Ecological Tolerance Research Articles

The discovery of devil's gardens: an ant–plant mutualism in the cloud forests of the Eastern Amazon

Abstract:Devil's gardens are one of the most remarkable mutualistic associations between ants and plants. Myrmelachista ants eliminate all vegetation from around their host plants, resulting in wide forest clearings which have intrigued scientists from the start. Despite their noticeability, here we report the discovery of devil's gardens in remote highland cloud forests of the Eastern Amazon, more than 2000 km away from their nearest known analogues in Western Amazonia. We describe the ecological characteristics of these gardens and consider what factors could have produced the geographic isolation of Eastern Amazonian devil's gardens. Three hypotheses are investigated: (1) the host plant distribution restricts the distribution of the mutualism, (2) the ecological tolerances of Myrmelachista explain the isolation, and (3) the devil's gardens of the Eastern Amazon constitute relicts from ancient forest refugia. The distribution of the possible associated myrmecophytes and previously described ecological ranges of devil's gardens cannot explain their ecological restriction to cloud forests in Eastern Amazonia, but our discovery is consistent with the biogeographic refuge hypothesis (i.e. highlands along the Amazon Basin constitute refugia for humid forests that spread during the Cenozoic). Our finding opens exciting perspectives for comparative studies of the origin, ecology and evolutionary history of this ant–plant mutualism.

Transcriptomic differences between euryhaline and stenohaline malaria vector sibling species in response to salinity stress.

Evolution of osmoregulatory systems is a key factor in the transition of species between fresh- and saltwater habitats. Anopheles coluzzii and Anopheles merus are stenohaline and euryhaline malaria vector mosquitoes belonging to a larger group of sibling species, the Anopheles gambiae complex, which radiated in Africa within the last 2 million years. Comparative ecological genomics of these vector species can provide insight into the mechanisms that permitted the rapid radiation of this species complex into habitats of contrasting salinity. Here, we use RNA-Seq to investigate gene expression differences between An.coluzzii and An.merus after briefly exposing both young and old larval instars of each species to either saltwater (SW) or freshwater (FW). Our study aims to identify candidate genes and pathways responsible for the greater SW tolerance of An.merus. Our results are congruent with the ability of gene induction to mediate salinity tolerance, with both species showing increasing amounts of differential gene expression between SW and FW as salt concentrations increase. Besides ion transporters such as AgAE2 that may serve as effectors for osmoregulation, we also find mitogen-activated protein kinases that may serve in a phosphorylation signalling pathway responding to salinity, and report potential cross-talk between the mosquito immune response and osmoregulation. This study provides a key step towards applying the growing molecular knowledge of these malaria vectors to improve understanding of their ecological tolerances and habitat occupancy.

The evolution of a mining lake - From acidity to natural neutralization

Along the border of Poland and Germany (central Europe), many of the post-mining lakes have formed “an anthropogenic lake district”. This study presents the evolution of a mining lake ecosystem (TR-33) based on subfossil phyto- and zooplankton, isotopic data (δ13C, δ15N), elemental analyses of organic carbon and nitrogen (C/N ratio and TOC) and sedimentological analyses. Recently, lake TR-33 became completely neutralized from acidification and an increase in eutrophication began a few years ago. However, the lake has never been neutralized by humans; only natural processes have influenced the present water quality. From the beginning of the existence of the lake (1920s) to the present, we can distinguish four stages of lake development: 1) very shallow reservoir without typical lake sediments but with a sand layer containing fine lignite particles and very poor diatom and cladoceran communities; 2) very acidic, deeper water body with increasing frequencies of phyto- and zooplankton; 3) transitional period (rebuilding communities of diatoms and Cladocera), meaning a deep lake with benthic and planktonic fauna and flora with wide ecological tolerances; and 4) a shift to circumneutral conditions with an essential increase in planktonic taxa that prefer more fertile waters (eutrophication). In the case of lake TR-33, this process of natural neutralization lasted approximately 23years.

