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This study was conducted to clarify the changes in vegetation that occurred due to changing environmental factors, especially climate, at Korean fir (Abies koreana) stands with different climatic conditions established on Mt. Halla, which is located on a southern island of South Korea. The difference of species composition between sites was large and depended on elevation and slope aspect at lower elevations, whereas not as much among stands or between sites at the highest elevations of each slope aspect. It was interpreted that differences and similarities among sites were dominated by the microclimate determined by the topographic conditions of each site. The result of vegetation dynamics analysis predicted that the Korean fir forests would be replaced by temperate forests such as Mongolian oak (Quercus mongolica) forests or shade intolerant forests composed of early successional species such as Korean cherry (Prunus maximowiczii) and Spreading yew (Taxus cuspidata) at lower elevations, while would continuously persist at the highest elevations. We interpreted the vegetation changes appeared at the lower elevations as an allogenic succession, as the recent rapid climate changes directly and indirectly dominated the change. The species distribution modeling predicted that the distributional range of Korean fir would decrease to 13.4 and 10.1% of the current distribution in 2050 and 2070, respectively. Further, the distribution modeling showed that the sites located at lower elevations would no longer be within the distributional range of Korean fir forest, and those at the highest elevations would be sparsely scattered in fragmented states.

The still-growing effect of human activities on aquatic habitats has led to proportionately increasing need for restoration activities. Paradoxically, restoration actions can constitute a major threat to freshwater assemblages if they do not respect the specific nature of the target biotopes. We investigated the dynamics of dragonfly assemblages in 20 mine-subsidence pools (habitats with very high and very unpredictable dynamics). We used multivariate methods and diversity indices to compare species richness and species composition of assemblages before and after reclamation actions. During the 10 y of the study, we recorded 10 cases in which aquatic habitats disappeared completely and 6 cases of recovery and successful recolonization of aquatic pools. Disturbances caused by reclamation actions led to significant reduction of diversity and to extirpation of sensitive dragonfly species. Moreover, unlike natural disturbances, disturbances caused by reclamation activity do not support the occurrence ...

13 páginas, 1 tabla, 4 figuras, The mechanisms underlying community assembly and promoting temporal succession are often overlooked in microbial ecology. Here, we studied an undisturbed salt marsh chronosequence, spanning over a century of ecosystem development, to understand bacterial succession in soil. We used 16S rRNA gene-based quantitative PCR to determine bacterial abundance and multitag 454 pyrosequencing for community composition and diversity analyses. Despite 10-fold lower 16S rRNA gene abundances, the initial stages of soil development held higher phylogenetic diversities than the soil at late succession. Temporal variations in phylogenetic b-diversity were greater at initial stages of soil development, possibly as a result of the great dynamism imposed by the daily influence of the tide, promoting high immigration rates. Allogenic succession of bacterial communities was mostly driven by shifts in the soil physical structure, as well as variations in pH and salinity, which collectively explained 84.5% of the variation concerning community assemblage. The community assembly data for each successional stage were integrated into a network co-occurrence analysis, revealing higher complexity at initial stages, coinciding with great dynamism in turnover and environmental variability. Contrary to a spatial niche-based perspective of bacterial community assembly, we suggest temporal niche partitioning as the dominant mechanism of assembly (promoting more phylotype co-occurrence) in the initial stages of succession, where continuous environmental change results in the existence of multiple niches over short periods of time., This research was supported by the Netherlands Organisation for Scientific Research (NWO).

Succession is one of the most studied processes in ecology and succession theory provides strong predictability. However, few attempts have been made to influence the course of succession thereby testing the hypothesis that the passage of one stage is essential to enter a next one. At each stage of succession ecosystem processes may be affected by the diversity of species present, but there is little empirical evidence showing that plant species diversity may affect succession. The main objective in the present study is to test if there is any effect of plant species diversity on the functioning of artificially-created grassland communities. We were mostly interested in how successful is the sowing of meadow species into newly abandoned land and how long do the effect of initial sowing persist, how is affected the set of natural colonizers, which includes both the weed species and also the later successional species arriving naturally into the zone. One of the main questions concerning succession is to which extent the trajectory may be predictable or not. What will be the consequence of the different succession pathways for ecosystem processes, such as productivity and resource utilization, as well as species composition of both above and belowground communities? What will be the subsequent effects of feed back to vegetation development through initial manipulation of vegetation after land abandonment? And, finally, how general may results be when obtained in specific conditions? Our hypothesis is that an increase in the initial plant species diversity at the start of secondary succession enhances the amount of biomass produced and consequently stimulates the soil microbial biomass and the abundance of soil invertebrates. It has been suggested that changes in plant species diversity affect several ecosystem processes, such as primary productivity, nutrient retention and vegetation dynamics. A positive impact of species diversity on plant productivity has been explained by the complementarity of resource use among plant species or their functional groups.

