The article analyses the dynamics of the population of 75 regional centers and second by population size cities of the regions in Russia. The analysis is based on the population census data from 1959 to 2010 and on the current recording data for 2011–2017. In the vast majority of regions, there is a significant dominance of the regional center over the second city. It manifests itself both in the absolute parameters of the population size and in the shares of regional centers and second cities in the population sizes of their regions. In 31 regions of the country, the share of the regional center by 2002 already reached 35% and continued to increase. Fifteen years later, in 13 regions of the country, it exceeded 45%. The maximum bar of possible concentration of the population in the regional center is not yet visible. Over time, the prevailing of regional centers over the second cities of the regions is increasing. The analysis showed that the opportunities for population increase in the second cities depend on their population size: gradually, between the second cities with a population of more than 250000 people, the number of growing cities is increasing; between second small cities, the share between depopulating and growing cities is practically unchanged. Thus, the tendencies of centrism in the regions take precedence over polycentricity. The population is increasingly concentrated in separate points, vested with power. These processes are based on historical and evolutionary (history of settlement, development and urbanization), functional-economic, administrative-territorial and demographic determinants. An increasingly important factor contributing to the concentration of the population is institutional factor (associated with the performance by the regional centers of the capital functions and reducing the costs of business and consumers).

The statistical relationships of interannual changes in the total duration of Long Arctic Invasion in Atlantic and Pacific sectors of the Northern Hemisphere with the formation of baric ridges between the Arctic and subtropical anticyclones with variations of climate indices of the El Niño–Southern Oscillation (ENSO) process are analyzed. Interannual changes in these indices in the 20th century significantly influenced the variations in the total duration of the considered Arctic invasions in the Pacific sector in February. For most indices, this effect was strongest if their ranks, ahead of the ranks of the processes studied for two months. The revealed relationships, in general, are not stationary and vary depending on the period under review. The relationship of ENSO indices and the total duration of the Arctic invasions in the Atlantic sector in November and October are significant in the 21st century, when the time shifts between these processes were 0–4 months.

The common types of non-standard employment among the rural population in Jewish Autonomous Oblast, and the main problems associated with their development in the border area are considered based on the analysis of statistical and sociological data on rural employment. It is revealed that in modern conditions the processes of development of non-standard forms of employment in the oblast are in its infancy and without changing the conditions the situation will remain the same. Currently, the population of rural areas prefers wage work (in agricultural and non-agricultural enterprises) even without official job placement, which corresponds to the all-Russian trends. The preference is given to employment in foreign farmers companies. The vast majority of the population sees no prospects for the development of their own business in rural areas; optimistic residents prefer to engage in small retail trade. The rural population is not ready to use as an additional source of income the production of decorative and applied products. Low financial literacy, lack of material resources and difficult socioeconomic situation in the oblast keep the active population from developing their own business.

The article presents the results of the study of the collective garden and dacha movement in the suburban area of Perm. The researcher offers a new definition of collective horticulture, gardening and dacha associations of citizens: “garden-dacha formations.” Such collective forms are special associations of people – territorial communities. They exist beyond working hours, within a limited space, mainly outside the urban environment. Such communities are characterized by seasonal activity and have specific interactions with the surrounding territory. The author proposes a methodology for identifying such communities. The study revealed their quantity, distinguishing features, and territorial distribution. The majority of Perm city residents have dachas in suburban Perm municipal district. Other inhabitants of Perm krai own dachas either in Perm municipal district, or in different municipal districts nearby. The various territorial levels of garden and dacha formations reflecting features of their interaction with each other and with the surrounding territory are defined: a site, a garden, an array, a cluster, an area. Factors of spatial distribution for garden and dacha formations across the territory are singled out; their distribution taking into account geographical peculiarities of Perm krai is considered.

The dependence of the understory alien plants distribution in urban forests of Yekaterinburg on such factors as urbanization, habitat fragmentation and structure of forest stands has been studied. Young growth and adult individuals of understory shrubs and trees were registered for 11 transects; 103 descriptions in round plots of 400 square meters have been analyzed. The first hypothesis was that the species richness and abundance of alien plants increased and the species richness and abundance of native plants decreased with the urbanization growth. It was partly confirmed for the statement that the species richness and abundance of alien plants increase with the growth of urbanization. However, the species richness and abundance of native species do not decrease. The second hypothesis is that the species richness and abundance of alien understory trees and shrubs are higher at the boundaries of the urban forests compared to their inner parts. This hypothesis has not been proved. The edge effect proper, implying changes of the understory state in the direction from boundary into the forest stand has not been observed either in the group of native species or in the group of alien species. The third hypothesis is that the species richness and abundance of alien understory trees and shrubs are higher in the urban forest areas adjacent to roads and in the forest stand with long-term boundaries. This hypothesis is partly confirmed. On the one hand, the species richness and abundance of alien understory trees and shrubs are higher in the urban forest areas adjacent to roads compared to areas, adjacent to wastelands. On the other hand, the species richness and abundance of alien understory trees and shrubs are higher in the urban forest areas with recently emerging forest stand boundaries compared to areas with the long-term forest stand boundaries.

