种组成的主要因子, TN与TK是影响群落物种分布格局的次要因子, 同时消落带土壤贫瘠, 受N、K的限制。库区植物群落物种多样性仍在下降, 需对植物群落和环境因子进行长期的监测与研究。;River systems around the globe are increasingly affected by damming to satisfy increasing demands for hydroelectricity, flood mitigation and reliable water supplies. The impoundment of the reservoirs can significantly alter river flow, shorelines, sediment and aquatic fauna and flora and can result in the loss of original riparian vegetation. After the first impoundment of the Three Gorges Reservoir (TGR) in June 2003 and the complete impoundment in 2010, the water level of the reservoir fluctuates from 145 m a.s.l in summer (May to September) to 175 m in winter (October to April), resulting in formation of the water level fluctuation zone (WLFZ) with a total area of 350 km² in the Reservoir. Compared with other reservoirs, the hydrological regime of the TGR is the exactly opposite of the natural flood rhythms of the Yangtze River with prolonged inundation duration (nearly half a year) and deep submergence depth (up to 30 m). The operation of the Three Gorges Reservoir had significant effects on the ecosystem of the riparian zone, causing a series of ecological problems such as the disappearance of original vegetation and reduced biodiversity in most of the riparian zone, as well as severe soil erosion. These changes might alter plant community characteristics in the WLFZ of the TGR. The study of plant community structure and species diversity in the WLFZ has been a research hotpot in plant ecology and restoration ecology. The purpose of studying the characteristics of plant communities and their influencing mechanisms in the WLFZ is to enrich the ecological research content of newborn wetlands, and to provide a scientific basis for the vegetation restoration, wetland protection and management in the WLFZ. The height, coverage and frequency of each plant species and the soil properties were measured at each elevation zone (145-155 m, 155-165 m, and 165-175 m) in the WFLZ of the Zigui region of the Three Gorges Reservoir (ZRTGR) in 2018. The two-way clustering analysis and canonical correspondence analysis (CCA) were used to analyze the spatial variations of the plant community characteristics and determine the key environmental factors influencing vegetation. The main results were as follows: (1) a total of 34 species of vascular plants, belonging to 15 families and 32 genera, were recorded in the WLFZ of the ZRTGR, with abundant species of Compositae and Gramineae. Vegetation was dominated by herbaceous plants amog which the annual herbs (i.e. Setaria viridis, Digitaria sanguinalis, Echinochloa crusgalli, Bidens pilosa, and Xanthium strumarium) and perennial herbs (i.e. Cynodon dactylon and Cyperus rotundus) accounted for 67.65% (23) and 32.35% (11) of the total number of species, respectively. (2) Species diversity showed an increasing trend with elevation and had significant differences between low, middle and high elevation area (P < 0.05). The species number, Shannon-Wiener diversity index, and Pielou evenness index of the plant community increased with the increasing elevation from the low to high elevation area, whilamonge the Simpson dominance index decreased with the increasing elevation. (3) Using two-way clustering analysis methods, the vegetation in the WLFZ consisted of three main plant community types: Ass. C. dactylon, Ass. S. viridis+D. sanguinalis and Ass. B. pilosa. The low and middle altitudes are dominated by monodominant community of C. dactylon, while the high altitudes are dominated by co-optimal communities of Setaria viridis, D. sanguinalis, B. pilosa and X. sibiricum. The CCA showed that elevation and flooding duration were the most important factors influencing the species composition of the plant community in the WLFZ, while TN and TK were the secondary important factors influencing the species distribution pattern of the community. The soil in the WLFZ was poor and limited by N and K nutrients. The diversity of plant communities in the reservoir area is still declining, which requires long-term monitoring and research of plant communities and environmental factors.

&lt;i&gt;WOLFFIA ARRHIZA&lt;/i&gt; (L.) HORKEL EX WIMM. RECORDS IN THE NOVOSIBIRSK REGION (WEST SIBERIA) - THE FIRST IN ASIAN RUSSIA

In 2020 the first record of Wolffia arrhiza was registered in Novosibirsk Region (West Siberia) in the floodplain lake. Wolffia arrhiza formed vast stands with an area of hundreds square meters and with high productivity. Besides monodominant communities, it was met as a component of the cenoses of such hydrophytes as Stratiotes aloides , Hydrocharis morsus-ranae , as well as of the helophyte communities formed by Typha latifolia and Eleocharis mamillata . According to local residents, the large stands of Wolffia was observed for some years, thus, most likely, the population winters safely at the latitude of Novosibirsk. The most likely source of Wolffia arrhiza appearance in the lake was a deliberate introduction from the aquarium. Although the probability of this plant entering to the lake from the waste water of the city septic tank of the Novosibirsk sewage waters also exists.