A Review of the Characteristics of Small-Leaved Lime (Tilia cordata Mill.) and Their Implications for Silviculture in a Changing Climate

Tilia cordata Mill. is a minor European broadleaved species with a wide but scattered distribution. Given its scarcity and low value in the wood market, it has received little attention from researchers and forest managers. This review summarizes the main aspects of T. cordata ecology and growth. Its main limiting factor is its need for warm summer temperatures to ensure successful seed production. It has a height growth pattern relatively similar to that of Acer pseudoplatanus L., with a slight delay in the early stages. Yield tables report great productivity, especially in eastern Europe. T. cordata used to be a major species in Europe, in contrast to its present distribution, but it is very likely to receive renewed interest in the future. Indeed, with the potential change of competition between species in some regions and the need for important diversification in others, T. cordata may play an important role in forest adaptation to climate change, especially owing to its wide ecological tolerance and its numerous ecosystem services. It is necessary to increase our knowledge about its regeneration and its responses to environmental and silvicultural factors, to establish clear management recommendations.

Chromosome numbers in three species groups of freshwater flatworms increase with increasing latitude.

Polyploidy in combination with parthenogenesis offers advantages for plasticity and the evolution of a broad ecological tolerance of species. Therefore, a positive correlation between the level of ploidy and increasing latitude as a surrogate for environmental harshness has been suggested. Such a positive correlation is well documented for plants, but examples for animals are still rare. Species of flatworms (Platyhelminthes) are widely distributed, show a remarkably wide range of chromosome numbers, and offer therefore good model systems to study the geographical distribution of chromosome numbers. We analyzed published data on counts of chromosome numbers and geographical information of three flatworm "species" (Phagocata vitta, Polycelis felina and Crenobia alpina) sampled across Europe (220 populations). We used the mean chromosome number across individuals of a population as a proxy for the level of ploidy within populations, and we tested for relationships of this variable with latitude, mode of reproduction (sexual, asexual or both) and environmental variables (annual mean temperature, mean diurnal temperature range, mean precipitation and net primary production). The mean chromosome numbers of all three species increased with latitude and decreased with mean annual temperature. For two species, chromosome number also decreased with mean precipitation and net primary production. Furthermore, high chromosome numbers within species were accompanied with a loss of sexual reproduction. The variation of chromosome numbers within individuals of two of the three species increased with latitude. Our results support the hypothesis that polyploid lineages are able to cope with harsh climatic conditions at high latitudes. Furthermore, we propose that asexual reproduction in populations with high levels of polyploidization stabilizes hybridization events. Chromosomal irregularities within individuals tend to become more frequent at the extreme environments of high latitudes, presumably because of mitotic errors and downsizing of the genome.

Heat shock improves stress tolerance and biocontrol performance of Rhodotorula mucilaginosa

Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeasts, is an eco-friendly management approach that has received considerable attention over the past three decades. A few yeast-based biocontrol products are either in advanced stages of development or commercially available. Ecological fitness, stress tolerance and biocontrol performance are essential attributes for yeasts used as biocontrol agents. In the present study, a mild heat shock (HS, 40°C for 30min) pretreatment of the biocontrol yeast, Rhodotorula mucilaginosa, increased its tolerance to subsequent high temperature (48°C), oxidative stress (70mM H2O2), salt stress (3M NaCl), and low pH (pH 4). Activation of the yeast antioxidant system by HS resulted in a lower accumulation of reactive oxygen species and less oxidative damage to proteins and lipids relative to control yeast cells when both were subjected to various abiotic stresses. Additionally, HS-treated yeast exhibited increased efficacy in controlling infection of apple fruit by Penicillium expansum, and a higher growth rate in apple wounds. These results suggest that stress adaptation is a viable approach for improving the efficacy of yeast biocontrol agents under the variable environmental conditions that exist in the postharvest environment of packing houses and storage facilities.

Temporal genetic dynamics among mosquitofish (Gambusia holbrooki) populations in invaded watersheds

The temporal components of genetic diversity and geographical structure of invasive mosquitofish populations are poorly known. Through the genetic monitoring of four consecutive cohorts of Gambusia holbrooki from three different river basins we aimed to determine temporal patterns of regional genetic variation and dispersal rates within invasive populations. Despite showing evidence of strong population size fluctuations, genetic diversity levels were maintained among local cohorts. We only detected temporal allele frequency changes associated with seasonal flooding that did not modify major trends on population structure among cohorts. Downstream gene flow coupled with increased connectivity at lowland locations to increase genetic diversity levels in these areas. A large proportion of local fish (up to 50 %) were dispersers, often originated from locations within the same river basin. High dispersal capability, ecological tolerance, and reproductive traits likely promote river colonization. Finally, our results also confirmed that human-assisted translocations promote within and among basin gene flow and maintained levels of genetic diversity, particularly in upstream locations.

