Primary Succession

Rehabilitated mine sites are suitable environments for the study of primary ecological succession. Plant and Orthoptera communities were simultaneously monitored for 4 years on 7 sites in the Limousin region (France), covering 9 years of rehabilitation. Insect and plant diversity varied in parallel when top soil had been restored. Absence of added soil did not modify the course of insect succession but had a clear effect on plant succession. For broom heaths, both insect density and diversity decreased from the second year on; although, several Tettigoniidae species settled in this habitat. In herbaceous habitats, insect density grows continually whereas diversity peaks at about the third year. In these habitats, multivariate analysis shows three Orthopteran seres which can be used as ecological markers of succession course. Résumé. Succession primaire d'Orthoptères sur des haldes de mines : rôle de la végétation. Les sites miniers réhabilités sont des milieux où les conditions sont requises pour étudier les successions écologiques primaires. Les communautés de plantes et d'Orthoptères ont été étudiées simultanément pendant 4 ans sur 7 sites dans la région Limousin (France), couvrant ainsi 9 annnées de réhabilitation. Les diversités de plantes et d'insectes varient parallèlement quand de la terre végétale est ajoutée lors de la restauration. L'absence de cet ajout rallentit nettement la vitesse de succession des plantes mais ne modifi e pas celle des insectes. Dans les formations à genêts, la diversité et la densité des insectes diminuent à partir de la deuxième année, et seuls quelques Ensifères s'y établissent. Dans les milieux herbacés, la densité des insectes augmente continûment tandis que la diversité culmine vers la troisième année. Dans ces mêmes milieux, des analyses multivariées mettent en évidence trois groupements d'espèces qui peuvent être utilisés comme marqueurs de l'âge des successions écologiques.

The present study investigates macrofouling development in the Mar Grande of Taranto (Central Mediterranean Sea), a wide confined area that has attracted considerable attention in recent years due to the establishment of numerous non-indigenous species (NIS). Different starting times of a yearly primary succession on artificial substrates were tracked so as to investigate the matching of the development pattern with contingency and/or convergence models, identifying NIS’s structural role in the community endpoint. Our results show that during the experiment all assemblages tended to converge towards multiple contingent communities according to starting times and depths. The differences are due to propagule availability which influence further species interactions. Thus the endpoint patterns are defined by a contingent community development determined by the seasonal species pool, their phenologies, pre- and post-settlement events, and species interactions. The most important structu...

Past research demonstrating the importance plant-microbe interactions as drivers of ecosystem succession has focused on how plants condition soil microbial communities, impacting subsequent plant performance and plant community assembly. These studies, however, largely treat microbial communities as a black box. In this study, we sought to examine how emblematic shifts from early successionalssp.(Sitka alder) to late successional(Sitka spruce) in primary succession may be reflected in specific belowground changes in bacterial community structure and nitrogen cycling related to the interaction of these two plants. We examined early successional alder-conditioned soils in a glacial forefield to delineate how alders alter the soil microbial community with increasing dominance. Further, we assessed the impact of late-successional spruce plants on these early successional alder-conditioned microbiomes and related nitrogen cycling through a leachate addition microcosm experiment. We show ...

The perennial gramineous grass Miscanthus condensatus functions as a major pioneer plant in colonizing acidic volcanic deposits on Miyake-jima, Japan, despite a lack of nitrogen nutrients. The nitrogen cycle in the rhizosphere is important for the vigorous growth of M. condensatus in this unfavorable environment. In the present study, we identified the nitrogen-cycling bacterial community in the M. condensatus rhizosphere on these volcanic deposits using a combination of metagenomics and culture-based analyses. Our results showed a large number of functional genes related to denitrification and dissimilatory nitrate reduction to ammonium (DNRA) in the rhizosphere, indicating that nitrate-transforming bacteria dominated the rhizosphere biome. Furthermore, nitrite reductase genes (i.e., nirK and nirS) related to the denitrification and those genes related to DNRA (i.e., nirB and nrfA) were mainly annotated to the classes Alpha-proteobacteria, Beta-proteobacteria, and Gamma-proteobacte...

Mechanisms underlying plant succession remain highly debated. A global quantification of the relative importance of species addition versus replacement is lacking due to the local scope of most studies. We quantified their role in the variation of plant communities colonizing the forelands of 46 retreating glaciers distributed worldwide, using both environmental DNA and traditional surveys. Both mechanisms concur in determining community changes over time but their relative importance varied over time along successions. Taxa addition predominated immediately after glacier retreat, as expected in harsh environments, while replacement became more important for late-successional communities. Those changes were aligned with total beta-diversity changes, which were larger between early successional communities than between late-successional communities (>50 years since glacier retreat). Despite the complexity of community assembly over plant succession, our global pattern suggests a g...

The succession in areas once vegetated before the disturbance to a forest as climax community is called secondary succession. Secondary succession is influenced by soil type and the vegetation that invades the community. During the literature survey we found that the cropping areas are abandoned in different parts of the world and the fallows left are under secondary succession. There the socio-economy of the people has been found to affect the succession. Species diversity, species richness, rate of replacement and the soil type etc. have been studied by succession researchers. Succession study has also been carried out by using the tools like remote sensing, geographical information system etc.

Tazekka National Park, located in the Eastern Middle Atlas, is known by a “Jbel Tazekka” mountain where a remarkable forest ecosystem, the cedar grove, is located. Analysis of the bryological flora of this mountain revealed the existence of 66 species including 59 mosses and 7 livers. From a morphological point of view, the listed taxa are divided into 41 acrocarps, 18 pleurocarps, 6 thalle livers and 1 leaf liver. From a systematic point of view, they are represented by 24 families and 39 genre encountered on different types of substrates. Three new taxa (two species and one variety) were inventoried (Anomodon attenuatus, Didymodon nicholsonii et Stegonia latifolia var. latifolia). In general, the distribution of bryophytic species in the study area depends primarily on the microclimate of the station. The humidity and especially the freshness of the environment are ensured by the forest formations here, especially the cedar grove. Three species, all livers, Lunularia cruciata, Tar...

