The article deals with complex studies of  the  Finnish case particularly migrants’ inclusion analysis into local cultural and political environments (as conditions to cultural and political environment stability) as well as public diplomacy impact evaluation of an important «soft power»  tool where migrants role is rather high. Authors scrutinize migrants’   interaction with  the  environment,   outline cause-and-effect   links of  this interaction, and unveil external factors that influence the respondents’ political behavior. The research  method is based upon interviews,  which result  in respondents’ typology development, political information channels were defined, and the influence of education and social inclusion upon political communication  was characterized. This method helps to perceive migrants’ integration policy at example of Finland, the fourth most attractive country  in the world in accordance  with the Migrant  Integration  Policy  Index.  Finnish experience could be highly useful for Russia in terms of both national migration policy development.   The resulting characteristics  of migrants’ political communication  might be of high interest in terms of migration policy regulation and understanding the issue of migration quotas, help to predict structural changes in society, also to provide the basis for making decisions on the effective use of public diplomacy tools.

The article deals with the analysis of student educational  migration and its role in origin of spatial contrasts at the territory of Russian early developed regions. In the paper ongoing processes are considered on the case of Yaroslavl oblast at the intra- and interregional levels and compared to processes abroad on the case of German federal state of Bavaria. The results are based on examination of official statistical data, surveys among students (disclosing their spatial behavior during the study and after degree completion) and  expert interviews   with  university   spokespersons.   Migration bonds of  Yaroslavl universities as well as space-time  features of educational  migration  (average distances, time costs, transportation means) in Yaroslavl oblast and Bavaria are revealed. The study found that educational  migration (together  with other population  mobility types) plays an important  role in spatial  polarization  at the research  territory due to importance  of Yaroslavl as big educational  centre for northern part of Non-Chernozem zone ( Vologda, Arkhangelsk, Kostroma oblasts and Komi Republic). School-leavers  from small cities and countryside come to the regional capital for bachelor ’s degree completion, next they try to go to Moscow, St. Petersburg  or other largest cities not only to get masters’ degree, but also in search of life conditions  improvement. They want to change place of permanent residence and to have a career on perspective labor market.

Eastern Kazakhstan   and  the  adjacent Gorno Altai of  southern Siberia encompass  very mosaic landscapes  across all the geographic  and geomorphic  zones enclosing numerous (pre-)historic monuments, some of them being a part of the UNESCO World natural  and cultural  heritage.  Excepting  the high-mountain  ranges (Rudno and Southern  Altai, Narym,  Tarbagatay  and Dzhungarskiy  Alatau) surrounding  the territory, the interior open arid steppes characterized by a broken relief of the granite-built Central Kazakhstan Hills as well as the barren rocky semi-deserts in the SE parts of the land remain largely unexplored  and tourism-uncovered. The extraordinary topographic  diversity was generated  by complex  geological processes  associated with the Cainozoic  orogenesis and the changing Quaternary  climates.  Geo-tourism  focusing  on the most exquisite landscape forms (geo-sites) and geological formations is a new trend in the country with still minor  activities that take advantage  of the region’s supreme geo-heritage potential. The unquestionable  touristic-recreational  attractiveness of this geographically marginal area of Central  Asia (historically a part of the Russian Empire’s Tomsk Gubernia)  reflects unique natural features – both geomorphic and biotic – including orographic, hydrologic, climatic,  mineral and pedogenic,  as well as rare endemic  plants and wildlife in addition to the colour ful national Kazakh and Russian traditions. In spite of these predispositions, an introduction of a vital, sustainable geo-tourism in East Kazakhstan is impeded by the limited accessibility to the region due to an insufficient year-round transport infrastructure and poor local accommodation  facilities in addition to the restricting boarder-zone entry regulations.

