Structure and Stock of Phytomass as Indicators of the Stage of Demutation of Steppe Fallow Lands in Tyva

Russian Journal of Ecology - Abstract—The following empirical conclusions have been statistically verified: each stage of succession has a definite duration; during succession, the stock of...     

Dynamics of plant communities in insular pine forests of Krasnoyarsk forest-steppe

The dynamics of vegetation have been studied in forest-steppe pine (Pinus symvestris L.) forests affected by anthropogenic factors such as felling and fires. Gradient analysis has been used to reveal specific ecological features of plant communities and trace the main directions of succession. The results show that these forests are at different stages of progressive succession, with the development of theircommunities following similar trends over the past few decades.     

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.     

Postfire succession in a forest of the cryolithozone: The example of central Yakutia

The results of studies on postfire succession in larch forests of the permafrost zone are discussed. The main directions of successional processes in burned-out areas of different ages are described. It has been shown that secondary pyrogenic successions in larch forests follow the scheme of rapid regeneration without tree species replacement and the model of succession tolerance. Groups of plant species with different life strategies and indicator species characterizing different stages of the overgrowing of burned-out areas have been identified.     

Inhibition of restorative succession by invasive plant species: Examples from southeastern Belarus

Consideration is given to the examples of suppression of restorative succession by invasive plant species (Solidago canadensis L., Helianthus subcanescens (A. Gray) E. Watson, Impatiens glandulifera Royle) in anthropogenic landscapes of southeastern Belarus. Characteristics of communities blocking the succession process have been revealed: low species richness, dominance of alien species in coverage, high level of synanthropization, and the absence of natural regeneration of trees and shrubs. It is suggested that a delay in succession is caused by the suppressing influence of transformer species on seed germination in apophytic trees.     

Succession in the Abra ovata Community on Soft Grounds of a Newly Flooded Area of the Caspian Sea

Studies on succession in the Abra ovata community inhabiting the flooded area in Sulak Bay, Caspian Sea, that have been carried out since the mid-1980s were continued. It has been found that the pioneer species A. ovata and Cerastoderma glaucum are still dominant in the structure of this community, determining the course of its succession. Its second stage does not fit the framework of the models characteristic of benthic communities. On the one hand, it conforms to the tolerance model: the pioneer species A. ovata, despite its dominance at all stages of succession, has not prevented the spread of other numerous colonizers of the same trophic level. On the other hand, it conforms to the facilitation model: due to their abundance, the pioneer species as grazing species have attracted organisms of a higher trophic level, namely, sturgeons.     

Vegetation restoration dynamics in the forest-steppe system of the middle Volga region

The current dynamics of ecosystems of the forest-steppe system is most adequately described via determining the probable trajectories of changes in its elements in a simple Markov chain. The obtained data have made it possible to determine the direction of succession and draw its scheme. Theoretically possible series of community development are presented. The succession of community restoration from the spread of shrubs over steppificated fallow lands to the formation of low forests of European bird cherry has been analyzed. The restoration cycle of ecosystem dynamics is described by eight age stages.     

Sequential impacts of Polynesian and European settlement on vegetation and environmental processes recorded in sediments at Whangapoua Estuary, Great Barrier Island, New Zealand

Whangapoua Estuary, Great Barrier Island, New Zealand, is central to a proposed Marine Reserve, and is currently managed for conservation by the Department of Conservation. This paper describes the sequential impacts of Maori and European people on the process of estuarine vegetation succession in time and space, and the rate of estuarine sedimentation. Multiple cores from one estuary gave confidence in assessing the temporal sequence of vegetation change, but bioturbation and other disturbance factors made it difficult to interpret ¹⁴C dates from the estuarine environment. The modern vegetation zonation pattern on the estuary is an active succession, which has been generated by rapid estuary in-filling, probably initiated as a consequence of erosion following Maori burning of the adjacent forest. European forest clearance for agriculture resulted in a further increase in estuarine sedimentation, and may have re-activated earlier sediments trapped in adjacent swamps. The combined effects of two phases of human exploitation have resulted in large-scale loss of nutrients and top-soil from catchments throughout Great Barrier Island. Conservation management of the estuary should take account of the anthropogenic impacts that have driven the plant succession and created the current vegetation zonation pattern. This pattern is neither static nor ‘natural’, but rather an on-going response to the changing human activities in the surrounding catchment.     

Experience in syntaxonomic and ordination analysis of progressive succession in cutover areas of boreal light conifer forests in the Southern Urals

Progressive succession of plant communities has been studied in cutover areas of bilberry-green moss forests of the alliance Dicrano-Pinion in the central upland part of the Southern Urals. The results are presented concerning the alpha-diversity and phytosociological spectrum of communities at different stages of succession.     

Processes of natural soil and vegetation recovery on a worked-out open pit coal mine (Bol’shezemel’skaya tundra)

The processes of soil and vegetation recovery after cessation of surface coal mining operations have been studied for the first time in the far north of Europe. Three stages of primary succession—from primitive algal groups to closed plant communities—have been identified, with the main role being played by soil algae at the zero stage, by herbs at the first stage, and by grasses at the second stage. A close relationship between the early stages in the development of phytocenoses and the stages of posttechnogenic soil formation is demonstrated.     

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.     

Association of sympatric small mammal species under contrasting environmental conditions

The transformation of microenvironmental conditions in habitats of small mammals and related changes in their spatial structure, manifested in changing levels of interspecific contacts, have been studied in microhabitats of plots affected by anemogenic (windfall) and pyrogenic influence in a protected area of the Middle Urals. The association of the dominant species (the bank vole) and other species of the community (grey red-backed vole, northern red-backed vole, and common shrew) increases in environments disturbed by disastrous natural factors. Association of species is less pronounced in the pyrogenic area, compared to the anemogenic area. The type of association between species differs between stages of progressive succession depending on conditions in particular microhabitats and specific features of functional organization in populations of small mammal species.     