Changes in species diversity following volcanic eruptions have been studied extensively, but our knowledge on functional diversity and community assembly under such conditions is very limited. Here, we study the processes following the destruction of vegetation after a volcanic eruption. Specifically, we investigate (1) the temporal patterns of taxonomic and functional diversity over time since a previous eruption (alpha diversity) and beta diversity, (2) the temporal patterns of 26 individual traits (vegetative characteristics, plant taxa ecological preferences, and regenerative characteristics) providing more detailed information on species strategies at the initial and later stages of succession, and (3) the processes driving species assembly and whether they changed over time since the eruption an eruption. We analyzed data recorded during five floristic censuses that took place between 1911 and 2011, calculated alpha and beta facets of taxonomic and functional diversity and exa...

1. Global change is likely to alter plant community structure, with consequences for the structure and functioning of the below-ground community and potential feedbacks to climate change. Understanding the mechanisms behind these plant-soil interactions and feedbacks to the Earth-system is therefore crucial. One approach to understanding such mechanisms is to use plant traits as predictors of functioning. 2. We used a field-based monoculture experiment involving nine grassland species that had been growing on the same base soil for 7 years to test whether leaf, litter and root traits associated with different plant growth strategies can be linked to an extensive range of soil properties relevant to carbon, nitrogen and phosphorus cycling. Soil properties included the biomass and structure of the soil microbial community, soil nutrients, soil microclimate and soil process rates. 3. Plant species with a high relative growth rate (RGR) were associated with high leaf and litter quality (e.g. low toughness, high nitrogen concentrations), an elevated biomass of bacteria relative to fungi in soil, high rates of soil nitrogen mineralization and concentrations of extractable inorganic nitrogen, and to some extent higher available phosphorus pools. 4. In contrast to current theory, species with a high RGR and litter quality were associated with soils with a lower rate of soil respiration and slow decomposition rates. This indicates that predicting processes that influence carbon cycling from plant traits may be more complex than predicting processes that influence nitrogen and phosphorus cycling. 5. Root traits did not show strong relationships to RGR, leaf or litter traits, but were strongly correlated with several soil properties, particularly the biomass of bacteria relative to fungi in soil and measures relating to soil carbon cycling. 6. Synthesis. Our results indicate that plant species from a single habitat can result in significant divergence in soil properties and functioning when grown in monoculture, and that many of these changes are strongly and predictably linked to variation in plant traits associated with different growth strategies. Traits therefore have the potential to be a powerful tool for understanding the mechanisms behind plant-soil interactions and ecosystem functioning, and for predicting how changes in plant species composition associated with global change will feedback to the Earth-system.

1. Global change is likely to alter plant community structure, with consequences for the structure and functioning of the below-ground community and potential feedbacks to climate change. Understanding the mechanisms behind these plant-soil interactions and feedbacks to the Earth-system is therefore crucial. One approach to understanding such mechanisms is to use plant traits as predictors of functioning. 2. We used a field-based monoculture experiment involving nine grassland species that had been growing on the same base soil for 7 years to test whether leaf, litter and root traits associated with different plant growth strategies can be linked to an extensive range of soil properties relevant to carbon, nitrogen and phosphorus cycling. Soil properties included the biomass and structure of the soil microbial community, soil nutrients, soil microclimate and soil process rates. 3. Plant species with a high relative growth rate (RGR) were associated with high leaf and litter quality (e.g. low toughness, high nitrogen concentrations), an elevated biomass of bacteria relative to fungi in soil, high rates of soil nitrogen mineralization and concentrations of extractable inorganic nitrogen, and to some extent higher available phosphorus pools. 4. In contrast to current theory, species with a high RGR and litter quality were associated with soils with a lower rate of soil respiration and slow decomposition rates. This indicates that predicting processes that influence carbon cycling from plant traits may be more complex than predicting processes that influence nitrogen and phosphorus cycling. 5. Root traits did not show strong relationships to RGR, leaf or litter traits, but were strongly correlated with several soil properties, particularly the biomass of bacteria relative to fungi in soil and measures relating to soil carbon cycling. 6. Synthesis. Our results indicate that plant species from a single habitat can result in significant divergence in soil properties and functioning when grown in monoculture, and that many of these changes are strongly and predictably linked to variation in plant traits associated with different growth strategies. Traits therefore have the potential to be a powerful tool for understanding the mechanisms behind plant-soil interactions and ecosystem functioning, and for predicting how changes in plant species composition associated with global change will feedback to the Earth-system.

AimTo assess the spatial‐temporal dynamics of primary succession following deglaciation in soil‐dwelling lichen communities.LocationEuropean Alps (Austria, Switzerland and Italy).MethodsFive glacier forelands subjected to relevant glacier retreat during the last century were investigated. In each glacier foreland, three successional stages were selected at increasing distance from the glacier, corresponding to a gradient of time since deglaciation between 25 and 160 years. In each successional stage, soil‐dwelling lichens were surveyed within five 1 × 1 m plots. In addition to a classical ecological framework, based on species richness and composition, we applied a functional approach to better elucidate community assembly mechanisms.ResultsA positive relationship was found between species richness and time since deglaciation indicating that richer lichen communities can be found at increasing terrain ageing. This pattern was associated with compositional shifts, suggesting that dif...

The mycorrhizal association between fungi and plants is thought to be an important component of the functional diversity of plant communities, although evidence is weak. We explored community-level changes to mycorrhizal features and leaf traits along a primary successional gradient on a sedimentation coast. We found that community weighted mean values of mycorrhizal features and leaf traits varied systematically along the successional series, representing a transition from communities dominated by more stress-tolerant plant species (less mycorrhizal colonization and lower specific leaf area) to less stress-tolerant plant species (higher mycorrhizal colonization and specific leaf area). Despite the covariation in leaf traits and mycorrhizal features at the community level, only mycorrhizal features showed an increasing functional diversity with successional age. These results suggest that mycorrhizal fungi should not be forgotten in trait-based plant community ecology.

Percutaneous angiography has been performed for decades, but it is not without complications, such as the formation of a clot within the arterial introducer, and its potential migration into the systemic circulation. However, it is not clear what the best approach is regarding the use of continuous perfusion in the introducer (pressure perfusion through the lateral port of the introducer with saline solution 0.9%) during diagnostic angiographic exams, in preventing the formation of clots inside the introducer, which is the access portal for the passage of catheters and guide wires. Objective: To determine the frequency of clot presence in the femoral artery introducer with and without continuous perfusion in cerebral angiographic studies. Method: A randomized clinical trial in patients undergoing cerebral angiography performed at the Hospital das Clínicas / EBSERH-UFPE and at Angiocor in João Pessoa-Paraíba, divided into two groups: Control group (GC), n=34 patients without continuous perfusion in the femoral arterial introducer during angiography. Experimental group (GE), n=34 patients with continuous perfusion in the femoral arterial introducer during angiography. Statistical analysis was performed using the u Mann-Whitney test, for continuous variables and the Fisher's exact test for categorical variables. The significance level was 0.05. Results: In the GC there was the presence of a clot in all introducers at the end of the angiographic exam, while in the GE, no clot was present in any introducers at the end of the angiographic exam. Conclusion: The use of continuous infusion prevented the formation of clots within the introducer during the angiographic exam in all cases.

