Impact of a hurricane on the herpetofaunal assemblages of a successional chronosequence in a tropical dry forest

Land‐use change is the main cause of deforestation and degradation of tropical forest in Mexico. Frequently, these lands are abandoned leading to a mosaic of natural vegetation in secondary succession. Further degradation of the natural vegetation in these lands could be exacerbated by stochastic catastrophic events such as hurricanes. Information on the impact of human disturbance parallel to natural disturbance has not yet been evaluated for faunal assemblages in tropical dry forests. To evaluate the response of herpetofaunal assemblages to the interaction of human and natural disturbances, we used information of pre‐ and post‐hurricane herpetofaunal assemblages inhabiting different successional stages (pasture, early forest, young forest, intermediate forest, and old growth forest) of dry forest. Herpetofaunal assemblages were surveyed in all successional stages two years before and two years after the hurricane Jova that hit the Pacific Coast of Mexico on October 2011. We registered 4093 individuals of 61 species. Overall, there were only slight effects of successional stage, hurricane Jova or the interaction between them on abundance, observed species richness and diversity of the herpetofauna. However, we found marked changes in estimated richness and composition of frogs, lizards, and snakes among successional stages in response to hurricane Jova. Modifications in vegetation structure as result of hurricane pass promoted particular changes in each successional stage and taxonomic group (anurans, lizards, and snakes). Secondary forests at different stages of succession may attenuate the negative effects of an intense, short‐duration, and low‐frequency natural disturbance such as hurricane Jova on successional herpetofaunal trajectories and species turnover.     

海南鹿回头岸礁造礁石珊瑚群落结构动态Ⅱ.物种多样性

根据石珊瑚物种的总数、石珊瑚覆盖的百分率、物种多样性和均匀度,对鹿回头岸礁造礁石珊瑚群落结构类型所处在演替阶段的时间状态和生境的空间状态进行分析。在中等和深水区物种多样性的时间变异,随演替的发展而有所下降;浅水区不随演替而变化。在不同生境区珊瑚生长的聚群上,与时间的发展无关;每个演替时期,物种多样性的类型与生境的变化有关。     

Phyllostomid bat assemblages in different successional stages of tropical rain forest in Chiapas,Mexico

Due to their role in seed dispersal, changes in the community of phyllostomid bats have direct consequences on ecological succession. The objective of this work was to document changes in the structure of bat assemblages among secondary successional stages of tropical rain forest in Chiapas, Mexico. Bats were mist-netted at ground level during 18 months in 10 sites belonging to 3 successional stages: four sites represented early succession (2–8 years of abandonment), four intermediate succession (10–20 years of abandonment), and two late succession (mature old-growth forest).We captured 1,179 phyllostomids comprising 29 species. Phyllostomid species richness was 17 (58% of all species) in the early stage, 18 (62%) in the intermediate stage and 24 (83%) in the late stage. The late successional mature forest possessed nine species that were exclusively found there, whereas early and intermediate successional stages contained only one exclusive species. Sturnira lilium, Artibeus lituratus, Carollia perpicillata, Artibeus jamaicensis and Glossophaga soricina represented 88% of all captured phyllostomid bats. Frugivores made up more than 90% of the species captured in early and intermediate successional stages and 84% in late successional forest. The Bray–Curtis index of dissimilarity showed a replacement of species through successional stages with the largest dissimilarity between early and late stages, followed by intermediate and late, and the lowest dissimilarity between early and intermediate stages. The number of gleaning insectivore species increased during succession. The carnivorous guild was exclusively found in the late stage (three species). We conclude that the late successional mature forest was the main reservoir for the gleaning insectivore and carnivore guilds; however, early and intermediate successional stages possessed a great diversity of species including many frugivores.     

