Invertebrate Species Richness Research Articles

Taxon‐ and vector‐specific variation in species richness and abundance during the transport stage of biological invasions

Recent empirical and statistical evidence suggest that propagule pressure (i.e., number of individuals introduced per event, and the number and frequency of events) and colonization pressure (i.e., number of species released per event, and the number and frequency of events) are of vital importance to invasion success. To explore possible changes in propagule and colonization pressure during the transport stage of the invasion process, we examine abundance and species richness of virus‐like particles, bacteria, diatoms, dinoflagellates, and invertebrates transported in commercial ships—a leading vector for global spread of aquatic nonindigenous species. We collected 154 ballast water samples from ships that had performed or were exempt from ballast water exchange (BWE) prior to arrival at Pacific and Atlantic ports in Canada and Laurentian Great Lakes ports. We found that abundance and species richness varied across taxa and regions, with ships arriving to the Atlantic region carrying the highest abundance of taxa. The highest species richness of invertebrates and diatoms was recorded from ships arriving to the Pacific, whereas the richest communities of dinoflagellates occurred in the Atlantic region. We also found that BWE had no effect on abundance or species richness of most taxa (dinoflagellates, diatoms, bacteria, and virus‐like particles), whereas the effect on abundance of invertebrates was not clear. Finally, longer voyages resulted in lower abundance of all taxa except dinoflagellates, and lower species richness of diatoms. Paradoxically, the elevated abundance and species richness of dinoflagellates following BWE suggest that this group could have enhanced invasion potential when ships manage ballast water by exchange.

Patterns of biodiversity in the northwestern Italian Alps: a multi-taxa approach

The current loss of biodiversity requires long-term monitoring of the distribution of living organisms, particularly in regions, such as mountains, which are highly sensitive to climatic and environmental changes. In 2007, three alpine parks in N-W Italy started a field program to determine the factors which influence animal biodiversity and identify the most appropriate methods for periodically repeatable monitoring. Twelve altitudinal transects (from montane to alpine belt) were chosen, each composed of 4–7 sampling units, for a total of 69 monitored plots. In each station, five taxonomic groups (carabids, butterflies, spiders, staphylinids, birds) were systematically sampled and topographic, environmental and micro-climatic variables were recorded. The aim was to assess the distribution of different taxa along altitudinal gradients and the relative influence of geographical, environmental and climatic factors. The data showed that species richness and community composition of invertebrates are mainly determined by altitude and microclimatic conditions, whereas birds are more sensitive to habitat structure. For invertebrates, the strong relationship with temperature suggests their potential sensitivity to climatic variations. The analysis of biodiversity patterns across vegetation belts indicated that the alpine belt hosts few species but a high percentage of endemic and vulnerable species, highlighting its importance for conservation purposes. This work offers a representative sample of the northwestern Italian Alps and it is a first step of a monitoring effort that will be repeated every five years to highlight the response of alpine biodiversity to climate and land-use changes.

Biodiversity value of a geographically restricted soft coral species within a temperate estuary

ABSTRACT A threatened and uncommon soft coral species, Dendronephthya australis found in large abundance in Port Stephens, within the Port Stephens–Great Lakes Marine Park (PSGLMP), New South Wales, Australia, was hypothesized to be an important habitat for many marine fishes and invertebrates, but is currently under threat from boat anchors, fishing debris entanglement and sand inundation. Surveys were undertaken to assess the biodiversity associated with the soft coral habitat and its adjacent habitats (sponge, seagrass and unvegetated sand), using a combination of Underwater Visual Census (UVC) and Baited Remote Underwater Video System (BRUVS) techniques. In total, 77 fish species and 21 invertebrate species utilized the D. australis habitat, and multivariate fish assemblages associated with soft corals were significantly different to those associated with nearby sponges, seagrass and sand habitats. Species richness of fishes and invertebrates were significantly higher in soft coral and sponge habitats than seagrass. The D. australis habitat was found to be of high importance to juvenile snapper (Pagrus auratus: Sparidae), a species of recreational and commercial fishery importance, which occurred in highest abundance within D. australis, and were significantly smaller in size within the soft coral habitat than the adjacent sponge habitat. Evidently, this rare soft coral habitat supports an extensive marine assemblage, potentially providing a valuable source of food and shelter for fishes and invertebrates, and given it is threatened by human‐induced impacts, its protection should be a priority. Copyright © 2013 John Wiley & Sons, Ltd.

