Evolutionary ecological analysis of adaptation strategies of rodent populations under extreme conditions

Adaptive strategies of cyclomorphic rodent populations (Rodentia) under extreme conditions of droughts (in 1975 and 2010) have been analyzed on the basis of functional–ontogenetic approach. The following features of these strategies have been revealed: minimization of metabolic processes, block of sexual maturation, intergenerational crossing, prolongation of breeding period, and species-specific features in the dynamics of intrapopulation processes. Profound changes in the level of long-term oscillations of abundance after the drought have been noted in different species. Evidence is provided for the possibility of extremely rapid population rearrangements on an evolutionary scale that are fixed in a series of generations.     

Host Specificity of Flukes of the Genus Sphaerostomum (Trematoda: Opecoelidae) within Their Geographic Ranges

The host specificity of flukes belonging to the genus Sphaerostomum (S. bramae and S. globiporum) in the center and at the periphery of the genus range is discussed. Both fluke species are specific parasites of cyprinids. However, fish of nine other families and one cyclostome species have also been recorded as their hosts. At the periphery of the range, the spectrum of definitive hosts is broader than in the center owing to a greater number of unspecific hosts. In the center, unspecific hosts are represented by six fish species (Esox lucius, Misgurnus fossilis, Perca fluviatilis, Lota lota, Gymnocephalus cernuus, and Salmo sp.), four of which are predators. At the periphery, 11 fish species, including six predators (Anguilla anguilla, Barbatula barbatula, Cottus gobio, Cobitis taenia, Coregonus lavaretus, Salmo trutta, Alosa sp., Potamoschistus minutus, E. lucius, P. fluviatilis, and L. lota), and the cyclostome Lampetra fluviatilis are unspecific hosts. In the peripheral populations, compared to central, flukes manifest greater adaptive plasticity and can infest new hosts.     

Artisanal fisheries of the Itaparica reservoir,São Francisco River,Brazil: socioeconomic profile,environmental dynamics,and management recommendations

Currently, artisanal fisheries in fresh water reservoirs have been losing ground to commercial fish farming and a great deal of fishery resources are being threatened by human interventions, such as reservoir management and increasing net-cage aquaculture. This study aims to understand the impacts of environmental changes on fishery resources and analyse the migratory fish breeding season as a missing link for fishery management in the semi-arid area of the São Francisco River Basin. Among the 870 fishermen operating in the Pernambuco part of the Itaparica Reservoir, 10% were interviewed and affirmed that fish stocks have been compromised due to the closed fishing period’s incoherence, exotic species insertion, and changes to the river flow caused by reservoir construction and operation. A significant correlation was observed between the Reproductive Activity Index (RAI) and precipitation (p?=?0.745) as well as between the RAI and the river’s flow (p?=??0.909). This shows how important it is to consider both the semi-arid climate setting and reservoir operation in determining the closed period which should safeguard fish reproduction. Monitoring the fish reproduction period and research on the reproductive biology of native fish species is needed in the São Francisco River Basin’s different stretches in order to guarantee valuable fish stocks and fisheries maintenance. Integrated action between the fish resource users, civil society, and federal bodies/agencies is essential in order to mitigate impacts and improve fish production systems, not only in Brazil, but in other regions experiencing a similar scenario.     

Changes in the structure of a <Emphasis Type="Italic">Dactylorhiza incarnata</Emphasis> (L.) Soó population during the overgrowing of a meadow-bog community complex in the Moscow region

The overgrowing of meadow-bog communities by shrubs and trees (age 5–40 years, crown closure 0.4–0.9) leads to a decrease in incident illumination. As a consequence, juvenile and generative plants disappear from D. incarnata population loci, their average ecological density decreases, and the loci enter the state of regression. The digging activity of wild boars disrupts phytocenotically closed groups of longirhizomatous herbs, thereby creating favorable conditions for seed reproduction of D. incarnata. The species begins to form population loci with a complete ontogenetic spectrum and high ecological density, eventually restoring the normal (definitive) population structure.     

The state of cenopopulations and survival strategy of <Emphasis Type="Italic">Lilium monadelphum</Emphasis> Bieb. in a stressful environment (the Elbrus Region)

The authors present the results of studies on the state of cenopopulations (demographic parameters, ontogenetic structure, ageness, self-maintenance capacity, and vitality structure) of the bulbiferous perennial Lilium monadelphum Bieb. and on the ontogenetic strategy of this rare species under stress.     