Participation of plants of different mycotrophic status in the succession leading to “agrosteppe” formation

An analysis is performed of the participation of plant species differing in mycotrophic status in succession leading to ??agrosteppe?? formation, i.e., purposefully initiated progressive succession of the steppe phytocenosis. The proportion of plant species obligatorily associated with arbuscular mycorrhizal fungi increases in the course of this succession, while the proportion of facultative mycotrophic species decreases. The ratio between the species of different mycotrophic status is stabilized after two years of succession, although both total number and composition of plant species continue to change during subsequent period.     

城市化系统与生态系统交互耦合时空特征及协调发展预警研究——以湖南省为例

基于“系统演进特征分析-动态耦合规律验证-协调状态诊断及预警”框架，对湖南省2001年以来的城市化系统与生态系统交互耦合时空特征进行实证分析。研究发现：（1）湖南省城市化进程加速推进，综合发展指数由2001年的0.537逐年提升至2015年的0.785，达到中高水平，市州发展悬殊仅长沙市达到高水平。（2）生态系统健康指数呈U型走势，2015年达到0.764，处亚健康状态，系统压力较大是关键性限制因素。（3）城市化系统与生态系统耦合协调度先降后升，2015年提高到0.622，处基本协调的较低水平，各市州大多处于轻度失调-基本协调临界水平，分属生态建设滞后型、城市化滞后型和结构性污染型等3种类型。（4）从系统演进看，城市化系统与生态系统由轻度失调-逆向演替逐步转为轻度失调-正向演替、进一步转为基本协调-正向演替，预计2020年耦合协调度将提高到0.633，未来较长时期仍将处绿灯区，应采取适当的区域发展政策，推动城市化系统与生态系统内部要素调整磨合，向良性发展。     

Patterns of Overgrowing in Different Water Bodies

The time course of overgrowing, i.e., the appearance and development of vegetation on the water surface, has been studied in different water bodies. The types of succession in aquatic phytocenoses and the stages, degree, rate, and patterns of overgrowing are characterized. It has been demonstrated that the patterns of overgrowing differ depending on the type of water body, the differences being determined mainly by the ratio between the contributions of exogenous and endogenous processes to the dynamics of the plant cover.     

水温分层对香溪河库湾浮游植物功能群季节演替的影响

三峡水库水环境问题近年来引起社会广泛关注，以浮游植物功能群为基础，通过对2010年1~12月香溪河库湾水温、浮游植物等进行跟踪监测，探究支流库湾浮游植物群落结构演替趋势及其影响因子。结果表明：香溪河库湾2010年共出现18个浮游植物功能群，其中B、X1、P、Y、X2、D、LO、J、MP、G是代表性功能群；水温分层的季节性发育和消失是浮游植物群落结构演替的主要影响因素；冬季以耐受水温及光照限制的CS/S策略藻种为主；春季弱分层时，CR/R策略藻种适宜生长；夏季汛期时，呈现CR/R/C/CS多种策略藻种混生格局，强分层时，适宜稳定生境的S型策略藻种占据优势；秋季分层被打破，群落结构演替为耐受频繁波动环境的R型群落格局占优势     

1980年来湖北省钉螺分布区域及其数量的消长分析

目前对钉螺分布及消长的研究主要是短期的、文字描述性的、数字和曲线图表示的,通过这些方式可以呈现出某个地域范围的钉螺消长的总体趋势。但是,若要呈现出以行政村为单位的各个地区钉螺分布及消长的长期变化,仅仅用文字和曲线图是不够的,而是需要用更复杂的方式,才能呈现各个行政村的钉螺消长时空分布情况。地理信息系统(GIS)可以通过地图清晰显示出这些复杂的动态变化。利用湖北省钉螺的螺情村级统计年报数据,以湖北省村级行政区划图为基本空间制图单元,利用ArcGIS软件的逻辑运算和统计功能,分析了各个村级行政区从1980~2009年每间隔5 a的钉螺分布的区域及面积大小,以及钉螺数量的消长情况,并用GIS软件详细制图,获得各个村级行政区的钉螺数量的消长变化情况。根据钉螺消长情况,将所有行政村分为八类,可以识别出钉螺反复出现和难以消灭的地区,并且在地图中清晰地呈现出来。针对各个钉螺消长类型,结合自然地理、人为治理途径等情况进行相关分析,总结出湖北省各地区钉螺消长类型分异的原因,这将有利于制定县市甚至细化到村级单位的钉螺防控计划,也有利于辨识过去30 a来钉螺分布及其数量消长的区域以及灭螺的效果,对今后血吸虫的防治工作有重要指导意义。     

The role of spring and rain floods in the development of zooplankton in beaver ponds

The role of spring floods as a factor determining the seasonal succession of zooplankton in beaver ponds is demonstrated. The absence of spring floods has an adverse effect on the zooplankton communities of beaver ponds. The taxonomic and trophic organization of communities becomes similar to that in areas exposed to anthropogenic imact. The rain floods in summer and autumn can return the system to early stages of seasonal succession.     

Effect of ecotone at the boundary of windfall- and fire-damaged forest biocenoses on the abundance of rodents and characteristics of their microhabitats

Environmental conditions developing at the boundary of windfall- and fire-damaged forest biocenoses at different stages of progressive succession have a positive effect on the total abundance of rodents, but the role of ecotone in forming the structure of their microhabitats is ambiguous. The complex of biotic and abiotic conditions in the ecotone has a positive influence on the size of shrub coverage area and the abundance of saplings, whereas the influence of the edge effect on other microhabitat parameters (namely, herbaceous and moss coverage) is negative or neutral.