Posthurricane Seedling Structure in a Multi‐aged Tropical Dry Forest: Implications for Community Succession

Hurricane‐caused tree mortality in tropical dry forests occurs predominantly in early successional species. Consequently, hurricanes may accelerate succession in these forests. Forest regeneration, however, must be measured over an extended posthurricane time period to demonstrate this pattern. In this study, we recorded tree seedlings in 19 Florida Keys forests during May–August 1995, 3 years after Hurricane Andrew. For these forests—spanning a chronosequence from 14 to over 100 years since the most recent clearing—we used weighted averaging regression on relative abundances of pre‐hurricane trees to calculate a successional age optimum for each species; and used weighted averaging calibration to calculate inferred successional ages for stands based on pre‐hurricane trees and on posthurricane seedlings. To test the hypothesis that successional stage of seedlings exceeded successional stage of pre‐hurricane trees, we compared inferred stand ages based on posthurricane seedlings with those based on pre‐hurricane trees. Across the study area, inferred stand ages based on posthurricane seedlings were greater than those based on pre‐hurricane trees (P < 0.005); however, more seedlings in the youngest stands were early successional than in older stands. Of 29 species present both as pre‐hurricane trees and posthurricane seedlings, 23 had animal‐dispersed seeds. These results provide evidence that: (1) hurricanes do not ‘reset’ succession, and may accelerate succession; and (2) a strong legacy of stand successional age influences seedling assemblages in these forests.     

Structure and succession of ant assemblages in a north European sand dune area

Ant assemblages of a successional dune area (Tvärminne, south Finland) were analysed at three levels: the distribution of species among habitats, the distribution of colonies within habitats and the spatio-temporal distribution of individuals. The distribution of ant species among habitat patches representing different stages of succession is correlated with the composition of the epigeic fauna, the number and condition of dead twigs on the ground and the vegetation architecture. The composition of ant assemblages seems relatively independent of the plant species composition, and there are uncoordinated successional steps between the vegetation and ant communities.
In the early successional stages interference competition is weak and insignificant, as indicated by the random spatial arrangement of colonies, the absence of postcompetitive niche segregation and the low encounter rates of ant workers on the ground and at baits. In the aggressive behavioural hierarchy, Formica cinerea is a submissive species as compared with either Formica sanguinea or Lasius alienus.     

Succession of Exotic and Native Species Assemblages within Restored Floodplain Forests: A Test of the Parallel Dynamics Hypothesis

Exotic plants pose a threat to restoration success in post‐agricultural bottomlands, but little information exists on their dynamics during succession of actively restored sites. We hypothesized that exotic assemblages would establish during succession and that their compositional trends during succession time would mirror those published for native species in other systems, with an early peak in herbaceous richness followed by a decline as woody species establish. In the summer of 2008, we sampled 16 sites across an 18‐year chronosequence of restored forests, with an additional four mature forest stands for comparison, within the Cypress Creek NWR, Illinois, U.S.A. We identified all vascular plant species and quantified canopy openness at three canopy strata, and soil texture and chemistry. Trends in exotic assemblages were significantly correlated with canopy openness at all strata. Richness of exotic and native herbaceous species was related to stand age and consistent with a Weibull regression model. Native and exotic herbaceous cover followed an exponential decay model. Woody native richness over time conformed to a logistic model; woody exotics exhibited no relationship with stand age and were present in sites of all ages. Our results indicate that although their rates of decline differ, herbaceous exotics and natives exhibit similar successional dynamics; therefore, herbaceous exotics may not pose a lasting threat to restoration success in reforested floodplains. Woody exotics can establish across a range of successional stages and persist under closed canopy conditions. Bottomland restorations are vulnerable to the invasion and expansion of exotic plant species even after canopy closure.     

