Microhabitat Types Research Articles

Diversity of Rotifers in Small Rivers Affected by Human Activity

The rivers flowing through Upper Silesia and the adjacent areas (Southern Poland) are affected by various anthropogenic pressures including urbanisation, agriculture and animal husbandry, as well as industry (e.g., mining), which are reflected in the measured physical and chemical water parameters. The species composition of rotifers relative to a variety of microhabitats was studied in eight small rivers of this region in 2017. Our research is a comprehensive and up-to-date analysis that focuses on the rotifers in small rivers and shows the diversity of rotifers relative to the microhabitats and environmental variables. The diversity of rotifers ranged from 0 to 23 taxa in individual samples. In the studied rivers, 129 taxa of rotifers were found. Notommata groenlandica, a species that has not been recorded in the country for 100 years, was found in two rivers. The Kruskal–Wallis one-way ANOVA and Dunn’s multiple comparison post hoc tests revealed statistically significant differences in the median number of rotifer taxa between the abiotic types of rivers, rivers, sampling sites, microhabitats and seasons. A multiple regression analysis revealed a significant relationship (correlation) between the number of rotifer taxa, and the concentration of nitrites, total dissolved solids and dissolved oxygen in the water.

Riparian buffer effects on headwater-stream vertebrates and habitats five years after a second upland-forest thinning in western Oregon, USA

Riparian-management zones protect aquatic species and their habitats in managed forests, yet the effects of riparian-management alternatives warrant further study. We examined effects of alternative riparian-buffer widths on fish and amphibians in small headwater streams with upland forest thinning in western Oregon, USA. Previously, we reported apparent lag-time effects developing 10 years after thinning of upland second-growth forest, and additional effects 1–2 years after a second-thinning harvest. Here, we analyze effects on fish and amphibian abundances, body-size metrics, and habitats 5 years after the second thinning at 58 stream reaches across eight study sites. Riparian-buffer effects were evident for several species and species groups: higher densities of fish and amphibians (e.g., coastal giant salamander [Dicamptodon tenebrosus], torrent salamanders [Rhyacotriton spp.], sculpins [family Cottidae]) were detected in reaches with a no-entry one site-potential tree-height buffer (∼70 m wide) in comparison with lower densities in two narrower no-entry buffers (6-m-wide, and a variable-width buffer with a 15-m minimum width) and a thin-through managed buffer (two site-potential tree-heights wide, ∼140 m). In addition, indicator-species analyses showed that torrent salamander densities were positively associated with stream reaches in unmanaged controls. Some amphibians changed habitat affinities slightly, being found during the most-recent sampling in locations with habitats related to larger stream sizes (i.e., more-perennial stream flows) than they had been in earlier sampling. Analyses of body-size metrics showed associations with buffers across 42% of species × post-treatment years analyzed, yet patterns were inconsistent within species, and more consistent associations of body metrics were found with microhabitat types, finding larger animals in pools. Although the mechanism driving changes is unclear, the positive associations of species’ densities with one-tree buffers suggest that either lag-time or cumulative effects of factors associated with treatments are developing, with benefits of wider streamside protections over longer time periods for headwater-associated fish and amphibians. Our findings of higher densities of headwater-reliant Rhyacotriton species in stream-reach treatments with the one-tree buffers, and affinities with unthinned control reaches, support the benefits of greater headwater-stream protections for that species complex, which includes species of conservation concern. The mix of different buffer widths and unmanaged units across our eight sites may be promoting site-scale persistence of a community of aquatic-vertebrate species—a mix of buffer widths with upslope forest management may be an alternative for larger-scale riparian forest-management objectives.

