Activity of Beavers as an Ecological Factor Affecting the Zooplankton of Small Rivers

The role of beavers in the transformation of small rivers is elucidated by analyzing the taxonomic and trophic structure of zooplankton in ponds differing in age, water flow rate, and the degree of overgrowing with higher aquatic plants. The building activity of beavers in the river system promotes the formation of biotopes of the ecotone type, in which the planktonic invertebrate community develops some features similar to or different from those of zooplanktonic communities from lakes and rivers undergoing anthropogenic eutrophication. The main distinctive feature of response to this activity in zooplankton is that its development reaches a plateau at the early and middle stages of succession, compared to that under conditions of anthropogenic eutrophication. For small rivers, the concept of zoogenic eutrophication (in addition to anthropogenic) is proposed.     

Study of Cause-and-Effect Relationships in the Formation of Biocenoses: Their Use for the Control of Eutrophication

The cause-and-effect relationships existing in freshwater biogeocenoses and changing with time are conventionally divided into three groups: direct, directly mediated, and indirect. The possibility of using the indirect relationships for the control over natural systems is exemplified by a new scheme of eutrophication control and water quality improvement.     

On the Classification of Aquatic Communities: An Example of Zooplanktonic Cenoses of Karst Lakes in the North of European Russia

Nine lakes in the Arkhangelsk oblast were analyzed with respect to their morphometry, hydrology, and hydrochemistry, and their zooplankton was studied for three years. The data on zooplankton abundance, biomass, the ratio of filter-feeders and predators, the Shannon index of species diversity, and average individual weight of zooplankters were obtained. Differences in the structure of zooplanktonic cenoses were revealed in lakes differing in morphometric parameters, prevailing ions (HCO₃ ^–, SO₄ ^2–), and their concentration.     

Ground Fires as a Factor of Maintenance of Pine–Larch Forests in the Southern Urals

Russian Journal of Ecology -     

Spatial Distribution of Animals and Variation in Their Trophic Activity Measured Using the Bait-Lamina Test in Sod-Podzolic Soil under a Spruce Forest

The mode of spatial distribution of soil animals and their trophic activity was studied in the sod-podzolic soil under a spruce forest. At the test point level, no apparent relationship between the distribution of soil animals and physicochemical characteristics of the soil was observed. The patterns of distribution of detritophages and the trophic activity (measured using the bait-lamina test) were similar. The perforation of laminae in the bait-lamina test resulted from the trophic activity of both micro- and mesofauna.     

Zooplankton as an Indicator of the State of Lake Ecosystems Polluted with Mining Wastewater in the Kola Peninsula

The most informative characteristics of the zooplankton-community response to the effect of industrial wastewater from mines have been determined using water bodies of the Kola Peninsula as an example. It has been demonstrated that qualitative and quantitative characteristics of zooplankton depend on the degree of industrial pollution of a water body and adequately reflect differences in the conditions of zooplankton growth between the whole water bodies and their individual parts. The role of zooplankton as an indicator has been assessed and the possibility of including it in the system of monitoring of water objects has been substantiated.     

超声波提取-恒波长同步荧光法测定淡水藻中叶绿素a的含量

针对绿藻,采用超声波提取,以荧光激发-发射波长差216nm,建立了同步荧光法测定绿藻叶绿素a含量的新方法,其线性范围为0.02～1.25 mg/L,检出限为1.6ug/L,加标回收率在97.0%～104%之间。与分光光度法测定叶绿素a的对比试验结果表明,两者无显著性差异,但该方法具有快速、灵敏,其他常见色素不干扰测定的优点,能够满足供水中绿藻叶绿素a含量快速检测的需要。     

Proliferative Activity of Corneal Epithelium and Specific Features of Morphogenesis in Postmetamorphic Rana arvalisNilss. in Urbanized Areas

The mitotic activity and sizes of corneal epithelial cells in postmetamorphic Rana arvaliswere studied in the populations exposed to different degrees of anthropogenic impact in the city of Yekaterinburg. The studies were conducted at the initial stages of frogs' terrestrial life in three consecutive years. Mitotic activity exhibited a slight positive correlation with the liver index, which indirectly reflects the general metabolic rate in young frogs. The combined estimation of proliferative activity, epithelial cell size, and relative liver weight had the highest information value. There was a relationship between the mitotic index and liver index in young frogs from habitats with the highest level of anthropogenic transformation. This indicates that morphogenesis is well-balanced and is likely to decrease the probability of morphological abnormalities in frogs developing in the unstable environment. This physiological property allows the populations to exist and reproduce in urbanized areas.     