Enhancing beetle and spider communities in agricultural grasslands: The roles of seed addition and habitat management

Over three years, a replicated block design was used to investigate the effects of seed mixtures (grasses only; grasses and legumes; grasses, legumes and non-legume forbs), establishment techniques and long term management on beetle and spider communities of grassland swards. We quantified trophic links between phytophagous beetles and their host plants to assess the effect of these seed mixtures and management practices on food web structure. When managed under low intensity cutting regimes the most diverse seed mixture supported the highest biomass of beetles and spiders (c. 3.6kgha−1). Species richness of predatory beetles, phytophagous beetles and spiders were all increased by the sowing of legumes, although the addition of other forbs tended to result in at most modest further increases in invertebrate species richness. Analysis of food web structure suggests that the number of host plants utilised by beetles was greatest within the most diverse seed mixtures, but that this declined rapidly after the establishment year. We demonstrate that by sowing cheap and simple seed mixtures agriculturally improved grasslands can be managed to support increased diversity of spiders and beetles. While seed mixtures do not necessarily need to be of the highest diversity to achieve these benefits, the inclusion of legumes does appear to be crucial. The lower costs of intermediate diversity seed mixtures increase appeal to farmers, increasing the likely uptake of these methodologies in voluntary agri-environment schemes.

A new species of Eualus Thallwitz, 1892 and new record of Lebbeus antarcticus (Hale, 1941) (Crustacea: Decapoda: Caridea: Hippolytidae) from the Scotia Sea

Eleven specimens representing two hippolytid genera, EualusThallwitz, 1892 and LebbeusWhite, 1847 were sampled recently from the Scotia Sea (1517–2598m). Seven specimens are described and illustrated as Eualus amandae sp. nov., and its morphology is compared with those of previously described species. Four female specimens, morphologically consistent with Lebbeus antarcticus (Hale, 1941), are described and illustrated to supplement previous descriptions of this rarely collected bathyal species. Partial COI mtDNA and 18S rDNA sequences were generated for both species. Only limited DNA sequences are available for the Hippolytidae. COI phylogenetic trees are presented to illustrate that the new species is genetically distinct from all other species in GenBank. This record enhances existing knowledge of Antarctic invertebrate biodiversity and species richness of decapod crustaceans in the Southern Ocean.

THE IMPORTANCE OF YOUNG PLANTATION FOREST HABITAT AND FOREST ROAD-VERGES FOR GROUND-DWELLING SPIDER DIVERSITY

The potential of forest roads to enhance habitat diversity within plantation forests is an important conservation issue. If properly managed, these open spaces allow structurally diverse vegetation to grow at the road-verges, which may support greater invertebrate abundance and species richness, increasing overall forest biodiversity. We investigated spider diversity along road edges in young plantation forests in Ireland, the influence of road-verge vegetation and the consequences of doubling the standard forest road-width currently used in Ireland. Active ground-dwelling spiders were studied in eight Sitka spruce (Picea sitchensis) plantations using pitfall trapping one year after planting and five years after planting. A total of 16,741 spiders were caught, from which 141 species were identified from 14 families. Ten spider species of conservation importance were found in the road-verges demonstrating their importance as habitats for spider diversity. We found no difference in ground-dwelling spider diversity between road-verge and forest interior plots at this stage in the rotation. We found no advantage or disadvantage of increasing the road-width of forest roads for ground-dwelling spider diversity of young plantation forests. The findings of this study are discussed in the context of the management of plantation forests for biodiversity conservation and associated forest policy development.