Butterfly community shifts over two centuries.

Environmental changes strongly impact the distribution of species and subsequently the composition of species assemblages. Although most community ecology studies represent temporal snap shots, long-term observations are rather rare. However, only such time series allow the identification of species composition shifts over several decades or even centuries. We analyzed changes in the species composition of a southeastern German butterfly and burnet moth community over nearly 2 centuries (1840-2013). We classified all species observed over this period according to their ecological tolerance, thereby assessing their degree of habitat specialisation. This classification was based on traits of the butterfly and burnet moth species and on their larval host plants. We collected data on temperature and precipitation for our study area over the same period. The number of species declined substantially from 1840 (117 species) to 2013 (71 species). The proportion of habitat specialists decreased, and most of these are currently endangered. In contrast, the proportion of habitat generalists increased. Species with restricted dispersal behavior and species in need of areas poor in soil nutrients had severe losses. Furthermore, our data indicated a decrease in species composition similarity between different decades over time. These data on species composition changes and the general trends of modifications may reflect effects from climate change and atmospheric nitrogen loads, as indicated by the ecological characteristics of host plant species and local changes in habitat configuration with increasing fragmentation. Our observation of major declines over time of currently threatened and protected species shows the importance of efficient conservation strategies.

Methods of Analysis of Environmental Diversity of Plants

There are considered new approaches to the analysis of an ecological variety of plants with use of ecological scales. There are offered the quantitative methods of determination of ecological valency and tolerance of species of plants. There are estimated ecological positions of forest and meadow plants in different parts of areas in the Mari El Republic, the Mos- cow, Tver regions of Russia. The carried-out analysis of conditions of cenopopulations’ habitats (central processing unit) of plants of various vital forms showed that all of them borrow in different parts of areas of the territory with rather narrow ranges of the considered abiotic factors. It testifies to their fitness to cumulative influence of a certain set of climatic and soil factors of different regions. Determination of potential ecological valency and the characteristic of species on scales of factors gives the chance to solve a problem of a quantitative assessment of ecological tolerance of t species of various vital forms and strategy in relation to separate factors. The indicators of the potential and realized ecological valency and an index of tolerance offered by us can widely be applied to the characteristic of ecosystems in which cenopopulation of plants, for an assessment of ecological positions of types are presented. Use of this approach is also actually in compar- ative floristics and in the ecological analysis of the protected plants.

Flood risk management in Flanders: from flood risk objectives to appropriate measures through state assessment

In compliance with the EU Flood Directive to reduce flood risk, flood risk management objectives are indispensable for the delineation of necessary measures. In Flanders, flood risk management objectives are part of the environmental objectives which are judicially integrated by the Decree on Integrated Water Policy. Appropriate objectives were derived by supporting studies and extensive consultation on a local, regional and policy level. Under a general flood risk objective sub-objectives are formulated for different aspects: water management and safety, shipping, ecology, and water supply. By developing a risk matrix, it is possible to assess the current state of flood risk and to judge where action is needed to decrease the risk. Three different states of flood risk are distinguished: a) acceptable risk, where no action is needed, b) intermediate risk where the risk should be reduced by cost efficient actions, and c) unacceptable risk, where action is necessary. For each particular aspect, the severity of the consequences of flooding is assessed by quantifiable indicators, such as economic risk, people at risk and ecological flood tolerance. The framework also allows evaluating the effects of the implemented measures and the autonomous development such as climate change and land use change. This approach gives a quantifiable assessment of state, and enables a prioritization of flood risk measures for the reduction of flood risk in a cost efficient and sustainable way.