INFLUENCE OF CLIMATE CHANGE ON THE SPREAD OF INVASIVE ALIEN PLANT SPECIES IN THE TERRITORY OF THE LOZENSKA MOUNTAIN

The paper presents a comparative analysis of the data on the main climatic components for three periods - 1921-1945; 1965-1975; 2000-2015 and their connection with the distribution of Invasive alien plant species (IAS) on the territory of Lozenska Mountain. Among the most important features of the mountain’s climate that favorably affect the spread of IAS are the two precipitation maximums and minimums and the period of drought. In response to climate and other environmental changes, IAS on the territory of the mountain are spread in two ways - by forming monodominant communities in extreme habitats or by integrating their populations into the local communities and gradually increasing their presence in them, accompanied by changing ecological conditions of the habitat. Four potential invasive alien plant species (PIAS) have been identified: Opuntia fragilis (Nutt.) Haw., Opuntia engelmannii Salm-Dyck ex Engelmann, Lupinus polyphylus Lindl., Impatiens baulfourii Hook.f., to which population monitoring and control measures need to be implemented.

Polyploidy‐promoted phenolic metabolism confers the increased competitive ability of Solidago canadensis

Allelopathy plays an important role in the successful invasion of alien invasive plants. Phenolic compounds are one of the primary classes of secondary metabolites with strong allelopathic activities. Polyploidy can cause significant effects on the production and yield of plant secondary metabolites. However, the effect of allelopathic potential of phenolic compounds on the competitiveness of different geographical cytotypes of Solidago canadensis remains unknown. We conducted a common garden field experiment in the invasive habitat of China to compare the competitive ability of native and introduced diploid, tetraploid and hexaploid S. canadensis against intentionally planted local weeds. Results showed that introduced tetraploids and hexaploids outcompeted local plants and formed a monodominant community due to superior competitive ability. Phenolic metabolism analysis showed these populations had a high accumulation of total phenolic compounds in aerial parts and rhizosphere soil throughout three developmental stages, which contributed to significant allelopathic effects on tested weeds. However, diploids and native polyploids showed less allelopathic activities due to the low level of total phenolic content. Together, these results suggest polyploidization is one of the reasons that driving the differentiation of phenolic metabolism in different geo‐cytotypes of S. canadensis, and the allelopathic abilities of introduced polyploids are further enhanced through a post‐introduction adaptive evolution. Polyploidy‐promoted allelopathic potential makes introduced polyploids more competitive against local plants than diploids and native polyploids, which contribute to its successful invasion.

Plant community dynamics during the growing season of typical ecosystems on the Tibetan Plateau

The relationships between vegetation and environmental factors have always been a core concern of ecologists. The dynamic characteristics of plant communities during the growing season can directly reflect these relationships, so we examined this issue for three typical ecosystems on the Tibetan Plateau. During the growing season, the dominant species remained stable while non-dominant species changed significantly in the alpine meadow and alpine steppe and a mono-dominant community was found in the temperate desert shrub. Due to the seasonal variations of temperature and soil water content, plant species diversity varied significantly during the growing season. Patrick richness, Pielou evenness and Simpson diversity indices differed significantly in the alpine meadow and alpine steppe. The total biomass of these three ecosystems was the largest during the middle growing season. Biomass was greater in the alpine meadow than the alpine steeps or temperature desert. The root-to-shoot ratio was the lowest during the middle growing season for the alpine meadow and alpine steppe and largest during the early growing season for temperate desert shrub. RDA showed the belowground and total biomass were greatly affected by soil physicochemical factors. Multiple linear stepwise regression showed the above ground biomass was greatly affected by relative atmospheric humidity and belowground and total biomass were greatly affected by soil organic carbon, total nitrogen at 0–20 cm soil depth and pH at 10–20 cm soil depth. These findings provide insights into understanding the relationships between vegetation and environmental factors and promote the sustainable utilization of local grasslands on the Tibetan Plateau.

