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1.
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.  相似文献   

2.
Coordinated soil–geobotanical studies revealed a close correlation between the species diversity of phytocenoses and soil properties in the Russkii Sever National Nature Park (Vologda oblast). Soil acidity, together with the concentrations of exchangeable calcium, potassium, and magnesium, is a factor determining variations of species diversity indices for vascular plants and bryophytes in forest biogeocenoses.  相似文献   

3.
Monitoring of A. uralensis populations in Kamenskii raion, Sverdlovsk oblast, in 1992–2002 and in Kaslinskii raion, Chelyabinsk oblast, in 2000–2001 revealed an increase in the proportion and diversity of minor morphogenetic aberrations and abnormalities in the structure of the cranium along the axis of the Eastern Ural Radioactive Trace (EURT). The samples from the southern and northern parts of the EURT (contaminated with 90Sr to 500 and 4 Ci/km2, respectively) were characterized by directed deviations from the control with respect to the frequencies of phenes of nonmetric cranial traits and an increase in the level of their fluctuating asymmetry in young females, which is indicative of epigenetic rearrangements in populations living in a radioactive environment.  相似文献   

4.
The index of cenotic significance and other indices calculated on its basis were used for revealing specific structural features of zooplanktonic communities in lakes differing in productivity. The results showed that new indices (complexity coefficient, index of cenotic significance of dominant species, and integrated cenotic significance of the zooplankton) strongly correlate with the trophic status of the water body and are more responsive to changes in the structure of the community than the Shannon–Weaver index of species diversity. The results confirm the hypothesis that the structure of zooplankton is simplified in the course of lake eutrophication.  相似文献   

5.
Two microbial extracellular enzyme activities (MEEA) were studied in HUMEX Lake Skjervatjern: acid phosphatase (APHA) and leucine aminopeptidase (LeuAMPA). Both enzyme activities varied in the vertical and horizontal scale in both lake sites. APHA varied in the acidfied Basin A between 945–1706 nmol L−1 h−1 and LeuAMPA between 3.7–25 nmol L−1 h−1. Both MEEA reached maxima in 0.5 m depth. In the control site (Basin B), APHA was lower by a factor of two, and varied between 156–669 nmol L−1 h−1. LeuAMPA reached similar values as in Basin A and varied between 7.8–34.8 nmol L−1 h−1. Maxima of APHA were found in the upper layer (0–2 m), while LeuAMPA had only one distinct maxima at 2–2.5 m depth. The number of bacteria (AFDC) varied between 4.4–8.8 106 cells mL−1 and was not significantly different in either side, but both had maxima in the thermocline. Highest specific LeuAMPA activities were found in the thermocline (3.2–4.5 fmol L−1 h−1 cell−1) in both sides and varied between 0.4–4.5 fmol L−1 h−1 cell−1 in both water columns. The main contributor (60–70%) to LeuAMPA was found in the microplankton fraction, retained on Nuclepore filters with pore sizes between 2.0-0.2 μm. APHA was retained less even on a filter with pore size smaller than 0.2 μm. About 50–70% of APHA passed through 0.2 μm-0.1 μm Nuclepore filters and could be found in the dissolved organic matter (DOM) fraction. APHA and bacteria counts (AFDC) showed a distinct gradient from the littoral zone to the pelagial in the surface water samples (0.2 m depth). APHA and LeuAMPA are regarded as important regulators for nutrient availability to microplankton. However, all data from vertical as important regulators for nutrient availability to microplankton. However, all data from vertical and horizontal samples showed that Lake Skjervatjern is a strongly gradient-dominated aquatic ecosystem. Watershed-littoral effects are more pronounced in the shallow, acidified Basin A than in the control side, Basin B.  相似文献   

6.
Radioactive contamination affects soil organisms and causes profound structural rearrangements in soil zoocenoses, which are manifested in the decreased species diversity of invertebrate communities and low relative abundance of large soil invertebrates. However, these communities gradually recover their initial structure. The soil biota near the epicenter of an underground nuclear explosion performed 30 years ago in Perm oblast has been studied to reveal specific structural features of the soil macro- and microfauna. Its structural diversity is considered with regard to such components as species (taxonomic) composition, the structure of dominance, and the ratio of ecological and trophic groups.__________Translated from Ekologiya, No. 3, 2005, pp. 171–179.Original Russian Text Copyright © 2005 by Kolesnikova, Taskaeva, Krivolutskii, Taskaev.  相似文献   

