Comparative analysis of the parasitocenoses of amphibians from the family Ranidae (Anura) in the urbanization gradient

The parasitofauna of frogs from the fam. Ranidae (R. arvalis, R. temporaria, and P. ridibundus) has been studied in the urbanization gradient. A total of 22 parasitic species belonging to the following four taxonomic groups have been found: Protozoa, Trematoda, Monogenoidea, and Nematoda. The transformation of parasitocenoses with the growth of urbanization along with the preservation of specifics typical for the adaptive subzone in each amphibian species is accompanied with their depletion as well as with an increase in the proportion of trematodes, which results in a decrease in the system stability and increases the probability of parasitic pollution of the environment.     

Ecological and faunistic characteristics of the leech fauna in the Bukhtarma Reservoir,Eastern Kazakhstan

The taxonomic diversity of the Hirudinea fauna and its dependence on the ecological conditions in the Bukhtarma Reservoir (Eastern Kazakhstan) have been studied. The morphological analysis has shown that these leeches belong to two orders and three families: Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and Arhynchobdellida (family Erpobdellidae). On the whole, eight leech species from five genera (Alboglossiphonia, Helobdella, Theromyzon, Piscicola, and Erpobdella) have been identified. Among them, there are three glossiphoniid species (A. heteroclite, H. stagnalis, and T. tessulatum), two species of piscicolids (Piscicola geometra and Piscicola sp.), and three species of predatory leeches (E. octoculata, E. vilnensis, and Erpobdella sp.). Possible effects of hydrochemical parameters of the aquatic environment on the species diversity have been analyzed. Correlation has been revealed between the abundance of species and the physical and chemical characteristics of the environment.     

Species-specific Features of Blood Plasma Amino Acid Spectrum of Bats (Mammalia: Chiroptera) in the Urals

The amino acid spectrum of blood plasma in three bat species (Myotis dasycneme, Pipistrellus nathusii, Vespertilio murinus) inhabiting the Urals has been studied for the first time. The bats were trapped in the zone of their high abundance in Chelyabinsk oblast (2013–2014). Free amino acids were determined by liquid ion exchange chromatography (a total of 384 determinations). It has been shown that the plasma amino acid spectrum consists of 22 amino acids in subadult bats of all three species, but there are species-specific differences in their concentrations. The total amino-acid pool concentration in migratory P. nathusii and V. murinus exceeds that in resident M. dasycneme by factors of 2.9 and 1.8, respectively. Migratory species are characterized by a high concentration of plasma arginine: it is six times higher in V. murinus than in M. dasycneme, and in P. nathusii arginine accounts for 25.4% of the amino acid pool. The group of glucogenic amino acids is prevalent in the blood plasma of migratory species (75% in V. murinus and 79% in P. nathusii), while in M. dasycneme the total proportion of lysine, glycine, and glutamic acid is 2.3 times lower than in P. nathusii and 1.7 lower than in V. murinus (p < 0.05). These results provide evidence for significant differences in the contents of free blood plasma amino acids between migratory and resident bat species.     

Drought Stress in Four Subalpine Species: Gas Exchange Response and Survivorship

An assessment of adaptability of saplings of four evergreen species (Picea abies Karst., Pinus mugo Turra, Pinus peuce Grisb. and Pinus heldreichii H. Christ.), native for Bulgarian treeline zone, was made on the basis of leaf gas exchange and survivability in artificially induced drought stress. The established low sensitivity of gas exchange to summer drought and the highest mortality of P. abies may be regarded as an evidence for a narrow zone of tolerance. P. peuce and P. heldreichii have low survivorship under drought conditions, regardless of the variable effect of soil moisture on the gas exchange parameters. The better survivability and significant reduction of gas exchange in response to soil water deficit of P. mugo probably will give him an advantage in future adaptation to climate change and in competition with other subalpine species. We conclude that the expected trends in climate change will most likely lead to a further narrowing of the ecological and physiological comfortable zone for two investigated endemic species.     

Interspecific interactions of amphipods <Emphasis Type="Italic">Gammarus lacustris</Emphasis> and <Emphasis Type="Italic">Gmelinoides fasciatus</Emphasis>

Experimental studies of interactions between two amphipod species (Gmelinoides fasciatus and Gammarus lacustris) showed that predation is the basic mechanism accounting for their mutual exclusion in nature. Mortality from predation among similar-sized specimens of both species at an equal abundance ratio was similar (24–25% in G. lacustris and 27–30% in G. fasciatus). The displacement of G. lacustris by G. fasciatus was observed when the latter was dominant. Adult G. fasciatus and G. lacustris successfully preyed on juveniles of their competitors and did not differ significantly in daily food consumption as a percentage of body weight: 6–24% at a fresh body weight of 18–24 mg in both species. The potential for rapid population growth under new conditions contributed to the success of the invasive Baikal species G. fasciatus in displacing G. lacustris from many water bodies of Russia.     

