Efficiency of buffer zones around ponds to conserve odonates and songbirds in mined peat bogs

Patch isolation resulting from habitat loss and fragmentation generally has detrimental effects on associated species. Peatlands may be especially sensitive to such effects because peat mining results in drastic changes in the hydrology of natural remnants. This study aimed to assess the efficiency of conservation zones surrounding ponds in mined bogs for two taxa: songbirds and odonates. We compared songbird distribution and odonate assemblages between ponds isolated by peat mining (n=6–12) and control ponds (n=11–13) located in natural bogs. Birds did not show major responses to pond isolation, whether in terms of their relative abundance or reproductive activity. However, longer‐term data would be required to confirm this trend. In contrast, odonate abundance, as estimated from exuviae, was higher in natural ponds than in isolated ones. Some taxa, especially bog specialists, were more sensitive than others. Hence, pond isolation by peat mining significantly altered the structure of odonate assemblages. Pond size also influenced odonate abundances and distribution. Effective conservation of bog ponds should account not only for variations in the response of different taxa, but also for pond structural diversity, which influence species response to isolation.     

Diversity and morphological disparity of desmid assemblages in Central European peatlands

Morphological disparity has increasingly been used as an alternative measure of biological diversity based on the shape features of organisms. In this study, we investigated the species diversity and morphological disparity of benthic Desmidiales in Central European peatland pools. The shape features of cells were determined using the 3-D elliptical Fourier analysis of their frontal and lateral views. The resulting morphospace was used to calculate the contributions of localities and species to the morphological variation. In addition, the disparity of samples and their average cell complexity (indicating intricacy of cell shapes) was evaluated. These data were related to species diversity data and to the abiotic factors. Species diversity was positively correlated with pH and conductivity. The low-pH localities generally supported a more variable species composition than did slightly acidic to neutral localities. Conversely, the total nitrogen concentrations of these areas negatively correlated with species diversity. Interestingly, partial morphological disparity (measuring the contribution of a sample to the overall morphological variation) did not correlate with species diversity. On the contrary, several mountain peat bog localities had high disparity values, irrespective of their rather low species diversity. In addition, several samples from minerotrophic fens with high diversity had average or low values of partial morphological disparity. These results indicate the relative importance of mountain peat bogs for the total morphological diversity of Desmidiales within the region that could not be ascertained solely from species diversity data. The inner morphological disparity of samples was highly correlated with their species diversity. Species of the genus Micrasterias, Hyalotheca dissiliens and Desmidium species had the highest partial morphological disparity, thus indicating their marginal position within the morphospace. Micrasterias and Euastrum species had the highest complexity values. The average cell complexity of individual samples did not correlate with their diversity or disparity; however, it was positively correlated with the levels of total nitrogen and phosphorus, and illustrates a pattern different from that arrived at by species diversity data. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Handling editor: J. Padisak     

Spatio-temporal nested patterns in macroinvertebrate assemblages across a pond network with a wide hydroperiod range

Nestedness has been widely used to measure the structure of biological communities and occurs when species-poor sites contain subsets of species-rich ones. Here, we examine nested patterns across the macroinvertebrate assemblages of 91 ponds in Doñana National Park, Spain, and explore temporal variation of nestedness and species richness in 19 temporary ponds over 2 years with differing rainfall. Macroinvertebrate assemblages were significantly nested; both pond spatial arrangement and environmental variation being important in driving nested patterns. Despite the nested structure observed, a number of taxa and ponds deviate from this pattern (termed idiosyncratic), by occurring more frequently than expected in species-poor sites, or having assemblages dominated by species largely absent from species-rich sites. Aquatic adults of winged insects, capable of dispersal, were more highly nested than non-dispersing taxa and life-history stages. Idiosyncratic taxa were found in ponds spanning a wide range of hydroperiods, although nestedness was higher in more permanent waterbodies. Monthly sampling demonstrated a gradual increase of species richness and nestedness from pond filling to April–May, when the most temporary ponds started to dry. Although the degree of nestedness of individual pond assemblages varied from month to month, the overall degree of nestedness in the two study years was practically identical despite marked differences in hydroperiod. Our results suggest that differential colonization and environmental variation are key processes driving the nested structure of Doñana ponds, that macroinvertebrate assemblages change in a predictable manner each year in response to cycles of pond wetting and drying, and that connectivity and environmental variability maintain biodiversity in pond networks.     