Human-induced changes negatively affect all components of freshwater ecosystems and comprise the major cause of global loss of diversity and the biotic homogenization of freshwater faunas. The high diversity of dragonflies in heavily industrialized areas is therefore paradoxical, to say the least. We compared diversity of dragonflies in three main freshwater habitat types (natural and human-made) occurring in Upper Silesia (Central Europe). We used multivariate methods and diversity indices for a general analysis, comprising both species richness and the species composition of assemblages. We recorded 50 species in mine subsidence pools from the total of 54 sampled species. These included a high proportion of habitat specialists (typically threatened species). We emphasize that secondary habitats (e.g. spontaneously originated mine subsidence pools) should not a priori be regarded as ecological traps, because these often are the available habitats with highest quality. These habitats significantly outweigh ponds in species richness and proportion of habitat specialists. The conservation potential of specific secondary habitats lies in the fact that these habitats can substitute for very rare natural wetlands often restricted to higher elevations. We assume that high diversity in this type of secondary habitats is not random, but rather that it depends on environmental heterogeneity caused by a specific allogenic succession process occurring as a direct consequence of mining.

The development of the composition and structure of northern taiga spruce forests on the Kola Peninsula under regeneration succession with a reduction in emissions from the metallurgical combine are described. Parameters of species diversity and ecological-coenotic structure of plant communities, including algosinusia of soils, are assessed under different technogenic impacts. Significant indices of stable transformations of plants from different layers during the regeneration succession were revealed. Strongly transformed communities in the vicinity of the combine are shown to remain in a critical state due to the preserved high level of soil pollution and demutation changes of the taiga components in the course of allogenic succession.

Stratigraphic records from peatlands suggest that the shift from a rich fen (calcareous fen) to an ombrotrophic bog can occur rapidly. This shift constitutes a switch from a species-rich ecosystem to a species-poor one with greater carbon storage. In this process, the invasion and expansion of acidifying bog species of Sphagnum (peat mosses) play a key role. To test under what conditions an acidifying bog species could invade a rich fen, we conducted three experiments, contrasting the bog species S. fucsum with the rich-fen species S. warnstorfii and S. teres. We first tested the effect of calcareous water by growing the three species at different constant height above the water table (HWT; 2, 7, and 14 cm) in a rich-fen pool and measured maximum photosynthetic rate and production and difference in length growth as an indicator of competition. In none of the species was the photosynthetic capacity negatively affected when placed at low HWT, but S. fuscum was a weaker competitor at low HWT. In our second experiment we transplanted the three species into microhabitats with different and naturally varying HWT in a rich fen. Here, S. fuscum nearly ceased to photosynthesize when transplanted to low HWT (brown moss carpet), while it performed similarly to the two rich-fen species at the intermediate level (S. warnstorfii hummock level). In contrast to S. fuscum, the rich-fen sphagna performed equally well in both habitats. The brown moss carpet was seasonally flooded, and in our third experiment we found that S. fuscum, but not S. teres, was severely damaged when submerged in rich-fen water. Our results suggest two thresholds in HWT affecting the ecosystem switch: one level that reduces the risk of submergence and a higher one that makes bog sphagna competitive against the rich-fen species.

In this paper the investigation results of successional processes in the vegetative cover appearing due to succession starting in native ecosystem inundation zone under Sayan-Shush reservoir influence are given.

Questions: How can studies of primary plant succession increase the effectiveness of restoration activities? Can restoration methods be improved to contribute to our understanding of succession? Results: Successional studies benefit restoration in six areas: site amelioration, development of community structure, nutrient dynamics, species life history traits, species interactions, and modeling of transitions and trajectories. Primary succession provides valuable lessons for understanding temporal dynamics through direct, long-term observations on severely disturbed habitats. These lessons assist restoration efforts on infertile or even toxic substrates. Restoration that uses scientific protocols (e.g., control treatments and peer-reviewed publications) can offer insights into successional processes. Conclusions: A century of studying successional dynamics has provided modern restoration activities with many useful lessons that are not being fully utilized.