The Toad-Headed Agama Phrynocephalus guttatus (Reptilia: Agamidae): The Correlates of Survival in a Translocated Population in the Southwestern Kalmyk Republic

Observations of a translocated population of toad-headed agamas (Phrynocephalus guttatus) in the south of the Kalmyk Republic (1998–2001) have shown that seasonal differences in animal survival are manifested only in juveniles and the survival rate of juveniles is higher than that of adult individuals. A significant correlation between survival rate and sex is also characteristic only of juveniles: survival rate is higher in females than in males. In adult males, survival positively correlates with the level of activity; in juvenile males, with body size. In adult females, survival inversely correlates with body size and weight.     

Developments in the Framing of Climate Change as a Public Health Issue in US Newspapers

News media are major channels for the transmission of information to the public and deliver news about the latest developments regarding health issues such as climate change. How the media frame such information may enhance public understanding and enable appropriate responses by individuals and communities. This study follows up on previous research examining media portrayals of climate change in US newspapers from 1 January 2007 to 31 December 2008. Here, we content analyze 270 news stories on climate change as a public health issue from five US newspapers between 1 January 2011 and 31 December 2012. Findings indicate that the total number of articles about climate change declined while emphasis on the public health dimension of climate change increased. The types of generic news frames (i.e., dramatic/substantive) most frequently used did not considerably change across the two time periods, however. To explain this, we discuss ways in which people may assess and spark change in news framing of public issues to better reach and influence a range of audiences.     

Dynamics of species and species complexes as a field of research in historical ecology

Specific features of research on the dynamics of species and species complexes are considered on the basis of data on Late Cenozoic subfossil and fossil bone remains. Special attention is given to the objects to be reconstructed, the principles of their classification, and the concept concerning three scales of these dynamics: the actual, historical, and evolutionary scales. Published in Russian in Ekologiya, 2006, No. 6, pp. 452–456. The text was submitted by the author in English.     

Analysis of methanol and organometallic MnO2 fuels as alternative fuels in a diesel engine

In this study, methanol and organometallic MnO₂ fuels were used to improve the properties of diesel fuel. In addition, the effect of methanol fuel on engine oil and a piston ring was also examined experimentally in a four-cylinder, direct injection diesel engine running at 200 bar. Three different diesel fuels were prepared by adding 5, 10 and 15% methanol to diesel fuel. In order to prevent phase separation, 1% dodecanol was added to the mixture. Organometallic compounds of manganese were synthesised to prepare the solutions. The most effective amount and performance of anti-freeze were determined. From the results, it was observed that carbon monoxide emissions decreased and NOx emissions increased with the increase in the amount of methanol. On the other hand, organometallic MnO₂ increased the cetane number and decreased the freezing point, viscosity and flame temperature.     

Short-term seasonal variability in Be wet deposition in a semiarid ecosystem of central Argentina

The ⁷Be wet deposition has been intensively investigated in a semiarid region at San Luis Province, Argentina. From November 2006 to May 2008, the ⁷Be content in rainwater was determined in 58 individual rain events, randomly comprising more than 50% of all individual precipitations at the sampling period. ⁷Be activity concentration in rainwater ranged from 0.7 ± 0.3 Bq l⁻¹ to 3.2 ± 0.7 Bq l⁻¹, with a mean value of 1.7 Bq l⁻¹ (sd = 0.53 Bq l⁻¹). No relationship was found between ⁷Be content in rainwater and (a) rainfall amount, (b) precipitation intensity and (c) elapsed time between events. ⁷Be ground deposition was found to be well correlated with rainfall amount (R = 0.92). For the precipitation events considered, the ⁷Be depositional fluxes ranged from 1.1 to 120 Bq m⁻², with a mean value of 32.7 Bq m⁻² (sd = 29.9 Bq m⁻²). The annual depositional flux was estimated at 1140 ± 120 Bq m⁻² y⁻¹. Assuming the same monthly deposition pattern and that the ⁷Be content in soil decreases only through radioactive decay, the seasonal variation of ⁷Be areal activity density in soil was estimated. Results of this investigation may contribute to a valuable characterization of ⁷Be input in the explored semiarid ecosystem and its potential use as tracer of environmental processes.     

Historical deforestation as a cause of alluviation in small valleys, subcarpathian loess plateau, Poland

The undulating loess Kanczuga Plateau, 250–270 m a.s.l., is located in the temperate climatic zone of Central Europe, within the northern foreland of the Carpathians. It is dissected by a network of valleys 30–60 m deep, infilled with several metres of complex minerogenic and organic deposits which started to accumulate during the early Holocene. The southern side of one of these valleys is dissected by several dry valleys. The mouth sections of these valleys have buried surface comprising peat and/or organic silts, overlain by sandy–silty alluvium. ¹⁴C dates indicate that the alluviation of these valley floors, which proceeded from the headwaters to the mouth sections, began in the 1100 ad. The gradual intensification of soil erosion in the upper part of the catchment and associated sedimentation probably encompassed only a few centuries, with greatest alluviation during the Little Ice Age. This plateau, which is under the influence of more continental climatic conditions than the low-mountain and upland regions of Western Europe, features more climatic contrasts. Here environmental changes triggered by land use were superimposed on climatic change. The most intensive processes of soil erosion and sediment transfer as well as alluviation, coincided with the first phase of cooling during the Little Ice Age. It was the final stage of the intensification of these processes, probably more intensive than its initial phase in the eleventh century, caused primarily by deforestation resulting from the development of agriculture.     