Knowing the past to forecast the future: a case study on a relictual,endemic species of the SW Alps, <Emphasis Type="Italic">Berardia subacaulis</Emphasis>

Future climate change may lead to a substantial loss of biodiversity, particularly affecting mountain regions, including the Alps. Range-size reduction in high mountain plant species is predicted to be more pronounced for endemic species. Investigating the broad temporal spectrum of range shifts is important for the conservation of biodiversity, since learning how species responded to climate change in the past provides useful insights on how they might react to warming trends in the present and future. Using species distribution models and an ensemble forecasting approach, we explored how the distribution of Berardia subacaulis, a monospecific genus endemic of the south-west Alps, may be affected by past and future projected climate change. During the last interglacial, the habitat suitability of Berardia was lower than present and a progressive increase was observed from the last glacial maximum until now. In the future, Berardia appears to lose more than 80 % of its range, becoming endangered by 2050. Our results suggest that Berardia probably survived past warmer periods in situ, expanding its distributional range during cooler periods. The severe future range contraction predicted for Berardia reflects similar results for other endemic species. As Berardia represents an interesting model species to evaluate the effects of climate warming on range size and shifts, demographic and precise range monitoring may be undertaken on this species.     

Ecological preferences of forest voles

Basic climatic parameters (annual average air temperature and annual amount of precipitation) over 12–25 years have been analyzed with regard to their values corresponding to different levels of abundance in three species of forest voles: Clethrionomys glareolus (in 11 areas of the species range), Cl. rutilus, and Cl. rufocanus (in three areas each). The results show that the abundance of all these species correlates significantly with fluctuations of annual average temperature, with the correlation being negative in Cl. glareolus and Cl. rufocanus but positive in Cl. rutilus. In addition, the abundance of Cl. rufocanus shows a significant correlation with annual precipitation. Voles inhabiting different geographic regions may reach high abundance under different conditions. As for the species range as a whole, however, Cl. glareolus is more ecologically flexible than the other two voles. This species is also more warmth- and moisture-loving, while Cl. rufocanus is more cold-loving and xerophilous, with Cl. rutilus occupying an intermediate position between them. Clethrionomys rutilus is most temperature-dependent and stenothermic among them, whereas Cl. glareolus is indifferent to the factors studied.     

A global change of specialization and generalization in pollination networks from the plant perspective

A view of pollination systems is that they tend to generalization. Here we show that patterns exist in pollination systems that suggest otherwise. We examine how specialization may be affected by latitude, species richness and plant life-forms in 33 plant-pollinator interaction networks. Connectance increases with latitude (P = 0.040), but specialization at the community level significantly declines with increasing latitude, with the strongest evidence in the Northern Hemisphere (P = 0.001). The relationship between specialization level and connectance is negative (P < 0.001). While plants are more specialized in tropical areas and are more generalized at higher latitudes, specialization level also increases with plant richness (P < 0.001), total species richness (P = 0.041) and network size (P = 0.009). Specialization level of life forms of 1129 species differ substantially (P < 0.001), with herbs showing the highest specialization (74%), and tree species the lowest (62%).     

Pollination ecology of <Emphasis Type="Italic">Eomecon chionantha</Emphasis> Hance (Papaveraceae), an endemic species in China

Eomecon chionantha Hance, the only species in the genus Eomecon, is an angiosperm species endemic to China. Here we investigated the pollination syndrome, pollinator generalization of E. chionantha. Our results showed that the individual flower longevity of E. chionantha was 3–5 days. The flowering phenology of E. chionantha can be divided into five phases. We found significant differences in the pollination efficiency of the different insects visiting E. chionantha with bees and flies being the most efficient pollinators. This, in addition to floral morphology and phenology, suggests that E. chionantha is generalized on bees and flies and possesses an outcrossing, partially self-compatible and pollinator-dependent breeding system.     