The article gives an analysis of a unique data of the thermistor chain, which installed on the D-6 oil platform in the coastal zone of the Baltic Sea. In total 10 temperature sensors were installed at different depths with a recording  interval of 1 min, the depth at the installation site was 29 m. Based on satellite data, ship measurements  and thermistor chain observation  the characteristics  and dynamics of the sharp decrease in water temperature which registered in the south-eastern  Baltic Sea (Gdansk Bay area), during June 5-12, 2016 are analyzed. The temperature decreasing caused by the simultaneous action of at least two factors: wind-driven Ekman upwelling and advection of cold water. Scales of temporal  and spatial  variability  of water temperature in a coastal zone of the south-eastern Baltic Sea near the coast of the Kaliningrad region are described. This event led to the considerable SST (sea sur face temperature) drop by more than 8 °C for two days. The rate of reduction of its temperature during certain upwelling periods can reach 0.3-0.4 ºС per hour, but the maximum  warming  rate between  phases varies from 0.25 to 0.28 ºС per hour. This dramatically changed  the conditions of the thermal balance of the sea sur face. The width of the upwelling, as seen in the SST data, was about 25 km. Satellite data were supplemented with data of a thermistor  chain and C TD measurements. The high correlation between  water temperature variability and changes in wind parameters: when the wind speed has decreased and its direction has changed, the response of the vertical thermal structure has occurred very quickly, sometimes within 1 hour. Thermistor chain data allow to evaluate the vertical temperature distribution and get more detailed analysis of temporal  variability and short pulsations of upwelling.

The Don River is the largest river in the southwestern  part of European Russia and the second largest  river system  in European  Russia. The Don River  basin is one of the most water deficient regions in Russia and the long term average water usage in the basin amounts to 45%. The period 2007-2016 was the longest long-term low-flow period observed, with an estimated total water resources deficit of 40.4 km³  over 8 years. The main reason for this deficit were anomalously  warm  winters (2-4 degrees  over average) with a low degree of soil frost penetration. This resulted in low spring flood volume  (37% of the average) due to heavy seepage losses combined  with thin snow cover.  A similar low-flow situation was observed in 2014, when the drought caused great damage to ecosystem of Tsimlianskoye water reservoir and the River Don. Most of the fish breeding  grounds  had dried up by May 2014. This caused the number of round fish whitebait to drop 5-10 times below the 2002-2014 average.  Inland shipping  and hydropower  industry also sustained losses of 42 million euro (according to interview from State Shipping company) due to low water level. This study shows that the main reasons for the 2007-2016 extreme hydrological drought are exceptional hydro-climatic conditions and anthropogenic  transformations in the watershed,  such as urbanisation growth  and afforestation.  The analysis  shows that the main cause in water deficit is associated with the left tributaries  of Don – Khoper and Medveditsa, while the flow in Upper Don remained more or less normal. The results can be interpreted as a “warning sign” to reduce water consumption in these sub-basins to avoid similar drought situations in future.

Building of scientific basis for harmonious exploitation and spatial organization of the economy  (land use) is one of the key issues of present-day geography. The study of land resources includes consideration of the relations between economic  development, profitability and potential opportunities for further development of the territory, possibility of disturbed lands recovery and returning to the economic turnover, and preservation – all of those things which are necessary for human life worth living. Identification and analysis of land use types and forms is a necessary step of any economic-and-geographic  study of a certain territory on the basis of statistical data and field survey. The creation of optimal land use schemes, taking into account  the assessment of the conditions  for certain types of management placement in given  territory, has practical  importance.

This paper presents  the logical  model of the area natural conditions  influence  on the evolution of urban land, shows the ways of creating the model of comfortable environment, where  all types of the place attractiveness – ecological, social and economic – should be balanced.

A constructive   formula  for the geomorphic  assessment  of territorial resources  includes the synthesis of benefit and profit. That is an engineering and ecologic-and-geomorphic assessment of lands in terms of the convenience for some sort of economic activity, taking into account the ecologic-and-geomorphic restrictions, as well as the economic evaluation of the engineering site preparation, taking into account  the availability of recreational and specially protected  areas,  as well as environmental  insurance  against adverse processes and phenomena – maintaining of favorable living conditions.

The trends and variability of climate change were studied through analyzing the trend of change in the annual temperature and rainfall averages  during  the period (1960 – 2016) in Al-Sheikh Badr Region  by using Normal  Distribution and De-Martonne index.  The results showed a (-189 mm) linear decrease in the general trend of the rainfall, associated with a (+0.9o C) increase in the general trend of the temperature between 1960 and 2016. Also, Normal distribution showed that the probability of extreme temperatures events  higher  than 17.5oC increased  from  3.3% during  the period  1960-1990  to 24.8% during the period 1991-2016. While the probability of an extreme  annual  rainfall (more than 1800 mm) decreases  from  5.3% to 4.7%,  nevertheless,  the probability  of rainfall events less than 800mm where increased.  Furthermore,  there is a significant  trend of drought in the studied area, where the De-Martonne index reaches (-10.75) through the period (1960-2016).

