Natural Recovery of Technogenic Landscapes in Open Larch Forests in Northeastern Russia

Studies on the vegetation and soil complexes in areas of the Kolyma River basin disturbed by mining, in the northeast of the Chukchi Peninsula, have been performed to reveal trends in natural restorative processes in posttechnogenic landscapes. Data on the flora, phytomass stock, chemical composition of plants pioneering in the overgrowing of disturbed areas, and physicochemical properties of soils and technogenic eluvia have been obtained. The results have shown that plant cover restoration in disturbed areas depends primarily on the type (genesis) of technogenic substrates, the content of fine earth in the surface layer, and the distance from natural plant complexes that serve as a source of seeds coming to the disturbed area.     

The Distribution of Tree Species in the Ridge Landscape (Southern Karelia)

The distribution of tree species in the landscape was studied using the approach based on the comparison of the ecological requirements of species and the properties of ecotopes distinguished by their position in the relief and peculiarities of basement rocks. The types and specificity of ecological regimes were determined for the typical ecotopes of the southern Karelian ridge landscape. The main environmental and successional factors determining the distribution of seven forest-forming tree species in the ecotopes of this landscape were identified. The results of this work can provide a basis for the prognosis of forest vegetation in the landscape studied.     

Effects of temperature and precipitation on radial growth of Siberian larch in ecotopes with optimal, insufficient, and excessive soil moistening

The effects of temperature and precipitation on the formation of annual rings in stem wood of Siberian larch in ecotopes with optimal, insufficient, and excessive soil moistening are discussed. It is shown that precipitation fallen in the period from April to June, when the needles are formed, has a favorable effect on xylem increment. This relationship is better manifested in trees growing under conditions of insufficient soil moistening. In all types of ecotopes, a positive correlation between the annual ring width and warm and dry weather in July has been observed.     

Effect of ecotopic factors and nature resource use on the diversity of forest communities in northern Kostroma oblast

The results of studies on southern taiga forests in northern Kostroma oblast are presented. They include the typing of old-growth forests, their phytocenotic and ecological characterization, and assessment of their structural and species diversity, successional status, and degree of anthropogenic disturbance. Geomorphological features of the study area and parameters of soils under plant communities of different forest type groups are described. On the basis of generalization of available data, conclusions were drawn concerning specific features of the structure and species diversity of forest communities in different ecotopes and at different stages of succession.     

Analysis of Catenae in the Kivach Reserve: Structure,Succession State,and Potential Composition of Forest Vegetation

Types of catenae of the moraine landscape of the Kivach Reserve have been described, and five ecotopes have been distinguished in their composition. The analysis of ecological ranges of the main forest-forming species has made it possible to predict the potential composition of a tree synusia that included five to seven species in the greater part of the catenae and three species in depressions with stagnant moistening. The population demographic approach has been used to determine the succession status of communities in the study area. Six variants of phytochores have been distinguished in the herb-dwarf shrub layer; the main ecological and succession factors of distribution have been determined for them.__________Translated from Ekologiya, No. 4, 2005, pp. 252–258.Original Russian Text Copyright © 2005 by Platonova.     

Monitoring of Vegetation Development in Technogenically Disturbed Areas of the Usinskoe Oil Field

Vegetation development and changes in the characteristics of the substrate in technogenically disturbed sites in the Usinskoe oil field were monitored for ten years (1992–2002). It has been demonstrated that 86 species of vascular plants and 12 species of bryophytes constitute the vegetation formed on fill-up soils during the first stages of recovery succession. A succession of dominant species was observed in the tenth year of monitoring. Differences in plant composition on the ground surface of different technological zones of plots located in different landscapes are described.__________Translated from Ekologiya, No. 4, 2005, pp. 269–274.Original Russian Text Copyright © 2005 by Zheleznova, Kuznetsova, Evdokimova, Turubanova.     