The use of biomass production and allometric models to estimate carbon sequestration of <Emphasis Type="Italic">Jatropha curcas</Emphasis> L. plantations in western Burkina Faso

The topic of carbon sequestration in plants has received much attention recently due to concerns about global climate change, which is being exacerbated by deforestation. In the early days of the global bioenergy boom, the private sector and non-government organizations enthusiastically promoted the planting of Jatropha curcas L. as a key candidate shrub species for the production of bioenergy in West Africa. This study investigates the aboveground biomass production and carbon sequestration potential of J. curcas, which is already widely cultivated for the production of oil seeds, biodiesel and biokerosene. The specific objective is to use a destructive method to develop allometric prediction equations of the aboveground biomass production of J. curcas plantations. 38 J. curcas shrubs were harvested and weighed in order to estimate biomass production. These data were used to develop allometric equations for the estimation of wood, leaf and total aboveground biomass production. The best-fit models found for estimating shrub component biomass and total aboveground biomass production were of the power form. All of the regression equations relating the prediction of leaf biomass, wood biomass and total aboveground biomass with J. curcas diameter at 20 cm above the ground (D) were statistically significant (p < 0.001) and also presented the highest goodness of fit (high R ²). The aboveground biomass carbon content was estimated using the ash method. Carbon content in leaves and wood was, respectively, 48 and 54 %. The current established allometric equations can be helpful to provide a rapid estimation of the aboveground biomass and C stock for J. curcas biofuel projects in semi-arid conditions.     

Role of bivalve mollusks in formation of aquatic invertebrate consortia in the littoral zone of an artificial eutrophic lake

General biological issues related to the formation and functioning of aquatic invertebrate consortia around Dreissena or Dreissena + Anodonta mollusks in shallow areas of an artificial eutrophic lake are considered. The environment-forming role of Dreissena in assembling the groups of companion (consort) species is shown.     

Most Interesting Findings from Remnants of Chironomid (Insecta: Diptera: Chironomidae) Larvae in Layers of a 200-Year-Old Stratum of Lake Oron Bottom Sediments

The remnants of chironomid larvae from layers of the 10-cm-thick bottom sediment in Lake Oron have been studied. Six taxons unknown in the current chironomid fauna of the lake have been identified: Abiskomyia rivalis, Corynoneura arctica-type, Mesocricotopus thienemanni, Metriocnemus eurynotus-type, Nanocladius rectinervis-type, and Robackia pilicauda. The most probable reasons for the disappearance of these species from the Oron fauna, which are related to environmental changes caused by global climate changes, are considered.     

Implications of future bioclimatic shifts on Portuguese forests

As climate is an important driver of vegetation distribution, climate change represents an important challenge to forestry. We (1) identify prevailing bioclimatic conditions for 49 relevant forest species in Portugal and (2) assess future shifts under climate change scenarios. We compute two bioclimatic indices (aridity and thermicity) and a new composite index, at ~1 km spatial resolution, and overlap with the species’ current ranges. Locations are based on a digital inventory, while climate parameters for both recent-past (1950–2000) and future climates (2041–2060), under RCP4.5 and RCP8.5, are provided by a multi-model ensemble of climate simulations. Results for future scenarios highlight an overall warming and drying trend. Supramediterranean and mesomediterranean climates will be significantly reduced, while thermomediterranean climates will dramatically increase, from their almost absence in current conditions to an area coverage of ~54 % in 2041–2060 for RCP8.5. There is also a clear shift from hyper-humid and humid to sub-humid and from the latter to semi-arid climates (area coverage of ~13 % in 2041–2060 for RCP8.5). Lower thermomediterranean sub-humid to semi-arid zones will cover the southern half of Portugal. These projections identify the most vulnerable (e.g. Betula pubescens, Quercus pyrenaica and Castanea sativa) and the most adapted (e.g. Quercus suber, Q. rotundifolia, Ceratonia siliqua, Pinus pinea, Quercus coccifera) species in future climates. Current bioclimatic zones associated with Eucalyptus globulus and Pinus pinaster, economically relevant species, will be moderately reduced and relocated. Possible adaptation measures are discussed to improve forest resilience to climate change, while maintaining its economic and environmental benefits.     

Effect of temperature and precipitation on linear increment of <Emphasis Type="Italic">Sphagnum fuscum</Emphasis> and <Emphasis Type="Italic">S. magellanicum</Emphasis> in Western Siberia

The linear increment of Sphagnum fuscum and S. magellanicum in ombrotrophic mires of Western Siberia has been measured during two years over a transect about 2500 km long extending from forest–steppe to forest–tundra. Along the latitudinal gradient, the increment of both species has proved to be correlated with annual average air temperature and, in S. magellanicum, also with annual precipitation. The determinants of their growth differ between the southern, central, and northern parts of the study region. At the regional level, the annual and summer precipitation plays a more important role than the average air temperature. The increment of S. fuscum in the southern part is positively correlated with the amount of precipitation and negatively correlated with summer temperature, whereas the situation in the central part is inverse. In S. magellanicum, the linear increment is directly dependent on the annual average temperature and annual and summer precipitation in the south and on the annual and summer precipitation in the north of Western Siberia. The dynamics of linear growth of both species in bog pine forests during the growing season are similar: its rate is the highest in June, when the linear increment of S. fuscum and S. magellanicum amounts to 60 and 85% of the annual total, respectively.     