Diatoms from the Spring Ecosystems Selected for the Long-Term Monitoring of Climate-Change Effects in the Berchtesgaden National Park (Germany)

We studied diatoms from the fifteen springs selected in the Berchtesgaden National Park on behalf of the Bavarian State Ministry for the Environment to be sentinel environments of climate-change effects. For three of these springs, diatom data based on samples taken in 1997 were also available. A total of 162 species belonging to 49 genera were found sampling three microhabitat types (lithic materials, bryophytes, surface sediments). The cumulative percentage of all species included in a threat category including endangered species was 43%, confirming previous findings for comparable environments of the Alps. We could find a statistically significant positive association between the Meinzer variability index for discharge and the cumulative relative abundance of aerial diatom species. This study thus highlighted once again the relevance of discharge (and associated water-level) variability as an environmental determinant of diatom assemblages in spring ecosystems. Increased nitrate concentrations in some springs, likely due to diffuse airborne pollution and, locally, to impacts such as forest management, game, and cattle, led to a relevant occurrence of eutraphentic diatom species. Our results show a segregation of the older data in non-parametric diatom-based ordinations, suggesting a strong potential for the use of spring diatoms in studies aiming at tracking the effects of climate and environmental change.

Photoprotection and high-light acclimation in semi-arid grassland lichens \u2013 a cooperation between algal and fungal partners

In lichens, each symbiotic partner cooperates for the survival of the symbiotic association. The protection of the susceptible photosynthetic apparatus is essential for both participants. The mycobiont and photobiont contribute to the protection against the damaging effect of excess light by various mechanisms. The present study investigated the effect of seasonality and microhabitat exposure on photoprotection and photoacclimation in the photo- and the mycobiont of six lichen species with different thallus morphology in inland dune system in the Kiskunság region (Hungary) with shaded, more humid and exposed, drier dune sides. High-Performance Liquid Chromatography, spectrophotometry, chlorophyll a fluorescence kinetic technique were used, and micrometeorological data were collected. The four years data series revealed that the north-east-facing side was characterized by higher relative humidity and lower light intensities compared to the south-west-facing drier and more exposed sides. The south-west facing side was exposed to direct illumination 3–4 hours longer in winter and 1–2 hours shorter in summer than the north-east facing side of the dune, influencing the metabolism of sun and shade populations of various species. Because rapid desiccation caused short active periods of lichens during bright and drier seasons and on exposed microhabitats, the rapid, non-regulated non-photochemical quenching mechanisms in the photobiont had a significant role in protecting the photosynthetic system in the hydrated state. In dehydrated conditions, thalli were mainly defended by the solar screening metabolites produced by the mycobiont and curling during desiccation (also caused by the mycobiont). Furthermore, the efficacy of light use (higher chlorophyll and carotenoid concentration) increased because of short hydrated periods. Still, a lower level of received irradiation was appropriate for photosynthesis in dry seasons and on sun exposed habitats. In humid seasons and microhabitats, more extended active periods lead to increased photosynthesis and production of solar radiation protectant fungal metabolites, allowing a lower level of photoprotection in the form of regulated non-photochemical quenching by the photobiont. Interspecific differences were more pronounced than the intraspecific ones among seasons and microhabitat types.

Substratum-dependent moss microhabitat types alter soil nematode community structure in the mixed coniferous forest of Dachigam National Park, Jammu and Kashmir

Mosses although lack a proper rhizosphere, and poorly exploit the substratum on which they grow, still play complex role in ecological processes by providing nutrients and shelter to various organisms. Among the moss fauna, nematodes are the most abundant inhabitants. Keeping this in mind, the present study investigates how nematode communities differ among substratum-dependent moss microhabitats from forest soil. For this, samples were collected from five different microhabitats (FS: forest soil, MS: mosses on soil, MR; mosses on rocks, MLT: mosses on lower tree trunk and MUT: mosses on upper part of tree trunk), from the mixed coniferous forest of Dachigam National Park, Srinagar, Jammu & Kashmir. Results showed that the distribution pattern of nematode assemblages mirror the variation of microclimate. Total nematode abundance, trophic abundance (bacterivores, fungivores, herbivores, predators) and diversity (Shannon index, Simpson index) were highest in FS and lowest in MUT. Maturity index indicated more stable nematode communities in forest soil compared to different moss microhabitats. Results from NMDS showed clear separation of samples between microhabitats forming isolated clusters. Enrichment index depicted more enriched condition in MUT and least in FS. In general, our findings provide insights that more abundant, diverse and stable nematode communities are supported in undisturbed forest soil compared to desiccation-prone moss microhabitats.