Evaluación del banco de semillas y su importancia en la rehabilitación de la vegetación de humedales del centro México

Los métodos de evaluación del banco de semillas tienen una e ciencia particular y cada uno aporta una imagen diferente de la vegetación de un área, no obstante, esta información puede ser muy útil en los programas de restauración de comunidades vegetales anegadas. El objetivo fue comparar cuantitativamente el banco de semilla de la Ciénega de Chignahuapan utilizando dos métodos e inferir si las comunidades vegetales podrían rehabilitarse a partir del mismo. En las zonas estacionalmente inundadas de la ciénega se recolectaron muestras de los 10 cm más superficiales de sedimento para evaluar el banco de semillas por el método de separación y el de germinación. Los métodos probados difirieron en la composición de especies y en la abundancia de las mismas. El método de separación de semillas predijo una riqueza, diversidad y densidad, significativamente mayor que el método de germinación. Este último mostró una similitud más alta con la vegetación establecida y predijo las especies que germinarán con mayor facilidad del banco. La baja similitud y la inexistencia de relación entre las especies de ambos métodos muestran que cada técnica tiene un poder predictivo diferente, por lo que su aplicación aislada debe evitarse. El banco de semillas de Chignahuapan tiene 60 especies y se caracteriza por la presencia de plantas con alta tolerancia ecológica, baja similitud con la vegetación establecida y la ausencia de acuáticas estrictas anteriormente registradas como elementos típicos de la región. Este banco de semillas puede usarse en futuros programas de restauración de la ciénega con la limitante de restituir principalmente, especies vegetales de estados sucesionales tempranos.

Biodiversity of Limestone Caves: Aggregations of Aerophytic Algae and Cyanobacteria in Relation to Site Factors

ABSTRACT The most numerous limestone caves are in the smallest national park in Poland (the Ojcow National Park). A total of 50 algal samples were collected from ten caves, each having different environmental factors such as light intensity, temperature and humidity. The morphological and ecological variability of cyanobacteria and algae were studied using fresh samples, cultures grown on agar plates, and documented with TEM, SEM and LM. Light microscopic observations showed that aerophytic cyanobacteria were the most important component of the cave′s photosynthetic microflora. Among cyanobacteria, the following genera were frequently encountered: Aphanocapsa, Chroococcus, Gloeocapsa, Leptolyngbya, and Synechocystis. Whereas the green algal genera, Apatococcus and Klebsormidium, often occurred with Chlorella, Muriella, Neocystis and the diatoms, Orthoseira and Pinnularia. Most of the algal species appeared to be cosmopolitan, ubiquitous, had simple nutrition requirements and wide ecological tolerance (the...