The Importance of Young Plantation Forest Habitat and Forest Road-Verges for Ground-dwelling Spider Diversity

The potential of forest roads to enhance habitat diversity within plantation forests is an important conservation issue. If properly managed, these open spaces allow structurally diverse vegetation to grow at the road-verges, which may support greater invertebrate abundance and species richness, increasing overall forest biodiversity. We investigated spider diversity along road edges in young plantation forests in Ireland, the influence of road-verge vegetation and the consequences of doubling the standard forest road-width currently used in Ireland. Active ground-dwelling spiders were studied in eight Sitka spruce (Picea sitchensis) plantations using pitfall trapping one year after planting and five years after planting. A total of 16,741 spiders were caught, from which 141 species were identified from 14 families. Ten spider species of conservation importance were found in the road-verges demonstrating their importance as habitats for spider diversity. We found no difference in ground-dwelling spider diversity between road-verge and forest interior plots at this stage in the rotation. We found no advantage or disadvantage of increasing the road-width of forest roads for ground-dwelling spider diversity of young plantation forests. The findings of this study are discussed in the context of the management of plantation forests for biodiversity conservation and associated forest policy development.

The Overlooked Biodiversity of Flower-Visiting Invertebrates

Estimates suggest that perhaps 40% of all invertebrate species are found in tropical rainforest canopies. Extrapolations of total diversity and food web analyses have been based almost exclusively on species inhabiting the foliage, under the assumption that foliage samples are representative of the entire canopy. We examined the validity of this assumption by comparing the density of invertebrates and the species richness of beetles across three canopy microhabitats (mature leaves, new leaves and flowers) on a one hectare plot in an Australian tropical rainforest. Specifically, we tested two hypotheses: 1) canopy invertebrate density and species richness are directly proportional to the amount of resource available; and 2) canopy microhabitats represent discrete resources that are utilised by their own specialised invertebrate communities. We show that flowers in the canopy support invertebrate densities that are ten to ten thousand times greater than on the nearby foliage when expressed on a per-unit resource biomass basis. Furthermore, species-level analyses of the beetle fauna revealed that flowers support a unique and remarkably rich fauna compared to foliage, with very little species overlap between microhabitats. We reject the hypothesis that the insect fauna on mature foliage is representative of the greater canopy community even though mature foliage comprises a very large proportion of canopy plant biomass. Although the significance of the evolutionary relationship between flowers and insects is well known with respect to plant reproduction, less is known about the importance of flowers as resources for tropical insects. Consequently, we suggest that this constitutes a more important piece of the ‘diversity jigsaw puzzle’ than has been previously recognised and could alter our understanding of the evolution of plant-herbivore interactions and food web dynamics, and provide a better foundation for accurately estimating global species richness.

Habitat associations of invertebrates in reedbeds, with implications for management

ABSTRACT Reedbeds in Europe and Asia have undergone substantial fragmentation and habitat degradation. Conservation action for reedbeds in the UK has focused on restoration and management. At present there is little evidence of how reedbed invertebrates respond to such changes. This study sampled Diptera and moths in three English reedbed nature reserves using pan traps and light traps. The aim was to elucidate habitat attributes that support a reedbed invertebrate fauna of conservation value. Habitat variables were tested for their relationship with (a) number of reedbed specialist Diptera and moths, (b) conservation importance of the invertebrates sampled, and (c) species richness of the invertebrates sampled. The fauna of old and recently created or restored reedbed was compared. Reedbed specialist Diptera and moths and species with a conservation status tended to be trapped more at points with lower standing water levels. Points with deeper litter also tended to trap more reedbed specialist Diptera and moths. Greater total numbers of moth species were trapped at points with partial flooding of the litter layer compared with total flooding. Pan traps in all hydrological categories trapped species of conservation importance at Ham Wall and species unique to each hydrology category were found. Recently restored or created reedbed hosted similar numbers of reedbed specialist moths to adjacent older reedbed at both Hickling Broad and Stodmarsh. The number of reedbed specialist Diptera species was comparable between restored and older reed at Hickling Broad. It is concluded that management aimed at maintaining a range of successional stages should maximize invertebrate conservation value and species richness. This involves keeping the ecosystem dynamic, maintaining the transitions between different habitats, and avoiding permanent long‐term flooding. The authors recommend phasing restoration spatially and temporally and taking into account the existing value of older reedbeds before any invasive restoration. Copyright © 2012 John Wiley & Sons, Ltd.