Diverging structures, perch heights, temperatures, and levels of sunlight of spatial niche dimensions ease the syntopic life of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata: Tropiduridae)

ABSTRACT To investigate divergences of ecological spatial niche dimensions, we evaluated if lizards Tropidurus hispidus and T. semitaeniatus used or selected structural (types of microhabitat and perch heights) and thermal resources (microhabitat temperatures and levels of sunlight) in ways that could ease living in syntopy. Most T. hispidus and T. semitaeniatus used rocks, resulting in a high overlap of structural niche dimensions. The former used such microhabitats according to the environmental availability and the latter selected rocks. Tropidurus hispidus selected shadier and colder microhabitats than T. semitaeniatus that selected warmer sites with full sunlight. Tropidurus semitaeniatus occupied regions further from vegetation shelters than from rock shelters. Larger T. semitaeniatus moved farther away from shelters than smaller individuals. Tropidurus hispidus perched higher than T. semitaeniatus. Distinctions regarding the use of spatial resources effectively reduced the overlaps of ecological niche dimensions, segregating the species and easing the life in syntopy.

Factors at multiple scales influence the composition of terricolous lichen communities in temperate semi-arid sandy grasslands

AbstractInland dune ecosystems are rich in terricolous lichen species. However, these communities are sensitive to human activities, both locally and globally. Since terricolous lichens have a dominant role in semi-arid sandy grasslands, it is important to explore the composition of their communities and the environmental factors affecting them. We studied the structure of the terricolous lichen assemblages of calcareous grassland in an inland duneland ecosystem by comparing the lichen communities of arid and humid dune sides on two sites with different disturbance histories. Microcoenological data were collected according to the Braun-Blanquet method. Environmental variables include the cover of bare soil, moss, litter, herb cover and height of herbs. We investigated the relationship of these variables and the presence and absence data of terricolous lichen species to sites and dune side. We found that the site had a significant effect on species richness that might reflect the different types and severity of previous disturbance events at the studied sites. On a smaller, ‘dune’ scale, in general lower herb cover and height and a higher moss cover were characteristic of arid dune sides. Most of the frequent species were negatively affected by higher moss cover. Some lichen species were more abundant (e.g. Cladonia furcata) or found only (e.g. Xanthoparmelia subdiffluens, Gyalolechia fulgens) on arid dune sides, while others preferred (e.g. C. pyxidata) or occurred only on (e.g. Peltigera species, C. rei) humid sides. It was observed that the impact of the dune side on several variables differed between sites. The diverse microhabitat types, microclimate and landscape structure, results in species-rich and valuable terricolous lichen communities forming in inland dune ecosystems.

Tadpoles' Resistance to Desiccation in Species of Leptodactylus (Anura, Leptodactylidae)

Desiccation may increase egg and tadpole mortality of anurans that reproduce in temporary ponds. Tadpoles of some species, however, can survive temporarily out of water. Among leptodactylids, desiccation-resistant tadpoles were reported only for species that use terrestrial foam nests for reproduction. To test whether Leptodactylus tadpoles' ability to survive out of water represents an exclusive trait of species with terrestrial nests, we compared survival and resistance to hydric stress of tadpoles of six different species of the Leptodactylus groups and one Physalaemus. We also present an exploratory discussion about the evolutionary association between dehydration-tolerant tadpoles, egg-laying microhabitat, and nitrogen excretion type. Tadpoles were divided into two groups, one staying in 100 mL of water and another subjected to hydric stress on moist paper substrate. Our results indicate that tadpoles resistant to desiccation are not common for all species tested, as only the species with terrestrial nests survived longer and lost less body mass than the other related species. As an estimate, tadpoles of terrestrial-nesting frogs were seven times more resistant to desiccation than those with eggs/nests placed directly into the water. A possible dehydration-resistance mechanism is the premetamorphosis ureotelism that has been shown in terrestrial breeding species with tadpoles that survive some time out of water. Therefore, the capacity of tadpoles to survive a few days after pool drying probably arose from the evolutionary association between terrestrial reproduction and the tadpole ability to prevent body dehydration by a mechanism such as ureotelism.