Six types of mangrove forests were distinguished on Kosrae Island (50°20’ N.L.; 163°00’ E.L.) and Pohnpei Island (6°55’ N.L.; 158°14’ E.L.) in Micronesia and Bohol Island (10°00’ N.L.; 124°30’ E.L.) in the Philippines based on phytosociological investigations. They are the Rhizophora stylosa forest on an inorganic habitat along the seaward fringe of a mangrove area, the Nypa fruticans thicket and the Barringtonia racemosa forest supported by clay deposits at the landward fringe of a mangrove region, and the Rhizophora apiculata-Avicennia marina forest, the Sonneratia alba-Bruguiera gymnorrhiza forest and the Xyrocarpus granatum-B. gymnorrhiza forest characteristically inhabiting peaty habitats. Accumulation of mangrove peat should be limited to a range corresponding to the upper half of the intertidal zone because mangrove forests themseves are restricted to this range. This range is estimated to be 75 cm or so in the areas investigated. A habitat with a peat layer equivalent to this range in thickness was usually found under the S. alba-B. gymnorrhiza forest. This type of forest is thought to have developed under the present, stable sea level condition through autogenic succession from the R. stylosa forest. On the other hand, a much thicker peat layer supporting the X. granatum-B. gymnorrhiza forest was found in the investigated area. Development of such a thick peat layer is assumed to have been proceeded by a rise in sea level, followed by filling up of the area with organic matter provided by the mangrove forest itself. Thus, this type of forest was considered to have been formed from the S. alba-B. gymnorrhiza forest through an autogenic process of succession in spite of the external effect of a rise in sea level.

“Ecological Succession” is an ordered progression of structural and compositional changes in communities toward an eventual unchanging condition, the climax community 1 –3. The term “Community” is used in two ways 4. The “Abstract Community” refers to an abstract group of organisms that recurs on the landscape, a definition, which usually carries with it an implication of a level of integration among its parts that in extreme could be called organismal or quasi-organismal; the “Concrete Community” concept refers to the collection of organisms found at a specific place and time. These terms and their meanings are topics of significant debate among ecologists, both historically and today 5, 6. These differences in the meaning and cause of ecological succession strongly affect the formulation of policies for ecosystems management and restoration.

Ecologists have documented the process of plant succession for centuries, yet the successional patterns exhibited by microbial communities have received relatively little attention. We examine recent work on microbial succession and show how, despite some key differences, studies of plant succession can serve as a template for understanding microbial succession. We divide the broad range of patterns of microbial primary succession into three categories based on the source of carbon inputs and present conceptual models for each of these categories to explain and predict microbial succession patterns. We show how studies of microbial succession can lead to the development of more comprehensive ecological models of succession and improve our understanding of the processes that regulate microbial diversity in natural and man-made environments.

This chapter summarises spatial and temporal changes of colonisation processes, in addition to the modes of succession proposed by Connell and Slatyer (i.e. facilitation, inhibition and tolerance) and subsequent studies. Processes creating space for colonisation are described. The early microbial phase of colonisation on natural rock is examined. Subsequent colonisations by macrobiota on intertidal rocky shore and in rockpools are addressed with emphasis on the role herbivores play on successional sequences. Changes in species diversity and the associated consequences for ecosystem functioning are discussed in relation to the intermediate disturbance hypothesis and the variations in biomass, species identity and richness throughout succession. Although patterns of succession are well identified, a full understanding of the functional consequences of these changes is still to be gained.

The concept of succession has a distinguished history in general ecology and has been applied to stream ecosystems with some success. Succession in streams is largely secondary, follows initial floristics models, and occurs through a variety of mechanisms. The process is moderately predictable but is highly influenced by “climatic” factors, particularly nutrient chemistry. In desert streams, succession does not result in a climax state. While evidence is slim, succession may not be a significant process in streams of certain types or in certain regions.

Preface Contributors List Glossary Forging a New Alliance Between Succession and Restoration.- Insights Gained from Succession for the Restoration of Landscape Structure and Function.- Aboveground-Belowground Linkages, Ecosystem Development and Ecosystem Restoration.- Retrogressive Succession and Restoration on Old Landscapes.- Succession and Restoration of Drained Fens: Perspectives from Northwestern Europe.- Manipulation of Succession.- Restoration as a Process of Assembly and Succession Mediated by Disturbance.- Integrating Restoration and Succession.- Index.

