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1.
2.
Abstract

Research into the basic qualitative characteristics (phens), their distribution and combinations (morphotypes) was undertaken in order to reveal the genetic diversity with respect to section Stenopoa in Asian Russia. About one and half thousands occurrences have been revealed, using herbarium samples and literature data, 1144 were involved in analysis. Four key characters have been used as phonetic markers: the presence or absence of the tuft of hairs on the lemma callus, rachilla surface, ligule length, and lemma surface between veins. Based on these characters and taking into account their xeromorphic level (4 character states), 46 different morphotypes among 96 possible ones were found; 24 morphotypes among 46 (56.5%) are suggested to be of hybrid origin, and 239 (20.89%) among 1144 investigated individuals seem to be of hybrid origin as well. High phenetic diversity of Stenopoa bluegrass indicated indirectly their high genetic diversity in Asian Russia. The highest morphological diversity and phenotypic richness were found in Altai-Sayan mountain systems and in the Baikal region.  相似文献   

3.
Phosphogypsum (PG) was used as substrate for the multiplication of eight ornamental species; six by cuttings and two by sowing. The results obtained showed a high rooting or percent germination for the six plants: Ficus benjamina, Pelargonium × Hortorum, Washingtonia filifera, Eucalyptus camaldulensis, Hibiscus rosa sinensis and Acalypha wilkesiana. For a percentage of 50% PG, only F. benjamina, H. rosa sinensis and W. filifera showed high percentage rooting. Plant vigour (height and biomass) depends on both species and treatment. Two species showed high sensitivity to PG during the propagation by cuttings, Nerium oleander and Myoporum laetum. We observed high variation in substrate characteristics; with 50% PG, pH was increased from 2.84 to 6.22, and electrical conductivity (EC) and gypsum concentration were reduced from 15.56 to 4.23 mS/cm from 36.23 to 11.82%, respectively. The results showed the possibility of using PG in nurseries for the multiplication and fertilization of several forest and ornamental plant species by cuttings and sowing.  相似文献   

4.
Microcosms of a boreal peatland originating from an oligotrophic fen in Eastern Finland were fumigated under four ozone concentrations (0, 50, 100 and 150 ppb O3) in laboratory growth chambers during two separate experiments (autumn and summer) for 4 and 6 weeks, respectively. Ozone effects on Sphagnum mosses and the fluxes of carbon dioxide and methane were evaluated. In both experiments, the three Sphagnum species studied showed only a few significant responses to ozone. In the autumn experiment, membrane permeability of S. angustifolium, measured as conductivity and magnesium leakage, was significantly higher under ozone fumigation (P = 0.005 and < 0.001, respectively), and there was a distinct dose-dependence. S. magellanicum showed no clear responses, either for membrane leakage or pigment content. There were no substantial ozone responses in the gross photosynthesis or net CO2 exchange during the 6-week-long summer experiment, but dark ecosystem respiration was transiently increased by ozone concentration of 100 ppb after 14 days of exposure (P < 0.05). Fumigation with 100 ppb of ozone, however, more than doubled (P < 0.05) methane emission from the peatland monoliths. Our results suggest that increasing tropospheric ozone concentration may cause substantial changes in the carbon gas cycling of boreal peatlands, even though these changes are not closely associated with the changes in Sphagnum vegetation.  相似文献   

5.
The objective of this study is to categorize the endogenous knowledge related to Syzygium guineense subsp. macrocarpum, a nectariferous plant in Benin, and to evaluate the impact of the use of different plant parts on its sustainability. The assessment of knowledge was based on the relative frequency of response, diversity index and equity index. In addition, the impact of different uses was measured by the degree of threat in the natural environment. Investigations identified many uses that have been categorized into 7 types, of which the most represented being energy (78%) and medicinal (51%). There is a significant variation in usage knowledge among ethnic groups (P-Value = 0.00). The degree of threat ranged from 15.17% to 46.39%. This study shows that S. guineense subsp. macrocarpum is a species for domestic, medicinal and oral use.  相似文献   

6.
Abstract

This article reports the species richness of vascular plants in the young fluvioglacial landscapes in the Severo-Chuiskiy centre of present-day glaciation using the example of the fluvioglacial deposits of the mountain-glacial basin Aktru. These landscapes are four well distinguished classes of habitats: open pebble fields with minimal vegetation, young larch forests on elevated parts of the relief, shrub thickets on the banks of the Aktru river, and sites with ground-frazil near the valley slopes. There are 132 species of vascular plants in the young fluvioglacial landscapes. These include 36 families and 77 genera. There are 3 species of pteridophytes (only Equisetum), 4 species of gymnosperms, and 125 species of angiosperms. The highest species diversity was recorded for Asteraceae, Poaceae and Salicaceae families, and for Salix, Poa, and Carex genera. The highest species richness – 100 species – were recorded for open pebble fields. There were 76 species in the young larch forests, and 58 species occurred in shrub thickets. The lowest richness is characterised for the sites with ground frazil, where 31 species were recorded.  相似文献   