Succession changes in diversity and assemblages composition of planthoppers and leafhoppers in natural ancient peat bogs in Belarus

Succession has a strong influence on species diversity and composition of terrestrial ecosystems. Peat bogs are among them. They have a large area in Belarus compared to other Central European countries. While in several studies have analyzed the effects of succession on vegetation in peat bog ecosystems, the response of peatland insects to succession has not been investigated yet. To address this issue were sampled Auchenorrhyncha abundance and environmental parameters on the ancient and one of the largest natural peat bog along a successional gradient from the margin to the bog dome. The results provide evidence that succession of peat bogs has influence on planthoppers and leafhoppers abundance, diversity and species composition. Along the successional gradient from younger towards older successional stages an increase abundance of specialized peat bog species, chamebionts, oligophagous and monophagous was observed. On the contrary, the younger stages of natural peat bog succession offer favorable conditions to eurytopic, polyphagous and chortobiont planthoppers and leafhoppers. The highest abundance and species richness of Auchenorrhyncha were in the lagg zone followed by early stages of natural peat bog succession. The highest diversity was in the middle stages of succession. A determinant of Auchenorrhyncha diversity was the cover of ericaceous dwarf shrubs. Linear models shrub cover and number of plants species had a positive effect on planthoppers and leafhoppers diversity and a negative effect on their abundance. Amount of ericaceous dwarf shrubs within the peat bog could be as a measure of heterogeneity.     

Morphological disparity in theropod jaws: comparing discrete characters and geometric morphometrics

Disparity, the diversity of form and function of organisms, can be assessed from cladistic or phenetic characters, and from discrete characters or continuous characters such as landmarks, outlines, or ratios. But do these different methods of assessing disparity provide comparable results? Here we provide evidence that all metrics correlate significantly with each other and capture similar patterns of morphological variation. We compare three methods of capturing morphological disparity (discrete characters, geometric morphometric outlines and geometric morphometric landmarks) in coelurosaurian dinosaurs. We standardize our study by focusing all our metrics on the mandible, so avoiding the risk of confounding disparity methods with anatomical coverage of the taxa. The correlation is strongest between the two geometric morphometric methods, and weaker between the morphometric methods and the discrete characters. By using phylogenetic simulations of discrete character and geometric morphometric data sets, we show that the strength of these correlations is significantly greater than expected from the evolution of random data under Brownian motion. All disparity metrics confirm that Maniraptoriformes had the highest disparity of all coelurosaurians, and omnivores and herbivores had higher disparity than carnivores.     

Diversity of desmids in three Thai peat swamps

Three peat swamps situated in the southern part of Thailand were investigated for their desmid flora in relation to a number of physical and chemical habitat parameters. Altogether, 99 species were encountered belonging to 22 genera. 30 species are new records for the Thai desmid flora. Laempagarung peat swamp showed the highest diversity (45 species), followed by Maikhao peat swamp (32 species) and Jud peat swamp (25 species). Despite its relatively low species richness, Jud swamp appeared to house a number of rare taxa, e.g., Micrasterias subdenticulata var. ornata, M. suboblonga var. tecta and M. tetraptera var. siamensis which can be considered Indo-Malaysian endemics. Differences in composition of the desmid flora between the three peat swamps are discussed in relation to environmental conditions. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

Effect of vegetation cover on the abundance and diversity of ladybirds (Coccinellidae) assemblages in a peat bog

Predaceous ladybirds are important natural enemies of many insect pests in terrestrial ecosystems such as peatlands, which are habitats for specialized cold-adapted plants. Ladybird assemblages of pristine peat bogs have not yet been assessed. In total, 15 ladybird species were recorded in peat bog in Belarus by using entomological sweep net. The present study shows low diversity, evenness and species richness of ladybird assemblages. However, a small number of species were present in high numbers. These are Coccinella hieroglyphica, Chilocorus bipustulatus, Coccinulla qutuordecimpustulata and Hippodamia tredecimpunctata. Ladybird abundance was positively related to shrub cover and number of vascular plant species, and negatively related to herb cover. In terms of ladybird diversity, only shrub cover had a significant negative effect.     