Assigning plant communities to a successional phase: Time trends in abandoned limestone quarries

We investigated spontaneous vegetation succession and the relationship between time and vegetation patterns in several abandoned quarries of the Botticino extraction basin (Lombardy, Italy) and then assigned plant assemblages to a predetermined theoretical successional phase using an original procedure. To recognise and validate the gradient due to time, an ordination approach of vegetation plots linked to constant variables and time since last mining Canonical Correspondence Analysis was conducted first. Then, to determine the durations of the vegetation succession phases and trends between the colonisers and late successional species, we used an original six-step procedure based primarily on the regression curve of the percent relative abundance of life forms (RALFs) over time. The results demonstrated that time is the primary factor that significantly affects life form turnover during succession. Vegetation establishment and development in the “pioneer phase” (0–6 years) were affected by abiotic filters, which determined the dominance of a few ruderal and annual/alien species, mostly therophytes. The successive phases were characterised by an increasing presence of perennial species (mostly phanerophytes) with a consequent influence of biotic filters. The RALF procedure may be applied to other environments to investigate the time trends of plant communities during successions.     

Is microclimate-driven turnover of dung beetle assemblage structure in regenerating coastal vegetation a precursor to re-establishment of a forest fauna?

We questioned the capability of post-mining rehabilitation and successional changes in coastal vegetation to achieve restoration of dune forest, dung beetle assemblages in the Maputaland Centre of Endemism, South Africa. A repeat 2010 study of structural turnover between dung beetle assemblages across a 33 year successional sere of rehabilitating vegetation and old-growth forest (>73 years) produced comparable results to an earlier study across the 23 year chronosequence of 2000. Despite overlap, three structural patterns along the 33 year chronosequence were associated with specific stages of vegetation succession and their characteristic microclimates as in 2000. Although species biased to unshaded habitat dominated the earliest succession, there was rapid re-establishment of dominance by shade-associated forest species. In concert with progression from unshaded, post-mining vegetation to strongly shaded, early successional, Acacia shrub-woodland, there was an initial increase in similarity of the dung beetle fauna (species-poor, low abundance) to that in strongly-shaded forest (also species-poor, low abundance). However, in concert with decreasing shade cover in late successional woodland, the dung beetle fauna became species-rich with high abundance so that the early successional trajectory of increasing similarity to forest fauna either levelled off to a plateau (species in 2000; abundance in 2010) or declined (species in 2010, abundance in 2000). It remains to be seen if gaps forming in the oldest Acacia woodland permit forest tree saplings of the exposed understorey to recreate a forest canopy that would be tracked by dung beetles to re-establish a typically species-poor, deep shade, forest assemblage with low abundance.     

Expanded view of the local–regional richness relationship by incorporating functional richness and time: a large‐scale perspective

Aim We investigate the relationship between local and regional richness in marine fouling assemblages using an expanded and globally replicated approach by incorporating two dimensions of diversity (taxonomic and functional) and different successional stages. Location Global. Methods In eight different biogeographic regions (Australia, Brazil, Chile, England, Italy, Japan, Portugal and Sweden) 68 polyvinylchloride (PVC) panels (15 × 15 × 0.3 cm) were deployed for colonization. Communities colonizing panels were analysed by measuring percentage cover at each of four different successional ages: 2, 4, 6 and 8 months. Local richness was assessed as the average number of species and functional groups (FGs) per panel and regional richness was evaluated as the estimated (Jack2) asymptote of the sample‐accumulation curves for species and FG on experimental panels. Results We found that the shape of the relationship between local and regional richness depended on successional stage and the type of richness considered, i.e. taxonomic or functional richness. Hardly any relationship was detectable between local taxonomic richness and regional taxonomic richness at any successional stage. In contrast, the relation between local functional and regional functional richness shows a unimodal pattern of change during succession, passing through the stages ‘independent’, ‘unsaturated rising’, ‘saturated rising’ and once again ‘independent’. Main conclusions The relationship between local and regional richness, whether taxonomic or functional, frequently displays independence of the two scales, particularly in early and late phases of the successional process.     