Spatial and temporal trends in parasite infections of the daggerblade grass shrimp Palaemon pugio in coastal Georgia

The daggerblade grass shrimp Palaemon pugio can be a host for many types of parasites including the microphallid trematode Microphallus turgidus and the haplosporidian hyperparasite Urosporidium crescens. Parasitic infection by trematodes can influence grass shrimp behaviors and may alter habitat selection. We conducted monthly sampling to determine the abundance, density, intensity, and prevalence of M. turgidus and U. crescens at two sites near Savannah, Georgia. The goals of this study were to determine which microhabitat type P. pugio frequented more often, either sandy substrates or rocks with the invasive and habitat altering red alga Agarophyton vermiculophyllum, which was present seasonally, and whether trematode infection corresponded to microhabitat usage. Additionally, we aimed to determine whether temporal changes in parasitic infection correlated to abiotic factors. The results indicated grass shrimp were more likely to be located over sand substrate, even when A. vermiculophyllum was present. Furthermore, the surveys did not detect a relationship between shrimp microhabitat usage and trematode abundance, density, or intensity. All analyzed measures of trematode and hyperparasite infection differed significantly among months with some instances of intraseasonal variation. A negative relationship was detected between salinity and trematode prevalence and mean abundance, but not with temperature. No relationship was observed between salinity or temperature and hyperparasite prevalence or mean abundance. Through consistent monthly sampling of a heterogeneous habitat containing a habitat-altering invasive species, this study supports previous findings that salinity plays a role in M. turgidus abundance within P. pugio and demonstrates that A. vermiculophyllum does not appear to influence host microhabitat preferences, regardless of trematode infection. However, salinity alone cannot account for all observed parasite patterns; thus, it is likely that a combination of fluctuating abiotic conditions, unaccounted for aspects of habitat structure, and the presence of other host species determines grass shrimp risk of parasite infection.

Seasonal fires shape the germinable soil seed bank community in eastern Mediterranean woodlands

AbstractWe explored if and how seasonal fires interact with microhabitat type (i.e. under Pistacia shrub, under Cistus shrub or a canopy gap) to influence the composition of the germinable soil seed bank (GSSB) community in a typical eastern Mediterranean woodland. We conducted a field experiment, involving prescribed spring and autumn burns, and thereafter quantified the seed germination patterns using soil samples collected from both burned and adjacent unburned control plots. Soil temperature was significantly higher during autumn burns, while being more variable during spring burns. Fire caused overall reductions in GSSB density, richness and diversity. The reductions in GSSB richness and diversity were significantly stronger under Pistacia and Cistus shrubs located within plots subjected to autumn burns, and these patterns were mainly evident among annuals. GSSB density of dwarf shrubs was higher in samples collected from burned plots, and this pattern was more pronounced in samples collected under Pistacia and Cistus shrubs. Together with the appearance of unique species, seasonal fires led to significant changes in the composition of the GSSB community. Our results illustrate that seasonal fires interact with spatial heterogeneity to influence the composition of the GSSB community mostly via differential effects on the germination densities of annuals and dwarf shrubs. These findings imply that the increase in the frequency of seasonal fires, which has occurred in the eastern Mediterranean basin during the last few decades, may translate into a shift in eco-evolutionary selection pressures, operating on plants inhabiting this unique ecosystem.

Different patterns of belowground fungal diversity along altitudinal gradients with respect to microhabitat and guild types.

Fungi are key components of belowground ecosystems with various ecological roles in forests. Although the changes in the richness and composition of belowground fungi across altitudinal gradients have been widely reported, only a few studies have focused on the microhabitat types along altitudinal gradients. Here, we analysed the effect of altitude on the ectomycorrhizal and non-ectomycorrhizal fungal communities in belowground microhabitats. We collected root and soil samples from 16 Pinus densiflora forests at various altitudes across Korea, and measured the soil properties as potential factors. Fungal communities were analysed by high-throughput sequencing of the internal transcribed spacer 2 (ITS2) region. We found that altitude negatively affected the species richness of root-inhabiting fungi but did not influence that of soil-inhabiting fungi. In addition, the composition of ectomycorrhizal (ECM) fungi was less influenced by altitude than non-ECM fungi. Most of the soil properties did not show a significant relationship with altitude, but the effect of soil properties was different across microhabitat types and ecological roles of fungi. Our results reveal that microhabitat types and altitudinal gradients differently affect the richness and composition of fungal communities associated with P. densiflora, providing a better understanding of plant-associated fungal communities.

