scholarly journals Climate-related changes in the vegetation cover of the taiga and tundra of Western Siberia in 1982–2015 according to satellite observations

Author(s):  
V. V. Zuev ◽  
E. M. Korotkova ◽  
A. V. Pavlinsky

The paper considers the results of the trend and correlation analysis of air temperature and vegetative index NDVI for the warm period for the territory of taiga and tundra of Western Siberia in 19822015. It was revealed that with significant ( = 0.05) positive air temperature trends in some months of the spring-summer period, both for the taiga zone and for the tundra zone, a significant increase in NDVI is observed. The trends of air temperature and NDVI for the taiga and tundra zones from April to October 19822015 have been calculated and the unevenness of their spatial distribution over the territory under consideration is shown. It is revealed that the development of vegetation in the warm period is largely determined by its development in the first month of the warm period May for taiga and June for tundra. It is shown that the NDVI value in May in the taiga zone is formed under the influence of April-May temperatures, and in June in the tundra zone under the influence of June temperatures; significant NDVI correlation coefficients with the average temperature of April-May and May-June are characteristic of practically the entire territory of the region, with the exception of the coastal northern regions in the first case and the south-western regions in the second.

Author(s):  
E. A. Romanenko ◽  
D. V. Moskovchenko ◽  
A. A Kudryavtsev ◽  
G. N. Shigabaeva

The total concentrations of metals (Fe, Mn, Cu, Ni, Cr, Sr) and their mobile forms extracted by an ammonium acetate buffer (pH = 4,8) were studied in soils samples collected from Nadym-Pur interfluve (West Siberia), near the northern limit of the taiga zone. The heavy metal content was determined in 55 background soil samples and in 25 pyrogenic ones. Gross content was determined on a spectrometer "SPECTROSCAN MAX-GV" using X-ray fluorescence analysis. Mobile forms of metals were determined on a ContrAA 700 atomic absorption spectrometer by flame and electrothermal methods. The statistics are calculated using the Excel software package. The study confirmed the weak accumulation of metals in the soils of the northern regions of Western Siberia. The total content below the soil world average for Fe is 5 times, Mn – 3 times, Sr – 2 times, Cr – 1,4 times. The content of mobile forms varies widely depending on the amount of organic matter. The percentage of mobile forms of metals from the total content was: Cr – 0.84%, Fe – 1,2%, Sr – 3,8%, Mn – 8,7%, Ni – 15%. In the profile of podzols, the distribution of mobile forms of metals has an eluvial-illuvial character. Mn and Sr accumulate intensively in the surface organogenic horizons, and the Fe content increases in the BF horizon. Minimum values are marked in horizon E. In pyrogenic soils, there is an increase in the content of mobile forms of metals due to the intake of ash. Metal content usually not exceeded the maximal permissible concentrations for soils.


Author(s):  
S. V. Grigorieva ◽  
A. V. Olshansky

The article is devoted to the problems of maintenance of overhead power lines in the Far North of Western Siberia. For improvement of quality and reliability of power supply of consumers in the conditions of the Far North of Western Siberia, decrease in operational costs and volumes of the carried-out emergency works the hardware-software complex for expeditious inspection, assessment and forecasting of change of technical condition of constructive part of air lines (VL) of 35-220 kV is developed, the structure of the hardware-software complex of registration of the condition of constructive part of VL of 35-220 kV and structure of the hardware-software complex of storage., processing and analysis of the obtained data on the States of the constructive part of the VL 35-220 kV. 


Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 165
Author(s):  
Allan Waniale ◽  
Rony Swennen ◽  
Settumba B. Mukasa ◽  
Arthur K. Tugume ◽  
Jerome Kubiriba ◽  
...  

Seed set in banana is influenced by weather, yet the key weather attributes and the critical period of influence are unknown. We therefore investigated the influence of weather during floral development for a better perspective of seed set increase. Three East African highland cooking bananas (EAHBs) were pollinated with pollen fertile wild banana ‘Calcutta 4′. At full maturity, bunches were harvested, ripened, and seeds extracted from fruit pulp. Pearson’s correlation analysis was then conducted between seed set per 100 fruits per bunch and weather attributes at 15-day intervals from 105 days before pollination (DBP) to 120 days after pollination (DAP). Seed set was positively correlated with average temperature (P < 0.05–P < 0.001, r = 0.196–0.487) and negatively correlated with relative humidity (RH) (P < 0.05–P < 0.001, r = −0.158–−0.438) between 75 DBP and the time of pollination. After pollination, average temperature was negatively correlated with seed set in ‘Mshale’ and ‘Nshonowa’ from 45 to 120 DAP (P < 0.05–P < 0.001, r = −0.213–−0.340). Correlation coefficients were highest at 15 DBP for ‘Mshale’ and ‘Nshonowa’, whereas for ‘Enzirabahima’, the highest were at the time of pollination. Maximum temperature as revealed by principal component analysis at the time of pollination should be the main focus for seed set increase.