7.
The air quality in a newly built preschool was investigated in a longitudinal study. Typical air contaminants emanating from building materials were determined, their variation over time (0–18 months) was measured, and the influence of the ventilation system (81%–91% recirculation of return air) on contaminant concentrations was studied. Volatile organic compounds were sampled by adsorption on porous polymer, analysed by a GC/FID system, and identified by MS. A spatial build-up in concentration (ppb or μg/m3 levels) is evident for all the organic compounds, as well as for CO2, from the outdoor air, through the ventilation system, and through the rooms to the exhaust air. The longitudinal comparison over time shows that all the organic compounds decline in concentration mainly within the first 6 months of occupancy: 1-butanol 4–14 times, toluene and pentanal + hexanal 2–4 times, while formaldehyde remained at a constant low level of 90 ppb (110 μg/m3). It is difficult to believe that the problems of poor air quality in 100 preschools in Stockholm are caused by the organic compounds alone unless interactions occur. A preschool building needs to be gassed off during the first 6 months after its construction with no recirculation of return air allowed (outdoor air rate approx 4–5 ach). During at least 1–2 additional years, it is desired that the recirculation rate of return air is restricted, perhaps to 50%.  相似文献   

8.
The state of gonads was analyzed in sea urchins Strongylocentrotus intermediuscollected in Amur Bay (Peter the Great Bay, the Sea of Japan) in August 1984, 1985, 1989, and 1997 at five stations: Skrebtsov Island (1), Sportivnaya Harbor (2), Cape Tokarevskii (3), Alekseev Bay on Popov Island (4), and Verkhovskii Islands (5). The first three stations were in the polluted inshore zone of Vladivostok; stations 4 and 5 were in the open (insular) part of the bay, remote from the main sources of pollution. The state of gonads of sea urchins collected in different years and areas strongly varied with respect to gonad index (GI), gonad maturity index, and indices of pathological changes in gonads. As compared with the data obtained in 1984, 1985, and 1989, the values of GI increased in sea urchins from stations 1–3 and decreased in sea urchins from stations 4 and 5. Although GI values were high, the indices of gonad maturity in animals from the coastal zone were very low. In general gonad maturity in sea urchins from the Amur Bay was lower in 1997 than in the previous years. The correlation analysis of long-term data revealed no positive correlation between the values of GI and gonad maturity index in sea urchins from stations 1–4. Histopathological changes were more serious in sea urchins from stations 1–3. In 1997, the indices of pathological changes in the gonads of sea urchins from the insular zone (stations 4 and 5) were higher than in the previous period (1984–1989). The influence of various ecological factors—temperature, salinity, environmental pollution, and food supply—on gametogenesis in sea urchins is discussed.  相似文献   

9.
Trends of changes in species richness and dominance in staphylinid communities depending on the age of pine plantations have been analyzed. The species richness of these communities is high in the plantations of age classes 1 and 2 (11 and 28 years, respectively) but decreases in the plantations of age class 3 (60 years). The highest and lowest indices of species diversity are observed in the plantations of age classes 2 and 3, respectively. Four groups of rove beetles have been distinguished by the criterion of their dominance in pine plantations of different ages.__________Translated from Ekologiya, No. 4, 2005, pp. 306–313.Original Russian Text Copyright © 2005 by Derunkov.  相似文献   

10.
The correlation between climatic changes and the numbers of trees in the generations of Siberian spruce (Picea obovata Ledeb.) in subgoltsy tree stands of the Southern Urals was analyzed over the past 200 years. The results showed that the most abundant generations appeared in 1809–1816, 1821–1827, 1839–1845, 1850–1867, 1875–1887, 1891–1896, 1900–1904, 1911–1918, 1923–1932, 1944–1952, 1958–1966, and 1975–1995. Their formation proved to be related to the improvement of thermal conditions of the warm season during the five to seven years before and after the emergence of trees and conditions of the cold season in the year of their emergence, as well as to the periods of increased snow depth in late April in the years 27–32 of tree growth.  相似文献   

11.
In experimental mesocosms differing in water pH, the communities of macroinvertebrates demonstrated marked differences in their species composition and the quantitative ratios between the main groups of members (oligochaetes, chironomids, mollusks, etc.). The highest species diversity was recorded at pH 4.09–8.65. It proved to decrease at pH below 4 and above 9. In experiments on determining tolerance to water pH, seven groups of invertebrates differing in their adaptive potential were distinguished among 40 species found en masse in the freshwater zoobenthos and zooperiphyton of the Upper Volga basin.  相似文献   