New insight into leaf drought tolerance

Drought-induced forest dieback appears to have increased in frequency over the last decade (Van Mantgem et al. 2009; Allen et al. 2010; Peng et al. 2011). These diebacks have occurred across a wide diversity of forest types, suggesting that no forest biome is invulnerable to climate change (Choat et al. 2012). However, drought-influenced mortality rates differ substantially between species growing at the same site (Breshears et al. 2005) and populations within the species’ distribution range (Benito-Garz on, Ruiz-Benito & Zavala 2013). These dieback episodes may therefore lead to major vegetation shifts, substantial decreases in carbon uptake by the ecosystem (Ciais et al. 2005), and interactions, with invading alien species, for example. We need to understand the mechanisms by which drought stress affects tree performance and causes tree dieback if we are to identify the forests most vulnerable to climate change and to predict important vegetation processes, such as changes in community composition caused by differential plant mortality among species. Many studies have tried to identify the traits associated with improved plant survival during periods of drought. Three main strategies have been identified: water stress tolerance, avoidance and escape (see Fig. 1). Escape is when plants are temporarily absent during the drought period, due to mechanisms such as the shedding of leaves, as in ephemerophytes that complete their life cycle very rapidly and enter a dormant state during the long dry period in deserts. Avoidance includes a variety of mechanisms delaying or preventing the negative impact of stress. For drought stress, this involves minimization of water loss in plants experiencing drought, for instance, through strong stomatal closure to prevent decreases in water potential and subsequent runaway embolism. Tolerance involves xylem vascular system and/or leaf cells resisting dehydration (in plants able to sustain very negative water potentials) through the construction of xylem conduits resistant to cavitation and the maintenance of cell turgor. New technologies developed over the last 15 years have made it possible to assess xylem resistance to cavitation in many species (Delzon et al. 2010; Cochard et al. 2013) and populations within species (Lamy et al. 2014). However, the broad characterization of turgor loss point has proved more of a challenge. In this issue of Functional Ecology, Mar echaux et al. 2015; report an investigation of the leaf water potential at turgor loss point (ptlp) for a broad range of tropical tree species (71 in total). They report significant differences in ptlp values between species and show that ptlp might be associated with ecological drought tolerance (species with high ptlp are more frequently distributed in the tropical forest studied). Species growing in drier biomes have also been shown to have more negative values of ptlp (Bartlett, Scoffoni & Sack 2012b). Mar echaux et al. 2015 also provide evidence for the absence of a link with leaf economic spectrum, particularly as concerns specific leaf area (SLA). Together with the lack of relationship between SLA and forest water availability, these results strongly suggest that the broad and untimely use of SLA to predict species drought tolerance and distribution is likely to yield misleading results. The inclusion of ptlp in process-based vegetation models could therefore improve the accuracy of predictions of climate change impacts on forest ecosystems. Future studies are nevertheless required to confirm the correlation between leaf water potential at turgor loss point and species habitat suitability over a broader range of soil water availability. In this study, Mar echaux et al. 2015; used a recently developed method based on the use of an osmometer to predict ptlp (Bartlett et al. 2012a). This method is based on the accurate prediction of ptlp by leaf osmotic water potential at full hydration, as experimentally determined for 30 species by Bartlett et al. (2012a). This is consistent with interspecific differences in ptlp being driven principally by osmotic rather than elastic adjustments (Lenz, Wright & Westoby 2006; Bartlett, Scoffoni & Sack 2012b). This technique is much faster than the commonly used pressure– volume curve approach, opening up new possibilities for studying leaf drought tolerance within (phenotypic plasticity and genetic differentiation) and between (at the community and biome levels) species. It is particularly useful for studies in tropical forests, in which most of the plant species present have long vessels, making it more difficult to measure xylem resistance to cavitation, and making it all the more necessary to identify traits useful for the assessment of drought tolerance. Many studies have shown that leaf water potential at turgor loss point (ptlp) plays a key role in maintaining gas exchanges and growth rate under moderate water stress (Brodribb et al. 2003; Mitchell et al. 2008), but the direct relationship between ptlp and drought-induced tree mortality has never been investigated. As in the xylem hydraulics community, which has used the xylem *Correspondence author. E-mail: sylvain.delzon@u-bordeaux.fr

The northern coast of the Ottnangian (middle Burdigalian, early Miocene) Molasse Sea in Germany: sediments, foraminiferal assemblages and biostratigraphy

This study provides new data on the litho- and biostratigraphy of the middle Burdigalian (Ottnangian) marine sediments at or close to the former northern coastline of the German Molasse Basin, based on cores from three boreholes (Burgau, Hamlar 2 and Lutzingen) and two outcrops (Haunsheim and Dattenhausen). Methods include quantitative analysis of benthic foraminiferal assemblages (90 samples), studies of planktonic foraminifers and ostracods and investigations of lithofacies. The data indicate that the transgressive–regressive marine sediments of the Upper Marine Molasse (OMM) at Burgau and Hamlar 2 can be subdivided into the well-known lower and middle Ottnangian sedimentation cycles, with the first cycle being represented by the “OMM-Basisschichten” and Kalkofen Formation and the second by the Baltringen and Steinhofe Formations. We show for the first time that also the northernmost marginal-marine OMM facies (Lutzingen, Haunsheim and Dattenhausen) can be correlated with the lower and middle Ottnangian sedimentation cycles. Consequently, our results do not support the presence of a previously suggested third sedimentation cycle within the OMM sediments. Our micropaleontological data reveal regionally diverse depositional environments, reflecting different water depths and co-varying environmental variables. Significant differences in abundance, diversity and species composition of the benthic foraminiferal assemblages demonstrate marginal-marine facies for Lutzingen, Haunsheim and Dattenhausen, nearshore facies for Hamlar 2 and shallow marine basin facies for Burgau. The characteristic lower Ottnangian benthic foraminiferal species exhibit restricted ecological tolerances. Hence, the absence or scarcity of these species in nearshore to marginal-marine deposits has no stratigraphic significance. The presence of two sedimentation cycles in the western German Molasse Basin alone may have resulted from the interplay of regional tectonics and basin development that have led to different rates of subsidence and sedimentation in the western and eastern sectors of the German Molasse Basin.