The Carbon Cycle in the Ecosystems of Thermal Springs in the Chukchi Peninsula as a Natural Model of Warming

Comparative studies on the ecosystems in the vicinity of thermal springs and in the typical tundra were performed in the southeastern Chukchi Peninsula in July and August 1997. Biogenic carbon fluxes during the greater part of the growing season were determined, the aboveground phytomass structure was studied, and the carbon reserve in the soil was estimated. It was demonstrated that the gross primary production and soil carbon in thermal ecosystems are greater than in similar permafrost ecosystems. The structural and ecophysiological changes leading to an increase in the gross production of plant communities were analyzed.     

Normalized Brain Weight as a Characteristic of the Relationship between the Body and Brain Weights in Birds

The growth of many internal organs of vertebrates is isometrically related to the growth of the body. Therefore, calculation of the index of an organ makes it possible to eliminate the basic dependence of organ weight on body weight and to reveal the effects of second-order factors. The relationship between the brain and body weights is allometric in all vertebrates, from fishes to birds and mammals, including man. To make this relationship isometric, brain weight should be divided by the square root of body weight, rather than body weight proper. This parameter was previously named normalized brain weight (NBW). The advantage of using NBW instead of cerebral index has been demonstrated for 88 subarctic populations of different bird species.     

Using Local Knowledge as a Research Tool in the Study of River Fish Biology: Experiences from the Mekong

River fisheries are extremely important for food-security among the rural poor in many tropical countries. The growing populations and rapid industrialisation of these countries require that appropriate action should be taken to sustain the resources for future generations. However, an incomplete understanding of river fisheries biology, at the managerial level, often hampers proper planning and management. This is partly due to the difficult access to large parts of such river basins, the complex nature of the fisheries, and in many cases a severe lack of research funds. In contrast, the thousands, or often millions of people who live along the shores of the rivers and rely on the fishery for their daily survival, have a very intimate knowledge of the behaviour and biology of the fish. In this situation, gathering the knowledge of the fishers may provide politicians or planners with baseline knowledge in a relatively quick and cheap way.This paper discusses two years of research using local knowledge in the study of fish migration and spawning in the Lower Mekong Basin. The study involves semi-structured interviews with 355 expert fishermen in four countries along 2,400 km of the Mekong mainstream. By piecing together information from fishermen in different areas, we were able to construct migration maps, and provide rough estimates of the spawning period for 50 fish species. We conclude that river fisheries research can benefit significantly from local knowledge as the basis for future research.     

Larvae of Sand Smelts (Atherina hepsetus L.) as a Bioindicator of Pollution in the Black Sea Coastal Waters

The activity of antioxidant enzymes and electrophoretic protein spectra were studied in sand smelt larvae inhabiting from five Sevastopol bays with different degrees of anthropogenic impact. The activity of antioxidant enzymes and the heterogeneity of electrophoretic protein spectra proved to increase in the larvae from the most polluted waters. The possibility of using these parameters as biological markers for assessing the influence of pollution on the early stages of fish ontogeny and the marine environment are discussed.     

Free radicals and chromosome aberrations in leaves of woody plants as a test system for the genotoxicity of the urban environment

A new method for estimating the genotoxicity of the urban environment is proposed. The method is based on the analysis of the lipid peroxidation (LPO) rate in leaves of woody plants. The mutagenicity of the urban environment was estimated using standard test systems, including plant root meristem (kidney beans germinated in water with suspended particles collected at different points along the Temernik River) and the Ames test (silt samples were tested). Sensitivities of elm, willow, and poplar leaf meristem cells to unidentified environmental mutagenes were compared. Frequencies of chromosome aberrations (CAs) in leaves of woody plants growing at different points along the Temernik River within the Rostov-on-Don city districts differed from those in the control zone. The frequency of CAs was found to correlate with the concentration of LPO products. This allows a biochemical estimation of the malonic dialdehyde (MDA) concentration in woody plants to be used as an express test for the mutagenicity of environmental factors. An advantage of the proposed test is the possibility of monitoring the level of unidentified environmental mutagens over many years, independently of its sporadic temporal variations.