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151.
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.  相似文献   
152.
Does status matter in community-based forest management? If so, are the high-status households more benefited than the low-status households? What drives status differences, if any, in the appropriation of forest resources? To address these questions, we draw on a theory of status and resource use that defines one’s status as one’s relative position in a group on the basis of power, prestige, honor and deference. Following this perspective, we surveyed the heads of 341 forest-based rural households in India from 2009 to 2010. We find that collective actions themselves are status-driven and the high-status households are more interested and involved in status-maintaining collective actions such as decision-making and implementation, while the low-status households perform general tasks like forest patrol. Moreover, the high-status households derive benefits from local forest significantly more than the low-status households. Further, decomposition analysis shows that a household’s prestige and honor measured by its access to social resources, problem faced and useful contacts explain about 56 % of the status gap in forest benefits, while socioeconomic characteristics explain only 16 % of the gap. Thus, due emphasis on household status from a broader socioeconomic perspective is required to reduce inequality in participation and the distribution of forest benefits in co-management.  相似文献   
153.
The diminishing resources and continuously increasing cost of petroleum in association with their alarming pollution levels from diesel engines has led to an interest in finding alternative fuels to diesel. Emission control and engine efficiency are two of the most important parameters in current engine design. The impending introduction of emission standards such as Euro IV and Euro V has forced research towards developing new technologies for combating engine emissions. This paper examines the effects of compression ratio, swirl augmentation techniques and ethanol addition on the combustion of compressed natural gas (CNG) blended with Honge oil methyl esters (HOME) in a dual fuel engine. The present results show that the combustion of HOME and 15% ethanol blend with CNG induction in a dual-fuel engine operated in optimized parameters at an injection timing of 27° Before Top Dead Centre and a compression ratio of 17.5 resulted in acceptable combustion emissions and improved brake thermal efficiencies. The implementation of swirl augmentation techniques increased brake thermal efficiencies (BTEs) and considerably reduced combustion emissions such as smoke, HC, CO and NOx. The addition of ethanol also increased BTEs. However, at more than 15% of ethanol in HOME, NOx emissions increased dramatically.  相似文献   
154.
155.
The structure of bumblebee communities has been studied in some ecosystems of Kunashir Island and Southern Sakhalin. The island taxocenes include five to eight bumblebee species. Bombus hypnorum is dominant in the majority of habitats. In geothermal areas near hot springs on Kunashir, the families of this species develop more rapidly than in areas without geothermal heating.  相似文献   
156.
Consideration is given to changes in the vegetation and climatic conditions on the eastern slope of the Northern Urals in the second half of the Holocene as reconstructed on the basis of integrated palynological, botanical, paleocarpological, and radiocarbon analysis of material from a peat bog section in the floodplain of the Loz’va River. The results show that the northern taiga zone of the study region in the period between approximately 5000 and 700 years BP was occupied by forests of southern taiga facies, as the climate was significantly warmer than it is today.  相似文献   
157.
Changes in the distribution and abundance of some game mammals have been analyzed over the past 100–150 years. Correlations between changes in the population density of species in slightly and strongly transformed habitats have been revealed, which show that the influence of anthropogenic factors on the population density of species has a highly complex pattern. Transformation of habitats leads to disturbances in the species composition of communities, changes in the population density of species, and disruption of functional relationships between them.  相似文献   
158.
An interdisciplinary approach based on high-resolution physical stratigraphy, biostratigraphy, organic matter analysis and clay mineralogy has been applied to the mixed siliciclastic/carbonate Kimmeridgian/Tithonian deposits of the Boulonnais (north-western France). These rocks are the age-equivalents of some of the offshore marine source rocks of the North Sea and were deposited in an overall storm-dominated homoclinal ramp setting which may represent one of the most shore-proximal sediments of this age cropping out in north-western Europe. Comparison with data from the Yorkshire, Dorset, Lorraine and Aquitaine areas allows the discrimination of three major transgressive-regressive sediment packages with disconformities of interregional extent: (1) from the Baylei Zone to top Eudoxus Zone; (2) from the Autissiodorensis Zone to base Scitulus Zone; (3) from the upper Scitulus Zone to the Pectinatus Zone. The lower two regionally correlative disconformities correspond to the sequence boundaries at the top of the Eudoxus Zone and the top of the Autissiodorensis Zone, formed by high-frequency relative sea-level variations during the periods of maximum transgression of the platform. The latter disconformity (the P1 nodule bed) reflects a major tectonically induced reorganization of the north-west European intrashelf sedimentary basin, characterized by a shift in both the location of the main depocentre and the sources of sediment production.  相似文献   
159.
Environmental Science and Pollution Research - Few studies have documented the air quality, noise, thermal comfort, and health risk assessment of household kitchens related to Sub-Sahara Africa. In...  相似文献   
160.
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