The European whitefish, Coregonus lavaretus (L.), under conditions of technogenic pollution in the Kostomuksha tailing pond

The population structure and biological parameters of the European whitefish, Coregonus lavaretus (L.), have been analyzed in a technogenically polluted water body. The biochemical state of the whitefish and the fauna and morphology of helminths parasitizing them have been assessed. It is shown that the species composition of the fish, plankton, benthos, and parasite faunas of this water body are depleted and the morphological parameters of common fish parasites are altered. It is noted that, in addition to adaptive rearrangements in biochemical metabolism, the whitefish from the transformed water body are characterized by a reduction in the level of protein synthesis in muscles and the rate of aerobic energy metabolism in the liver and muscles.     

Change in the Life Cycle Strategy of Fish under the Effect of Chronic Water Pollution

Fish of a polymorphic and evolutionarily young species Coregonus lavaretusfrom a subarctic lake that has been polluted for more than 60 years are used as an example for analyzing principal trends in the dynamics of structural and functional organization of fish populations. It is shown that fish exposed to sublethal doses of toxic substances for a long time have a smaller body size, the period of their sexual maturation becomes more variable, and the frequency of spawning and life span decrease. The biochemical and bioenergetic mechanisms of variation in populations are analyzed. The ecological expediency of change in the life cycle strategy corresponding to r-selection (conversion to a short reproductive cycle) is substantiated.     

Climate changes and tree stand dynamics at the upper limit of their growth in the North Ural mountains

The composition and structure of tree stands near the timberline have been studied on different slopes and at different elevations in the Tylaisko-Konzhakovsko-Serebryanskii Massif, the North Urals. It has been found that the upper limits of tree stands with different degrees of canopy closure have risen considerably (by about 100 m of elevation) since the mid-19th century, although the formation of these stands started as early as the late 18th century. Woodless areas in the eastern part of the massif started to be colonized by Larix sibirica in the late 18th to early 19th centuries; those in the western part, by Picea obovata in the mid-19th century; and in the southern part, by Betula tortuosa in the late 19th century. Analysis of meteorological data provides evidence for warming and increasing humidity of the climate since the late 19th century. Favorable climatic changes that facilitated the expansion of the forest have taken place both in the summer (prolongation of the growing period) and in winter seasons (increase of air temperature and precipitation). The observed differences in the composition and dynamics of tree stands between the studied areas of the mountain range are most probably explained by different requirements of tree species for the depth of snow cover and the degree of soil freezing.     

Characteristics of parasitic infection in the least cisco, Coregonus sardinella valenciennes, 1848, in the Ural tributaries of the lower Ob

Data on the parasite fauna of the least cisco, Coregonus sardinella Valenciennes, 1848 in Ural tributaries of the Ob downstream of the city of Salekhard have been obtained for the first time. The formation patterns of the parasite fauna in this species and the rate (prevalence and intensity) of infection by Ichthyocotylurus erraticus (Odening, 1969), a parasite specific to coregonids, have been revealed. Infection of the least cisco with six parasite species (out of the 12 species found) occurs as the fish feed on zooplankton and benthic organisms. The dominant parasites are trematode larvae of the genera Ichthyocotylurus and, in some years, Diplostomum; this composition of dominants is evidence that the least cisco fattens up mainly in shallow areas. All sexually mature fish of this species were found to be infected by I. erraticus, but the average intensity of infection was rather low: the abundance index of the parasite did not exceed 40 ind. per fish. Analysis of the distribution of I. erraticus metacercariae in the least cisco shows that the relationship in the host-parasite system is stable and the parasite has no pathogenic effect on individuals of older age classes.     

Understanding the dynamics of heavy metals in a freshwater ecosystem through their toxicity and bioavailability assay

The current study investigates on correlating the heavy metal contamination, its distribution, and the human health risk associated with all three components of an aquatic ecosystem. For this purpose, water, sediment, and fish samples (three species, notably Notopterus notopterus, Clarias batrachus, and Channa striata) from Deepor Beel were considered, and their heavy metal contamination and distribution were determined. The corresponding health risks were then evaluated for six different heavy metals; Cr, Cd, Fe, Mn, Cu, and Pb. Pb and Mn were found to significantly impact the non-carcinogenic human health risks for the water column. Simultaneously, Cd was considered to possess the highest potential for both carcinogenic and non-carcinogenic health effects in the sediment column. Cd also played a critical role in the fish samples' bioaccumulation factor, with the liver showing the maximum bioaccumulation potential. Furthermore, children were found to have considerably higher effects (both carcinogenic and non-carcinogenic) than adults. Finally, the sediment column was found to substantially contribute to the bioaccumulation factor in the fish biota, compared to the water column. The results of this investigation will thus prove consequential in designing, monitoring and restoring aquatic ecosystems.