Vegetation succession in riparian zones is traditionally considered to be mainly driven by allogenic hydrogeomorphological factors, while the importance of autogenic, plant-induced processes may become more significant as landform stability is achieved. This conventional notion was tested at selected point bars and cutbank edges along a salt marsh creek system in southwestern Denmark. It was predicted that, within each narrow habitat (ca. 5 m width), sites closer to creeks experience more dynamic changes in hydrogeomorphology, and hence, more changes in plant species composition than those farther away from creeks. These sites were compared in terms of the rate of vegetation succession between 2006 and 2011, using nonmetric multidimensional scaling. In the resulting two-dimensional diagram, the Euclidean distance between any two samples representing the same quadrat of different time periods was interpreted as the degree of change in species composition. The predicted differences in succession rates among sites with varying distances from the channel were not observed. Locations adjacent to the creek have experienced the most intensive allogenic fluvial-geomorphic processes. However, the rate of allogenic succession under such physical dynamism has not necessarily been greater than that of the autogenic succession that was highly dominant at locations slightly away from creeks. Allogenic and autogenic factors are probably equally, or at least simultaneously, important to vegetation dynamics even under dynamic hydrogeomorphology. Such a view is in disagreement with the conventional belief in fluvial ecology, calling for a more explicit inclusion of autogenic processes in modeling the evolution of vegetation–landform complexes in the riparian zone. In other words, a true biogeomorphic nonlinearity exists in highly dynamic fluvial systems in that output (i.e., vegetation and landform dynamics) is not necessarily a direct product of input (i.e., hydrogeomorphic effects), due to an unexpectedly significant intervening variable, autogenesis.

Successional change is thought to be at least partially driven by forees originating from within the community, namely by ‘reaction’ and competition. Both processes operate through changes in the environment, but from the literature on the subject it is not clear how they differ. To clarify these issues successiens of model communities are studied. This leads us to conclude that competition represent an instantaneous interaction, whereas reaction has historical aspects since it relies on cumulative changes in the environment. The three models considered-one relying on reaction to cause vegetational change, one relying on competition and differential growth rates, and a hybrid third one-yield very similar predictions: roughly bell-shaped curves displaced along the time axis. This shows that the mere fit of a certain model to successional data may easily be spurious (recently some workers have empirically fitted models identical to one derived here from first principles). The three models do behave radically different under perturbation, however: any model relying completely or partially on historical interactions cannot account for the well known possibility of artificially arresting succession. Even if the importance of historical interactions in succession (i.e. the Markovian character of succession) cannot easily be ascertained, one can nevertheless ask whether historical interactions are at all necessary for the explanation of successional change. It is argued here that succession can be entirely understood in terms of instantaneous interactions, notably competition. The argument rests upon the well known relationship between colonizing and competitive ability, and on the fact, proven here, that stress, defined as expressing itself in severe random fluctuations in the growth parameters, is negatively correlated with competition intensity.

Succession involves changes in a community through time, whether internally or externally controlled. As succession progresses, niche specialization, species diversity (variety and equitability), complexity of food chains, and pattern diversity increase; net production and species growth rate decrease. We apply the succession concept to three types of ancient community sequences: 1) fossil reefs (Ordovician—Cretaceous in age), 2) short-term successions occurring through thin stratigraphic intervals, and 3) long-term successions occurring through thicker stratigraphic intervals. Ancient reefs show four vertical zones: (1) a basal stabilization zone (autogenic), 2) the overlying colonization zone (autogenic, pioneer stage), 3) the diversification zone, the bulk of most reefs (diversification culminating in climax), and 4) the uppermost domination zone. The first three zones represent autogenic succession but the final stage may involve allogenic succession. Short-term succession usually occurs where periodic allogenic catastrophes wipe out the community which is rebuilt through autogenic succession. Opportunistic pioneer species are important and in our examples (Ordovician, Silurian, and Cretaceous) are species which pave soft substrata. Paleozoic strophomenid brachiopods filled this role, and inoceramid pelecypods served the function in the Mesozoic. The succession which begins with opportunists progresses to a climax community of equilibrists. Repetition of catastrophe-succession couplets produces a cyclic stratigraphic record. Long-term successions are recorded in thicker stratigraphic sequences, and are of two types: 1) autogenic succession in unchanging physical environments and 2) allogenic succession in changing physical environments. Our examples of these are from the Devonian Haragan-Bois D'Arc formations of Oklahoma and the Lime Creek Formation of Iowa. This type of succession represents a temporal-spatial mosaic. The Haragan data (unchanging environments) indicate characteristic, intergrading, and ubiquitous species in the brachiopod communities. Most ubiquitous species in the pioneer community were eurytopic opportunists. The Lime Creek data allows testing of the prediction that environmental changes cause regression to an earlier succession stage. The brachiopod communities after environmental changes have more ubiquitous and intergrading eurytopic species. These represent an earlier stage in the succession.