Do restoration measures rehabilitate fauna diversity in raised bogs? A comparative study on aquatic macroinvertebrates

To assess whether raised bog restorationmeasures contribute to the conservation andrestoration of the fauna diversity,macroinvertebrate species assemblages werecompared between water bodies created byrewetting measures and water bodies whichhave not been subject to restorationmeasures, but are remnants offormer peat cuttings and trenches used forbuckwheat culture in the past.The restoration sites were inhabited bycharacteristic raised bog species and rarespecies, but their numbers were higher atthe remnant sites not affected byrestoration management. A considerablenumber of characteristic and rare faunaspecies were only found at the remnantsites. The remnant sites includedconsiderably more variation inmacroinvertebrate species assemblages andhad a higher cumulative species richness.The number of characteristicmacroinvertebrate species was not clearlyrelated to the presence of a characteristicraised bog vegetation. In restoration sitesnumbers of rare and characteristic speciesper site tended to increase with the timeelapsed after rewetting. However,restoration measures will not automaticallyresult in restoration of a more or lesscomplete macroinvertebrate speciesspectrum, as restoration measures have sofar resulted in habitats for only a limitednumber of the characteristic species.When planning restoration measures, it isrecommended to protect the populations ofrare and characteristic species present inthe area, as these populations may becomethe sources for colonization of rewettedsites. Safeguarding habitat diversityduring the restoration process andrestoration of different elements of thehabitat diversity of complete raised bogsystems will result in the characteristicfauna diversity being conserved andrestored more successfully.     

Spatial Distribution of Algal Assemblages in a Temperate Lowland Peat Bog

Samples of phytobenthos were collected during three different seasons in 2005 along a linear transect of a lowland peat bog at various spatial scales (10 cm, 1 m, 10 m) to investigate the seasonal dynamics, diversity, and factors influencing the spatial patterns of microalgal communities. Non‐metric multidimensional scaling (NMDS), similarity percentage (SIMPER) analyses, ANOSIM, Mantel tests and diversity indices were used to analyze the data. Seasonal dynamics were exhibited by an increase in diversity, and a decrease in dominance from May to October, with significant differences in species composition. Mantel tests showed the significant influence of distance, microhabitat type, and conductivity on maintaining the similarity of species composition on scales of 1 m and 10 m. The small‐scale processes (colonization and niche differentiation), microhabitat type, geographic distance and conductivity were found to be the main factors influencing the distribution of algal assemblages. We conclude that these factors are related to winter disturbance, and the consequent colonization and subsequent niche differentiation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Wisconsin desmids. II. Aufwuchs and plankton communities of selected soft water lakes,hard water lakes and calcareous spring ponds

This report summarizes the results of summer studies of five soft water lakes, five hard water lakes and six calcareous spring ponds in Wisconsin with respect to the composition of the plankton and aufwuchs communities and the relative role of desmids in those communities. The results are compared with similar data obtained from selected acid bog lakes, alkaline bog lakes and closed bogs. Soft water lakes harbored a greater aufwuchs and plankton desmid diversity than hard water lakes or spring ponds; however, diversity in acid bog lakes was substantially greater than in any other lake type. Utricularia contained the greatest desmid diversity and population density in every lake where it occurred. Staurastrum was the most prevalent genus in the plankton and it was the only one recorded from hard water lakes and calcareous spring ponds. Desmid aufwuchs population densities were roughly comparable in hard water lakes, soft water lakes and acid bogs and the contribution of desmids to the total aufwuchs population was similar for the latter two lake types. However, the plankton of acid bog lakes generally harbored substantially greater desmid populations and these populations contributed much more to the total population than in any other lake type. Aufwuchs data are presented for several hosts and comparisons of population densities are given among hosts within a given lake and between the same host in different lakes of a given type. Data for other algal groups are also included.     