Objective: Systolic anterior motion (SAM) may rarely occur after mitral valve reconstruction due to different anatomic factors. Several techniques have been described to reduce the incidence of post-repair SAM, e.g. leaflet sliding plasty. However, SAM can still occur after these special procedures. We reviewed data of patients developing SAM with significant mitral regurgitation due to non-obstructive septal bulge. Methods: During a 2-year period mitral valve repair was performed in 358 patients. Five of 358 (1.4%) patients with a mean age of 52 ^10.5 years developed post-repair SAM with severe mitral insufficiency due to non-obstructive septal bulge. Data of these patients were analyzed retrospectively and controlled after a mean follow-up of 18 ^2.7 months. Results: Preoperative echocardiography showed enddiastolic septum diameter of 7, 10, 10, 11 and 15 mm. The ratio between end-diastolic septum diameter and free wall diameter was 1 in four patients and 1.25 in one patient. There was no left ventricular outflow tract obstruction (LVOT). Intraoperative data revealed large myxomatous anterior (four patients) and posterior (three patients) leaflets. Quadrangular resection of posterior leaflet was carried out in four patients and sliding plasty in one patient. Cause for post-repair mitral regurgitation was a non-obstructive septal bulge. During a second pump run septal bulge was resected. Mean aortic cross-clamp time and cardiopulmonary bypass time for this procedure was 15 ^1.4 and 28 ^3.1 min, respectively. Mitral regurgitation disappeared in all patients immediately after this procedure. The grade of mitral regurgitation at follow-up was 0 -1 in all patients. One patient had subaortic gradient of 36 mmHg. Conclusions: If mitral regurgitation occurs after primary successful mitral repair, septum bulge should always be considered as the primary cause for SAM even there is no preoperative gradient in LVOT. Before performing time-consuming corrective operations to relieve SAM, a septum resection should be carried out during a short second pump run.

The coastal dunes of the Basque Country have suffered a significant anthropic process of regional-scale destruction and fragmentation. This has led to the loss of seven, and endangerment of 14, of the 37 species of plants recognized as exclusive to these dunes. In response to this situation, the restoration of one of the lost dune systems, the Laida Dune, began in 2002 with the installation of sand trapping devices and the plantation of two dune-building species of plants. This study shows the results of a program that monitored the process of natural colonization of plant species in the restored dune over a period of seven years, until the loss of the dune by the action of storms in 2008. The results show that the vegetation dynamics in the restored dune followed a process of primary succession, with a progressive increase in species number, coverage and heterogeneity. The establishment of species was driven by the strong environmental gradient present perpendicular to the coastline. The results indicate that natural colonization in this coastal sector is now possible due to the large number of dune species present, and in spite of the isolation of the restored dune system and the loss and fragmentation of the dune habitats in the region. Over the seven years, 42 plant species became established on the dune, of which 18 were dune-exclusive species, representing 62.1% of the total number of species of the same type in the region. Five of these species are considered to be rare or threatened. Comparison with reference data allowed the evaluation of the trajectory of the plant community assembly. The results indicate that the highest similarity to a reference dune system was to the one located closest to the restored dune.

The arbuscular mycorrhizal (AM) grass Calamagrostis epigejos and predominantly ectomycorrhizal (EcM) tree Salix caprea co-occur at post-mining sites spontaneously colonized by vegetation. During succession, AM herbaceous vegetation is replaced by predominantly EcM woody species. To better understand the interaction of AM and EcM plants during vegetation transition, we studied the reciprocal effects of these species' coexistence on their root-associated fungi (RAF). We collected root and soil samples from three different microenvironments: stand of C. epigejos, under S. caprea canopy, and contact zone where roots of the two species interacted. RAF communities and mycorrhizal colonization were determined in sampled roots, and the soil was tested for EcM and AM inoculation potentials. Although the microenvironment significantly affected composition of the RAF communities in both plant species, the effect was greater in the case of C. epigejos RAF communities than in that of S. caprea RAF communities. The presence of S. caprea also significantly decreased AM fungal abundance in soil as well as AM colonization and richness of AM fungi in C. epigejos roots. Changes observed in the abundance and community composition of AM fungi might constitute an important factor in transition from AM-dominated to EcM-dominated vegetation during succession.

The evolutionary history of the symbiotic association between arbuscular mycorrhizal fungi (AMF) and embryophytes dates back to the Devonian period. Previous ecological and physiological studies have described the presence of arbuscules, inter-and intracellular hyphae, vesicles, coils and spores, in liverworts and hornworts, which are considered absent in mosses. This study aimed to report the presence of AMF in a community of bryophytes (mosses and liverworts) from Punta Lara Natural Reserve, Argentina. Senescent and green sections of gametophytes were stained and, following microscopic observation, revealed AMF structures. We found intracellular hyphae, vesicles, spores and sporocarps associated with thallus and rhizoids of mosses and liverworts and senescent moss caulidia. The morphological characterization of spores resulted in the determination of Rhizophagus intraradices and Dominikia aurea. The species D. aurea is reported for the first time for Argentina. Sequencing of the D1 variable domain of the LSUrDNA from AMF spores mixes plus hyphae resulted in high similitude to the Dominikia sequences available from NCBI. This study reported the presence of AMF associated with declining and senescent gametophytes of bryophytes (mosses and liverworts) in a Natural Reserve in Argentina. These findings open up new lines of study, which should further investigate these associations and their diversity, physiology and significance.