Fire, flood and monodominance of Tabebuia aurea in Pantanal

Environmental filters affect species diversity. Understanding their influence on plant communities is one of the main challenges of ecology in the search for solutions to the management and conservation of floodable savannas. To shed more light on this challenge, the present work asked if the interactions between flood and fire influence the richness of community and favor the abundance and basal area of the monodominant Pantanal species Tabebuia aurea. We also asked what role earth-mounds play in this process. To address these questions, we used Landsat-5 and -8 and Resourcesat-1 satellite data; to access the fire history in monodominant stands of T. aurea in the Pantanal from 2003 to 2017. We chose 37 areas with 2 to 9 annual fire episodes. A total of 125 25 × 25 m plots were established in the different areas, to sample arboreal strata. We sampled all individuals ≥3.18 cm in diameter at breast height (dbh). In each plot, we measured height by the watermark from the last flooding on each individual as a proxy of inundation level. We applied generalized linear model (GLM) analyses to compare effects of flood and fire on abundance, richness and basal area, on and off earth-mounds using negative binomial, Poisson and Gaussian distribution, respectively. We sampled 2411 individuals distributed among 19 families, 31 genera and 36 species. Under higher fire frequency, abundance, richness and basal area of all species decreased with increase of water level. However, the abundance and basal area of Tabebuia aurea remained higher than those of other species. Under lower fire frequency, the abundance and richness of all species in the community increased with water level. Basal area, however, decreased with increasing water level, such that individuals with larger basal area were found under lower fire frequency. Under high fire frequency earth-mounds protected T. aurea individuals from fire and flood. Earth-mounds influenced species richness and basal area only under medium-low fire frequency. Results show that monodominance of T. aurea benefits from the interaction between fire and flood, with some help from earth-mounds. Individuals of other tree species, show tolerance to high flood levels or high fire frequencies, but not the interaction between fire and flood. This dynamic strengthens the monodominance of T. aurea, as the number of individuals also increases. Our results show that flood and fire are important to the conservation of this monodominant community.

Thladiantha dubia Bunge in Bryansk Region: Distribution, Ecology, and Biochemical Characteristics

Thladiantha dubia Bunge is an East Asian species, a perennial herbaceous climbing vine, which naturally grows in the Russian Far East, in Northeast China, and on the Korean Peninsula. It is a secondary species in Central Europe, North America, South America (Ecuador), and Japan. Th. dubia is not an invasive plant for the majority of European countries. Th. dubia is bred in the European part of Russia as an ornamental plant, and it is found in a variety of disturbed habitats. In some regions of Russia, it has an invasive status. The distribution of Th. dubia in Bryansk Region was studied using grid mapping. The species was observed in 69 out of 223 examined squares (30.94%). Th. dubia occurs in disturbed habitats, wastelands, and homes. We have discovered and studied communities dominated by Th. dubia. The species forms monodominant resistant communities in anthropogenic habitats. On the basis of the analysis of geobotanical descriptions of the communities, we established the association Thladianthetum dubiae ass. nov. The formation of a monodominant community is possible owing to vegetative propagation and decrease in the illumination of the soil cover. Th. dubia secretes growth inhibitors, colins. Presumably, an invasion vector of Th. dubia is anthropochoria. Th. dubia is a potentially invasive species for Bryansk Region. The biomass of the plant is characterized by a good absorption capacity of some heavy metals, and it can be used as a soil remediator.

Species and coenotic composition of phytocoenoses in Jurassic clay dumps of the Callovian layer of the Mikhailovsky Mining and Processing Plant of Kursk Magnetic Anomaly

The paper presents the results of research on overgrowth rate in Jurassic clay dumps of the Callovian layer of the Mikhailovsky mining and processing plant of the Kursk magnetic anomaly with herbaceous and woody-shrub vegetation. The authors have revealed some features of dumps overgrowth of different dumping times (5, 15, 25 years) and the nature of various exposures of dumps overgrowth. The study has shown that by the age of 5 a pioneer grouping is formed on the Callovian clay, where the dominant species are the coltsfoot Tussilago farfara L. and the meadow horsetail Eguisetum pratense Ehrh. By the age of 15 a thicket-group community is formed, belonging to the category of simple, since it is represented by single species or has a bed character of overgrowth with a small number of weeds and meadow species. The authors have established that by the age of 25 the predominant types of overgrowth are group-thicket communities, where edificant species (the silver birch Betula pendula Roth and the common pine Pinus sylvestris L.) have a sparse distribution. It was found that the areas occupied by grassy vegetation on 25-year-old dumps in general have a bed character of overgrowth and are represented by monodominant communities of medicinal melon, which has a two-year period of development. At intervals of a year, with a dominance of the coltsfoot and the dandelion medicinal Taraxacum officinale L., the projective coverage reaches one hundred percent. A number of ruderal and meadow species (yarrow Achillea millefolium L., coltsfoot, narrow-leaved cypress Chamerion angustifolium L., forest parsnip Pastinaca sylvestris Mill., dandelion medicinal, sagebrush Artemisia compestris L., meadow bluegrass Poa pratensis L.) have a relatively sparse distribution. Additionally, the distribution of species depending on the exposure of slopes is described. The authors present species composition, projection coating and the number of plants and species per 1 m for all dumps. The dependence of the coenotic composition of vegetation on the age of dumps is established.