The new concept of bioremediation  of anthropogenic water bodies and quarry wastewaters treatment by phytoextraction and phytotransformation in the Subarctic conditions is presented.  This technology is based on transformating  the man-caused water reservoirs  into nature-like  marsh ecosystems.  At the first stage,  a new patented method for advanced waste treatment using floating bioplate was developed and implemented. After implementing  the bioplate, the concentration of ammonium ions in water decreased by 53-90%, nitrate nitrogen reduced by 15-20%. At the second stage, the floating bioplate technology was modified into the highly efficient purificating marsh ecosystem, which allowed to cover the waterbody  territory to the greatest possible extent. The technology is based on the creation of phytomats enabling in the accelerated mode to form plant blocks of three different types. They are aimed both at local grassing down, and at swamping deep and shallow areas of sediment ponds. In forming phytomats, two soil substitutional substrates (thermovermiculite  and wood sawdust) and regionally-optimized  assortment of 24 plant species are used. The proposed technology does not require energy, chemicals and soil components which are scarce in the region. The predominance of natural ecosystem  processes in the formed phytocenoses allows to achieve maximum efficiency, and the use of available materials contributes to minimizing the costs of creating and maintaining the system. The introduction of this technology and formation of the artificial phytocenosis  with the area of about 30% of the man-caused  reservoirs territory made it possible to increase the efficiency of wastewater treating from mineral nitrogen compounds  by 22%.

In  the past, most of the open lands of arid areas were used as rangelands because of the pivotal role of grazing in the life of the indigenous populace. Currently, because of the competition  between grazing  and other types of land management (crops’ breeding, urbanisation, etc.) and the seemingly destructive effect of the grazing on the ecosystem, only a reduced part of the open lands is used for grazing. Even in the lands that are allocated  to pasture,  many restricting’ legislations  have been enforced  by the authorities.  Consequently,  these policies have resulted in the dramatic reduction in the profits of the herd owners and a drastic decrease in the rate of grazing, which  resulted by ecological catastrophes such as wide spread of fires and invasion of exotic species. In order to achieve a sustainable and profitable utilization of these open lands, we used an alternative approach,  which based on the physical interactions of the animals with the ecosystem. This scheme takes  into consideration  the physical  interactions  of the bred animals with the ecosystem there, the statutory state of the lands, and the social patterns of the indigenous farmers, as parameters  for a holistic solution  for arid lands.

The  paper reports   on  the  results   of  the  pollen, plant macrofossil   and geochemical  analyses and the AMS 14C-based  chronology  of the «Rüdersdorf»  outcrop situated  east of Berlin  in Brandenburg  (Germany).  The postglacial  landscape  changed from an open one to generally forested by ca. 14 cal.  kyr BP. Woody  plants  (mainly  birch and pine) contributed up to 85% to the pollen assemblages ca. 13.4–12.5 cal. kyr BP. The subsequent Younger Dryas ( YD) interval is characterized by a decrease in arboreal pollen (AP) to 75% but led neither to substantial deforestation nor spread of tundra vegetation. This supports the concept  that the YD cooling was mainly limited to the winter months, while summers  remained  comparably  warm and allowed  much broader  (than initially believed) spread of cold-tolerant boreal trees. Further support for this theory comes  from the fact that the relatively low AP values persisted until ca. 10.6 cal. kyr BP, when  the «hazel phase» of the regional  vegetation  succession   began. The postglacial  hunter-gatherer occupation is archaeologically confirmed in Brandenburg since ca. 13 cal. kyr BP, i.e. much later than in the western part of Germany and ca. 1000 years after the major amelioration in the Rüdersdorf environmental record.