12.
The study was conducted to assess the potential of Norwegian agricultural ecosystems to sequester carbon (C) based on the data from some long-term agronomic and land use experiments. The total emission of CO2 in Norway in 1998 was 41.4 million metric ton (MMT), of which agriculture contributed only 0.157 MMT, or <0.4% of the total emissions. With regards to methane (CH4) and nitrous oxide (N2O) gases, however, agricultural activities contributed 32.5% and 51.3% of their respective emissions in Norway. The soil organic carbon (SOC) losses associated with accelerated soil erosion in Norway are estimated at 0.475 MMTC yr–1. Land use changes and soil/crop management practices with potential for SOC sequestration include conservation tillage methods, judicious use of fertilizers and manures, use of crop residues, diverse crop rotations, and erosion control measures. The potential for SOC sequestration is 0.146 MMTC yr–1 for adopting conservation tillage, 0.011–0.035 MMTC yr–1 for crop residue management, 0.026 MMTC yr–1 for judicious use of mineral fertilizer, 0.016–0.135 MMTC yr–1 for manure application, and 0.036 MMTC yr–1 for adopting crop rotations. The overall potential of these practices for SOC sequestration ranges from 0.591 to 1.022 MMTC yr–1 with an average value of 0.806 MMTC yr–1. Of the total potential, 59% is due to adoption of erosion control measures, 5.8% to restoration of peat lands, 21% to conversion to conservation tillage and residue management, and 14% to adoption of improved cropping systems. Enhancing SOC sequestration and improving soil quality, through adoption of judicious land use and improved system of soil and crop management, are prudent strategies for sustainable management of soil, water and environment resources.Readers should send their comments on this paper to: bhaskarn ath@aol.com within 3 months of publication of this issue.  相似文献   

13.
The understanding and evaluation of the possible interactions of various naturally occurring radionuclides in the world's third largest man-made dam, Nagarjuna Sagar located in Andhra Pradesh, India and built on river Krishna assumed significance with the finding of uranium deposits in locations near the dam. For the present work, surface soil samples from the mineralized area of Lambapur, Mallapuram, Peddagattu and sediment core samples from the Nagarjuna Sagar dam were analyzed for naturally occurring radionuclides namely uranium and thorium using gamma spectrometric technique. Also toxic elements lead and chromium were analysed by the Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF) technique. Surface soil samples show a variation from 25 to 291 Bq/kg (2.02–23.5 mg/kg) for 238U and 32–311 Bq/kg (7.9–76.9 mg/kg) for 232Th. U/Th concentration ratio in surface soil samples ranged from 0.19 to 0.31 and was found comparable with the nation wise average of 0.26. The study of sediment core samples reflected higher U/Th concentration ratio of 0.30–0.33 in the bottom section of the core as compared to 0.22–0.25 in the upper section. The concentration ratio in the upper section of the core was similar to the ratio 0.23 found in the western Deccan Basalt region through which the river originates. A higher concentration of lead and chromium was observed in the upper section of the core compared to bottom section indicating the impact of river input on the geochemical character of dam sediment.  相似文献   

14.
A method for estimating floristic diversity at the species, genus, and family levels and the taxonomic structure of the flora of protected natural areas is proposed. The method is illustrated using the example of three nature reserves located in the Northern, Middle, and Southern Urals. The dependence of the characteristics of the regional floras on their positions in the system of botanical–geographic zones, the size of the protected area, and other factors have been studied in these reserves. The proportion of endemic plants and the degree of flora synanthropization have been determined.  相似文献   