Coalescent Method in Conjunction with Niche Modeling Reveals Cryptic Diversity among Centipedes in the Western Ghats of South India

BackgroundThere has been growing interest in integrative taxonomy that uses data from multiple disciplines for species delimitation. Typically, in such studies, monophyly is taken as a proxy for taxonomic distinctiveness and these units are treated as potential species. However, monophyly could arise due to stochastic processes. Thus here, we have employed a recently developed tool based on coalescent approach to ascertain the taxonomic distinctiveness of various monophyletic units. Subsequently, the species status of these taxonomic units was further tested using corroborative evidence from morphology and ecology. This inter-disciplinary approach was implemented on endemic centipedes of the genus Digitipes (Attems 1930) from the Western Ghats (WG) biodiversity hotspot of India. The species of the genus Digitipes are morphologically conserved, despite their ancient late Cretaceous origin.Principal FindingsOur coalescent analysis based on mitochondrial dataset indicated the presence of nine putative species. The integrative approach, which includes nuclear, morphology, and climate datasets supported distinctiveness of eight putative species, of which three represent described species and five were new species. Among the five new species, three were morphologically cryptic species, emphasizing the effectiveness of this approach in discovering cryptic diversity in less explored areas of the tropics like the WG. In addition, species pairs showed variable divergence along the molecular, morphological and climate axes.ConclusionsA multidisciplinary approach illustrated here is successful in discovering cryptic diversity with an indication that the current estimates of invertebrate species richness for the WG might have been underestimated. Additionally, the importance of measuring multiple secondary properties of species while defining species boundaries was highlighted given variable divergence of each species pair across the disciplines.

Geographic location alters the diversity–disturbance response

Despite extensive research on the link between disturbance and diversity in ecology and several eloquent models to describe the relationship, a universally applicable model remains elusive. However, most investigations of the diversity–disturbance relationship have been limited in spatial coverage. Recent theoretical and conceptual advances in macroecology suggest that such spatially constrained studies may limit interpretation. To explore the effect of geographic location on the disturbance–diversity relationship, we examined invertebrate assemblages in streams of northern Spain and New Zealand (NZ) and in multiple regions within NZ. Habitat characteristics were similar across all sites and locations, except that undisturbed sites (springbrooks) differed from disturbed sites (rhithral streams) by having constant thermal and hydrologic regimes. The resource base and the density of invertebrates were greater in the more-stable habitats in all regions. However, patterns of invertebrate species richness differed markedly between locations in the Northern and Southern Hemispheres. Springbrooks in all regions within NZ had greater richness than rhithral streams. In contrast, springbrooks in Spain had considerably lower species richness than rhithral streams. Thus, low hydrological disturbance in Spain yielded low diversity, whereas in NZ it yielded high diversity. Amphipoda dominated the springbrook faunas in Spain, whereas insects dominated in NZ. Thus, differences in the diversity patterns between Spain and NZ are potentially related to phylogenetic differences or environmental constraints on life-history cues. A universal model to link disturbance and diversity is more likely to be successful if it incorporates life-history traits rather than morphological traits.

Spies of the ocean: improving our understanding of biodiversity and ecosystem functioning using fish as sampling tools

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 454:1-18 (2012) - DOI: https://doi.org/10.3354/meps09773 FEATURE ARTICLE Use of fishes as sampling tools for understanding biodiversity and ecosystem functioning in the ocean A. M. Cook*, A. Bundy Population Ecology Division, Department of Fisheries and Oceans, B.I.O., Dartmouth, Nova Scotia B2Y 4A2, Canada *Email: adam.cook@dfo-mpo.gc.ca Across the globe, regulatory bodies are moving towards an ecosystem-based approach to management (EAM) of oceans. As part of this directive, criteria have been outlined for defining ecologically and biologically significant areas and marine protected areas. One of the first steps in identifying either is the development of an inventory of species’ spatial distributions and the identification of habitats used by different life history stages of these species. Many of these data have been gleaned from research vessel trawl surveys that only sample a slice of the ecosystem. Here, for the first time, food habits data collected from a trawl survey were integrated with the original trawl data to improve estimates of species richness, distribution, and habitat associations with the objective of providing additional information for an EAM. The inclusion of stomach content data increased the number and size range of species observed: its greatest value was in describing invertebrate and small finfish species richness. We found differences in the spatial patterns and the influence of environmental factors on species richness between stomach and trawl samples. We conclude that the addition of stomach data can en rich the de finition process for spatial management tools, adding dimensions that would otherwise be missed. This has important implications for EAM since we may not be using all of the resources at our disposal. KEY WORDS: Ecosystem · Biodiversity · Species richness · Environmental factors · Marine · Survey Full text in pdf format Information about this Feature Article NextCite this article as: Cook AM, Bundy A (2012) Use of fishes as sampling tools for understanding biodiversity and ecosystem functioning in the ocean. Mar Ecol Prog Ser 454:1-18. https://doi.org/10.3354/meps09773 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 454. Online publication date: May 21, 2012 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2012 Inter-Research.