Pollen analysis was carried out on an 80-cm sedimentary section on the shore of Lake Tere-Khol (southeastern Tuva). The section consists of peat overlapping lake loams and covers the last 2800 years. The alternation of dry-wet and cold-warm epochs has been established, and changes in heat and moisture occurred non-simultaneously. The first half of the studied  interval, from 2.8 to 1.35 kyr BP was relatively arid and warmer on average. Against this background, temperature fluctuations occurred: relatively cold intervals 2.8–2.6 and 2.05–1.7  kyr BP and relatively warm 2.6-2.05 and 1.7-1.35  kyr BP. The next time interval 1.35-0.7  kyr BP was relatively humid. Against this background, the temperatures varied from cold 1.35-1.1  kyr BP to relatively warm  1.1–0.7 kyr BP. The last 700 years have been relatively cold with a short warming from 400 to 250 years ago. This period included a relatively dry interval 700–400  years ago and more humid climate in the last 400 years. The established  climate  variability largely corresponds  to other climate reconstructions in the Altai-Sayan  region.  The general  cooling trend corresponds  to an astronomically determined  trend towards  a decrease  in solar radiation  in temperate  latitudes  of the Northern  Hemisphere,  and the centennial  temperature  fluctuations  detected against this background  correspond  well to changes in solar activity  reconstructed  from  14C production  and the concentration  of cosmogenic isotopes  in Greenland  ice.  Against the general  tendency  towards  aridization, alternating  wet and dry phases  correspond well to changes in the activity of the Asian monsoon, established by the oxygen-isotope composition of speleothems in South China.

Changes   in vegetation  in the southern  Sikhote-Alin  Mountains,  which are in the upper reaches of the Ussuri  R., are shown respond to minor climatic fluctuations over the past 5.4 ka. The largest mountain,  Muta mire,  chosen for  paleoenvironmental reconstructions,  is located within the main regional  watershed.  The studies include diatoms  and pollen analyses.  Chronology is based on radiocarbon  dating and position of B-Tm tephra of the Millennium  eruption of Baitoushan  volcano.  The cooling and warming reconstructed from the regional data correlate with global paleoclimatic events. The regional  humidity  changes notably  along with the temperature  fluctuations.  Fire chronology was established and its significance  for vegetation was estimated. Periods of frequent  forest fires coincided  with reduced moisture supply during cooling events. The analysis per formed revealed a considerable human impact on the vegetation in the 20th century.

Many studies report  asymmetrical  spatial distribution  of soil respiration caused by presence of areas with significantly higher emission rates (so-called hot spots). For seasonally dry tropical  forest soil respiration  was measured on 1 ha plot with 20m, 5m and 1 m scale in the first half of dry season. 457 measurements made in 9 series at 54 sampling points. The results suggest  that lognormal  spatial distribution  model appears to be much more supported  rather than the normal one. A statistical method  proposed for estimation the mean value and its confidence  interval of lognormally distributed data. The mean emission rate E(R_S) for the lognormal distribution amounted  to 4.28 µmol m^-2 s^-1, the 95% confidence  interval is 3.93 to 4.76 µmol m^-2 s^-1. However, the standard sample mean can be used as an estimator of the mean of lognormally distributed values of soil respiration  if their coefficient  of variance remains approximately the same as in our study (CV=0.35).  Based on the data obtained and literature  sources,  recommendations  are given on the number of sampling  points for estimating the spatial average value with a given accuracy.

The influence  of the very strong 2015–16 El Niño event on local and regional meteorological   conditions,  as  well as  on  energy and CO₂   fluxes in  a  mountainous primary  tropical  rainforest  was investigated  using ERA-Interim  reanalysis  data as well as meteorological  and eddy covariance  flux measurements   from  Central Sulawesi  in Indonesia. The El Niño event led to a strong increase of incoming monthly solar radiation and air temperature, simultaneously with the increasing Niño4 index. Monthly precipitation first strongly decreased  and then increased  reaching  a maximum  in 3–4 months after El  Niño culmination.  Ecosystem  respiration  increased  while gross  primary  production showed only a weak response  to the El  Niño event resulting  in a positive  anomaly  of net ecosystem CO₂ exchange (reduced CO₂ uptake). The changes of key meteorological parameters and fluxes caused  by the strong  El Niño event of 2015–16  differed from the effects  of moderate  El Niño events  observed  during  the period  2003-2008,  where net ecosystem CO₂ exchange  remained largely unaffected. In contrast to earlier moderate  El Niño events, the strong El Niño 2015–16 affected mostly the air temperature  resulting  in a weakening of the net carbon  sink at the rainforest site in Central Sulawesi, Indonesia.