Nestedness and successional trajectories of macroinvertebrate assemblages in man-made wetlands

Current successional models, primarily those based on floral succession, propose several distinct trajectories based on the integration of two key hypotheses from succession theory: convergence versus divergence in species composition among successional sites, and progression towards versus deviation from a desired reference state. We applied this framework to faunal succession, including differential colonization between active and passive dispersers, and the nested patterns generated as a consequence of this peculiarity. Nine man-made wetlands located in three different areas, from 0–3 years from wetland creation, were assessed. In addition, 91 wetlands distributed throughout the region were used as references for natural macroinvertebrate communities. We predicted the following: (1) highly nested structures in pioneering assemblages will decrease to lower mid-term values due to a shift from active pioneering taxa to passive disperser ones; (2) passive idiosyncratic taxa will elicit divergent successional trajectories among areas; (3) the divergent trajectories will provoke lower local and higher regional diversity values in the mid-term assemblages than in pioneer assemblages. Our results were largely congruent with hypotheses (1) and (2), diverging from the anticipated patterns only in the case of the temporary wetlands area. However, overall diversity trends based on hypothesis (3) did not follow the expected pattern. The divergent successional trajectories did not compensate for regional biodiversity losses that occurred as a consequence of pioneering colonizer decline over time. Consequently, we suggest reconsidering wetland construction for mitigation purposes within mid-term time frames (≤3 years). Wetlands may not offset, within this temporal scenario, regional biodiversity loss because the ecosystem may not support idiosyncratic taxa from natural wetlands.     

Secondary dune succession on Inhaca Island,Mozambique

Old field succession was studied on coastal dunes supporting tropical evergreen forest on Inhaca Island, Mozambique. Plots of 10×10 m were sited in three early successional stages and in relatively undisturbed forest. Woody species increased in number during succession; leptophylls were most frequent in younger vegetation, whereas microphylls and mesophylls were most frequent in forest. Grasses, shrubs and forbs dominated initially following abandonment, and shrubs persisted as dominants in the three early successional stages. The initial floristic composition model was generally supported by the pattern of species sequences, with many forest species entering early in the succession. Of the few species conforming to the relay floristic model, many were grasses and forbs of the forest understorey. Similarity between plots of equivalent vegetation age indicated that, at least in early succession, there was linearity in the successional pathway; there was no evidence for divergence or multiple pathways. In early succession, no accumulation was detected in either soil organic matter or extractable nutrients, thus providing little support for the facilitation model of succession. It is stressed that the findings are probably scale-dependent.     

Do lianas shape ant communities in an early successional tropical forest?

Almost half of lowland tropical forests are at various stages of regeneration following deforestation or fragmentation. Changes in tree communities along successional gradients have predictable bottom‐up effects on consumers. Liana (woody vine) assemblages also change with succession, but their effects on animal succession remain unexplored. Here we used a large‐scale liana removal experiment across a forest successional chronosequence (7–31 years) to determine the importance of lianas to ant community structure. We conducted 1,088 surveys of ants foraging on and living in trees using tree trunk baiting and hand‐collecting techniques at 34 paired forest plots, half of which had all lianas removed. Ant species composition, β‐diversity, and species richness were not affected by liana removal; however, ant species co‐occurrence (the coexistence of two or more species in a single tree) was more frequent in control plots, where lianas were present, versus removal plots. Forest stand age had a larger effect on ant community structure than the presence of lianas. Mean ant species richness in a forest plot increased by ca. 10% with increasing forest age across the 31‐year chronosequence. Ant surveys from forest >20 years old included more canopy specialists and fewer ground‐nesting ant species versus those from forests <20 years old. Consequently, lianas had a minimal effect on arboreal ant communities in this early successional forest, where rapidly changing tree community structure was more important to ant species richness and composition.     

