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761.
Data are presented on the ecology of Siberian stone pine and Siberian larch in recent Altai mountain glacial basins at elevations above 2100 m a.s.l. The representative example of the Aktru basin is used to demonstrate the ranges of tolerance of these tree species to a series of ecological factors. 相似文献
762.
763.
Long-term studies have been performed on the seed progeny of B. inermis from test plots established along the radioactive contamination gradient in the zone of the Eastern Ural Radioactive Trace (EURT), where dose loads on maternal plants and embryos of seeds from chronically irradiated cenopopulations (with natural background radiation taken into account) exceed control values by factors of 2 to 107. Interannual and individual variation in the viability, mutability, and radiosensitivity of the seed progeny has been revealed. Against the background of high interpopulation variation in test parameters in the EURT zone, weather conditions appear to have no significant effect on seed quality, while such effects are appreciable in background cenopopulations. It has been shown that a positive correlation exist between the initial viability of the seed progeny and their radioresistance. Chronic irradiation in a wide dose range induces an increased frequency of different mutations and morphological modifications. The contents of low-molecular antioxidants in seedlings from impact cenopopulations proved to be higher than in the background sample. The results obtained characterize the potential of protective and restorative mechanisms acquired in the course of evolution that allow plants to survive in the changing environment under exposure to technogenic stress. 相似文献
764.
The aim of research was to assess the changes of annual radial increment of Scots pine forests in the vicinity of intensive and moderate industrial pollution of “Achema” factory producing mineral fertilizers. Our results indicate that the radial growth of the pine tree can be divided into three different periods: growth promotion, growth inhibition and growth recovery. Low levels of nitrogen emissions were beneficial for tree growth: the radial increment in the intensive and moderate pollution zones increased by 15–25% and 10%, respectively compared to control. During the growth inhibition period, the total annual industrial emission was 37–40 kt, and 40–45% radial growth loss was observed for the closest and 15–20% for the most distant stands. The radial growth decrease slowed down and the recovery of damaged stands began in 1990–1992 then air pollution was considerably reduced. The rate of forest recovery was high for the most damaged stands: their radial growth was close to control in 2000–2011. 相似文献
765.
766.
To restore food security to a traditional African cropping system following a sudden loss of seed, genetic diversity must be re-established. This study examines the extent to which Cowpea diversity was reinstated two years after a flood disaster in Gaza Province, Mozambique. The contribution that seed from various sources made to the recovery was assessed using semi-structured interviews and morphological and molecular data. Data suggest that diversity had recovered to some extent yet there was evidence of a narrowing of the genetic base, with fewer rare alleles and differences in the distribution of allele frequencies. Although the main channels for accessing seed after the flood were seed relief and markets, these sources contributed to minimal and different diversity. It appears that diversity was regained primarily through social networking in the form of loans or gifts of seed from friends and relatives. The results of the study are discussed in relation to seed relief approaches. 相似文献
767.
E. Yu. Zakharova 《Russian Journal of Ecology》2012,43(2):162-168
Phenotypic variation in the widespread Siberian and Mongolian butterfly species Coenonympha amaryllis (Stoll, 1782), an indicator of undisturbed steppe communities, is analyzed. It is shown that its size variation is influenced
by a complex of climatic factors, the most important of them being the average starting date of the frost-free period and
average annual temperature in the region. Longitude-dependent variation in size is described by a “sawtooth curve” characteristic
of species with changing voltinism. 相似文献
768.
The current state of the ecology of the impact regions is outlined. It is argued that the complex of ecosystems situated around
a point polluter (an impact region) is an appropriate model for solving several fundamental and applied ecological problems
related to the exploration of strong external impacts on biota. Typical methodological errors resulting from insufficient
attention to specific features of passive experiments are analysed, and ways to avoid them are proposed. The principles of
spatial arrangements of study sites within the impact region and of the selection of experimental and evaluation units are
discussed. 相似文献
769.
G. N. Tikhonova I. A. Tikhonov E. V. Kotenkova A. I. Munteanu I. G. Uspenskaya Yu. N. Konovalov V. I. Burlaku V. F. Kiku S. D. Georgitsa N. K. Karaman V. B. Nistreanu A. N. Mal’tsev 《Russian Journal of Ecology》2012,43(3):236-242
Comparative analysis of the structure of small mammal communities has been performed in two European cities located in different biomes: Chisinau (2008?C2009) and Yaroslavl (1994?C2002). The parameters studied included abundance, species composition, similarity and difference of faunas, species diversity, and proportions of groups differing in predisposition to synanthropy. It has been found that the structure of small mammal communities in these cities depends on specific physiographic conditions of the surrounding areas and on the distinctive features of the cities themselves (their structure, age, etc.). The similarity between the faunas is accounted for by the common ecological patterns of fauna formation in the biota of urban cenoses. 相似文献
770.
Integrated studies on the temperature regime in a limestone outcrop area have been performed, including analysis of the latitudinal trends and dynamics of direct solar radiation input onto slopes of different exposures and the redistribution of temperatures depending on mesotopographic features of the slopes. Assessment of the diversity of ecological conditions in this model landscape has shown that about 3.3% of its area is potentially suitable for the formation of a relict lithophytic floristic assemblage. 相似文献