Forest stand structure and coarse woody debris determine the biodiversity of beetle communities in Mediterranean mountain beech forests

The relationships between structural complexity, deadwood abundance, microhabitat type and species-diversity indicators are excellent tools to monitor biodiversity in forest ecosystems.In spite of their importance, correlations between structural traits and Coleoptera communities in Mediterranean mountain forests have only rarely been investigated. Consequently, the magnitude and direction of the relationships between forest traits and biodiversity indicators remain poorly understood. In this study, we analyzed whether biodiversity indices of saproxylic and non-saproxylic beetle communities could be influenced by stand structure, microhabitat type, and deadwood abundance in two protected beech forests located in the central and southern Apennines (namely Gran Sasso e Monti della Laga National Park, GSML, and Cilento, Vallo di Diano e Alburni National Park, CVDA). Standard measurements of forest structural traits and quantitative assessment of tree microhabitats and deadwood were carried out. Adult beetles were collected using window flight traps and emergence traps on decaying deadwood. The two beech forests were different in terms of both beetle communities and structural traits. A two-block partial least squares analysis 2B-PLS highlighted differences in biodiversity indices and structural traits between the two forest ecosystems. In GSML, we observed that biodiversity indices were positively correlated with the volume of coarse woody debris and the presence fungal infections, clefts into the sapwood, and woodpecker cavities, while more dominant beetle communities were found under denser canopy cover. In CVDA, Coleoptera abundance was positively correlated with the basal area and crown broken microhabitats. Our results point toward the relevance of ecological attributes in tracking changes in beetle biodiversity in specific forest contexts. In these protected Mediterranean mountain beech stands, in which the main forest management strategies have the primary objective of biodiversity conservation, we suggest to progressively increase the structural diversity and canopy dynamics, as well as the volume of coarse woody debris.

Seasonal Diversity of mosquito species in Dakshina Kannada district, Karnataka, India.

Dakshina Kannada is one of the districts of Karnataka state of India with high incidences of mosquito-borne diseases, especially malaria and dengue. The larval stages of the mosquitoes are very important in determining the prevalence of adult mosquitoes and associated diseases. Hence, the occurrence of mosquito species was investigated by sampling different water bodies present in the Dakshina Kannada district from June 2014 to May 2017. Random sampling was carried out from permanent and temporary, artificial and natural water bodies belonging to 11 types of microhabitats using dippers and suction pumps. A maximum of 37 mosquito species belonging to 12 genera were recorded with the dominant genera being Culex. Most species have been recorded from temporary bodies of water with the highest number of species in receptacles. Monsoon is the most productive season, both in terms of occurrence and abundance followed by post-monsoon and pre-monsoon. The abundance of mosquito larvae was significantly higher in temporary water bodies compared to the permanent. Abundant rainfall in the study area which produces many natural and domestic temporary water bodies accounts for mosquito breeding throughout the year.

Agricultural activities compromise ecosystem health and functioning of rivers: Insights from multivariate and multimetric analyses of macroinvertebrate assemblages.

Agricultural activities often lead to nutrient enrichment and habitat modification in rivers, possibly altering macroinvertebrate assemblages and hence ecosystem functioning. For the sake of environmental management and conservation, therefore, assessing the impacts of agricultural activities becomes indispensable, especially when these activities are predicted to be intensified in the future. In this study, the plain river network in the Lake Chaohu Basin was chosen to examine how agricultural activities influence the functioning of rivers by assessing land use, water quality, habitat condition and macroinvertebrate assemblages, followed by calculating the macroinvertebrate-based multimetric index (MMI) to indicate overall ecosystem health of the rivers. We found that agricultural activities lowered the diversity of macroinvertebrates (e.g. total number of taxa and Simpson index) primarily due to elevated ammonium concentrations in water and reduced microhabitat types, thereby impairing the habitat integrity and nutrient cycling of rivers. The macroinvertebrate-based MMI was positively correlated with increasing habitat quality but negatively with increasing nutrient concentrations, suggesting its high reliability for indicating the impacts of agricultural activities, which was further substantiated by classification and regression tree (CART) analysis. We recommend analyzing macroinvertebrate assemblages using both multivariate and multimetric approaches to offer a more comprehensive evaluation of the impacts of agricultural activities on ecosystem health. Some environmental (CODMn, NH4+-N and PO43--P) and biological parameters (total number of taxa), however, can be used as good proxies for MMI, when time and resources for gathering information to develop MMI are limited.