Forest  clearing  strongly  influences  the energy,  water and greenhouse  gas exchange at the land sur face - atmosphere inter face. To estimate effects of clear cutting on sensible (H), latent heat (LE) and  CO₂ fluxes the continuous eddy covariance measurements were provided at the recently clear-cut  area situated in the western  part of Russia from spring 2016 to the end of 2018. The possible effects of surrounding  forest on the air flow disturbances and on the spatial pattern of horizontal advection terms within the selected clear-cut area were investigated using a process-based 3D momentum, energy and CO₂ exchange  model.  The modeling  results showed a very low contribution  of horizontal advection term into total turbulent momentum  fluxes at flux tower location in case of the southern wind direction. The results of field flux measurements  indicated  a strong inter- and intra-annual  variability of energy and CO₂ fluxes. The energy budget is characterized by higher  daily and monthly   LE fluxes throughout  the entire  period  of measurements excepting the first two months after timber harvest. The mean Bowen ratio (β=H/LE) was 0.52 in 2016, 0.30 - in 2017 and 0.35 - in 2018. Analysis of CO₂ fluxes during the first year following harvest showed  that the monthly CO₂ release at the clear-cut area consistently exceeded the CO₂ uptake  rates. The mean net ecosystem  exchange  (NEE) in the period was 3.3±1.3 gC∙m-2∙d-1. During the second and the third years of the flux measurements the clear-cut was also a prevailed sink of CO₂ for the atmosphere excepting short periods in June and in the first part  of July when daily CO₂  uptake was higher than CO₂  release rates. The mean NEE rates  averaged   for  the entire warm period of corresponding  years were 1.2±2.3  gС∙m^-2∙d^-1 in 2017 and 2.8±2.5  gC∙m^-2∙d^-1 in 2018, respectively.  The mean ratio between  gross  primary  production  (GPP) and ecosystem  respiration (TER) was 0.58 in 2016, 0.84 - in 2017 and 0.74 - in 2018.

The retrospective  dynamics  of major components  of the carbon cycle under land use changes in the Central Forest zone of European Russia was investigated. This area is known as one of the most important agricultural and economical regions of the country. We applied the process-based simulation model DNDC (DeNitrification-DeComposition) recommended  by UNCCC and world widely used.  In  this study the DNDC model was parameterized  for Russian arable soils using official statistical information and data taken from published sources. Three main carbon  variables in agrolandscapes were modelled: soil organic carbon, soil respiration, and net ecosystem exchange over the period of 1990-2017. For the analysis  six administrative regions  were selected:  three with unchanged (permanent)  arable land structure   (Kaluga,  Moscow,  and Yaroslavl),  and other three with changed crop rotation (Kostroma, Smolensk, and Tver). All regions in the study are characterized by homogeneous  soil cover and similar cultivated crops. The results of the modelling were verified using the data from field CO₂ fluxes observations in the European part of Russia. In growing  season, the agrolandscapes function as a net carbon  sink and accumulate C from the atmosphere  into plant biomass. The dynamics of organic carbon in soil under growing  crops depends on organic  fertilizers in cultivation  technologies, and if they aren’t inputted, soil loses carbon. During the last 30 years the cumulative rates of net ecosystem exchange and soil respiration had decreased  mostly due to reduction of arable land area. CO₂ emission and soil organic carbon  losses are the most important controls of land degradation.  Based on the dynamic  patterns of CO₂  fluxes, the regions of the Central  Forest zone could be separated into two groups. The group with central location characterized  by intensive  soil respiration  and high rate of accumulation  of organic carbon  in soil, whereas peripheral group characterized by losses of soil organic carbon and low rates of soil respiration. According  to the modelling, within the period of observations the inter-annual changes of carbon fluxes are mainly controlled by rising air temperature and heat supply, variable precipitation, and increasing concentration  of CO₂ in the atmosphere. Among human activity the most important are change of arable land area and decreasing amount of fertilizers. 

The continuous field measurements  of net ecosystem exchange (NEE) of CO₂ were provided at ridge-hollow oligotrophic bog in the Middle Taiga zone of West Siberia, Russia  in 2017-2018. The model of net ecosystem  exchange  of CO₂  was suggested  to describe  the influence  of different  environmental  factors  on NEE and to estimate  the total carbon budget of the bog over the growing  season. The model uses air and soil temperature, incoming  photosynthetically  active radiation (PAR) and water table depth, as the key factors influencing gross primary production  (GPP) and ecosystem respiration (ER). The model coefficients were calibrated using the data collected  by automated soil CO₂  flux system with two transparent long-term  chambers  placed at large hollow and small ridge sites.