The potential effects of energy related activities on the seasonal trajectories of epiphytic marine diatoms

Seasonal successional trajectories of transplanted and experimental diatom communities were studied during the summer of 1973. Manipulation of these diatom assemblages was accomplished through the development of an in situ experimental apparatus capable of incubating these organisms without doing violence to the community itself.In one set of experiments the effects of water quality were tested on the development of inocula from grossly similar but fairly distant locations. In another set the native inoculum was incubated in the continual presence of Fe, Cu, Cr, Pb, Zn and crude oil. Seasonal succession took place in all of the control and experimental communities. During the course of succession the trajectories of assemblages under some conditions converged while others diverged. Since the random fluctuations in the environment were constant for all assemblages, the abundances of individual species were due to niche packing and interspecific restraints on the biotic potential of selected diatom species as well as the changes in water quality. The most diverse community was an experimentally mixed one. The high diversity of this community was probably due to niche packing a phenomenon which restricted the realized niches of many species and hindered their blooming. Paradoxically twice as many species (40%) had their greatest niche breadth in the mixed community as did species in the transplanted (20%) or native controls (17%). Enrichment of the incubation medium with heavy metals and oil altered the community structure and diversity of most experimental vessels. Growth of some species was depressed while that of others was enhanced. The trajectories of the communities enriched with oil and Pb were quite similar throughout the summer. The Cu and Cr assemblages initially followed the trajectory of oil and Pb but later diverged. Greatest species diversity was consistantly found in the community incubated in the presence of Cu. The Fe enriched community generally diverged from all the others. Recurrent group analysis identified distinctive groups of species for each of the experimental assemblages as well as controls.The response of these diatom communities incubated under natural conditions were characteristic of resilient communities in which populations with different structures were quickly established.Supported by ERDA Contract E (11-1) 3254, Reference Number (COO) 3254-28. The authors would like to acknowledge Dr. Howard Rubin for his assistance in writing the many computer programs used in this investigation.This paper represents a revised expansion of a thesis project accepted by the CCNY Biology Faculty in partial fulfillment of the requirements of the M.A. degree in September 1976.     

Effects of disturbance intensity and frequency on early old‐field succession

Abstract. Early old‐field succession provides a model system for examining vegetation response to disturbance frequency and intensity within a manageable time scale. Disturbance frequency and intensity can interact with colonization and competition to influence relative abundance of earlier and later successional species and determine, respectively, how often and how far succession can be reset. We tested the joint effects of disturbance frequency and intensity on vegetation response (species richness, abundance, canopy structure) during the first six years of succession by clipping the dominant species (D) or all species (T) in spring and fall of each year (S), once per year in summer (Y1), each two years in summer (Y2), or each four years in summer (Y4). Vegetation response reflected disturbance effects on expansion of a later monospecific dominant perennial herb, Solidago altissima, and persistence of the early, richer flora of annuals. A more abundant and taller top Solidago canopy developed on plots clipped each 2 yr or less frequently. Plots clipped yearly or seasonally were richer, but had less abundant, shorter, and differently stratified canopy. Disturbance mediated the relative abundance of early and later successional species; however, frequency and intensity effects were not completely congruent. Persistence of a richer early successional flora increased through the most frequent disturbance (S), and was magnified by disturbance intensity. Disturbance as extreme as clipping all vegetation twice yearly did not cause a drop in species richness, but maintained the early successional community over the first six years of succession. We conclude that clipping disturbance influenced the rate of succession, but the early community could rebound through the range of disturbance frequency and intensity tested.     