The paleoecological study of the peat deposit of the floodplain terrace eutrophic peatland located in south of the taiga zone of Western Siberia was carried out. The work is based on an integrated approach including the following methods: radiocarbon dating, macrofossil analysis, rhizopod analysis, humification degree and physico-chemical characteristics of humic acids of peats. Comparison of the results obtained by different methods allowed us to reconstruct the history of the development of floodplain terrace eutrophic peatland determined by the local hydrological, geomorphological and geochemical conditions on the background of climate change. At the first stage of development, the peatland was often flooded by the river, which provided additional introduction of mineral matters and followed by increased ash content of peat. Then the influence of the river had weakened, and the growth of the peat deposit was more determined by the factors of endogenous peat bog formation and the level of surface hydrological runoff. This led to the formation of peats with normal ash content; hygrophytic grasses were replaced with sedges and hypnum plant assemblages. The eutrophic peatland showed the highest sensitivity to climate change over the last 8500 years. It is confirmed with synchronous variations of surface wetness in different bogs of the study area.

Methodological approaches to assessing the water potential of the territory, its resource and ecological components, are proposed and tested on the case study of Volgograd oblast. Data are presented on its main elements: local river runoff and inflow of river water from neighboring areas, surface and groundwater resources. The size and structure of its water-resource potential of Volgograd oblast is estimated. The current trends in the influence of water management, agricultural activities and climate on water resources are revealed. A hydroecological assessment of their changes is given. It is shown that the oblast has a significant potential for further use of its water resources, if not to consider the need in irrigation of the neighboring Astrakhan and Rostov oblasts by the Volga and Don waters. Taking into account the low quality of river waters, the water potential of Volgograd oblast can be judged as largely exhausted. The specifics of the current hydroecological situation are characterized.

The approbation of the DNDC (DeNitrification-DeComposition) model was done. The aim of research was to evaluate an opportunity of model using for analysis of carbon and nitrogen exchange and greenhouse gases dynamics in agroecosystems of arable soils in the Central Non-Chernozem zone in Russia. The verification of the model on the base of literature data detected that, as a rule, in arable Non-Chernozem soils modeled values of carbon biogeochemical cycle components and carbon dioxide emission are no higher than real ones. For nitrogen uptake by crops and nitrogen, leaching under fertilizing conditions, there was not conformity between modeled results and field experiments data. The method of verification on the base of carbon content in crop biomass calculation was presented. DNDC is good for spring grain crops modeling, but often the values of plant biomass are decreased by model plant biomass.

The case study of Tver oblast of the Russian Federation shows the possibility of obtaining a quantitative estimation of premature mortality caused by direct and delayed exposure to smoke from forest fires. It is based on an analysis of the mortality of the population, data on the duration of exposure to toxic substances contained in smoke from forest fires, and their concentrations. The materials of the space survey for smoke areas, the volumes of pyrolysis products released into the environment and statistical data on the death rate of the population for the period from 2007 to 2015 are analyzed. The dependence between the mortality of the population arising from diseases of the organs of the circulatory and respiratory systems and fires in forest territories has been revealed. Increased mortality is recorded both in years with the observed smoke caused by forest fires, and the following year, which may be due to direct and delayed exposure to smoke. It is determined that the increase in mortality from the pathology of the functioning of the circulatory system occurs directly during the period of forest fires, and from the respiratory disease in the following year.

The way of life of the outstanding Russian geographer, traveler, humanist, one of the initiators of creation and the founders of the Russian Imperial geographical society, honorary member of the St. Petersburg Mineralogical Society and one of the first successful climbers in the world Platon Aleksandrovich Chikhachev was bright, full of discoveries, adventures, tragic episodes, public recognition and oblivion. He was born in 1812, was on military service from 1828 to 1831, traveled to North and South America in 1835–1837, and in 1840– 1845 to Europe and Russia, where he took part in the creation of the Imperial geographical society. At the very beginning of his life, being a 16-years-old officer, he participated in 3 wars, later in the famous Khiva campaign of 1839–1840, and in the Crimean war in 1855. In 1856, he married and went to Europe. He died in Versailles in 1892, and was buried in Nice at the Russian cemetery. After retiring from the army in 1833, he devoted himself to travelling to Europe and the New World. He became the first Russian who in the early 19th century crossed Mexico from the East to the western coast of the Pacific Ocean; made a dangerous crossing on horseback in South America – from Chile through the Andes and pampas of Argentina reached Buenos Aires. Platon Chikhachev first conquered the mountain peaks – Pichincha volcano in Ecuador and Aneto peak, the highest point of the Pyrenees, and became one of the first climbers in Europe. The article adds new data to the well-known features of the biography of a guard officer, scientist, and traveler: little-known episodes of life, including those related to his stay in the homeland; it is clarified the sequence of events and the chronicle of the life of a scientist and traveler based on primary sources. The facts of Platon Chikhachev’s routes were specified, and contribution to the development of national and world geography was assessed.

Environmental atlases available online are considered. They were classified on the following criteria: the content, the territorial level of displaying, purpose of placement, relevance of the information, data format, and free access. The problems that arise when placing environmental atlases on the Internet are analyzed and the prospects of development of this direction of cartography are formulated.

Book review: In heritage focus. Collection of articles, M.E. Kuleshova, Ed., Moscow: Institute of Geography, RAS, 2017. 688 p.