Does functional redundancy of communities provide insurance against human disturbances? An analysis using regional-scale stream invertebrate data

Human-induced reductions in species richness might alter the quality of ecosystem services when the remaining species are not able to substitute the functions provided by extirpated species. We examined how human disturbances (nutrient enrichment, land use intensification, instream habitat degradation and the presence of alien species) influence the species richness of stream invertebrates. Stream invertebrates (425 native species) were collected by kick and sweep sampling technique at 274 stream sites covering the entire area of Hungary. We measured the species richness, functional richness (i.e. number of unique functional roles provided by community members) and functional redundancy (i.e. the functional insurance of the community) using information on the feeding habits of each species. To remove the effect of natural variability, we tested the effect of stressors on the residuals of models relating species richness, functional richness and functional redundancy with natural environmental gradients. Our results showed that species richness was negatively influenced by instream habitat degradation and nutrient enrichment. Independent of the way of quantifying functional richness and functional redundancy, we found that functional richness is more sensitive to human impact than functional redundancy of stream invertebrates. The finding that a reduction of species richness is associated with a loss of unique functional roles (functional richness) is important for conservation issues, because the number of unique functional roles is usually regarded as driver of ecosystem functioning.

Collembola diversity in the critically endangered Cape Flats Sand Fynbos and adjacent pine plantations

Abstract The replacement of indigenous vegetation by commercial alien plantations can strongly affect invertebrate species richness and composition. This has been demonstrated for some invertebrate taxa in the Fynbos vegetation of the Western Cape, but the response of litter-dwelling Collembola has not been documented. Here we compared the richness and abundance of litter-dwelling Collembola assemblages in Pinus radiata plantations and in adjacent rehabilitated Cape Flats Sand Fynbos (CFSF) in the Tokai Forest Reserve, Western Cape, South Africa. A total of 48 Collembola morphospecies was identified, of which 14 species were recorded exclusively from the pine plantations, and six exclusively from the CFSF. Abundance and morphospecies richness was higher in the pine plantations than in the CFSF, with 34 morphospecies found in the CFSF, and 42 morphospecies in the pine plantations. Fourteen species were likely invasive taxa, of which eight were found in CFSF, and 13 in the pine plantations. Multivariate analyses indicated significant differences in the assemblages of the two habitat types based on abundance, but using presence–absence data only, no difference was found. Significant relationships were found between springtail richness and abundance and site humidity, which differed between the CFSF (drier) and pine plantation (moister), likely accounting for the differences in richness and abundance among habitat types.

Influence of habitat quality, landscape structure and food resources on breeding skylark (Alauda arvensis) territory distribution on restored landfill sites

The skylark (Alauda arvensis) lost half its number after it underwent a decade of rapid decline from the mid-1970s onwards and since then has continued to decline albeit at a reduced rate. Its listing as a UK Red-List and Biodiversity Action Plan (BAP) Priority Species has helped focus conservation action in an attempt to halt the decline and stabilise populations by restoring degraded habitats or by creating new habitats. Newly created grassland on restored landfill sites are semi-natural habitats that could potentially contribute to this process, however the extent to which these areas support breeding populations is unknown. Territory densities of breeding skylarks were studied on nine restored landfill sites in the East Midlands region of the UK during May to July 2008. The effects of restoration were investigated by examining how habitat quality, landscape factors and food resources determined territory densities. Mean vegetation height and size of sites were found to be significant predictors of the number of breeding skylarks at the local scale, whilst percentage of woodland, grassland and open habitat in the surrounding landscape had an influence at a larger scale. Mean larval and adult invertebrate abundance and species richness in skylark territories in restored landfill sites were found to be similar to that of reference sites of recognised nature conservation value. Restoration of landfill sites could be targeted toward species-specific goals since such sites could play a role in meeting targets for habitat and/or species restoration targets in the UK BAP.