7.
This paper reports an assessment of the effects of wood waste burning on air quality and the perceived human health in an urban setting. The concentrations of particulates and selected gases were monitored within the vicinity of sawmills in Abeokuta metropolis. The levels of CO, CO2, SO2, NOx, NO2, H2S, CH4 and particulates at distances from sawmill dumps were measured using portable samplers. Additionally, information on sawmill operations and health problems encountered by the exposed population were collected from a community survey. From the data analyses, between 60 and 100% of wood waste generated by sawmills were burned openly, leading to pollutants emission. The mean concentrations of PM0.3–0.5 (32 523–40 284 μg/m3), NO2 (1.0 ppm), SO2 (3.3 ppm), CO (759 ppm) and CO2 (4.9%) were higher than the permissible limits at 0–15 m from the dump sites. Almost all sampled parameters showed positive association (R = 0.90–0.98; p < 0.05) at sample sites. Moreover, distance of sites to the dumps explained 51–93% of the variation in parameters levels. Both respiratory and dermal diseases were frequently experienced by the exposed population. Strict land-use zoning, pollution abatement measures, environmental quality monitoring and waste-to-energy interventions are urgently required in the study area.  相似文献   

8.
Titanium concentrations and Ti inventories (total Ti in the sample) in living Sphagnum mosses from the surfaces of eight ombrotrophic peat bogs of five different regions of Germany and Belgium were studied over a period of two years (1995-7). Six to ten peat moss samples with a given surface area (100 cm2) and length (5 cm) were collected at different sites in the peat bogs studied several times (every six weeks to three months) during a year. Variability of Ti concentrations and inventories were determined within each peat bog for the species S. magellanicum, S. rubellum, S. papillosum, and S. cuspidatum, for the microhabitats 'lawn', 'slope' and 'hollow', as well as for the studied peat bogs of different regions and for each season. Likewise, Ti concentration values were determined for the moss plant segments: 'capitulum', 'living green' and 'dead brown'. Ti concentrations and inventories were found to be highly variable, even in one species of the same peat bog and at the same time. Moreover, median Ti concentrations and inventories of different species and microhabitats were quite similar to one another. As a result, we suggest that more productive species might be able to accumulate more Ti onto their bigger surface areas than the less productive ones. Besides, Ti particles might be transported downwards with the water and accumulated by the mosses over a longer time period than only one year. To reliably specify the variations in the geochemistry of peat mosses on the peat bog surface the annual production of each collected Sphagnum sample has to be exactly known and samples of equal ages and time periods they were exposed to atmospheric deposition have to be studied.  相似文献   

9.
Abstract

An assessment of the genetic diversity of nine microsatellite loci in honeybees of different origin (evolutionary lineages M, C, and hybrids) from different geographical regions of Siberia was conducted in order to find the genetic markers of the Siberian ecotype of dark-coloured forest bee (Apis mellifera mellifera). The greatest genetic diversity (both in the number of alleles and the calculated expected heterozygosity) was shown for loci A008, A113, Ap049, and A043 in honeybees from the Tomsk region, as bees from the southern districts had higher genetic diversity than bees from the northern districts. Honeybees from the Eastern region of Siberia (Yenisei population) had the lowest level of genetic diversity on these loci compared to Tomsk bee populations. Allele 162 pb of the locus A008, allele 126 bp of the locus A043, and allele 218 bp of the locus A113 can be considered as genetic markers of the A. m. mellifera Siberian ecotype.  相似文献   

10.
Peat mosses of the genus Sphagnum constitute the bulk of living and dead biomass in bogs. These plants contain peculiar polyphenols which hamper litter peat decomposition through their inhibitory activity on microbial breakdown. In the light of the increasing availability of biologically active nitrogen in natural ecosystems, litter derived from Sphagnum mosses is an ideal substrate to test the potential effects of increased atmospheric nitrogen deposition on polyphenol content in litter peat. To this aim, we measured total nitrogen and soluble polyphenol concentration in Sphagnum litter peat collected in 11 European bogs under a chronic gradient of atmospheric nitrogen deposition. Our results demonstrate that increasing nitrogen concentration in Sphagnum litter, as a consequence of increased exogenous nitrogen availability, is accompanied by a decreasing concentration of polyphenols. This inverse relationship is consistent with reports that in Sphagnum mosses, polyphenol and protein biosynthesis compete for the same precursor. Our observation of modified Sphagnum litter chemistry under chronic nitrogen eutrophication has implications in the context of the global carbon balance, because a lower content of decay-inhibiting polyphenols would accelerate litter peat decomposition.  相似文献   