2021 ◽  
Author(s):  
Zhaomin Ding ◽  
Renguang Wu

AbstractThis study investigates the impact of sea ice and snow changes on surface air temperature (SAT) trends on the multidecadal time scale over the mid- and high-latitudes of Eurasia during boreal autumn, winter and spring based on a 30-member ensemble simulations of the Community Earth System Model (CESM). A dynamical adjustment method is used to remove the internal component of circulation-induced SAT trends. The leading mode of dynamically adjusted SAT trends is featured by same-sign anomalies extending from northern Europe to central Siberia and to the Russian Far East, respectively, during boreal spring and autumn, and confined to western Siberia during winter. The internally generated component of sea ice concentration trends over the Barents-Kara Seas contributes to the differences in the thermodynamic component of internal SAT trends across the ensemble over adjacent northern Siberia during all the three seasons. The sea ice effect is largest in autumn and smallest in winter. Eurasian snow changes contribute to the spread in dynamically adjusted SAT trends as well around the periphery of snow covered region by modulating surface heat flux changes. The snow effect is identified over northeast Europe-western Siberia in autumn, north of the Caspian Sea in winter, and over eastern Europe-northern Siberia in spring. The effects of sea ice and snow on the SAT trends are realized mainly by modulating upward shortwave and longwave radiation fluxes.


Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Arkadiusz M. Tomczyk ◽  
Ewa Bednorz ◽  
Katarzyna Szyga-Pluta

The primary objective of the paper was to characterize the climatic conditions in the winter season in Poland in the years 1966/67–2019/20. The study was based on daily values of minimum (Tmin) and maximum air temperature (Tmax), and daily values of snow cover depth. The study showed an increase in both Tmin and Tmax in winter. The most intensive changes were recorded in north-eastern and northern regions. The coldest winters were recorded in the first half of the analyzed multiannual period, exceptionally cold being winters 1969/70 and 1984/85. The warmest winters occurred in the second half of the analyzed period and among seasons with the highest mean Tmax, particularly winters 2019/20 and 1989/90 stood out. In the study period, a decrease in snow cover depth statistically significant in the majority of stations in Poland was determined, as well as its variability both within the winter season and multiannual.


Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 824
Author(s):  
Egor Dyukarev ◽  
Evgeny Zarov ◽  
Pavel Alekseychik ◽  
Jelmer Nijp ◽  
Nina Filippova ◽  
...  

The peatlands of the West Siberian Lowlands, comprising the largest pristine peatland area of the world, have not previously been covered by continuous measurement and monitoring programs. The response of peatlands to climate change occurs over several decades. This paper summarizes the results of peatland carbon balance studies collected over ten years at the Mukhrino field station (Mukhrino FS, MFS) operating in the Middle Taiga Zone of Western Siberia. A multiscale approach was applied for the investigations of peatland carbon cycling. Carbon dioxide fluxes at the local scale studied using the chamber method showed net accumulation with rates from 110, to 57.8 gC m−2 at the Sphagnum hollow site. Net CO2 fluxes at the pine-dwarf shrubs-Sphagnum ridge varied from negative (−32.1 gC m−2 in 2019) to positive (13.4 gC m−2 in 2017). The cumulative May-August net ecosystem exchange (NEE) from eddy-covariance (EC) measurements at the ecosystem scale was −202 gC m−2 in 2015, due to the impact of photosynthesis of pine trees which was not registered by the chamber method. The net annual accumulation of carbon in the live part of mosses was estimated at 24–190 gC m−2 depending on the Sphagnum moss species. Long-term carbon accumulation rates obtained by radiocarbon analysis ranged from 28.5 to 57.2 gC m−2 yr−1, with local extremes of up to 176.2 gC m−2 yr−1. The obtained estimates of various carbon fluxes using EC and chamber methods, the accounting for Sphagnum growth and decomposition, and long-term peat accumulation provided information about the functioning of the peatland ecosystems at different spatial and temporal scales. Multiscale carbon flux monitoring reveals useful new information for forecasting the response of northern peatland carbon cycles to climatic changes.