Temporal dynamics of aquatic communities and implications for pond conservation

Conservation through the protection of particular habitats is predicated on the assumption that the conservation value of those habitats is stable. We test this assumption for ponds by investigating temporal variation in macroinvertebrate and macrophyte communities over a 10-year period in northwest England. We surveyed 51 ponds in northern England in 1995/6 and again in 2006, identifying all macrophytes (167 species) and all macroinvertebrates (221 species, excluding Diptera) to species. The alpha-diversity, beta-diversity and conservation value of these ponds were compared between surveys. We find that invertebrate species richness increased from an average of 29.5 species to 39.8 species between surveys. Invertebrate gamma-diversity also increased between the two surveys from 181 species to 201 species. However, this increase in diversity was accompanied by a decrease in beta-diversity. Plant alpha-, beta- and gamma-diversity remained approximately constant between the two periods. However, increased proportions of grass species and a complete loss of charophytes suggests that the communities are undergoing succession. Conservation value was not correlated between sampling periods in either plants or invertebrates. This was confirmed by comparing ponds that had been disturbed with those that had no history of disturbance to demonstrate that levels of correlation between surveys were approximately equal in each group of ponds. This study has three important conservation implications: (i) a pond with high diversity or high conservation value may not remain that way and so it is unwise to base pond conservation measures upon protecting currently-speciose habitats; (ii) maximising pond gamma-diversity requires a combination of late and early succession ponds, especially for invertebrates; and (iii) invertebrate and plant communities in ponds may require different management strategies if succession occurs at varying rates in the two groups.

A field experiment links forest structure and biodiversity: epiphytes enhance canopy invertebrates in Chilean forests

Epiphytes represent a conspicuous component of the canopy of old‐growth forests, reaching biomass values of up to 44 t/ha. Forest epiphytes host a rich invertebrate community; however, the contribution of epiphytes to the richness and abundance of canopy invertebrates is still quite unknown, and has not been experimentally assessed in old‐growth forests. We studied the contribution of epiphyte loads to invertebrate species composition and abundance in the crown of large old individual trees of Eucryphia cordifolia (Cunoniaceae) in old‐growth forests from southern Chile. We accessed the canopy using arborist techniques and contrasted the invertebrate species richness and biomass inhabiting four large canopy trees (25–30 m high, 1.2 m DBH), two of them with intact epiphytes and two trees from which epiphytes were manually removed. For over a year (April, 2006 to May, 2007) we made monthly collections of invertebrates from each tree's crown using flight‐interception and eclector traps (the latter designed to capture walking invertebrates from trunks and limbs). Once every season we collected samples of epiphytes and their soil to quantify invertebrates using Berlese funnels. We found significantly greater invertebrate species richness and abundance in the control trees' crowns (with epiphytes) compared to the trees from which epiphytes were removed. Predators (such as spiders and centipedes) were disproportionately more abundant on trees with epiphytes, and an entire functional group (detritivores), associated with arboreal soils under the epiphytes, was absent in the trees from which epiphytes were removed. Invertebrate abundances were lower in winter and higher in summer for trees with epiphytes, while for trees without epiphytes invertebrate numbers fluctuated markedly, but with no seasonal pattern. We show that large old trees are an important structural component in forests, supporting additional structure represented by the epiphyte load, which, in turn, sustains a rich community of invertebrates with functional groups not otherwise present in the forest canopy. Our findings strongly recommend that forest managers retain large old trees with their epiphytes in order to sustain biodiversity and important ecosystem processes.

Does delaying the first mowing date benefit biodiversity in meadowland?

