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221.
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
222.
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
223.
V. G. Papchenkov 《Russian Journal of Ecology》2003,34(1):15-19
The time course of overgrowing, i.e., the appearance and development of vegetation on the water surface, has been studied in different water bodies. The types of succession in aquatic phytocenoses and the stages, degree, rate, and patterns of overgrowing are characterized. It has been demonstrated that the patterns of overgrowing differ depending on the type of water body, the differences being determined mainly by the ratio between the contributions of exogenous and endogenous processes to the dynamics of the plant cover. 相似文献
224.
Long-term stationary studies on the ecology of the northern mole vole (Ellobius talpinus Pall.), performed by the mark–recapture method from 1985 to 1997, have provided original data on population dynamics and structure. The analysis shows that, to reveal cyclic fluctuations of population size in this species, the period of three years should be taken as a unit of time for estimating the duration of one phase. The 12-year population cycle in E. talpinus has four distinct phases: an increase, a peak, a decline, and a minimum. At each phase, the population is characterized by certain features of family structure, age composition, birth and death rates, and the composition of migrants. 相似文献
225.
Geraskin SA Dikarev VG Zyablitskaya YY Oudalova AA Spirin YV Alexakhin RM 《Journal of environmental radioactivity》2003,66(1-2):155-169
The genetic consequences of radioactive contamination by the fallout to agricultural crops after the accident at the Chernobyl NPP in 1986 have been studied. In the first, acute, period of this accident, when the absorbed dose was primarily due to external beta- and gamma-irradiation, the radiation injury of agricultural crops, according to the basic cytogenetic tests, resembled the effect produced by acute gamma-irradiation at comparable doses. The yield of cytogenetic damage in leaf meristem of plants grown in the 10-km zone of the ChNPP in 1987-1989 (the period of chronic, lower level radiation exposure) was shown to be enhanced and dependent on the level of radioactive contamination. The rate of decline with time in cytogenetic damage induced by chronic exposure lagged considerably behind that of the radiation exposure. Analysis of genetic variability in three sequential generations of rye and wheat revealed increased cytogenetic damage in plants exposed to chronic irradiation during the 2nd and 3rd years. 相似文献
226.
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
227.
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
228.
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
229.
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
230.
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