Growth and establishment of monodominant stands affected by ENSO and flooding in the Pantanal

Climatic factors can influence the establishment and growth of wood species, but little is known about the effect of these factors on monodominant communities in wetlands. Therefore, we asked how climatic factors, such as ENSO (El Niño-Southern Oscillation), precipitation and flooding, influence growth and establishment of the dominant species Erythrina fusca in the Pantanal. We determined the age of sampled individuals, the age of the population and evaluated the effects of climate on tree growth. We obtained samples for dendrochronological analyses using destructive (seven individuals) and non-destructive methods. We cross-dated and built a chronology, correlating results with climatic factors. We sampled 0.6 ha of the population and separated individuals into diameter classes to determine age based on diameter/age ratio obtained through dendrochronological analyses. We obtained a chronology with individuals up to 34 years old, while in the population sample, the oldest individual was 54 years old. The factors that influenced growth during the study period were precipitation (positive correlation) and El Niño (negative correlation). E. fusca individuals seem to grow more during the period of highest precipitation, and El Niño events reduce precipitation in the Pantanal, resulting in a decrease in the growth of E. fusca individuals. We detected a decrease of young individuals in the last nine years, which seems to be related to the decrease in minimum flood levels. This indicates a future decline in the number of individuals. These results allow us to propose measures to protect these monodominant formations, which mainly involve avoiding further anthropic activities, that could reduce flooding levels.

Классификация сообществ с инвазионными видами на Южном Урале. IV. Сообщества с видами рода Solidago, Lupinus polyphyllus и Phalacroloma annuum

Классификация сообществ с инвазионными видами на Южном Урале. IV. Сообщества с видами рода Solidago, Lupinus polyphyllus и Phalacroloma annuum

Factors of Formation of Communities with Ambrosia artemisiifolia L. on the Periphery of the Mass Distribution Zone

The aim of this study is to identify the main environmental factors of the formation of plant communities with Ambrosia artemisiifolia L. on the periphery of the mass distribution zone in the Central Chernozem region. Four types of communities with Ambrosia artemisiifolia L. were identified in the study area. Their ecological determination is demonstrated as a result of the analysis of different species and species with the greatest activity by identifying differences in ecological regimes of habitats and DCA-ordination of releves. Habitat disturbance is a leading factor in the formation of these studied phytocenoses. The degree of habitat disturbance affects the abundance of Ambrosia artemisiifolia. Monodominant communities with the species are formed on severely disturbed sites with sparse vegetation cover. In ruderal phytocenoses with denser herbage, ambrosia is not abundant, but can it be present in them for a long time due to their periodic disturbances. Moisture of soils and substrates is the second strongest factor influencing the differentiation of communities. The studied communities are formed on a rather wide gradient of this factor. In the study area, we identified not only xerophytic communities common in many regions of Central and Eastern Europe, but also communities emerging in coastal ecotopes with variable moisture regimes. These phytocenoses are formed in sites disturbed both under human influence and under the influence of natural factors such as river spills or heavy rains. As a result, along with xerothermic technogenic ecotopes, banks of rivers are habitats of phytocenoses with high density of Ambrosia artemisiifolia.

Dynamics of Mouselike-Rodent Abundance and Rodent Community Structure in Sakhalin

The patterns of structural transformation in forest rodent communities of Sakhalin have been considered using data from long-term comparative studies of two communities of a somewhat similar species composition. An analysis of species abundance dynamics and dominance structure show that the monodominant community structure in northern Sakhalin is characterized by the absence of interannual rearrangements and high stability, with the overall animal number in rodent communities dependent only on the abundance of the northern red-backed vole (M. rutilus). The community in the southern part of the island could assume one of the two structural types: the monodominant structure with M. rutilus or the gray red-backed vole (M. rufocanus) prevailing or a bidominant structure with both species acting as codominants. The numbers of secondary species vary independently of the numbers of dominant species. Changes in the abundance of M. rutilus and M. rufocanus within the same community are synchronized, whereas the population cycles of these species in the southern and northern communities are not conjugated.

Vegetation and Climate History of the Harenna Forest (Bale Mountains, Ethiopia) in the Holocene

The results of spore-pollen analysis and analysis of non-pollen palynomorphs of the Katcha zoogenic deposit, located in the Harenna Forest (Bale Mountains National Park, Ethiopia) are presented. It is revealed that bamboo monodominant communities have inhabited areas at altitudes of 2700–2800 m above sea level for at least the past 6500 years. A trend towards a decrease in bamboo communities due to climate aridization in the last 5000 years has been revealed. It is established that active human impact on these ecosystems began 1000 years ago.