Ecosystem succession and development of biological turnover are analyzed in a succession series from solonchakous meadow to meadow steppe in the forest steppe zone of Western Siberia. Characteristics of flow processes, biological turnover, and functional and structural diversity of ecosystems are considered. From the initial stages of succession to the final ones the intensity of abiotic flows drops, the degree of openness of the ecosystem decreases sharply and the role of biological turnover grows. The reserves of chemical elements in biomass, net primary production and biogeocenotic activity are maximal at the intermediate stages of succession. Humus reserves in soil increase from the initial stages of succession to the final ones. The diversity of soil processes is maximal at the initial stage of succession, the diversity of life form types, cenotic groups and ecological types of plants at the intermediate stages, and species diversity-in the final stage.

Vibrio spp. predominated in the culturable bacterial community of surface waters of the Puerto Rico Trench at the site of disposal for nearly ten years of pharmaceutical wastes. In this area and surrounding waters as far as 1000 km north of the dumpsite and south into the Caribbean Sea, Vibrio spp. comprised up to 100% of the culturable bacteria, with Acinetobacter spp. being the second most prevalent group. Pseudomonas spp., reported to be common in these waters a decade earlier, were virtually absent from all samples examined during a three year study involving 9 cruises. Staphylococcus spp. were also found in water samples collected within the dumpsite. Using cultures isolated from surface water samples collected at the dumpsite, laboratory experiments confirmed that pharmaceutical waste can enrich for Vibrio spp., in preference to Pseudomonas spp., with growth of the strains proportional to the amount of waste added.

Botanists have dominated the study of secondary succession, and as a result, models and theories have focused on plants. Recent work, however, has revealed several complex relationships between plants and insects during succession, including adaptations of life-cycle strategies. Furthermore, insect herbivores play a key role in the course and rate of plant succession.

Changes of plant communities (or biotic communities) are classified according to their causes. The term succession is restricted inClements' original sense to gradual directional replacemental changes of phytocenoses (or biocenoses) caused by their reaction upon the environment including soil development and a classification of succession is proposed. Gradual changes of communities caused by external factors are termed adaptive changes. The connection between succession and soil development as a unified process as well as the concept of climax as its result are discussed. A brief historical survey of the theory of succession as well as soil development is presented and definitions of some successional terms are proposed.

The area studied comprises four different ecosystems. Each is differentiated into various habitats distinguished according to their physiography, edaphic conditions and plant cover. Any particular habitat supports a definite community which could be identified by the dominant species. The physiography and the physical soil properties, especially texture and depth, are the major factors affecting the distribution of the plant communities. This is mainly due to their effect on the water resources of the different habitats. The plant coverage increases by the increase of the soil depth. There may be a sort of allogenic succession among the differentiated communities which is closely related to building up of soil and the water resources. Das untersuchte Gebiet umfast vier unterschiedliche Okosysteme. Diese sind entsprechend ihrer Physiographie, den edaphischen Bedingungen und der Pflanzenbedeckung in verschiedene Habitate unterteilt. Jedes einzelne Habitat umfast eine bestimmte Gemeinschaft, die jeweils durch vorherrschende Arten charakterisiert wird. Die physiographischen und physikalischen Bodenverhaltnisse, besonders Struktur und Tiefe, sind die wichtigsten Faktoren, die die Verbreitung der Pflanzengemeinschaften beeinflussen; von ihnen sind hauptsachlich die Wasserreserven der verschiedenen Habitate abhangig. Die Pflanzendecke ist umso dichter je tiefer der Boden ist. Zwischen den verschiedenen Gemeinschaften gibt es eine Art allogenischer Sukzession, die enge Beziehungen zum Aufbau des Bodens und den Wasserreserven hat.

In many forests, most energy utilization and nitrogen transformations of carbon compounds take place below ground (Harris et al. 1980; Fogel 1980). This is true throughout secondary succession. The above-ground patterns of changes in species composition and vegetative structure with forest succession are accompanied by and indicative of major qualitative and quantitative changes below ground. One stage in succession may be affected by prior stages through processes that occur below ground, but the extent of this influence is little known and is of considerable current research interest.

The starting point in the last chapter was the idea of homeostasis. Life-critical properties of the internal milieu are the objects of control. The key to the extension of the analysis to communities and ecosystems is that some features of the external milieu are drawn into this orbit of control. Organisms and communities either control their environment or are replaced by new organisms and communities, leading to a sequence of changes which can only be terminated by the appearance of a community which does control its environment. In the short run this is the ecological succession process. In time frames sufficient for genetic adaptation it is the evolution process.

Up to this point, the types of positive feedback considered have involved single species or communities of species. The ecosystem, however, includes not only interactions among species, but also interactions between species and their physical and chemical environment, therefore involving such factors as energy flow, nutrient cycles, soil conditions, and microclimate.