On Characteristics of Production and Destruction Processes in Lowland and Mountain Tundras of the Extreme North

Parameters of the production and destruction processes in different types of tundras are compared. It is shown that there is a fairly high degree of correspondence between the structure of tundra communities and the ecotopes occupied by them. On the other hand, typologically similar lowland and mountain tundras markedly differ in the functional respect. The rate of decomposition processes is higher under environmental conditions of the mountain tundra belt.     

Plant cover synanthropization in the pechora-Ilych biosphere reserve along an altitudinal gradient

Trends in plant cover synanthropization along a plain-foothills-mountains gradient have been revealed in the reserve. Characteristics of plant communities in anthropogenically disturbed habitats, centers of concentration of anthropophytes and apophytes, and pathways of their migration are described.     

The use of ecological scales for indication of the current state of forest communities

A method for estimating the current state of plant communities based on the ecological amplitudes of constituent species is proposed. An original program, Fitoindikatsiya, has been developed to compute the indices of disturbance and homogeneity of plant communities from species ecological scale values. The current state of pine forests in the part of Novosibirsk oblast east of the Ob River has been analyzed; slightly, moderately, and severely disturbed zones have been distinguished.     

Species richness,structure, and conservation of <Emphasis Type="Italic">Nitraria retusa</Emphasis> communities in the coastal salt marshes of Kuwait

Although the coastal salt marshes of Arabian Gulf have been altered extensively by human development activities, there is a paucity of data describing changes in the distribution and abundance of native coastal plant communities. The main objectives of this study are to determine vegetation condition, size structure, and conservation status of Nitraria retusa, a medicinal and salt-tolerant shrub, in disturbed and non-disturbed coastal salt marshes of Kuwait. Size measurements of Nitraria shrubs and nabkas, which are mounds of sediment developed around shrubs, were carried out in 50 quadrats (20 × 20 m²), randomly selected inside and outside Sabah Al-Ahmad Natural Reserve. Species richness and soil properties of nabkas and interspaces, the open areas between the nabkas, were also measured. The results revealed that nabkas of Nitraria in non-disturbed sites are more stable and rich in plant diversity than those in disturbed sites. Mean height and mean canopy diameter of Nitraria shrubs, total plant cover, and species richness are significantly higher in non-disturbed sites than disturbed sites, which indicate the positive influences of conservation for long term on vegetation structure and species richness. The results of soil analyses indicate the important role of nabkas in providing refuges for plant life and species diversity. The present study indicates that more than 50 % of the N. retusa community has been lost during the last few decades. Therefore, N. retusa should be considered an endangered species in Kuwait. The reduction in vegetation cover, a decline in species richness, and the overall degradation of salt marshes are attributed to human development activities along the coast of Kuwait. Effective conservation actions for threatened species in degraded coastal salt marshes of this region include establishment of protective enclosures, prohibitions on development that adversely affects native plant communities, and the planting native salt-tolerant shrubs to facilitate regeneration.     

Structure and dynamics of marginal Gymnadenia conopsea (L.) R. Br. (Orchidaceae) populations on limestones in the northeast of European Russia

Data are presented on the abundance, structure, and dynamics of hemipopulations of G. conopsea protocorms and autotrophic individuals at the northern boundary of the species range. The dynamics of ontogenetic structure of G. conopsea cenopopulations have a fluctuating pattern. Their response to adverse weather conditions is manifested in short-term reduction of density and increase in cenopopulation ageness in subsequent years. Deterioration of growing conditions in a series of ecotopes is accompanied by an increase in the proportion of young individuals, which allows the species to level off the impact of adverse weather factors on population size.     