During the processes of primary succession and soil development, large stocks of organic C with very long residence times accumulate in many soils. Soluble organic C adsorbed by soils may contribute to the stock of organic C accumulating during soil development. We determined whether the mineralization rate of water-soluble organic C and the insoluble residue from 14 C-labelled leaf litter added to soils from a weathering chronosequence decrease as soil age and adsorption capacity increase. The soils were formed on mudflows of andesitic material deposited about 75, 255, 616 y ago, and another older but undetermined time before this study. The percentage of the DOC adsorbed by the soils increased with age. After 1 year of incubation there were no significant differences in the mineralization rates of DOC added to soils of different ages. The DOC appeared to be comprised of two fractions, one that comprises about 32% of the total that mineralized with a half decay time of 0.02 y (7 d) and a second fraction comprising 68% with a half decay time of about 1.6 y. Consequently, the slowly mineralized fraction of the soluble C contributed to the accumulation of slowly mineralized C in the soil. Both the slowly and rapidly mineralized fractions of the insoluble residue decomposed more slowly than the corresponding fractions in DOC. We found no support for the idea that increased adsorption capacity due to weathering resulted in protection of soluble organic C from microbial mineralization.

Net nitri®cation in forest soils is potentially problematic as it can promote nitrogen and cation losses as well as soil acidi®cation and favor competing vegetation in regenerating forests. Rates of net nitri®cation have been associated with vegetation and soil types. However, this phenomenon is dicult to predict. Our objectives were to describe the relationships between stand types and net nitri®cation in the forest ¯oor of ®ve stand types (Paper birch: Betula papyrifera, trembling aspen: Populus tremuloides, white spruce: Picea glauca, jack pine: Pinus banksiana, white cedar: Thuja occidentalis ) typical of the boreal mixedwood of northwestern Quebec and to experimentally verify the eect of pH and ammonium availability as well as the occurrence of persistent allelopathic inhibitors on net nitri®cation rates. All samples came from well-drained lacustrine clay soils and all forest stands originated from wild®res. The net accumulation of nitrate and ammonium was measured during the course of 6-week laboratory incubations. Nitrate accumulation was highest under aspen and birch, low under white spruce and cedar and not detectable under jack pine. The forest ¯oor of jack pine had the lowest pH and exchangeable bases and the widest C:N ratio. Ammonium addition did not promote a signi®cant increase in net nitri®cation. Increase of forest ¯oor pH had a positive eect on net nitri®cation while acidi®cation depressed it. The absence of net nitrate production in jack pine forest ¯oor appeared to be related to the absence of nitri®ers as it was stimulated by the addition of a small amount of nitrifying forest ¯oor. Our results suggest that jack pine and aspen, which occupy the same habitat, may have the capacity to change soil conditions in order to favor or depress nitri®cation. Observed rates of nitri®cation under these species is coherent with their preference for a particular form of mineral N. Although pH appeared as an important regulator of net nitri®cation, the eects of other factors are yet to be established.

The present study investigates macrofouling development in the Mar Grande of Taranto (Central Mediterranean Sea), a wide confined area that has attracted considerable attention in recent years due to the establishment of numerous non-indigenous species (NIS). Different starting times of a yearly primary succession on artificial substrates were tracked so as to investigate the matching of the development pattern with contingency and/or convergence models, identifying NIS's structural role in the community endpoint. Our results show that during the experiment all assemblages tended to converge towards multiple contingent communities according to starting times and depths. The differences are due to propagule availability which influence further species interactions. Thus the endpoint patterns are defined by a contingent community development determined by the seasonal species pool, their phenologies, pre-and post-settlement events, and species interactions. The most important structuring species was Mytilus galloprovincialis, which was present in almost all the endpoint assemblages, in particular when it recruits at early stages of the community development. Another abundant species at the endpoint was the alien Branchiomma boholense; which was a persistent structural component contributing to an alternative state in which Mytilus galloprovincialis loses its structural importance and where B. boholense becomes dominant, leading to an increase in fouling biodiversity of the endpoint assemblage.

The aim of this paper is to describe the changes of Mediterranean pasture phytomass and their dependence on succession, slope geomorphology and herbivore consumption. Four neighbouring slopes of similar aspect and steepness, located in a pasture area of Central Spain, were chosen for sampling. The slopes had not been cultivated for 1, 3, 8 and 40 years respectively. On each slope both the upper, erosion zone and the lower, accumulation zone were sampled during the months of plant growth (April to July), phytomass being recorded in plots where herbivore consumption was avoided with protection cages and in unprotected plots. Results from the protected plots show that the upper and lower parts of slopes undergo a different development during succession. The highest values of phytomass reached, tended to decrease during succession in the upper zones, the same being true for production. However in the lower zones both parameters tended to increase in time. The ratio P/B, widely known in ecology to decrease with time, did not seem to behave as a usual index of succession in the studied ecosystem. In the upper zone this ratio tended to decrease but in the lower zone it increased with succession after the first years. Phytomass consumption by herbivores was progressively concentrated during succession in the slope sectors of greater production, mainly in the lower zone, which increased its productivity as the slope-talweg system became functional. The evolution of the ecological structure of a slope should be interpreted not only as a result of the tolerance of species to phsysico-chemical factors. It may also reveal the existence of an important interaction between the pasture and the grazing behaviour of exploiting animals. Multivariate analysis of phytomass records revealed a trend of temporal variation which should be identified with the progress of succession.

This paper analyzes successional changes in trophic structure of aquatic insect communities of a set of ponds subjected to different environmental conditions during the first year of existence. The colonization aiid successional sequences of nine of ten ponds exhibited a common reasonably predictable pattern, that was determined by quality of available food in these systems. Detritus constituted the main source of food in the ponds, with more of 50% of species being detritivorous.

percutaneous transluminal angioplasty of stenosed aortocoronary bypass grafts was attempted 44 times in 31 patients who had developed disabling angina pectoris four months to seven years after coronary bypass surgery. The primary success rate was 93%. Two (4-5%) patients developed myocardial infarction related to the procedure. No emergency aortocoronary bypass surgery was required and there was no mortal- ity. Although the primary success rate was high, the incidence of recurrence after one or more angioplasties was 50%/o. Despite this recurrence rate the condition of 10 of the first 16 (62%) patients was clinically improved after a mean follow up of 26 months.

TravInfo is part of the Federal Highway Administration (FHWA) Field Operational Test (FOT) program. It aims to develop a multi-modal traveler information system for the San Francisco Bay Area, combining public and private sector talents. This report presents the results of year two of the institutional evaluation, which is part of the overall TravInfo evaluation. Nineteen core participants were interviewed, including all of the Management Board and most of the Steering Committee members and project staff. Separately, twenty Advisory Committee members were interviewed. The second year was dominated by TravInfo implementation issues, chief among which were: resolution of public/private controversies in the design of TravInfo and the attempt to ensure the completion of Caltrans' Traffic Operations System (TOS) for meeting the TravInfo schedule. Based on the interviews, the partners thought that the TravInfo organization has been effective at resolving both of these issues.