Diversity and microhabitat use of benthic invertebrates in an urban forest stream (Southeastern Brazil)

ABSTRACT This work aimed to assess the diversity and microhabitat use of benthic invertebrates in an urban forest stream in southeastern Brazilian region. The invertebrates were sampled in a headwater stream, located at the Tijuca Forest, Rio de Janeiro. Three types of microhabitats were sampled (litter, sand and stone) using a Surber sampler. Specimens were identified to the family-level and rarefaction curves were constructed for the total sampling and for each type of microhabitat. Community structure indices (abundance, taxonomic richness, diversity, and dominance) were calculated for each microhabitat. Differences among indices were tested through a repeated measure ANOVA, and differences among microhabitatsʼ composition through a PerMANOVA. A total of 9,800 specimens were registered in which Chironomidae was the most abundant. The rarefaction curves did not reach the asymptote. Community structure indices exhibited differences (RM ANOVA; p < 0.001), as well as microhabitats’ composition (PerMANOVA; p < 0.001). Abundance and taxonomic richness were the highest in litter, diversity was higher both in litter and stone, and sand had the highest dominance. Results highlighted that the variety of microhabitats may enhance local diversity and that the differences in resources availability of each type of microhabitat determine the distribution of these invertebrates.

广西扶绥白头叶猴对栖息地的选择与利用

为了解白头叶猴（Trachypithecus leucocephalus）的栖息地利用规律及其影响因素，2016年2月至2017年1月，采用瞬时扫描取样法对广西崇左白头叶猴国家级自然保护区一群白头叶猴的栖息地利用进行了研究。结果表明，白头叶猴对山体不同部位的利用存在显著性差异（χ² =39.467，df=3，P<0.001），其中，对崖壁（56.75±9.55）%的利用比例最大，其次是对山坡（39.42±10.93）%和山顶（2.98±2.54）%的利用，而对山脚（0.84±1.47）%的利用频率最低。白头叶猴对不同微生境类型的利用存在差异（χ²=27.709，df=3，P<0.001），其中对乔木（49.37±12.31）%的利用比例最大，其次是裸岩（24.05±13.61）%，随后依次为藤本（15.48±8.01）%和灌木（10.87±5.45）%。白头叶猴主要在山坡上觅食，利用崖壁移动、休息，进行社会活动；主要利用裸岩进行社会活动，觅食、移动、休息主要发生在乔木上。从整体来看，白头叶猴在雨季对乔木的利用频率显著大于旱季（Z=-2.680，n=12，P=0.007）；雨季在山坡觅食频率显著大于旱季（Z=-2.517，n=12，P=0.012），而在崖壁觅食频率刚好相反（Z=-2.842，n=12，P=0.004）；白头叶猴雨季在乔木休息的频率显著大于旱季（Z=-2.355，n=12，P=0.019）。白头叶猴对栖息地的利用受到温度的影响。白头叶猴对乔木的总体利用频率随着平均温度的升高而增加（r=0.664，n=12，P=0.018）；觅食时，对崖壁、裸岩的利用频率均与平均温度成负相关关系（崖壁：r=-0.685，n=12，P=0.014；裸岩：r=-0.600，n=12，P=0.039）；休息时，对乔木的利用频率与平均温度呈正相关关系（r=0.650，n=12，P=0.022）。不同季节，白头叶猴对栖息地的利用方式不同。白头叶猴的栖息地利用模式可能是在觅食利益和捕食风险之间作出的权衡，并受到环境温度的影响。;In order to understand the habitat utilization rule of the white-headed langur and its influencing factors, a group of white-headed langurs (Trachypithecus leucocephalus) was investigated from February 2016 to January 2017 in the Chongzuo White-headed Langur National Nature Reserve, Guangxi, China by instantaneous scanning sampling method. The results indicated that significant difference in the utilization of different limestone hill parts of white-headed langur was found (χ² =39.467, df=3, P<0.001). The cliff was used most frequently (56.75±9.55)%, followed by the slope (39.42±10.93)%, the hill-top (2.98±2.54)%, as well as the valley (0.84±1.47)%. There were significant differences in the utilization of different microhabitat types of langurs (χ²=27.709, df=3, P<0.001). Tree as the preferred microhabitat, and its percentage (49.37±12.31)% was higher than bare rock (24.05±13.61)%, liana (15.48±8.01)%, and bush (10.87±5.45)%. The langurs mainly fed on slope, and other activities, such as moving, resting and social activity were on cliff. Besides, social activity was the only behavior occurred most often in bare rock, while other behaviors occurred most often in trees. There were seasonal differences in limestone hill parts and microhabitat. In overall activities, langurs used trees significantly more in the rainy season than in the dry season (Z=-2.680, n=12, P=0.007). When feeding, langurs used slope significantly more in the rainy season than in the dry season (Z=-2.517, n=12, P=0.012), while the use of cliff was opposite (Z=-2.842, n=12, P=0.004). When resting, in the rainy season the langurs used trees significantly more than in the dry season (Z=-2.355, n=12, P=0.019). Habitat use of white-headed langurs was also influenced by temperature. The utilization frequency of overall activities of the trees increased with the average temperature (r=0.664, n=12, P=0.018). Besides, the utilization frequency of resting of the trees increased with the average temperature (r=0.650, n=12, P=0.022). In contrast, the utilization frequency of cliff and bare rock in feeding was both negatively correlated with the average temperature (cliff:r=-0.685, n=12, P=0.014; bare rock:r=-0.600, n=12, P=0.039). In different seasons, white-headed langurs used its habitat in different ways. Thus, the habitat utilization pattern of white-headed langurs may be a trade-off between feeding benefits and predation risk, and is also influenced by ambient temperature.