Rate of succession in restored wetlands and the role of site context

Question: Are changes in plant species composition, functional group composition and rates of species turnover consistent among early successional wetlands, and what is the role of landscape context in determining the rate of succession? Location: Twenty‐four restored wetlands in Illinois, USA. Methods: We use 4 years of vegetation sampling data from each site to describe successional trends and rates of species turnover in wetlands. We quantify: (1) the rate at which composition changes from early‐successional to late‐successional species and functional groups, as indicated by site movement in ordination space over time, and (2) the rate of change in the colonization and local extinction of individual species. We correlate the pace of succession to site area, isolation and surrounding land cover. Results: Some commonalities in successional trends were evident among sites. Annual species were replaced by clonal perennials, and colonization rates declined over time. However, differences among sites outweighed site age in determining species composition, and the pace of succession was influenced by a site's landscape setting. Rates of species turnover were higher in smaller wetlands. In addition, wetlands in agricultural landscapes underwent succession more rapidly, as indicated by a rapid increase in dominance by late‐successional plants. Conclusions: Although the outcome of plant community succession in restored wetlands was somewhat predictable, species composition and the pace of succession varied among sites. The ability of restoration practitioners to accelerate succession through active manipulation may be contingent upon landscape context.     

Consequences of abandonment for a regional fen flora and mechanisms of successional change

Abstract. Until the 1960s, species-rich vegetation on minero-trophic peaty soüs (fen sites) were characteristic of the alluvial plains in Schleswig-Holstein (Northwest Germany). Today, many of these habitats undergo successional changes due to abandonment. Vegetation development after abandonment can be characterized as a sequence of different successional stages and described in terms of a successional model. Successional stage I includes grazed, mown and recently abandoned sites without dominants. Stages II and III are characterized by the dominance of highly competitive herbaceous species whüe stage IV consists of woody vegetation. Ca. 3000 phytosociological relevés were assigned to the respective successional stages. Mean cover values were calculated for 250 species of the regional fen flora and assigned to successional categories according to their changes in cover in the successional series. According to our results 141 species decrease during succession, while 100 species were restricted to early successional stages and 85 species increased. Abandonment of all fen sites in Schleswig-Holstein will probably lead to the regional loss of 23 species of the fen flora. To identify mechanisms underlying successional change, the successional categories were correlated with life history traits and ecological requirements of the species. Results indicate that both light competition and limitation of sexual reproduction of small-seeded species might play a major role in the decrease and extinction of species during succession. Finally, conservation strategies for endangered species in a cultural landscape are discussed.     

Can Establishment Characteristics Explain the Poor Colonization Success of Late Successional Grassland Species on Ex‐Arable Land?

Abstract Many grassland restoration projects on former arable land face problems because early successional grassland species establish vigorously and persistently but late successional grassland species fail to establish. Differences in establishment characteristics of early and late successional species might provide an explanation for the failure of many late successional species to colonize grasslands on ex‐arable land. I examined whether early and late successional species had different establishment rates in the initial years of a grassland succession, whether a specific establishment stage (seedling emergence, mortality or growth) could be identified as the key process controlling establishment, and what management would enhance the establishment of late successional grassland species. Seeds of three early and three late successional species were sown separately in ex‐arable plots with bare soil, 1‐year‐old vegetation, and 2‐year‐old vegetation. Emergence, mortality, and seedling growth were monitored for 1 year. Early successional species established successfully in the bare soil plots but failed to establish in plots with 1‐ and 2‐year‐old vegetation. Late successional species showed either lower establishment rates in the younger succession stages or decreased establishment with succession that nevertheless resulted in significant establishment in the oldest plots. Seedling emergence proved to be the key factor determining the establishment pattern of early and late successional species. In absolute numbers, emergence of late successional species was, however, similar or higher than that of early successional species, even in the earliest succession stage. The poor establishment of late successional species on former arable land could therefore not be explained solely by differences in establishment characteristics between early and late successional grassland species. Competitive processes between early and late successional species later in the life cycle probably play an important role. The results do point out that establishment of late successional species can be promoted by creating vegetative cover from the start of the restoration effort.     