Worldwide, mountain glaciers are shrinking rapidly and projected to disappear largely by 2100. Consequently, large areas are becoming available for novel alpine ecosystems. These harsh environments, however, slow down primary succession. In this study with a local community, we conducted an inclusion experiment to investigate if and how Llama glama influences soils and vegetation primary succession following glacial retreat. At the foot of the Uruashraju glacier in the Cordillera Blanca, Peru (~ 4680 m.a.s.l.), we established four llama inclusion plots and four control plots that we studied from 2019 to 2022, 24–40 years after glacial retreat. After three years, the llama plots had significantly increased soil organic carbon and soil nitrogen. In the llama plots, we found a large, significant increase in vascular plant cover (+ 57%) between the second and third years of experimentation, and we identified four new species that were not present in 2019. Our results suggest that Llama ...

The recent deglaciation of large polar areas has exposed stretches of land, allowing spontaneous primary succession. The exposed substrate is colonized by soil biota participating in soil formation -a process in which soil characteristics and the biotic community affect each other mutually. Soil fauna was studied along three transects in glacier valleys around Petunia Bay on Svalbard in the High Arctic, representing chronosequences of soil development on plots deglaciated for ten to approximately ten thousand years. Community development was characterised by progressive addition of species, with many pioneer species remaining present throughout soil development. Generally, the abundance and species richness of soil animals increased from the initial to the well-developed sites. Altogether 93 taxa of soil fauna were identified, including 21 species of rotifers, 38 genera of nematodes, 8 species of tardigrades, 21 species of springtails and 4 species of enchytraeids. Rotifers were the earliest colonizers, found already in the initial stage, followed by nematodes in plots several tens of years old. They were followed by tardigrades, which -although in low abundances -established populations in the third stage of the chronosequences, 10 3 -year-old. Collembolans formed stable populations at the end of the chronosequence in the third and fourth stages, 10 3 to 10 4 years old. Enchytraeids only appeared at the end of the chronosequence. Assemblages were significantly driven mostly by the age of the plot, association with a given transect and nutrient availability.

Background The process of ecosystem development over time that takes place on a new substrate devoid of biological activity (such as, for example, lava) is called primary succession. Research on primary succession is not easy, as it is limited to rare occasions when a piece of land totally lacking in any pre-existing life occurs. The emergence of volcanic islands is such an occasion; it is a unique event that allows a natural experiment in the study of colonisation processes and primary succession. Surtsey (located in the Vestmannaeyar archipelago off the southern coast of Iceland) is an iconic example of a place where primary succession has been studied for decades and where human disturbance has been minimised due to significant geographic isolation and early protection efforts. Here, we present a georeferenced dataset of vacular plant occurrences collected during the field studies carried out on Surtsey Island during the first three decades of its existence. New information To da...

In Arctic macroalgal belt ecosystems, macrozoobenthic production is thought to be an important link between primary production and higher trophic levels. Macrozoobenthic biomass and secondary production were studied along transects (2.5-15 m depth) in the macroalgal belt at Hansneset in Kongsfjorden, Svalbard, from 2012 to 2013. At 2.5 m, the standing stock reached its maxima of 174.8 ± 54.4 g ash-free dry weight per 1 m 2 , while density (4341 ind. m-2 ± 1127 95 % CI) and production (7.0 g C m-2 y-1 ± 2.8 95 % CI) were highest at 5 m water depth in 2012/13. Compared to a study from 1996/98, this re-sampling indicated a drastic change in the depth distribution of macrozoobenthic biomass and secondary production at Hansneset. While both biomass and secondary production increased with water depth in 1996/98, this pattern was inversed in 2012/13 owing to a tenfold increase in biomass and secondary production in the upper most sublittoral (2.5-5 m). Variability of macrozoobenthic biomass and secondary production corresponded to differences in the physical environment and macroalgal vegetation along the depth gradient. In the last decade, the number of ice-free days per year increased probably due to Arctic warming. As a result, shallow rocky habitats (2.5-5 m) are less affected by ice scouring, thereby opening new space for colonisation by benthic fauna. However, faunal secondary production was low compared to macroalgal primary production, indicating a considerable export of most of the algal production from the shallow habitats to the adjacent areas. Keywords Arctic Á Macrozoobenthic Á Kelp-associated fauna Á Benthic biomass Á Somatic production Á P/B ratio Á Kongsfjorden This article belongs to the special issue on the ''Kongsfjorden ecosystem-new views after more than a decade of research'', coordinated by Christian Wiencke and Haakon Hop.

Tazekka National Park, located in the Eastern Middle Atlas, is known by a “Jbel Tazekka” mountain where a remarkable forest ecosystem, the cedar grove, is located. Analysis of the bryological flora of this mountain revealed the existence of 66 species including 59 mosses and 7 livers. From a morphological point of view, the listed taxa are divided into 41 acrocarps, 18 pleurocarps, 6 thalle livers and 1 leaf liver. From a systematic point of view, they are represented by 24 families and 39 genre encountered on different types of substrates. Three new taxa (two species and one variety) were inventoried (Anomodon attenuatus, Didymodon nicholsonii et Stegonia latifolia var. latifolia). In general, the distribution of bryophytic species in the study area depends primarily on the microclimate of the station. The humidity and especially the freshness of the environment are ensured by the forest formations here, especially the cedar grove. Three species, all livers, Lunularia cruciata, Tar...

This study focuses on the concentration of trace-, microelement- and organic components in initial horizons of sandy soil (Arenosole) and of the tissues of Corynephorus canescens, a pioneer species typical of unstable environments that initiates pedogenic processes by enriching poor quartz sand in organic- and mineral matter from its own tissues. Soil samples were taken from a root-zone humus horizon (A) averaging ∼15 cm in thickness and from parent rock. Concentrations of Ca, Mg, K, Na, Fe, Si, Al, Zn, Mn, Co, Cd, Pb, Sr, Mo, C, N and P in plant material and soil were analyzed. High concentrations of Si (6368±16.3 mg·kg-1), K (2310±165.2), Ca (302±24.6 mg·kg-1), Fe (2196±316.3) are found in the above-ground part of the plant whereas Si (9150±20), Fe (5948± 43), K 3752±3.21) and Al (2370±52.6 mg·kg-1) dominate in the roots. Soil organic carbon (OC) contents in the humus horizon and in parent rock are 0.276±0.041 and 0.206±0.041%, respectively. The concentration of nitrogen in the hu...