Functional responses of multitaxa communities to disturbance and stress gradients in a restored floodplain

Summary Trait‐based approaches can reveal the mechanisms through which disturbances or stress impact communities, allowing comparisons of the role of different mechanisms in shaping communities among taxonomic groups. Such information can lead to higher comparability, transferability and predictability of the outcome of restoration projects. However, multitaxa trait‐based approaches were rarely used in the context of ecosystem restoration. We investigated the responses to environmental gradients of seven taxa (vascular plants, staphylinid and carabid beetles, spiders, isopods, diplopods and earthworms) in a restored floodplain using a species traits approach. We assessed the impact of flood disturbances and soil hydric stress on the functional diversity (FD) and community‐weighted mean (CWM) response of traits for each taxon. Ordination of hydrological variables revealed two main gradients. The first was related to the spatiotemporal dynamics of flood disturbances and the second to the average changes in soil hydric conditions. The analysis of CWM revealed that larger, poorly mobile species with narrow ecological tolerances were filtered by regular floods and/or changes in soil hydric conditions. Functional diversity patterns differed between the two gradients: decreasing with increasing flood disturbance, but increasing along the soil hydric stress gradient. This suggests that the mechanisms shaping community composition differ between the two gradients with environmental filtering being dominant with increasing flood disturbances and competition decreasing with more soil hydric stress. Synthesis and applications. Our study shows that the impact of restored flood disturbances and soil hydric stress on plant and invertebrate functional diversity and community‐weighted mean can be positive, negative or more complex depending on the taxonomic group and environmental gradient considered. The patterns can to some extent be explained by the specific characteristics of each group. Larger, poorly mobile species with narrow ecological tolerances were particularly vulnerable to changes in disturbance and stress regime following floodplain restoration. These species may therefore be lost in the initial phases of restoration projects, but other more characteristic species of dynamic floodplains will be favoured. Understanding the consequences of these contrasted responses for biodiversity conservation and ecosystem functioning constitutes the next challenge for ecosystem restoration.

Expression patterns of five heat shock proteins in Sesamia inferens (Lepidoptera: Noctuidae) during heat stress

Heat shock proteins (HSPs) play important roles in the adaptation of organisms to environmental changes. In this study, we explore the role of HSPs during heat stress in Sesamia inferens (Walker) (Lepidoptera: Noctuidae), an important pest of rice. In order to understand the mechanistic basis of ecological adaptability and stress tolerance, we analyzed the expression profiles of genes encoding five S. inferens heat shock proteins (Sihsps) across temperature gradients by real-time quantitative PCR. Our results indicated that genes encoding ribosomal protein S13 (RPS13) and β-actin (ACTB) were the most stable reference genes under high temperature stress. The mRNA levels of Sihsp19.6, Sihsp20.6 and Sihsp83 were significantly up-regulated by heat stress; however, the expression of Sihsp21.4 and Sihsc70 did not vary significantly. The massive increase in the expression of Sihsp19.6 and Sihsp20.6 by thermal stress suggests a critical role in preventing cellular damage to S. inferens. Moreover, the threshold temperatures (39°C for Sihsp19.6, Sihsp20.6 and Sihsp83) may partly explain the more southern distribution of S. inferens. Our results also support the contention that the absence of introns may favor the expression of stress-responsive genes (e.g. Sihsp19.6, Sihsp20.6 and Sihsp83 in the present study).

Genetic and Physiological Diversity in the Diatom Nitzschia inconspicua.