11.
Abstract

The paper presents research in eco-coenotic features of cryopetrophyte communities of the Osevoi Ridge in the Western Sayan Mts. All communities studied are in the association Saxifrago oppositifoliaeRhodioletum quadrifidae. This association includes all communities with a predominance of alpine and arctalpine petrophytes, which are largely facultative and obligate calciphile plants. The coenoflora of the association Saxifrago oppositifoliaeRhodioletum quadrifidae is represented by 54 species of higher vascular plants. The dominant species in its structure are those of Holarctic distribution and species generally confined to the Altai-Sayan mountain region, with Papaver pseudocanescens, Poa smirnowii, Sajanella monstrosa, Saussurea foliosa and Saxifraga melaleuca being endemics. In the structure of the belt-zonal groups, arctalpine and alpine species dominate. Among ecological groups, obligate and facultative petrophytes, generally cryophytes, are dominant. The predominance of some particular belt-zonal and ecological groups of species indicates greater specificity of the environmental conditions in which the communities were formed and are currently being formed.  相似文献   

12.
Abstract

The criteria for assessing conservation categories of rare species are not identical in drafting the red lists of Russia and the IUCN. By the example of genus Saussurea (Compositae), we have shown that the conservation measures for some endangered species do not match their state. We conducted indicator analyses on two factors of more than 9000 relevés with Saussurea species with large ranges and determined their rarity types according to D. Rabinowitz. Only 2 Siberian Saussurea species are not characterised by any type of rarity. The other 54 taxa all feature a small range, low abundance or high habitat specificity.  相似文献   

13.
Abstract

This article describes the results of studying the Culicidae species composition in Tomsk region, during 8 years, 2008–2015. The survey revealed 31 mosquito species of five genera, namely Anopheles, Culex, Culiseta, Coquillettidia, Aedes. Dominant, numerous, common and rare species of Aedes genus were detected. The complete list of Culicidae species in Tomsk region was recorded. Ae. annulipes and Ae. sticticus were included in the species composition of Siberia; their presence in Tomsk region had previously been doubted. Some other species were deleted from the list because they were absent at the present time.  相似文献   

14.
Chlorpyrifos and lambda-cyhalothrin are two of the most commonly used insecticides in agriculture. Their residues reach water courses, affecting aquatic fauna and subsequently human beings. Aspergillus viridinutans and Penicillium implicatum isolated from water drains at El-Giza and El-Ismailia governorates were grown in potato dextrose broth media supplemented with different concentrations of chlorpyrifos and lambda-cyhalothrin. Samples, taken at 0, 7 and 14 days, were analysed for pesticide residues by gas chromatography. The fungal species showed biodegradation potentials of 2.5, 5 and 20 ppm of chlorpyrifos and lambda-cyhalothrin. Degradation percentage reached 100% after 14 days of incubation of both pesticides (2.5 ppm) individually with the two tested fungal species. The values of degradation rate, besides the weights of dry fungal biomasses ensured that the optimum chlorpyrifosconcentration for A. viridinutans and P. implicatum was 5 ppm, while the optimum lambda-cyhalothrin concentration for A. viridinutanswas 5 ppm and 2.5 ppm for P. implicatum.  相似文献   

15.
Problem, research strategy, and findings: Little research examines the effect of diversity on regional economic resilience to natural disasters. We examine whether economic diversity benefits regional economies in typical circumstances and in recovery after a natural disaster, using the case of the 1993 U.S. Midwest flood. By matching counties in the nine states affected by the flood to control counties, we isolate the influence of diversity on employment and income in normal circumstances and after a substantial shock. We found economic diversity to have mixed associations with employment and income in typical circumstances. On average, economically diverse counties tended to experience faster employment gains but slower growth in per capita income than less diverse areas. The effect of economic diversity upon resilience following a natural disaster was unambiguous. Economic diversity aided counties in weathering the downturn following the flood and sped their return to long-term patterns of employment and income growth.

Takeaway for practice: In promoting policies to enhance economic diversity, planners in communities located in areas prone to natural disasters should consider both the goal of disaster resilience and the potential tradeoffs between different aspects of economic performance.