Assessing butterfly diversity and their response to habitat condition in pristine peat bogs in Belarus

Peat bogs are valuable ecosystems because they support regional and local hydrological conditions, and store carbon and other greenhouse gases. Nevertheless, their area in Europe is extremely reduced due to human activities. As a result, the number of studies on biodiversity and the environmental factors affecting the distribution of insects, including butterflies, in large intact peatlands is limited. Such studies provide an important baseline for the subsequent analysis of changes during climate warming and for the assessment of succession in degraded peatlands. The results of such research have shown how butterfly assemblages react to local peat bog habitat conditions and contribute new information on the relations of consumers and the very specific environment of peat bogs. The presented research targets the relationship between characteristics of butterfly assemblages and key environmental variables in intact peat bog habitats. A total of 1427 individuals belonging to 23 butterfly species were recorded. In this study, I found that butterfly abundance, diversity and species composition varied significantly among three main habitat types, namely lagg zones, pine bogs and open bogs, although these habitats did not differ in species richness. The highest abundance was in the pine bogs which are characterized by higher plant community structural complexity and, as a result, higher butterfly food resources. The results confirmed positive responses of species richness and abundance of butterflies to nectariferous flower cover. On the other hand, open, sunny, but windy sites on the peat bogs contribute to a decrease of abundance.     

Spatial distribution of insect indicator taxa as a basis for peat bog conservation planning

Peat bogs are highly endangered ecosystems worldwide. In the Western Balkans, they represent fragmented habitat patches, where insect diversity and implications for the habitat loss are poorly known. Carabid beetles and ants, widely used environmental indicators, were sampled by pitfall trapping in the largest and oldest Croatian peat bog and at its edges. We found that tyrphobiontic—bog specialist—species were absent in both taxonomic groups, which is likely due to biogeographical limitation for dispersal of these species into this region. With this study, tyrphophilous—typical of bogs—species have been recognised as environmental indicators in the Western Balkans peat bogs. Assemblages of both taxa were strongly affected by specific conditions in the peat bog – high soil moisture and Sphagnum moss dominance, showing that edges are more favourable habitats for both taxa. Overall, carabid beetle activity density was significantly higher at the edge than at the peat bog, while species richness increased for both taxa at the edge, but not significantly. Spatial distribution of tyrphophilous species differed between studied taxa, with ants being more abundant in the peat bog, and carabid beetles at the edge. Additionally, some stenotopic and globally endangered species preferred edges. Occurrence of tyrphophilous and globally endangered species highlights the great conservation value of peat bog habitats in the Western Balkans. However, successional changes in vegetation are changing hydrological conditions of the peat bog. Here we suggest active conservation measures to preserve these unique soil invertebrate zoocoenoses.     

Terrestrial isopod community as indicator of succession in a peat bog

Terrestrial isopods were studied in the Dubravica peat bog and surrounding forest in the northwestern Croatia. Sampling was conducted using pitfall traps over a two year period. Studied peat bog has a history of drastically decrease in area during the last five decades mainly due to the process of natural succession and changes in the water level. A total of 389 isopod individuals belonging to 8 species were captured. Species richness did not significantly differ between bog, edge and surrounding forest. High species richness at the bog is most likely the result of progressive vegetation succession, small size of the bog and interspecific relationships, such as predation. With spreading of Molinia grass on the peat bog, upper layers of Sphagnum mosses become less humid and probably more suitable for forest species that slowly colonise bog area. The highest diversity was found at the edge mainly due to the edge effect and seasonal immigration, but also possibly due to high abundance and predator pressure of the Myrmica ants and lycosid spiders at the bog site. The most abundant species were Trachelipus rathkii and Protracheoniscus politus, in the bog area and in the forest, respectively. Bog specific species were not recorded and the majority of the species collected belong to the group of tyrphoneutral species. However, Hyloniscus adonis could be considered as a tyrphoxenous species regarding its habitat preferences. Most of collected isopod species are widespread eurytopic species that usually inhabit various habitats and therefore indicate negative successive changes or degradation processes in the peat bog.     