Rahmonov O., Szymczyk A.: Relations between vegetation and soil in initial succession phases in post-sand excavations. Ekológia (Bratislava), vol. 29, No. 4, p. 412-429, 2010. open-mined sand exploitation always leads to the total liquidation of vegetation and soil cover. The given study presents the relations between vegetation appearing in the excavation and soil development in the initial phases of succession. investigations were carried out in the kuznica Warezynska sandpit, located in the Silesian Upland in southern Poland. results obtained indicate that at uncovered sands, due to exploitation in unreclaimed places, spontaneous regeneration of vegetation-soil cover occurs. in the succession series observed in the excavation, 3 stages were distinguished (primary, secondary and terminal), which were divided into 6 phases. The oldest observed succession stage was made by communities from the Dicrano-Pinion connection. The duration of succession of the oldest surfaces is estimated at 25 years. Considering morphology, the forming soil differs at every succession stage. in respect to observed soil formation processes, advancing soils, even the oldest surfaces, have initial character; they are poor in nutrients and characterized by acidic, slightly acidic to alkaline pH-reaction. Physico-chemical properties of soil, forming in the area of the sandpit, are conditioned most of all by the ground water level, its chemical composition and the duration of succession. investigations proved that the course of succession at habitats fed mainly by waters, originated from the seepage of waters of deep circulation, and this differs from this those in places fed by the precipitation of waters. These differences appear most of all in the first phase of optimum stage. The sandpit is also characterized by a large differentiation of vegetation, resulting from the mosaic character of habitats. Habitat differentiation of the sandpit bottom is connected with its diversified relief and hydrogeological situation.

This study focuses on the concentration of trace-, microelement- and organic components in initial horizons of sandy soil (Arenosole) and of the tissues of Corynephorus canescens, a pioneer species typical of unstable environments that initiates pedogenic processes by enriching poor quartz sand in organic- and mineral matter from its own tissues. Soil samples were taken from a root-zone humus horizon (A) averaging ∼15 cm in thickness and from parent rock. Concentrations of Ca, Mg, K, Na, Fe, Si, Al, Zn, Mn, Co, Cd, Pb, Sr, Mo, C, N and P in plant material and soil were analyzed. High concentrations of Si (6368±16.3 mg·kg-1), K (2310±165.2), Ca (302±24.6 mg·kg-1), Fe (2196±316.3) are found in the above-ground part of the plant whereas Si (9150±20), Fe (5948± 43), K 3752±3.21) and Al (2370±52.6 mg·kg-1) dominate in the roots. Soil organic carbon (OC) contents in the humus horizon and in parent rock are 0.276±0.041 and 0.206±0.041%, respectively. The concentration of nitrogen in the hu...

Rahmonov O., Szymczyk A.: Relations between vegetation and soil in initial succession phases in post-sand excavations. Ekológia (Bratislava), vol. 29, No. 4, p. 412-429, 2010. open-mined sand exploitation always leads to the total liquidation of vegetation and soil cover. The given study presents the relations between vegetation appearing in the excavation and soil development in the initial phases of succession. investigations were carried out in the kuznica Warezynska sandpit, located in the Silesian Upland in southern Poland. results obtained indicate that at uncovered sands, due to exploitation in unreclaimed places, spontaneous regeneration of vegetation-soil cover occurs. in the succession series observed in the excavation, 3 stages were distinguished (primary, secondary and terminal), which were divided into 6 phases. The oldest observed succession stage was made by communities from the Dicrano-Pinion connection. The duration of succession of the oldest surfaces is estimated at 25 years. Considering morphology, the forming soil differs at every succession stage. in respect to observed soil formation processes, advancing soils, even the oldest surfaces, have initial character; they are poor in nutrients and characterized by acidic, slightly acidic to alkaline pH-reaction. Physico-chemical properties of soil, forming in the area of the sandpit, are conditioned most of all by the ground water level, its chemical composition and the duration of succession. investigations proved that the course of succession at habitats fed mainly by waters, originated from the seepage of waters of deep circulation, and this differs from this those in places fed by the precipitation of waters. These differences appear most of all in the first phase of optimum stage. The sandpit is also characterized by a large differentiation of vegetation, resulting from the mosaic character of habitats. Habitat differentiation of the sandpit bottom is connected with its diversified relief and hydrogeological situation.

Biological nitrogen fixation (BNF) is a key process for ecosystem development on new substrates. On young volcanic substrates, the near absence of nitrogen (N) and the presence of available phosphorus (P) in the soil should stimulate the activity of diazotrophic, N-fixing, bacteria. Our main hypothesis is that ecosystem N gain through BNF is tightly coupled to the development of progressive and maximum phases of ecosystem succession, as element contents build up. We investigated ecosystem development in a well-established 60 000-year-old chronosequence in Llaima volcano, south-central Chile. Tree basal areas and total carbon (C), N and P contents in soils showed declining trends over the millennial chronosequence following maximum values between 326 and 3470 years of succession. Maximum rates of BNF (3-6 kg N ha -1 year -1 ) were recorded in the interval from 776 to 3470 years of substrate age, partly associated with high soil C and P contents, and with the lowest denitrification ra...

Primary succession is an ecological process of fundamental importance and refers to the settlement and development of vegetation on an area that has not previously been occupied by a plant community, such as a newly exposed rock, sand surface, lava flows, or glacial tills. Because such strong geomorphologic and topographic changes affect a relatively minor part of the Earth's surface, there are not many opportunities to study naturally ongoing primary succession. The bulk of knowledge on primary succession comes from areas affected by relatively recent volcanic eruptions (ca 500-300 years ago to present), hence from regions of main volcanic activity such as Japan (Titus and

Question: What is the population viability of a critically endangered seashore grass, Arctophila fulva var. pendulina. Location: Liminka Bay, W Finland, 25°21'70 N, 64°51'90 E. Methods: We constructed a matrix population model based on colonization and disappearance events and patch size changes of A. fulva. Patches were divided into hydric and nonhydric zones according to proximity to the seashore and intensity of disturbance. Perturbation analyses were carried out in order to identify transitions critical for population growth. Seed bank and seed germination studies provided background information for the model design. Results: A. fulva patches observed in the more disturbed hydric zone (closest to the sea) increased in number, as did the total number of patches. However, the number of patches in the less disturbed non-hydric zone decreased. Conclusions: Short-term dynamics of the A. fulva population at Liminka Bay seem to be determined by environmental fluctuations, which cause annual variation in transition rates between patch size classes. The long-term dynamics are probably governed by initiation of primary succession by isostatic land uplift. Increased disturbance at the water's edge may promote persistence of A. fulva through reduced interspecific competition. Our results suggest that shoreline disturbance of the hydric zone is sufficient for maintaining a viable population. Competitive exclusion of A. fulva in the non-hydric zone may be delayed by management practices, such as mowing.