Research support: None.  相似文献   

16.
ABSTRACT

There are approximately 6.6 million dwellings in the UK built before 1919, predominantly constructed with suspended timber ground floors whose thermal performance has not been extensively investigated. The results are presented from an in-situ heat-flow measuring campaign conducted at 27 locations on a suspended timber ground floor, and the estimated whole-floor U-value compared with modelled results. Findings highlight a significant variability in heat flow, with increased heat loss near the external perimeter. In-situ measured-point U-values ranged from 0.54?±?0.09?Wm?2 K?1, when away from the external wall perimeter, to nearly four times as high (2.04?±?0.21?Wm?2 K?1) when near the perimeter. The results highlight the fact that observing only a few measurements is likely to bias any attempts to derive a whole-floor U-value, which was estimated to be 1.04?±?0.12?Wm?2 K?1 and nearly twice that derived from current models. This raises questions about the validity of using such models in housing stock models to inform retrofit decision-making and space-heating-reduction interventions. If this disparity between models and measurements exists in the wider stock, a reappraisal of the performance of suspended timber ground floors and heat-loss-reduction potential through this element will be required to support the UK’s carbon-emission-reduction targets.  相似文献   

17.
The current study examines biometric parameters and concentration of some heavy metals in soft tissues of Saccostrea cucullata in the Asaluyeh coast, Persian Gulf, Iran. The metals concentration in the soft tissue of the Saccostrea cucullata ranged as: Zn: 765–3411 mg kg?1, Cu: 120.3–580.6 mg kg?1, Cd: 0.13–3.5 mg kg?1, As: 0.39–3.3 mg kg?1, Pb: 0.05–1.64 mg kg?1, Ni: 0.02–0.44 mg kg?1, V: 0.06–0.32 mg kg?1, Cr: 0.02–0.16 mg kg?1 and Hg: 0.002–0.068 mg kg?1. The results showed that the concentration of total heavy metals in oysters of the control station (CA) is usually lower. The results also indicated lack of correlation between oyster biometric parameters and bioaccumulated heavy metals, except between Cu and longitudinal diameter (R = 0.77). The concentration of heavy metals is higher than limits recommended by the World Health Organization, except for Cd and Pb.  相似文献   

18.
The presence of fungi in water systems represents a threat to human health. Hydrogen peroxide is known for its disinfecting properties and easy decomposition to water and oxygen. Its activity can be enhanced by the addition of iron as a catalyst, a reagent known as Fenton?s reagent. In the present study, different Fenton concentrations were investigated on the spores of Aspergillus flavus, Aspergillus niger and Penicillium citrinum at different time intervals. The results indicate that complete inactivation of spores was noticed after 60 min of exposure to both 2 and 3% H2O2 catalyzed by 0.025 g Fe2+/100 ml for A. niger, and 3% H2O2 catalysed by 0.075 g Fe2+/100 ml for P. citrinum. The activity of two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), was determined in mycelial mat harvested after 7 days. Their activities were either highly increased or reached their minimum values prior to inactivation of spores.  相似文献   

19.
A new isolate of bacterium Lysinibacillus sphaericus YMM capable of degrading malathion insecticide in liquid media was isolated and characterised. Biodegradation factors were investigated using Plackett–Burman factorial design, and the rest of the insecticide was monitored by high-performance liquid chromatography analysis. The near optimum conditions for degradation of 200 mg malathion/L were 30 mL medium, 2% of L. sphaericus suspension (0.70 OD600nm), pH 5,10 g/L glucose, 1.0 g/L NaCl, 0.3 g/L MgSO4, 1.0 g/L NH4Cl and incubation for 24 h without yeast extract and peptone or beef extract. In addition, the significant variables including the medium volume, inoculum and incubation time were further optimised using Box–Behnken response surface design. These conditions were found to be 30.10% medium and inoculum of 0.706 (OD600nm) for 23.636 h of incubation to achieve 98.974% degradation. Therefore, L. sphaericus YMM showed a potential degradation of malathion. Further studies should be conducted to understand the mechanism of biodegradation in liquid media.  相似文献   

20.
Sulfur source identification previously reported has been based on sulfur isotopic ratios in either rainwater or mosses. The δ34S values of rainwater sulfate and the epilithic moss Haplocladium microphyllum in Nanchang region (China) were determined for comparisons and used to delineate atmospheric sulfur sources. At the urban and rural sites, similar mean δ34S values were observed between rainwater sulfate (+ 1.6‰ and − 0.2‰, respectively) and epilithic mosses (+ 1.7‰ and + 0.6‰, respectively), suggesting that mosses acquire δ34S values similar to those found for rainwater sulfate. This has further demonstrated that moss δ34S signatures hold valuable source-specific information as rainwater δ34S values do. The δ34S values of both rainwater sulfate and epilithic mosses indicated that atmospheric sulfur in Nanchang region was mainly associated with coal combustion. The lower δ34S values at the rural site can be explained by higher contribution of local coals (lower δ34S values relative to those of north Chinese coals) and biogenic sulfur.  相似文献   

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