     

Radionuclide transfer to freshwater biota species: review of Russian language studies

Around 130 publications reporting studies on radionuclide transfer to freshwater biota species conducted in the former USSR were reviewed to provide the concentration ratio values. None of these studies were available up to now in the English language reviews or publications. The values derived have been compared with the CR values used for freshwater systems in the International reviews. For some radionuclides reviewed in this paper, the data are in good agreement with the mean CR values presented earlier, however for some of them, in particular, for ²⁴¹Am (bivalve molluscs, gastropods and pelagic fish), ⁶⁰Co (gastropods, benthic fish and insect larvae), ⁹⁰Sr and ¹³⁷Cs (benthic fish and zooplankton), the mean values given here are substantially different from those presented earlier. The data reported in this paper for thirty five radionuclides and eleven groups of freshwater species markedly improve the extent of available data for evaluation of radiation impact on freshwater species.     

Microorganisms: Indicators of pollution in integrated livestock-fish farming systems

Twelve fishponds each measuring 1,000 m² stocked with 2,000 fish consisting of 85% Oreochromis niloticus, 14% Cyprinus carpio and 1% Ophicephalus striatus were used to determine the level of fecal coliforms in the pondwater and fish flesh and the presence of Salmonella in the pondwater. Water samples for coliforms were collected at weekly intervals while those for Salmonella were done biweekly from three pond sites. Fish were randomly sampled by seining the pond over a three-month period. Both water and fish samples were analyzed for coliforms with the multiple-tube fermentation technique and for Salmonella using the swab technique. Results showed coliform counts with mean concentrations varying from 29,700/L of water in the middle of the pond to 18,100/L farthest from the manure dumping site. Differences in concentration between collection sites were not significant (P > 0.05) but mean values obtained weekly differed significantly (P < 0.05). Tilapia had coliform counts of 1.7 while carp had 1.1/g flesh. Differences among fish samples of the same species were not significant (P > 0.05) but were significant between species (P < 0.05). Biochemical tests revealed the presence of E. coli and Klebsiella sp. and more commonly S. cholerasuis.     

Changes of leaf morphology in <Emphasis Type="Italic">Betula pendula</Emphasis> roth and <Emphasis Type="Italic">B. pubescens</Emphasis> Ehrh. along a zonal-climatic transect in the Urals and Western Siberia

Leaf size, shape, and parameters of venation in Betula pendula and B. pubescens have been studied along a 1600-km latitudinal zonal transect in the Urals and Western Siberia. The results show that leaf size and venation density depend on the geographic location of population, with these parameters in the two species changing in opposite directions along the transect. In its northern part (forest tundra-southern taiga), B. pubescens shows a positive correlation of leaf area with long-term-average air temperature, while this correlation in B. pendula is negative. In the southern part, correlations of leaf size with long-term average precipitation in the two species are also opposite in sign. Parameters of leaf shape in both species depend mainly on weather conditions in the current year rather than on long-term average climatic parameters. The conclusion is drawn that B. pendula and B. pubescens have different mechanisms of structural adaptation of leaves to climate and weather conditions that are based on changes in leaf size and shape.     

Assessment of phytomass changes in an alpine <Emphasis Type="Italic">Geranium-Hedysarum</Emphasis> meadow after the removal of dominants: The results of a ten-year experiment

Changes in the aboveground phytomass of a Geranium-Hedysarum meadow community and its constituent species after the removal of dominants, Geranium gymnocaulon and Hedysarum caucasicum, over ten years have been studied in the Northwestern Caucasus. Responses of individual species to this intervention have been revealed. It has been shown that the phytomass of nondominant species increases under such conditions, but this cannot fully counterbalance the loss of phytomass resulting from the removal of dominants. Dominant species of Geranium-Hedysarum meadows exert different influences on the community structure and also compete with each other. However, this competition is fairly weak, which is probably due to considerable divergence of these species with respect to resource consumption.     

Assessment of the reproductive capacity of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> trees growing under conditions of chronic exposure to radionuclides of uranium and thorium series

The reproductive capacity of Scots pine (Pinus sylvestris L.) has been estimated in trees from the population growing in an area used to store tailings from uranium ore processing and radium production. Under such conditions, 12- to 15-year-old trees produce seeds of a quality inferior to that in areas with a normal background radiation level. As the weighted absorbed dose rate (at a weighting coefficient of 5) for generative organs increases from 0.002 ± 0.0003 to 0.344 ± 0.059 mGy/day, a proportional increase is observed in the proportion of empty seeds and the frequency of cytogenetic disturbances in the root meristem of seedlings, while the survival rate of seedlings decreases. The minimum absorbed dose rate leading to these changes in the pine population is 0.027 mGy/day, i.e., 12 times as high as the control value.     