Urinoma (collection of urine) formation secondary to extracorporeal shock wave lithotripsy (ESWL) is one of the rare complications encountered postprocedure and co-existence of urinoma with steinstrasse is a rare and challenging scenario to manage in the setting of obstructive uropathy. ESWL is known for being noninvasive for breaking kidney and ureteric
stones. Urinoma is a collection of urine outside the collecting system in the retroperitoneum or perirenal space. Early detection and management are necessary to prevent complications related to urinoma and steinstrasse. This case report is about a patient who developed urinoma
and steinstrasse in the setting of obstructive uropathy after sessions of ESWL on the right side and was managed with a nephrostomy tube and trans-ureteral lithotripsy on the right side and percutaneous nephrolithotomy on the left side after 1 month.

Glaciers are receding at unprecedented rates in the alpine tropics, opening-up new areas for ecosystem assembly. However, little is known about the patterns/mechanisms of primary succession during the last stages of glacier retreat in tropical mountains. Our aim was to analyze soil development and vegetation assembly during primary succession, and the role of changing adaptive strategies and facilitative interactions on these processes at the forefront of the last Venezuelan glacier (Humboldt Peak, 4,940 m asl). We established a chronosequence of four sites where the glacier retreated between 1910 and 2009. We compared soil organic matter (SOM), nutrients and temperatures inside vs. outside biological soil crusts (BSCs) at each site, estimated the cover of lichen, bryophyte and vascular plant species present, and analyzed changes in their growth-form abundance and species/functional turnover. We also evaluated local spatial associations between lichens/bryophytes and the dominant ru...

In attendance were more than 100 oncologists, epidemiologists, biostatisticians, surgeons, biochemists, pathologists, radiologists, and endocrinologists who are involved with research utilizing the intraductal approach. Reverend Michelle Woodhouse, PhD, the Chair of the Foundation's Board of Directors, opened the Symposium by welcoming everyone to the conference and by noting that the intraductal approach to the breast "isn't a flicker; it's a flame" that will advance the detection, prevention, and treatment of breast cancer. Reverend Woodhouse introduced the Foundation's President and Medical Director, Susan Love, MD. "This conference, dedicated to the intraductal approach to the breast, provides a unique opportunity for researchers throughout the world," said Dr. Love. "And as testament to these researchers and the importance of their work, we have grown each year in the amount of money we give out, the number of grant proposals we receive, and the amount of science we can present." Over a two-day period, prominent breast cancer researchers presented results of their studies in which they used the intraductal approach. The last session of each day gave researchers interested in applying for pilot grant funding for new studies the chance to present their ideas to the entire group for review.

Questions: Have predictable relationships between environmental variables and vegetation developed in primary succession following a volcanic eruption? Has the rate of succession changed? Have vegetation trajectories converged or diverged? Location: The Abraham Plain of Mount St. Helens, Washington, USA (46112 0 42 00 N, 122108 0 27 00 W, elevation 1360 m), was sterilized in 1980 by a blast, scoured by lahars and buried by pumice. Method: We monitored 400 100 m 2 contiguous permanent plots annually (1988-2008), and classified each plot from every year into ten community types (CTs). We characterized the terrain by topography and surface features. Redundancy analysis assessed relationships between vegetation and possible explanatory variables, which included sample location. We used detrended correspondence analysis (DCA) to assess successional rates and trends. Results: Relationships between species composition and explanatory variables were only significant after 1996, when position and presence of rills became significant. By 2006, explained variation remained low (13%) but significant. Species accumulated slowly, restricted by stress and isolation. Changes in mean DCA position slowed. Composition shifted from pioneer to persistent species and vegetation became more stable with time. Species accumulated for two decades and then stabilized, while cover has continued to increase. Diversity increased and then declined slightly as dominance developed and pioneer species became less common. Conclusions: We demonstrate weak but increasingly predictable trends in species composition using environmental variables. The rate of succession slowed and trajectories formed a reticulate network of transitions dominated by divergence. Convergence was not evident because vegetation responded distinctively to minor topographic features that allowed alternative stable communities to develop.

Questions: (1) How do seres differ with respect to vegetation changes? (2) What are the directions of succession? (3) How do species numbers change? (4) How do target species, i.e. those typical of natural and semi-natural vegetation, participate in succession? (5) Are spontaneously developed successional stages acceptable from the point of view of ecosystem restoration? Location: Extracted peatlands, bulldozed sites in forests destroyed by air pollution, an emerged bottom of a water reservoir, corridors of former Iron Curtain, artificial fishpond islands and barriers, sedimentary basins, spoil heaps from mining, stone quarries, forest clearings, road verges, sand and gravel-sand pits, ruderal urban sites, river gravel bars and abandoned arable fields, located in various parts of the Czech Republic in Central Europe. Methods: Phytosociological relev es were recorded in 10-25 m 2 plots located in the centre of representative successional stages defined by their age, ranging from 1 to 100 yrs. In total, we obtained 2392 vegetation samples containing 951 species. We performed DCA ordination to compare 19 seres. Desirable target species were considered as those representing (semi)-natural vegetation and all Red List species. Results: The seres studied are more similar in their species composition in the initial and early stages, in which synathropic species prevail, than in the later stages when the vegetation differentiates. This divergence is driven mainly by local moisture conditions. In most cases, succession led to woodland, which usually established after ca. 20 yrs. In very dry or wet places (with limited presence of woody species) open vegetation developed, often highly valuable from the restoration and conservation point of view. The total number of species and the number of target species increased in the majority of seres with successional age. Conclusions: The vegetation in the sites studied formed a continuum along a moisture gradient and by successional age. The individual seres largely overlapped in their species composition; the sere identity was not significant. Spontaneous succession usually proceeded towards woodland, except at very dry or wet sites, and generally appeared to be an ecologically suitable way of ecosystem restoration of disturbed sites because target species became dominant over time.