Patterns of Assemblage Structure Indicate a Broader Conservation Potential of Focal Amphibians for Pond Management

Small freshwater ponds host diverse and vulnerable biotic assemblages but relatively few conspicuous, specially protected taxa. In Europe, the amphibians Triturus cristatus and Pelobates fuscus are among a few species whose populations have been successfully restored using pond restoration and management activities at the landscape scale. In this study, we explored whether the ponds constructed for those two target species have wider conservation significance, particularly for other species of conservation concern. We recorded the occurrence of amphibians and selected aquatic macro-invertebrates (dragonflies; damselflies; diving beetles; water scavenger beetles) in 66 ponds specially constructed for amphibians (up to 8 years post construction) and, for comparison, in 100 man-made ponds (created by local people for cattle or garden watering, peat excavation, etc.) and 65 natural ponds in Estonia. We analysed nestedness of the species assemblages and its dependence on the environment, and described the co-occurrence patterns between the target amphibians and other aquatic species. The assemblages in all ponds were significantly nested, but the environmental determinants of nestedness and co-occurrence of particular species differed among pond types. Constructed ponds were most species-rich irrespective of the presence of the target species; however, T. cristatus was frequent in those ponds and rare elsewhere, and it showed nested patterns in every type of pond. We thus conclude that pond construction for the protected amphibians can serve broader habitat conservation aims in the short term. However, the heterogeneity and inconsistent presence of species of conservation concern observed in other types of ponds implies that long-term perspectives on pond management require more explicit consideration of different habitat and biodiversity values. We also highlight nestedness analysis as a tool that can be used for the practical task of selecting focal species for habitat conservation.     

Projecting mechanics into morphospace: disparity in the feeding system of labrid fishes

In no group of organisms has the link between species richness, morphological disparity, disparity in mechanics and functional or ecological diversification been made explicit. As a step towards integrating these measures of diversity, we examine how the mechanics of the anterior-jaw four-bar linkages of 104 species of Great Barrier Reef (GBR) labrid fishes maps into a scale-independent morphospace. As predicted from theory, no relationship exists between overall size and the mechanics of velocity and force transmission in labrid anterior-jaw linkages. Nonetheless, mechanics associated with the anterior jaw appear to have constrained diversification of labrid anterior-jaw morphology. Furthermore, simulations depict a generally nonlinear relationship between the length of individual links and transmission of motion. In addition, no relationship was found between morphological disparity and mechanical disparity among the most species-rich labrid groups from the GBR. It is also established that regions of morphospace equivalent in morphological disparity differ over nearly an order of magnitude in mechanical disparity. These results illustrate that without an explicit interpretation of the consequences of per unit change in morphology, conclusions about diversification drawn only from morphological disparity may be misleading.     

Aquatic microinvertebrate abundance and species diversity in peat bogs of Tierra del Fuego (Argentina)

Peat bogs are regarded as extreme environments due to their low pH and low nutrient concentration, and thus hold a unique biota adapted to these particular conditions. The island of Tierra del Fuego encompasses the southernmost extensive peat bog area in the world, and is therefore particularly interesting from a biogeographical viewpoint. Within the same peat bog, different environment types can be identified: clear ponds, vegetated ponds and Sphagnum patches. In this study we compare the abundance, richness and species diversity of microinvertebrates (Copepoda, Cladocera and Rotifera) in these three types of environments from two peat bogs (Andorra and Rancho Hambre). Out of the 29 taxa recorded, 19 were common to both peat bogs, including four cladocerans endemic to Southern Patagonia and three rotifers endemic to Fuegian peat bogs. The rotifers were the dominant group in all environment types from Rancho Hambre, while in Andorra the Sphagnum moss was dominated by copepods, particularly harpacticoids. The results revealed that the environment type rather than peat bog was the key factor at explaining differences in species richness and diversity among microinvertebrate communities. This study highlights the importance of Sphagnum moss as a low diversity extreme environment which supports highly endemic species.     