Coastal Dune Forest Development and the Regeneration of Millipede Communities

The rehabilitation of disturbed ecosystems through ecological succession should lead to the recovery of indigenous biological assemblages typical of a region. However, rehabilitation may give rise to unusual successional pathways and lead to atypical assemblages. We compared millipede assemblages along a chronosequence of habitats developing in response to a post‐mining coastal dune forest rehabilitation program with those developing spontaneously in the same area. Our comparison suggests that active rehabilitation mimics and even surpasses spontaneous successional development. On both chronosequences, the total number of species, as well as the mean density, diversity, and species richness increased, and dominance decreased, with habitat regeneration age. Moreover, the similarity of millipede assemblages on the two chronosequences to those on three sets of reference sites (mature forests) increased with regeneration age, but this recovery of community composition occurred faster on the rehabilitating chronosequence than on the spontaneously regenerating chronosequence. This suggests that successional processes are leading to a recovery of the predisturbed state, but factors like protection from further disturbances, which occur on the spontaneously regenerating chronosequence, is probably important to ensure success. The distance between a regenerating site and a colonization source area apparently affects the direction of community recovery—assemblages on the rehabilitating chronosequence converged faster onto assemblages on closer reference sites than onto those on reference sites farther away.     

Early succession of butterfly and plant communities on set-aside fields

 Hypotheses on secondary succession of butterfly and plant communities were tested using naturally developed 1- to 4-year-old set-aside fields (n = 16), sown fields (n = 8) and old meadows (n = 4) in 1992 in South Germany. Pioneer successional fields (1st and 2nd year of succession, dominated by annuals) and early successional fields (3rd and 4th year of succession where perennials, especially grasses became dominant) had fewer plant species than mid-successional fields (old meadows). In contrast to established hypotheses, mean number of plant species decreased from 1- to 4-year-old set-aside fields. Species richness of butterfly communities did not change during the first four years of succession, but species composition changed greatly. Pioneer successional fields were characterized by (1) specialized butterflies depending on annual pioneer foodplants (e.g. Issoria lathonia), and (2) species preferring the pioneer successions despite their host plants being more abundant on early and mid-successional fields (e.g. Papilio machaon). The variability in butterfly species richness was best explained by flower abundance which was closely correlated with plant species richness. Species whose abundance was correlated with habitat connectivity were significantly smaller than species which correlated with flower abundance. Numbers of caterpillar species were correlated with numbers of adult butterfly species. Life-history features of butterflies changed significantly from pioneer to early and mid-successional fields. We found decreasing body size and migrational ability, decreasing numbers of species hibernating as imago, decreasing numbers of generations and increasing larval stage duration with age of succession, but, contrary to expectation, host plant specialization, numbers of egg-cluster laying species and egg diameter did not change with successional age. Received 18 September 1995 / Accepted: 17 July 1996     

Seasonal dynamics and composition of cladoceran and copepod assemblages in ponds of a Hungarian cutaway peatland

Seasonal dynamics of cladoceran and copepod zooplankton were studied over a one‐year period in five permanent ponds of a cutaway peatland, situated in the Danube−Tisza Interfluve, Central Hungary. 17 cladoceran, 11 cyclopoid copepod and 6 harpacticoid copepod species were identified and most of them were typical of small lowland ponds. Nevertheless, some taxa like Cyclops insignis, Ceriodaphnia setosa and Macrocyclops distinctus are considered to be rare in Hungary. The microcrustacean assemblages exhibited apparent seasonal succession with typical seasonal species. There appears to be at least two main successional patterns in the five ponds. After general cyclopoid copepod dominance in winter (Cyclops strenuus and Cyclops insignis), at sites with higher proportion of open water and submerged vegetation, spring was characterized by the dominance of the large cladoceran Daphnia curvirostris, which declined during summer, when microcrustacean assemblages composed mainly of smaller, littoral cladocerans. At these sites, species richness and diversity reached their maximum in autumn. In the case of duckweed covered ponds, succession led to less diverse autumn assemblages with fewer species, dominated by Simocephalus exspinosus. Our results draw the attention to the importance of long‐term investigations and the often neglected winter sampling in the accurate evaluation of species richness (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)