15.
Human breast milk samples collected in 2007–2008 from four countries, Vietnam (Hanoi), China (Beijing), Korea (Seoul) and Japan (Sendai, Kyoto and Takayama), were analyzed for persistent organic pollutants (POPs) such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane-related compounds (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Comparing with previous surveys, the present study indicates that the DDTs in breast milk from China and Vietnam had gradually decreased during the last decade, but were still 5–10 times higher than those in other nations. The ratios of p,p′-DDE/p,p′-DDT and o,p′-DDT/p,p′-DDT were higher in Beijing than in the other countries, suggesting that there is less fresh intake of commercial DDT products and a possible exposure to dicofol in China. CHL and PCB levels were relatively higher in mothers from Japan, whereas β-HCH and HCB were more common in Chinese women. In Japan, it is suspected that mothers in the urban/coastal area (Sendai) were more continuously exposed to organochlorine pesticides (OCPs) than mothers in the rural/inland area (Takayama). In addition, OCP levels in primiparae were significantly higher than those in multiparae from Japan and Korea. These indicate that both parity and regional factors are major determinants of the levels of OCPs and PCBs in human milk. On the other hand, higher concentrations of PBDEs were observed in mothers' milk from Korea. The congener was dominated by BDE-47 (43–54%), followed by BDE-153 (23–33%) in all regions except for Beijing where BDE-28 (23%) was relatively abundant. In Japanese breast milk, regional and parity-dependent distributions were not observed for PBDEs. Among PBDE congeners, age-dependency was observed for BDE-153, which was negatively correlated (p < 0.05) to the age of mothers in Kyoto (17 participants were housewives), while it increased with age in Sendai (10 participants were clerks). No such correlation was seen for BDE-47, indicating that BDE-47 was ingested and assimilated via different kinetics or routes from BDE-153 in Japan.  相似文献   

16.
The relationship between growth indices and renewal rates of the Siberian larch (Larix sibiricaLedeb.) stands that have grown at the timberline in the Kuznetsk Ala Tau mountains during the past 350 years was analyzed. The age generations of larch were formed in the 1640s, 1660s, 1680s, 1700s, 1720s, 1740s, 1760s–1770s, 1800s–1810s, 1850s, 1870s–1880s, 1900s, 1920s, and 1930s–1940s. It was shown that the formation of these age generations coincided with 10- to 30-year periods of increased growth of larch and improved temperature conditions in summer.  相似文献   

17.
The communities of intestinal helminths found in the winter sample of ide (December–May, 45 fish) and in the summer sample (August–September, 42 fish) were compared. They consisted of 10 and 11 species, respectively, with Sphaerostomum globiporum being dominant in both communities. The species Parasymphylodora markewitschi and Capillaria tomentosa were found only in the summer community. Dominance and diversity (the Simpson and Brillouin indices) in the winter community were higher. All helminth species in the intestinal community of ide were of broad specificity. Therefore, host specialization does not play an important role in the forming of intestinal helminth community in this fish species.  相似文献   

18.
The Guanabara Bay basin, SE Brazil, is shown as an experimental site to evaluate development and sustainability in coastal areas. We developed a Driver–Pressure–State–Impact–Response (DPSIR) framework in a practical context to integrate natural and socio-economic indicators. Sustainability reflects public policies towards the utilization of natural resources. Cost-benefit analysis (CBA) included in DPSIR evaluates losses and benefits resulting from such policies. CBA has some limitations due to the difficulty of valuating environmental goods and services. Instead of valuating them we propose to combine sustainability indicators and defensive expenditures for the implementation of public policies. This approach agrees with the environmental conservation paradigm implicit in sustainable development. It allows an estimation of the physical natural capital depreciation (PNCD), by using it to correct the gross domestic product (GDP) of the study area, and demonstrating the present non-sustainable characteristics of the current policies applied to the area.  相似文献   

19.
Management of an Agroecosystem   总被引:4,自引:0,他引:4  
Agroecosystems (AESs) are autotrophic ecosystems managed by man. The goal of the management is to obtain the maximum possible amount of high-quality agricultural products while preserving agricultural resources, primarily the soils and biodiversity. The main components of the management of AES structures and functions, including primary and secondary biological production, the ratio between the energy flows in the plant–man and plant–livestock–man food chains, the efficiency of energy transfer in the plant–livestock link, and conservation of agricultural resources, are considered.  相似文献   

20.
Monitoring of 239,240Pu in surface air of Prague started in 1986 in connection with the Chernobyl accident. Measurable activities of 10–28 μBq m−3 were found from 29 April 1986 to 5 May 1986. In the most of the monitoring periods of 1987–1996, activities of 239,240Pu in air were not measurable. Positive values for 239,240Pu and 238Pu in air could be obtained after installation of an aerosol sampler with higher flow-rate in 1997. Activity concentrations of 239,240Pu and 238Pu in Prague air in the most of quarters of 1997–2006 were in the range 0.53–5.06 and <0.16–1.10 nBq m−3, respectively. Seasonal fluctuations can be found in content of 239,240Pu in air. Activity ratios of 238Pu/239,240Pu in air are higher than those in top soil, so it can be supposed that 238Pu is coming to air of Prague also from other sources than resuspension of fallout from atmospheric nuclear tests.  相似文献   

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