2020 ◽  
pp. jech-2020-215148
Author(s):  
Raphael E Cuomo

IntroductionSince the first case of COVID-19 was recorded in California, the geospatial distribution of disease cases has fluctuated over time. Given documented racial disparities in other parts of the country, longitudinal convergence of COVID-19 rates around race groups warrants assessment.MethodsCounty-level cases for COVID-19 were collected from the Johns Hopkins University, and racial distributions were collected from the American Community Survey. Pearson’s correlation coefficients were computed for each day since COVID-19 was first reported in California, and the longitudinal distribution of each race-specific set of correlation coefficients was assessed for stationarity, linear trend and exponential trend.ResultsEarlier in the outbreak, the distribution of COVID-19 was most highly correlated with Asian American communities; after approximately 100 days, the distribution of COVID-19 most closely resembled that of African American communities. For every day in this dataset, the county-level distribution of COVID-19 was negatively correlated with the distribution of White American communities in California.DiscussionThe geospatial distribution of COVID-19 in California has increasingly resembled that of African American communities within the state. Further study should be conducted to characterise potentially disproportionate impacts of the COVID-19 pandemic across race groups.


2021 ◽  
Vol 56 (1-2) ◽  
pp. 635-650 ◽  
Author(s):  
Qingxiang Li ◽  
Wenbin Sun ◽  
Xiang Yun ◽  
Boyin Huang ◽  
Wenjie Dong ◽  
...  

2016 ◽  
Vol 13 (1) ◽  
pp. 1036 ◽  
Author(s):  
Necla Türkoğlu ◽  
Serhat Şensoy ◽  
Olgu Aydın

It is known that the increase in air temperature from 1980 to present has dramatically changed the phenological periods of the plants in a large part of the world. In this study, the relationships between phenological periods of wheat plant, apple and cherry trees planted large areas in Turkey and climate change were investigated. In this study, the climate and phenological data for 1971-2012 period belonging to the General Directorate of Meteorology were used. The correlation coefficients between temperature and phenological data were calculated, and their trends were examined using Mann-Kendall trend analysis. In Turkey, positive temperature anomalies have been observed since 1994 until present days. Negative relationships were found between phenological periods of apple, cherry and wheat and the average temperatures of February-May period when the plants grow faster. This situation shows that the plants shift their phenological periods to the earlier times in response to the increasing temperatures. The trend calculated for harvest times of apple, cherry, and wheat are -25, -22, -40 days/100 years respectively. It was calculated that an increase of 1.0ºC in the temperatures of the February-May period will shift the harvest times of apple, cheery and wheat by 5, 4 and 8 days earlier respectively. Özet1980’lerden günümüze hava sıcaklıklarındaki artış, Dünya’nın büyük bir bölümünde bitkilerin fenolojik dönemlerini önemli ölçüde değiştirmiştir. Bu çalışmada Türkiye’de geniş alanlar kaplayan buğday, elma ve kiraz bitkilerinin fenolojik dönemleri ile iklim değişikliği arasındaki ilişkiler araştırılmıştır. Çalışmada Meteoroloji Genel Müdürlüğü’ne ait 1971-2012 döneminin iklim ve fenolojik verileri kullanılmıştır. Sıcaklık ile fenolojik veriler arasındaki korelasyon katsayıları hesaplanmış ve Mann- Kendall trend analizi ile eğilimlerine bakılmıştır. Türkiye’de 1994 yılından bu yana pozitif sıcaklık anomalileri bulunmuştur. Elma, kiraz ve buğdayın fenolojik dönemleri ile bitki gelişiminin fazla olduğu şubat-mayıs ortalama sıcaklıkları arasında negatif ilişki saptanmıştır. Bu durum bitkilerin artan sıcaklıklara tepki olarak fenolojik dönemlerini erkene kaydırdıklarını göstermektedir. Elma, kiraz ve buğdayın hasat tarihleri için hesaplanan trend sırasıyla-25, -22, -40 gün/100 yıl şeklindedir. Şubat-mayıs arası sıcaklıklarda 1.0°C’lik artışın anılan bitkilerin hasat tarihlerini sırasıyla 5, 4 ve 8 gün erkene kaydıracağı hesaplanmıştır.


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