Experimental and modeling results showed that the Mukhrino bog acted over the study period as a carbon  sink, with  an average NEE of –87.7 gC m^-2 at the hollow site and –50.2 gC m^-2  at the ridge  site. GPP was – 344.8 and –228.5 gC m^-2  whereas ER was 287.6 and 140.9 gC m^-2  at ridge and hollow  sites, respectively.  Despite of a large difference in NEE estimates  between 2017 and 2018 the growing  season variability  of NEE were quite similar.

Climate  change  has distinct regional and local differences in its impacts on the land sur face. One of the important parameters determining the climate change signal is the emissivity (ε) of the sur face. In forest-climate interactions, the leaf sur face emissivity plays a decisive   role.  The accurate  determination  of leaf emissivities  is crucial for  the appropriate  interpretation  of measured  energy and matter fluxes between the forest and the atmosphere. In this study, we quantified the emissivity of the five broadleaf tree species Acer pseudoplatanus, Fagus sylvatica, Fraxinus excelsior, Populus simonii and Populus candicans. Measurements of leaf sur face temperatures were conducted under laboratory conditions in a controlled-climate chamber within the temperature range of +8 °C and +32°C. Based on these measurements, broadband  leaf emissivities ε (ε for the spectral range of 8-14 µm) were calculated. Average ε_{8-14 µm} was 0.958±0.002 for all species with very little variation among species. In a second step, the soil-vegetation-atmosphere  transfer model ‘MixFor-SVAT ’ was applied to examine the effects of ε changes on radiative, sensible and latent energy  fluxes of the Hainich  forest in Central Germany.  Model experiments  were driven by meteorological data measured at the Hainich  site. The simulations  were  forced with the calculated ε value as well as with minimum and maximum values obtained from the literature.  Significant  effects  of ε changes were detected.  The strongest  effect was identified for the sensible heat flux with a sensitivity of 20.7 % per 1 % ε change. Thus, the variability of ε should be considered in climate change studies.

Forest vegetation can affect the climate and weather patterns in multiple ways. What are the main mechanisms of such influence and how the land-use and vegetation changes may affect the weather and climate conditions in different geographical regions are still not quite clear. In our study, the possible impact of land use and forest cover changes in the central part of the East European plain on regional meteorological conditions was investigated using the regional COSMO model. In our modeling experiments we used two extreme land-use change scenarios imitating total deforestation and afforestation of experimental area located between 55° and 59ºN and 28° and 37°E in the central part of the East European plain. Modeling results conducted for the year 2016 showed that deforestation results in increase of the temperature difference between summer and winter months by up to 0.6ºС and in reduction of the annual precipitation by 35 mm. On the contrary, afforestation leads to decrease of the annual temperature range by 0.3° С and to growth of annual precipitation by 15 mm. Moreover, the deforestation results in higher frequencies of stronger winds and lower number of fog events, while the afforestation leads to opposite effects. Analysis of the Khromov and Gorchinsky indexes of continentality showed that the deforestation of the selected experimental area may lead to increase of the climate continentality in the study region, whereas the afforestation results in milder climate conditions.

The possible impact of the climate changes on vegetation is a key topic of various research studies in geography and ecology. In this study we tried to provide a «one-time survey»  of the phenological development  of Prunus padus L.  in the Yekaterinburg city as a part of the large-scale project “A Single Phenological Day ” and show the data on a map. The registration of a seasonal development  of bird cherry was provided annually in the years of 2012-2018 on one and the same date in the city of Yekaterinburg,  on 15 May. Yekaterinburg is the largest city located on the eastern foothills of the Middle Urals, Russia. The city has residential  areas,  parks,  water reservoirs,  as well as large industrial facilities that affect microclimatic conditions, resulting in an increase of the temperatures. Such microclimatic heterogeneity results in uneven development of bird cherry in spring. It was revealed the slowing of the bird cherry development  in the areas situated close to large water reservoirs. At the same time bird cherry trees growing  inside large industrial areas, on the contrary, developed much faster. The development  rates of Prunus padus L. also differed though  years: in years with dry and warm weather during the period of late April - early May the vegetation began earlier.