Plant Species Richness and Developmental Morphology Stage Influence Mycorrhizal Patagonia Plants Root Colonization

The objectives of this study were to determine the percentage of root colonization by arbuscular mycorrhizal (AM) fungi at various levels of plant species richness and developmental morphology stages in various perennial grass, and herbaceous and woody dicots species using experimental plots during 2013 and 2014. An auger was used to obtain six replicate root + soil samples at each sampling time on each of the study parameters. Roots were washed free of soil, and percentage AM was determined. The shrub Larrea divaricata was the species which showed the lowest percentage of colonization by AM at the vegetative developmental morphology stage at the monocultures and six-species-mixtures on the experimental plots. Dicots, but not grass, species showed a greater percentage colonization by AM fungi at the greatest (i.e., six-species-mixtures) than lowest (i.e., monocultures) species richness. Although at different degrees of species richness and developmental morphology stages, the perennial grasses Nassella longiglumis and N. tenuis, the herbaceous dicot Atriplex semibaccata, and the shrubs L. divaricata and Schinus fasciculatus showed a greater (p < 0.050) percentage colonization by AM fungi during the second than the first study year. Even though it was species- and sampling time-dependent, percentage colonization by AM fungi increased as species richness also increased most of the times. Our results demonstrated that the plant species differences in percentage colonization by AM fungi in the experimental plots were species richness-, developmental morphology stage-, and sampling-time dependents.     

Factors affecting on the susceptibility of vetch cultivars to infestation by <Emphasis Type="Italic">Acyrthosiphon pisum</Emphasis> L. (Hemiptera,Aphididae)

Current trends in organic agriculture have led to the need of seeking alternative methods of pest control. For that reason the influence of weather conditions, some morphological and chemical traits of common vetch (Vicia sativa) cultivars–“Liya”, “Loryna”, “Villena”, “Moldavskaya 82” (Moldovan cultivars) and “Obrazets 666” (Bulgarian cultivar), and hairy vetch (V. villosa)–“Violeta” and “Viola” [Moldovan cultivars]) on the dynamic and preference of Acyrthosiphon pisum were determined. Moldovan cultivars belonging to V. sativa were distinguished by lower aphid numbers as they had shorter duration of the flowering period unlike the V. villosa cultivars, where that duration was significantly longer. The plant morphological traits as height, branch, flower and leaflet numbers influenced on the aphid density. The aphid density was affected by branch and leaflet numbers more than by height and flower plant. “Villena” had a shorter vegetative period, lowest flower and leaflet numbers as well as low nitrogen and phosphorus content, which resulted in the lowest A. pisum population. The use of vetch cultivars with some characteristics of tolerance would result in a reduction of losses due to pea aphids. That will provide an environmentally safer option for aphid control.     

Species richness,structure, and conservation of <Emphasis Type="Italic">Nitraria retusa</Emphasis> communities in the coastal salt marshes of Kuwait

Although the coastal salt marshes of Arabian Gulf have been altered extensively by human development activities, there is a paucity of data describing changes in the distribution and abundance of native coastal plant communities. The main objectives of this study are to determine vegetation condition, size structure, and conservation status of Nitraria retusa, a medicinal and salt-tolerant shrub, in disturbed and non-disturbed coastal salt marshes of Kuwait. Size measurements of Nitraria shrubs and nabkas, which are mounds of sediment developed around shrubs, were carried out in 50 quadrats (20 × 20 m²), randomly selected inside and outside Sabah Al-Ahmad Natural Reserve. Species richness and soil properties of nabkas and interspaces, the open areas between the nabkas, were also measured. The results revealed that nabkas of Nitraria in non-disturbed sites are more stable and rich in plant diversity than those in disturbed sites. Mean height and mean canopy diameter of Nitraria shrubs, total plant cover, and species richness are significantly higher in non-disturbed sites than disturbed sites, which indicate the positive influences of conservation for long term on vegetation structure and species richness. The results of soil analyses indicate the important role of nabkas in providing refuges for plant life and species diversity. The present study indicates that more than 50 % of the N. retusa community has been lost during the last few decades. Therefore, N. retusa should be considered an endangered species in Kuwait. The reduction in vegetation cover, a decline in species richness, and the overall degradation of salt marshes are attributed to human development activities along the coast of Kuwait. Effective conservation actions for threatened species in degraded coastal salt marshes of this region include establishment of protective enclosures, prohibitions on development that adversely affects native plant communities, and the planting native salt-tolerant shrubs to facilitate regeneration.     