Spatial distribution and seasonal dynamics of non-biting moth flies (Diptera, Psychodidae) in confound conditions of a stable

Many small Diptera adopted at some level endophilic life style, including man-made buildings. Stables create a specific type of microhabitat, which provides shady and relatively humid conditions in combination with excess of organic matter. Unlike the parasites (mosquitos, biting midges, etc.), the commensal fauna of stables is poorly studied. Moth flies (Psychodidae) were collected in cow stable located in Šenkvice, SW Slovakia. Special traps (derived from Malaise traps) were installed along the stable internal wall and in three different heights. In total, we recorded 6325 moth flies belonging to 8 species. The flight period lasted from spring to autumn. Seasonal dynamics was strongly influenced by rainfall and mean week temperature, e.g. high temperature in mid-summer caused drop in moth flies captures. The moth flies clearly preferred the ground and moderately preferred the interior of stable.

Factors influencing the persistence of enteropathogenic bacteria in wetland habitats and implications for water quality.

To better understand the persistence dynamics of enteropathogenic bacteria in freshwater wetland habitats, we constructed lab-scale mesocosms planted with two different wetland plant species using a subsurface flow wetland design. Mesocosms were treated with either a high-quality or a poor-quality water source to examine the effects of water quality exposure and plant species on Escherichia coli, Salmonella spp. and Enterococcus spp. in the rhizoplane, rhizosphere and water of wetland habitats. Quantities of study micro-organisms were detected using real-time PCR in wetland mesocosms. A combination of molecular and culture-based methods was also used to enumerate these organisms from surface water and plant material at high, medium and poor water quality sites in the field. We found that all three enteropathogenic micro-organisms were influenced by microhabitat type and plant species. Organisms differed with respect to their predominant microhabitat and the extent of persistence associated with wetland plant species in the mesocosm study. Of the monitored pathogens, only E. coli was influenced by both water quality treatment and plant species. Salmonella spp. quantities in the rhizoplane consistently increased in all treatments over the course of the mesocosm experiment. Plant species selection appears to be an overlooked aspect of constructed wetland design with respect to the removal of enteropathogenic micro-organisms. Escherichia coli and Enterococcus concentrations in wetland outflow were significantly different between the two plant species tested, with Enterococcus concentrations being significantly higher in mesocosms planted with Phalaris arundinaceae and E. coli concentrations being higher in mesocosms planted with Veronica anagallis-aquatica. Furthermore, there is evidence that the rhizoplane is a significant reservoir for Salmonella spp. within wetland habitats. This is the first time that Salmonella spp. has been shown to proliferate under natural conditions within the rhizoplane. This will contribute to our understanding of wetland removal mechanisms for enteropathogenic bacteria. This study identifies the rhizoplane as a potentially important reservoir for human pathogenic micro-organisms and warrants additional study to establish whether this finding is applicable in non-wetland habitats.