Questions: What is the variability of succession over a large geographical area? What is the relative importance of (1) local site factors and (2) landscape factors in determining spontaneous vegetation succession?Location: Various regions of the Czech Republic, Central Europe. The regions represent two categories characterized by agrarian lowlands, with a relatively warm and dry climate, and predominant woodland uplands with a relatively cold and wet climate.Methods: Gravel‐sand pits ranged in age from 1–75 years since abandonment. Three types of sites were distinguished: dry, wet and hydric in shallow flooded sites. Vegetation relevés were recorded with species cover (%) visually estimated using the space‐for‐time substitution approach. Local site factors, such as water table and soil characteristics, and landscape characteristics, namely climatic parameters, presence of nearby (semi‐) natural plant communities and main land cover categories in the wider surroundings, were evaluat...

We performed detrended correspondence analysis (DCA) ordination to compare seven successional seres running in stone quarries, coal mining spoil heaps, sand and gravel pits, and extracted peatlands in the Czech Republic in central Europe. In total, we obtained 1,187 vegetation samples containing 705 species. These represent various successional stages aged from 1 to 100 years. The successional seres studied were more similar in their species composition in the initial stages, in which synathropic species prevailed, than in later successional stages. This vegetation differentiation was determined especially by local moisture conditions. In most cases, succession led to a woodland, which usually established after approximately 20 years. In very dry or wet places, by contrast, where woody species were limited, often highly valuable, open vegetation developed. Except in the peatlands, the total number of species and the number of target species increased during succession. Participation of invasive aliens was mostly unimportant. Spontaneous vegetation succession generally appears to be an ecologically suitable and cheap way of ecosystem restoration of heavily disturbed sites. It should, therefore, be preferred over technical reclamation.

Sand mining strongly alters the existing landscape, transforming an area into a mosaic of native (sand deposits) and foreign soils, strongly influencing biotic development. The method of restoration of such excavated areas is often debated: natural succession or active restoration. We investigated how natural succession shapes harvestman communities, as part of the soil-dwelling community. We sampled harvestmen over a continuous period of 14 months in 25 plots in an abandoned sand quarry in Belgium using pitfall traps. We found significant increases in harvestman activity-density, species richness and diversity with time since abandonment of the various sections of the quarry. After about 15 years, a drastic change in species composition was observed with the establishment of forest species that more strongly depend on humid conditions to complete their life cycle. Colonisation of harvestmen closely followed vegetation succession despite their limited mobility. We argue that natural...

Glaciers are receding at unprecedented rates in the alpine tropics, opening-up new areas for ecosystem assembly. However, little is known about the patterns/mechanisms of primary succession during the last stages of glacier retreat in tropical mountains. Our aim was to analyze soil development and vegetation assembly during primary succession, and the role of changing adaptive strategies and facilitative interactions on these processes at the forefront of the last Venezuelan glacier (Humboldt Peak, 4,940 m asl). We established a chronosequence of four sites where the glacier retreated between 1910 and 2009. We compared soil organic matter (SOM), nutrients and temperatures inside vs. outside biological soil crusts (BSCs) at each site, estimated the cover of lichen, bryophyte and vascular plant species present, and analyzed changes in their growth-form abundance and species/functional turnover. We also evaluated local spatial associations between lichens/bryophytes and the dominant ru...

The study of temporal changes in riparian vegetation is essential for understanding the paths taken by the ecosystem during ecological succession. In order to evaluate the changes in floristic composition, structure, and dynamics of the arboreal vegetation in an area of Semideciduous Seasonal Alluvial Forest, we aim to understand the secondary succession that occurs in the Paraná River floodplain. Based on a study conducted 20 years ago, in the municipality of Batayporã, Mato Grosso do Sul, a resampling was carried out in the same area, using the same methodology. Phytosociological and ecological parameters between the two temporal samplings were collected and compared using Student's 't' test, where it was possible to find statistically significant variations (p<0.05) in the vegetation structure. A total of 603 individuals were sampled, distributed among 51 species and grouped in 46 genera and 31 families. The analysis of the distribution of abundance and importance values (IV) of species visualized in the histogram indicated an expected pattern in forest communities, which is the substitution of early successional species for late successional species. For the successional categories, the comparison of IVs revealed higher values for secondary species in both surveys and changes in the positions of climax and pioneer species, directly influencing the IVs values of these categories for the zones. When compared to the result obtained in the previous study, a replacement of the IV values of pioneer species with climax and dead species is noted. The comparisons showed that this phytocoenosis is evolving to a mature successional stage, a result of the decrease in the main anthropic impacts in the area. The results obtained highlight the importance of temporal monitoring of forest areas to expand the understanding of the pathways of ecological succession in this type of environment and provide information to assist in biodiversity conservation.

We measured plant recruitment patterns, successional dynamics, and biophysical processes on laterally expansive floodplains of the Kwethluk River, Alaska. The main channel of this gravel-bed river frequently avulses and possesses an anabranching plan form. Fluvial processes were interactive with life history processes of riparian plants in determining initial stages of primary succession. Reproductive strategies and herbivory became important factors later in succession. We conducted plant age and compositional surveys to assess patterns of propagule deposition. We found that dispersal strategies of species were an important factor influencing recruitment patterns. Flood-dispersed seeds resulted in even-aged cohorts of species persistently segregated in space, based on age data. Sediment characteristics and inundation potential had little influence on seedling distributions. Recruitment was also segregated on the basis of dispersal strategy. At the heads of bars, where vegetative propagules (live drift wood) were entombed during floods, the distributions of species were random. This size-selective nature of recruitment persisted through time. Vegetation age and distribution patterns were further diversified by the river's legacy of gravel deposition that diversified the primary successional pathway: one associated with ridges and another with swales. Interactions between these pathways and beaver herbivory initiated secondary succession. We used satellite imagery to quantify the extent of floodplain influenced by herbivory and to assess the importance of this driver of secondary succession. We also used high-resolution aerial imagery and randomly selected sites to provide an unbiased analysis. We classified this imagery to quantify the spatial extent of herbivory and its influence on the initiation of secondary succession. The results showed, in addition to recruitment and successional dynamics, the flood-plain habitat mosaic was diversified by the initiation of secondary succession. Patch and species composition within the vegetation mosaics were significantly different than those portions of the floodplain engaged in primary succession.