Background: Meadows are regularly mown in order to provide fodder or litter for livestock and to prevent vegetation succession. However, the time of year at which meadows should be first mown in order to maximize biological diversity remains controversial and may vary with respect to context and focal taxa. We carried out a systematic review and meta-analysis on the effects of delaying the first mowing date upon plants and invertebrates in European meadowlands. Methods: Following a CEE protocol, ISI Web of Science, Science Direct, JSTOR, Google and Google Scholar were searched. We recorded all studies that compared the species richness of plants, or the species richness or abundance of invertebrates, between grassland plots mown at a postponed date (treatment) vs plots mown earlier (control). In order to be included in the meta-analysis, compared plots had to be similar in all management respects, except the date of the first cut that was (mostly experimentally) manipulated. They were also to be located in the same meadow type. Meta-analyses applying Hedges’d statistic were performed. Results: Plant species richness responded differently to the date to which mowing was postponed. Delaying mowing from spring to summer had a positive effect, while delaying either from spring to fall, or from early summer to later in the season had a negative effect. Invertebrates were expected to show a strong response to delayed mowing due to their dependence on sward structure, but only species richness showed a clearly significant positive response. Invertebrate abundance was positively influenced in only a few studies. Conclusions: The present meta-analysis shows that in general delaying the first mowing date in European meadowlands has either positive or neutral effects on plant and invertebrate biodiversity (except for plant species richness when delaying from spring to fall or from early summer to later). Overall, there was also strong between-study heterogeneity, pointing to other major confounding factors, the elucidation of which requires further field experiments with both larger sample sizes and a distinction between taxon-specific and meadow-type-specific responses.

Soil Properties and Species Richness of Invertebrates on Afforested Sites after Brown Coal Mining

Variation in soil properties may influence diversity of invertebrate communities, a crucial component of every ecosystem, and their impact should be considered also in restoration management. Although most spoil heaps have been reclaimed after brown coal mining, some post‐mining sites are left to natural succession. Little is known, however, about the effects of these two fundamentally different approaches on diversity of invertebrates inhabiting these stands. While controlling for habitat characteristics, we analyzed the effects of soil properties on species richness of seven invertebrate groups representing various trophic levels and diverse spatial niches at afforested spoil heaps and adjacent pits managed under these two basic restoration approaches in the North Bohemia Brown Coal Basin (Czech Republic, central Europe). Forty‐seven percentage of 140 invertebrate species occurred on both reclamations and successions, but many were found exclusively on successions (37%) or reclamations (16%). The species richness of various groups was affected by different soil properties either independently of other variables or in interaction with microclimatic conditions or management history. These results imply a need for diverse management approaches in post‐mining areas to support the diversity of invertebrate communities. Technical reclamations with artificial plantations and spontaneous forest development on bare substrate (thus creating mosaics of open patches and afforested stands with different soil deposit materials) were found to be reasonable alternatives to support invertebrate richness on post‐mining forested stands. We conclude that these two approaches should properly be combined in practice.

Non‐local genotypes of a resident grass species reduce invertebrate species richness

Abstract.1. Effects of the genotypic identity of a plant can extend beyond the individual phenotype to the community. Because plant material is moved around at an increasing rate, introductions of non‐local plant genotypes that are difficult to distinguish from local ones are probably common. Even though such introductions can cause cryptic invasions, their effects on local communities remain largely unexplored.2. Ammophila arenaria is transported and planted throughout the world for dune stabilisation. We used this grass to address the impact of the introduction of non‐local genotypes on the diversity of the local invertebrate community. We installed plants from the local population and five introduced populations from regions throughout the natural range in a common environment and identified all naturally colonising aboveground invertebrates.3. The diversity of the entire invertebrate community, as well as that of herbivores, decreased with increasing geographical distance of the plants’ location of origin. Differences between plant populations in predator and detritivore diversity were less consistent with this pattern. Invertebrate species turnover was not related to genetic distance between populations.4. Our study demonstrates that introduction of non‐local genotypes of a resident plant species can negatively affect the invertebrate community. This confirms the idea that caution should be exerted when selecting plant material for restoration or sand stabilisation purposes. Hitherto, explanations for the invasiveness of A. arenaria in other continents have been sought in its release from belowground pathogens. Our observation of lower shoot herbivore diversity on non‐local plants, however, may indicate a role for release from aboveground enemies.