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71.
Phosphate rock samples collected from the Dange Formation within the Sokoto basin were analyzed for trace element constituents using instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRFA) techniques, while natural activity concentrations due to 235U, 232Th, and 40K were determined by gamma-ray spectrometry. The analytical results show that the average concentrations of some toxic elements (As, Sb, Cr, and Zn) in phosphate rocks are not appreciably different from that in agricultural soils. However the U and Th contents are enriched significantly in comparison. The results were used to assess the environmental toxicity of heavy metals and radiation hazard attributable to the direct application of phosphate rock as fertilizer. 相似文献
72.
N. P. Kosykh N. P. Mironycheva-Tokareva A. M. Peregon E. K. Parshina 《Russian Journal of Ecology》2008,39(7):466-474
New experimental data on biological productivity of plant communities in oligotrophic and mesotrophic bogs of the middle taiga subzone over the past five years are presented. The relationship between net primary production and the stock of live phytomass is estimated. The stock of necromass in oligotrophic bog ecosystems increases from west to east, while the stock of live phytomass and net primary production decrease. 相似文献
73.
Tanay B. Yıldırım Tutku Ak Zuhal Ölmez 《Environment, Development and Sustainability》2008,10(6):871-881
While the world is going into different tourism expectations, the tourism understanding in Turkey is defined as tourism in the sea-sand-sun triangle. However, it is possible to contribute to the income and local development of the indigenous people by developing nature-based tourism. Besides, with the sustainable use and preservation of the natural-cultural assets, the damage of the traditional tourism industry on the natural and cultural environment could be reduced. In this study, it is aimed to bring up the nature-based tourism concept in Çanakkale by evaluating the nature-based tourism industry in the general of Turkey and assessing the natural-cultural resources that Çanakkale comprehends. The most important areas that have a nature-based tourism potential in Çanakkale and the tourism activities that are most suitable for these areas have been determined. 相似文献
74.
Studies on paleosols under an archaeological landmark of a rare type (a complex of kurgans with “whiskers”) dating from the Early Iron Age (the fourth century AD) have been performed in the steppe zone of the Transural Plateau. The size and shape of third-order soil polygons under stony ridges (“whiskers”) between the kurgans have been described in detail. The results have shown that the paleosol under the kurgans erected at the turn of the Late Sarmatian and Hun times (1600 years ago) is characterized by a higher humus content and deeper location of the carbonate horizon, compared to the recent soil. This indicates that an increase in atmospheric humidity took place in the fourth century AD. 相似文献
75.
I.?M.?GrenEmail author M.?Bussolo M.?Hill D.?Pinelli 《Regional Environmental Change》2003,3(4):146-153
The paper calculates the implications of including monetary measurements of environmental emission changes for the welfare
impacts of ecological tax reforms in Italy and Sweden. Taxes on emissions of SO2, NOx and CO2 are investigated. Country-specific computable equilibrium models are used for estimating net welfare changes of the introduction
of these taxes, the incomes of which are used for reducing distorting labour taxes. The results indicate that the inclusion
of environmental benefits reduces the costs of ecological tax reforms considerably for both countries, and may even turn into
net welfare gains. 相似文献
76.
V. E. Zverev 《Russian Journal of Ecology》2009,40(4):254-260
Long-term monitoring of mountain birch populations (1992–2006) was performed in 14 test plots located at distances of 1 to 63 km from the copper-nickel smelter in Monchegorsk (Murmansk oblast) and differing in the degree of disturbance. In the period from 1999 to 2006, atmospheric emissions of sulfur dioxide and heavy metals amounted to only one-third of those between 1992 and 1998, but birch mortality in heavily polluted areas (with nickel concentrations in leaves exceeding 160 mg/kg) remained at the same level, being absent (as previously) in less polluted areas. Throughout the observation period, birch recruitment was observed only in areas where nickel concentrations in the leaves were below 160 mg/kg; i.e., this concentration proved to be the threshold with respect to both mortality and recruitment of mountain birch. The course of demographic processes in its populations has remained unchanged after the reduction of emissions, confirming the hypothesis of the “inertial“ effect of industrial emissions on ecosystems. In some areas of industrial barrens, mountain birch may perish completely within the next decade. 相似文献
77.
V. V. Tuzhilkina 《Russian Journal of Ecology》2009,40(4):227-232
To estimate the response of conifers to long-term industrial air pollution at the pigment system level, the dynamics of photosynthetic pigments have been studied in needles of Scots pine (Pinus sylvestris L.) and Siberian spruce (Picea obovata Ledeb.) growing at different distances from the emission source (a pulp and paper mill). It has been shown that the pigment apparatus of spruce. The results show that in spruce, unlike in pine, the pigment apparatus remains unchanged under the effect of weak pollution. Long-term exposure at high levels of industrial emission results in suppression of chlorophyll and carotenoid syntheses in pine but stimulates pigment production in spruce. An increase in the contents of pigments in the needles of conifers growing in the impact zone of the pulp and paper mill reflects a compensatory mechanism of adaptation of their pigment system to long-term stress exposure. 相似文献
78.
The paper is devoted to the phenomenon of methanogenic activity of woody debris, i.e., methane production in the course of wood decomposition by fungi, which are not directly involved in methane synthesis but form an initial link in the trophic chain leading to methanogenic archaea. Expert evaluation of probable amounts of methane emission is made. The results show that woody debris is an important global source of this greenhouse gas. 相似文献
79.
Species composition of fishes was studied in rivers (capture sites) inhabited by the riffle minnow. In some localities, this species proved to occupy a leading position in the ichthyofauna, being obviously dominant. In small rivers, 16 species were caught together with it, including seven species regularly occurring in catches. The relative abundance of riffle minnow showed a moderate positive correlation with that of the gudgeon (0.568) and a nonsignificant negative correlation (?0.399) with that of the bleak. It is probable that the population dynamics of riffle minnow are determined mainly by natural intraspecific mechanisms rather than by water quality, which has changed only slightly in the rivers studied. 相似文献
80.
S. M. Shafigullina 《Russian Journal of Ecology》2009,40(3):218-226
Interannual changes in geobiont and chortobiont abundance on the islands of Kuibyshev Reservoir are largely determined by flood conditions, because the seasonal average abundance of many taxa is negatively correlated to the water level in May and June. Floods influence the abundance of these animals both directly and indirectly, through biocenotic connections and some aspects of behavior. Long-term positive trends are observed in the abundance of many species. The hypothesis is proposed that this increase in the abundance of geobionts and chortobionts is a consequence of adaptation processes in these communities, which are stimulated by the flood regime of the reservoir. 相似文献