Nitzschia inconspicua is an ecologically important diatom species, which is believed to have a widespread distribution and to be tolerant to salinity and to organic or nutrient pollution. However, its identification is not straightforward and there is no information on genetic and ecophysiological diversity within the species. We used morphological, molecular (rbcL and LSU D1-D3), ecophysiological and reproductive data to investigate whether N. inconspicua constitutes a single species with a broad ecological tolerance or two or more cryptic species with shared or different ecological preferences. Molecular genetic data for clones from upstream and deltaic sites in the Ebro River basin (Catalonia, Spain) revealed seven N. inconspicua rbcL + LSU genotypes grouped into three major clades. Two of the clades were related to other Nitzschia and Denticula species, making N. inconspicua paraphyletic and suggesting the need for taxonomic revision. Most clones were observed to be automictic, exhibiting paedogamy, and so the biological species concept cannot be used to establish species boundaries. Although there were morphological differences among clones, we found no consistent differences among genotypes belonging to different clades, which are definable only through sequence data. Nevertheless, separating the genotypes could be important for ecological purposes because two different ecophysiological responses were encountered among them.

English

The purpose of this paper was to provide a practical guide assisting field workers in identification and interpretation of frequently occurring bioerosional textures created in limestone by intertidal organisms along the coasts of Langkawi Islands, Malaysia. The discussion follows the textural succession from the supratidal down to the lower intertidal zone. Traces left by lichens, boring sponges, molluscs (littorinid snails, the chiton Acanthopleura, the bivalve Lithophaga) and the echinoid Echinometra are illustrated. Products of bioconstructing organisms, specifically oysters and barnacle are also described. Ecological tolerance of each group is given.

Pest species of Macrolepidoptera in the Game Reserve of Velyka Dobron’ (Transcarpathia, Ukraine)

The Game Reserve of Nagydobrony extends on a marginal area of a former peatland and is covered with extended hardwood gallery forests and oak-hornbeam forests and is surrounded by a mosaic-like agricultural landscape. Due to its richness of nature-like and semi-natural habitats it supports a diverse insect assemblage. By light and bait trapping 383 species of macro-moths were recorded from which larvae of 85 species are feeding either on forest trees and scrubs or on cultivated plants thus these can be considered as potential pest species. Thirteen species (mostly Geometridae and Erebidae: Lymantriinae) have a special significance for forestry due to defoliating activity in gradation periods. Considering the habitat connections, the composition of moth assemblage is dominated by generalist species with broad spectrum of ecological tolerance but the species connected with humid forested habitats are also richly represented. The bulk of species consists of widely distributed Euro-Siberian species, but also some Holo-Mediterranean species with more southern character and Mediterranean-Subtropical migrant species were registered. The bait trapping provided significant results on the phenology of the dominant species. The faunistically significant and/or protected species were observed in a low number of individuals only, thus the applied trapping methods did not damage the faunal composition.

Diversity and ecological tolerance of bacteria isolated from the rhizosphere of halophyton plants living nearby Kiskunság soda ponds, Hungary.

Many halophytes and halophilic microorganisms are capable to adapt to the extremities of saline habitats. This study reveals the taxonomic diversity and ecological tolerance of bacteria isolated from the rhizosphere of three different halophytes (Bolboschoenus maritimus, Puccinellia limosa and Aster tripolium) living in the vicinity of Kiskunság soda ponds. Following a sampling in September 2013, altogether 76 bacterial strains were isolated using two different media. The strains were identified on the basis of 16S rRNA gene sequencing following ARDRA grouping. Salt and pH tolerance of the strains were examined by measuring their growth in broths containing 0-15% NaCl (w/V) and characterized with pH 7-12 values. Among the strains genera of Anaerobacillus, Bacillus and Exiguobacterium (Firmicutes), Agromyces, Isoptericola, Microbacterium, Micrococcus, Nocardiopsis, Nesterenkonia and Streptomyces (Actinobacteria), Halomonas and Idiomarina (Proteobacteria) and Anditalea (Bacteroidetes) were identified. The Bolboschoenus and Puccinellia samples characterized with the highest pH and electric conductivity values were dominated by Bacillus, Halomonas and Nesterenkonia, respectively. The salt tolerance of the bacterial strains was strongly dependent on the sampling location and plant species. In contrast, growth of bacterial strains in broths with alkaline pH values was more balanced. The strains from the Puccinellia sample showed the widest salt and pH tolerance.