Diversity and Nitrogen-Fixing Activity of Phototrophic Mycetobionts of Xylotrophic Fungi

It is shown that the basidiocarps of many wood-decomposing fungi are inhabited by taxonomically and biomorphologically various eukaryotic (Charophyta, Chlorophyta, and Ochrophyta) and prokaryotic (Cyanophyta/Cyanobacteria) algae. They represent widespread eurybiont species and do not include any specialized mycetobionts. The communities formed by them have a host preference and green algae are their basic and obligate component, while other organisms are facultative components. Basidiocarps in which mycetobionts include heterocytic cyanoprokaryotes (Anabaena sp., Calothrix parietina, Hassallia byssoidea, Nostoc commune, N. punctiforme, Nostoc sp., and Scytonema ocellatum) are capable of molecular nitrogen fixation. Its activity is 0.044–0.903 mg of C₂H₄/m²/h in the basidiocarps of Bjerkandera adusta, Cerrena unicolor, Gloeophyllum sepiarium, and Trametes ochracea and 0.001–0.008 mg of C₂H₄/m²/h in the basidiocarps of Onnia leporina, Phellinus chrysoloma, Ph. tremulae, and Trametes pubescens. Basidiocarps without algae and those inhabited only by eukaryotic algae have no nitrogenase activity.     

Total soil available nitrogen under perennial grasses after burning and defoliation

Total soil available nitrogen concentrations (NO^–3 + NH ₄ ⁺ ) were determined underneath plants of the more-competitive Poa ligularis, mid-competitive Nassella tenuis and the less-competitive Amelichloa ambigua exposed to various combinations of controlled burning and defoliation treatments. Defoliations were at the vegetative (V), internode elongation (E) or both developmental morphology stages (V + E) during two years after burning in northeastern Patagonia, Argentina. Hypotheses were that (1) concentrations of total soil available nitrogen after burning are greater underneath burned than unburned plants. With time, these differences, however, will gradually disappear; (2) greater total soil available nitrogen concentrations are underneath plants of the more- than less-competitive perennial grasses; and (3) total soil available nitrogen is similar or lower underneath plants defoliated at the various developmental morphology stages in all three study species than on untreated controls at the end of the study. Concentration of total soil available nitrogen increased 35% (p < 0.05) on average after the first six months from burning in comparison to control plants. However, these differences disappeared (p > 0.05) towards the end of the first study year. Total soil available nitrogen concentrations were at least 10% lower underneath the less competitive N. tenuis and A. ambigua than the more competitive P. ligularis on average for all treatments, although differences were not significant (p > 0.05) most of the times. Defoliation had practically no effect on the concentration of total soil available nitrogen. Rather than any treatment effect, total soil nitrogen concentrations were determined by their temporal dynamics in the control and after the experimental fire treatments.     

The structure of absorbing roots in invasive and native maple species

Specific structural features of absorbing roots have been studied in Acer negundo (an invasive species in the southern Cisural region), compared to native Acer platanoides and A. tataricum. A comparative analysis of the diameter of fine roots, stele and bark volumes, and the frequencies of roots with retained primary bark, root hairs, arbuscular mycorrhiza, and dark septate endophytes has been performed in the invasive and native species from four habitats (by two habitats in the forest–steppe and steppe zones). The roots of A. negundo have been additionally studied in trees from two monospecific stands. It has been found that the structure of fine roots significantly differs between the invasive and native species: the roots of A. negundo are larger, with relatively poorly developed root hairs and low occurrence of dark septate endophytes. In monospecific stands, the frequency of mycorrhiza in A. negundo roots is very low, with arbuscules and dark septate endophytes being totally absent. It is concluded that specific structural features of the belowground absorbing apparatus in A. negundo are accounted for mainly by traits autonomously formed in a plant, rather than by characteristics of symbiotic relationships, and that they are not consistent with the assumption that the invasive species can utilize soil resources more effectively or more rapidly than taxonomically close native species.