Natural peat bog remnants promote distinct spider assemblages and habitat specific traits

Peat bogs are very sensitive and highly endangered ecosystems. They were once typical landscape elements in northern Germany, but today only a few remnants exist. On-going habitat degradation has alarming adverse effects on biodiversity, and, from a conservation viewpoint, it is imperative to evaluate the current ecological quality of the remaining peat bog remnants to assess the intensity of degradation and to suggest reasonable management strategies. In 2007, spiders were sampled in 23 study sites representing typical peat bog habitat types in the northern parts of Westphalia (NW Germany). In all, 214 species from 18,413 adult individuals have been collected. Multivariate analyses showed that different peat bog successional stages harbour distinct spider assemblages with succession being the main driver for species separation. Pardosa sphagnicola, Pirata piscatorius and P. uliginosus can be considered as flagship species for near-natural or natural peat bogs. Trait analyses showed that habitat specialisation for high moisture is negatively affected by succession. Peat bogs are now only small remnants, but, nevertheless, they have a high conservation value as they still harbour a distinct species assemblage and specialised species.     

Environmental factors explaining the vegetation patterns in a temperate peatland

Although ombrotrophic temperate peatlands are important ecosystems for maintaining biodiversity in eastern North America, the environmental factors influencing their flora are only partly understood. The relationships between plant species distribution and environmental factors were thus studied within the oldest temperate peatland of Québec. Plant assemblages were identified by cluster analysis while CCA was used to related vegetation gradients to environmental factors. Five assemblages were identified; three typical of open bog and two characterized by more minerotrophic vegetation. Thicker peat deposit was encounter underlying the bog assemblages while higher water table level and percentage of free surface water distinguished the minerotrophic assemblages. Overall, the floristic patterns observed were spatially structured along the margins and the expanse. The most important environmental factors explaining this spatial gradient were the percentage of free surface water and the highest water-table level. To cite this article: S. Pellerin et al., C. R. Biologies 332 (2009).     

Functional groups of phytoplankton shaping diversity of shallow lake ecosystems

Phytoplankton of eutrophic shallow lakes are frequently dominated by one species or species of the same functional group, resulting in species-pure algal assemblages. Knowledge of the structure of these assemblages is essential to understand their functioning; therefore, species and functional diversity were investigated in five sub-types of eutrophic shallow lake. Among the sub-types, astatic saline lakes and hypertrophic ponds had type-specific assemblages dominated by S_N and W0, W1 codons. The diversity of the phytoplankton in the sub-types was quite similar, except for the astatic saline lakes, which were characterised by lower values of both functional and species diversity. We found that both functional and species diversity were low when bloom-forming cyanobacteria (H1, S_N functional groups) became dominant. Dominance of other groups (J, Y, L_O and W1) did not coincide with decrease in species diversity. Analysis of the biovolume versus diversity relationships revealed that decrease in diversity might be expected at biovolume >20 mm³ l⁻¹ for shallow lakes.     

A novel,combined approach to assessing species delimitation and biogeography within the well-known desmid species <Emphasis Type="Italic">Micrasterias fimbriata</Emphasis> and <Emphasis Type="Italic">M. rotata</Emphasis> (Desmidiales,Steptophyta)

Morphological species of freshwater microalgae often have broad geographic distribution. However, traditional species concepts have been challenged by the results of molecular phylogenetic analyses that mostly indicate higher diversity than was previously recognized by purely morphological approaches. A degree of phenotypic differentiation or different geographic distribution of species defined by molecular data remains largely unknown. In this study, we analyzed a pair of well-known and widely distributed desmid species (Micrasterias fimbriata and M. rotata) and tested for their phylogenetic and morphological homogeneity as well as their geographic distribution. Geometric morphometric and morphological attributes of cells were used in combination with genetic analysis of the trnG ^ucc sequences of 30 strains isolated from a variety of European locations and obtained from culture collections. Micrasterias rotata proved to be phylogenetically homogenous across Europe while M. fimbriata turned out to be composed of two firmly delimited lineages, differing by molecular as well as by morphometric and morphological data. Published records of traditional M. fimbriata were also included in the classification discrimination analysis and were placed into the newly identified lineages upon comparison to the morphometric data collected from living material. Largely disparate geographic patterns were revealed within traditional M. fimbriata. One phylogenetic lineage is frequent in central and eastern Europe, but occurs also in the British Isles. A second lineage has been recorded in North America and in Western Europe, where its distribution is possibly limited to the west of the Rhine River. Interestingly, the morphometric analyses of the published records illustrated that the geographic differences have remained largely unchanged since the 1850s indicating a previously unknown distributional stability among microalgal species groups such as the desmids.