Altitude dependent 137Cs concentrations in different plant species in alpine agricultural areas

The Gastein valley in the Central Part of the Austrian Alps was one of the regions most heavily affected by fallout of the Chernobyl nuclear catastrophe, depositing (137)Cs inventory up to 70 kBq/m(2) in May 1986. In many studies dealing with the uptake of (137)Cs by vegetation used for farming, a significant correlation between (137)Cs concentration in the plants and altitude a.s.l. has been observed. In order to quantify the influence of the composition of plant communities on the average (137)Cs concentration in vegetation on farmland, plant-specific activity concentrations in plant species have been determined. Alongside a transect from valley sites at 850 m a.s.l. to alpine pastures at 1660 m, the aggregated transfer factors C(ag) (m(2)/kg) have been measured for plant communities and plant species. C(ag) values for mixed vegetation are more or less similar in valley sites, but they increase exponentially with a doubling height of 122+/-22 m above appr. 1200 m altitude a.s.l. On average all species are affected by this increase in a similar way. C(ag) values of ubiquitous plant indicate that the composition of plant communities is of minor importance for the contamination of mixed vegetation.     

Residual Effect of Induced Water Stress and Nitrogen Addition on the Mycobiota in Scots Pine Stands

Mycobiota (fungi, lichens and myxomycetes) was examined in permanent plots following experiments of artificial drought (D) and nitrogen addition (N) and compared with untreated forest (C), in Scots pine stand planted on Arenosols. Species diversity and relationships between fungal community structure and environmental variables (plant species numbers and cover, bryophyte cover, soil and bark pH, tree mortality) were explored. Both D and N treatments lead to decrease of fungal species in general, however, responses of individual trophic and ecological groups varied. The strongest effect of the treatments was observed for soil fungi, especially mycorrhizal: numbers of fruiting species and ectomycorrhizal root tips decreased, and species composition has changed. Saprotrophic fungi reacted by changes in species composition but not in numbers. Of the studied environmental variables, the most significant effect on mycobiota had bryophyte and vascular plant cover as well as vascular plant species numbers.     

水位变动下三峡库区消落带植物群落特征

水位变动是湿地的基本特征之一，对湿地生态系统意义重大。为了解水位变动对三峡库区消落带植物群落的影响，于2010年8月对白夹溪消落带植物群落进行调查，采用TWINSPAN分类法对植物群落进行分类。结果表明:共发现维管植物85种，隶属34科70属；植物群落可划分为18个类型，狗牙根等5种群落为白夹溪消落带代表性植物群落；随着淹水程度的加深，群落组成呈现出由旱生植物到湿生植物的过渡趋势；植物群落香农指数、均匀度指数、丰富度指数和生物量指数随水位梯度呈“∧”型变化趋势，辛普森指数呈“∨”型变化趋势。与156 m蓄水周期相比，植物物种数量、群落类型及组成、多样性均发生改变。水位变动是消落带新生湿地植物群落变化的主要驱动因子     

Vegetation-permafrost relationships in the zone of sporadic permafrost distribution in the Kamchatka Peninsula

Studies on vegetation and permafrost table depth in the zone of sporadic permafrost distribution in the Uksichan River valley (the central Kamchatka Peninsula) have provided evidence that these components of biogeocenosis are interrelated and develop coordinately. In open larch forests with green forest mosses dominating in the ground vegetation layer, the permafrost table lies approximately 60 cm below the soil surface. When the ground vegetation layer is dominated by sphagnums, the permafrost table rises to 40–20 cm. In areas with a dwarf shrub-lichen ground layer, the soil thaw depth increases. A hypothesis is proposed that cyclic successional replacement of plant communities may take place in open larch forests on permafrost soils, including four consecutive stages with dominance of green mosses, sphagnums, lichens, and dwarf shrubs. In areas disturbed by fires, pioneer moss or herbaceous communities develop in the ground layer.     