Distribution of PCB congeners in aquatic ecosystems: A case study

Polychlorinated biphenyls (PCB) congeners were determined in water samples, sediments, and animal species in the frame of a survey of the River Arrone (Central Italy, near Rome) after a major contamination episode. Animal species were selected on the basis of their living and feeding habits and evaluated as candidate bioindicators of PCB pollution in this lotic ecosystem. Total PCB concentrations in water were found to be low (ng/L level), and in sediments, ranged from about 10 to 200 μg/kg dry weight, depending on the distance from the contamination source. PCB patterns in sediments showed a prevalence of higher chlorinated congeners over time. Concentrations in macroinvertebrates (Calopteryx splendens and Anax imperator) ranged from 60 to 400 μg/kg dry weight, showing significantly different species to species patterns. PCB concentrations were almost parallel in sediments for different sampling stations, while differences in patterns among species can be explained in terms of bioaccumulation/excretion mechanisms. Freshwater shrimps (Palaemonetes antennarius) were not found close to the contamination source, as a consequence of their extreme sensitivity to chemicals, and showed a peculiar pattern (almost exclusively determined by congeners 153, 138, and 180) probably originating from biodegradation mechanisms. Fish samples (Rutilus erythrophthalmus) showed the highest concentrations, as a combination of feeding habit, lipid content, and, probably, less effective biodegradation/excretion pathways. Congener patterns closely match those of Aroclor 1260, which originates from the contamination source. This study confirms that congener physical and chemical parameters, different degradation rates, feeding habits, and mobility of the analysed aquatic organisms, metabolism, and excretion mechanisms, are to be considered to explain the distinctive PCB patterns of different samples.     

Integrated climate governance in regions? Assessing Catalonia’s performance using the ‘climate learning ladder’

While developing climate change policies, regional governments and agents may have different purposes, follow different strategies, and use different appraisal procedures than those of national governments or other regions within the same countries. Climate change adds an additional source of problematisation to the functioning of traditional nation-states structures, not only at the international level but also with regard to their relations with sub-national agencies. This paper tests this hypothesis by analysing the emergence of climate strategies and capacities in region of Catalonia, north-east Spain, through the use of a novel integrated assessment tool called the ‘climate learning ladder’ that looks at four main dimensions: (1) how perceptions on climate change have evolved in this region since the beginning of the 1990s, (2) what type of incentives or systems of sanctions have triggered climate action, (3) what specific options are available or have been developed, and (4) what new institutional arrangements have been put in place during this time. Results indicate that although in Catalonia distinctive climate appraising processes have been tried, new measures have been implemented and new institutions have been created, not much of a distinctive progress regarding Integrated Climate Governance (ICG) has been achieved. Furthermore, this research shows that so far the main incentives which triggered climate action and innovation have been largely exogenous to the region.     

Consumptive values and local perception of dry forest decline in Burkina Faso,West Africa

Traditional ecological knowledge and local experience of resource management and the usefulness of plant species can make important contributions to attempts to understand forest ecosystems and to develop effective sustainable management strategies for them. Therefore, the utilization of tree species by local people, their perceptions of changes in the surrounding forests, and suggested solutions for associated problems, were studied in the Sissili province of southern Burkina Faso. Information was collected through a combination of participatory rural appraisals, household interviews, and observational methods. Principal component analysis was used to analyze the consumptive values of woody species and their respective parts. A total of 82 species were identified, 90% of them were used for medicinal purposes, 78% for fodder, 73% for food, 67% for house construction, and 58% for wood carving. This suggests that forests play a key role in sustaining the rural livelihood and contributing to poverty reduction. The various stakeholders perceived that vegetation clearing for cultivation of cash crops (agribusiness) was the main driver of the change in forest cover. Species reported to be declining in the area included Parkia biglobosa, Pterocarpus erinaceus, Afzelia africana, Bombax costatum, Tamarindus indica, and Diospyros mespiliformis. Thus, a concerted effort should be made to manage the remaining natural forests in the country. Appropriate management strategies should be developed jointly by the local communities and external support groups to integrate the valuable local knowledge about forest species with the stakeholders’ suggestions in order to promote sustainable management of the region’s forest ecosystems.