The multiple origins of sexual size dimorphism in global amphibians

AbstractAimBody size explains most of the variation in fitness within animal populations and is therefore under constant selection from ecological and reproductive pressures, which often promote its evolution in sex‐specific directions, leading to sexual size dimorphism (SSD). Several hypotheses have been proposed to explain the vast diversity of SSD across species. These hypotheses emphasize: (a) the mate competition benefits to larger male size (sexual selection); (b) the benefits of larger female size for fecundity (fecundity selection); (c) the simultaneous benefits of niche divergence for males and females to reduce intersexual competition for ecological resources (natural selection); and (d) the underlying impact of geographical variation in climatic pressures expected to shape large‐scale patterns of SSD in synergy with the above selection pressures (e.g., intensification of fecundity selection as breeding seasons shorten). Based on a new, global‐scale amphibian dataset, we address the shortage of large‐scale, integrative tests of these four hypotheses.LocationGlobal.Time periodExtant.Major taxa studiedClass Amphibia.MethodsUsing a &gt; 3,500 species dataset spanning body size, ecological, life‐history, geographical and climatic data, we performed phylogenetic linear models to address the sexual, fecundity, ecological and climatic hypotheses of SSD.ResultsEvolution of SSD is discordant between anurans and salamanders. Anuran SSD is shaped by climate (male‐biased SSD increases with temperature seasonality) and by nesting site. In salamanders, SSD converges across species that occupy the same types of microhabitats (“ecodimorphs”), whereas reproductive or climatic pressures have no effects on their SSD. These contrasts are associated with latitudinal gradients of SSD in anurans, but not in salamanders.Main conclusionsAmphibian SSD is driven by ecological and climatic pressures, whereas no roles for sexual or fecundity selection were detected. We show that macroevolutionary processes determined by different forms of selection lead to latitudinal patterns of trait diversity, and the lack of them.

The effects of taxonomy, diet, and ecology on the microbiota of riverine macroinvertebrates.

Freshwater macroinvertebrates play key ecological roles in riverine food webs, such as the transfer of nutrients to consumers and decomposition of organic matter. Although local habitat quality drives macroinvertebrate diversity and abundance, little is known about their microbiota. In most animals, the microbiota provides benefits, such as increasing the rate at which nutrients are metabolized, facilitating immune system development, and defending against pathogenic attack. Our objectives were to identify the bacteria within aquatic invertebrates and determine whether their composition varied with taxonomy, habitat, diet, and time of sample collection. In 2016 and 2017, we collected 264 aquatic invertebrates from the mainstem Saint John (Wolastoq) River in New Brunswick, Canada, representing 15 orders. We then amplified the V3‐V4 hypervariable region of the 16S rRNA gene within each individual, which revealed nearly 20,000 bacterial operational taxonomic units (OTUs). The microbiota across all aquatic invertebrates were dominated by Proteobacteria (69.25% of the total sequence reads), but they differed significantly in beta diversity, both among host invertebrate taxa (genus‐, family‐, and order‐levels) and temporally. In contrast to previous work, we observed no microbiota differences among functional feeding groups or traditional feeding habits, and neither water velocity nor microhabitat type structured microbiota variability. Our findings suggest that host invertebrate taxonomy was the most important factor in modulating the composition of the microbiota, likely through a combination of vertical and horizontal bacterial transmission, and evolutionary processes. This is one of the most comprehensive studies of freshwater invertebrate microbiota to date, and it underscores the need for future studies of invertebrate microbiota evolution and linkages to environmental bacteria and physico‐chemical conditions.