三峡水库忠县至秭归县段消落带植被群落特征研究

为了研究三峡水库周期性的水位调节对消落带植被群落特征的影响，选择重庆忠县至宜昌秭归段的消落带植被群落进行研究，运用重要值和多样性指数分析不同高程的植物种类组成、生活型分布特征及物种多样性。结果表明：（1）研究区域统计植物共32科70属73种，禾本科、菊科和豆科是3个优势科，单种、属现象明显；狗牙根、苍耳、鬼针草、苘麻、鳢肠、酸模叶蓼、莲子草是3个高程的共存种，其中，狗牙根和苍耳在3个高程均为优势物种。（2）研究区域共统计11种植物生活型，在消落带下部和中部，一年生草本植物占绝对优势；在消落带上部，多年生草本植物成为优势生活型，生活型类型多样化，蕨类、藤本、灌木以及乔木植物开始出现。（3）消落带植物群落的丰富度、多样性、均匀度指数均随海拔变化表现出显著差异，并且随海拔升高呈现上升趋势。由此可见，水位变化对植物群落结构和物种多样性产生很大影响，在低海拔区段，消落带物种组成简单化，耐水淹和繁衍能力强的植物成为优势物种；随着海拔上升，水淹胁迫减弱，出现更多适应水位变化的植物种类，使植物群落沿海拔变化形成不同的分布特征。这些研究结果对三峡库区消落带生态修复植物的筛选，以及物种多样性的提高具有参考价值。     

Small mammals in undisturbed and restored tundra biogeocenoses

Small mammal communities have been studied in undisturbed and restored zonal biogeocenoses in the southern subzone of eastern European tundras. The results show that the consequences of anthropogenic disturbances to the environment have an adverse effect on parameters of abundance, spatial distribution, and population dynamics of species comprising zonal communities. Soil and plant components of the disturbed biogeocenosis recover more rapidly than its small mammal community.     

Expansion of invasive alien plant species in the republic of Bashkortostan, the Southern Urals: Analysis of causes and ecological consequences

The causes and ecological consequences of alien plant species invasions in the Southern Urals are analyzed. Aggressive invasive species of North American origin??Ambrosia trifida L., A. psylostachya DC., Cyclachaena xanthiifolia (Nutt.) Fresen., Hordeum jubatum L., Oenothera biennis L., Bidens frondosa L., etc.??have invaded synanthropic and natural plant communities and became dominant, with their proportion varying from 10 to 99%. The biomass of these plants may reach 6 kg/m²; density, more than 1000 shoots per square meter; and seed production, up to 30000 seeds per plant, which explains their dominance in communities. The ecological hazard they pose lies in the displacement of native species, overgrowing of disturbed land areas, and allergenicity of their pollen.     

Specific Features of the Population Ecology of Creeping Thistle, Cirsium arvense(L.) Scop. s. l.

Two populations of creeping thistle (Cirsium arvense) growing in a field uncultivated for many years and on the sloping bank of an artificial pond were studied with respect to the demographic and chemical composition. The results showed that the contents of some elements in plants depend on specific features of the soil and plant population parameters (abundance, biomass, and ontogenetic composition). Some indices of the content of mineral substances in the population and soil proved to be difficult to interpret unambiguously.     

向家坝水电站不同修复模式下根际土壤微生物化学计量特征

为探究水电站扰动区人工植被恢复后土壤质量及肥力的变化，以向家坝植被混凝土、厚层基材和框格梁3种典型边坡下优势物种荩草根际与非根际土壤为研究对象，对土壤的养分和微生物生态化学计量比进行研究。结果表明：（1）植被混凝土、厚层基材样地的养分平均含量均显著高于框格梁样地；植被混凝土、框格梁样地下土壤养分含量在根际存在一定的富集，以有机碳的富集作用最为明显，而厚层基材样地则表现为土壤全量养分在根际土壤中存在亏缺;（2）植被混凝土和框格梁修复模式样地的土壤微生物量为根际土壤较高，MBC/MBN、MBC/MBP表现为非根际土壤较高，3种样地下根际与非根际土壤微生物生态化学计量比差异性显著（P＜0.05）;（3）相关性分析表明，土壤微生物碳、微生物氮、有机碳和全氮之间具有显著的正相关性（P＜0.01），微生物量磷与土壤有机碳和全磷具有极显著的正相关性（P＜0.01）。综合评价十数年后向家坝水电站工程扰动区人工修复土壤技术，植被混凝土和厚层基材修复措施对该区土壤全量养分含量的累积作用较好，框格梁样地的植物生长发育受到磷素营养的限制较大。