Air Temperature In May Research Articles

Влияние орошения на продуктивность отечественных сортов картофеля в условиях предкамья Республики Татарстан

The article presents the results of the study of varieties of Russian selecia presented by the Federal State Budgetary Scientific Institution "Federal Potato Research Center named after A.G. Lorch". In the studies conducted in 2023 on the basis of Agrobiotechnopark LLC at the Kazan State Agrarian University, the following potato varieties of domestic selection were presented: early-ripening - Meteor and Gulliver; medium-early potato varieties Ariel, Krasa Meschery and Surprise; medium-ripe - Grand and Pennant and Purple potato variety. Irrigation has had a positive effect on all the studied domestic potato varieties. When analyzing such indicators as the flatness of the development of the leaf surface, the height of the plant, the increase in the mass of the tops and tubers and taking into account the yield, all the studied varieties on irrigation gave the highest indicators than when cultivated on the bogar. The weather conditions of the growing season of 2023 differed significantly from the average long-term data. Since the air temperature in May, July and August was higher than the average annual values. As for, 46.79 mm of precipitation fell in May, which is 23 % higher than the average annual data, June was drier (only 6 mm of precipitation fell, which is 10% of the norm), in July and August precipitation fell only – 50.3 and 37.1 % of the monthly norm, respectively. According to the results of the analysis of the leaf surface area of domestic varieties, it can be judged that the use of irrigation on potatoes in 2023 showed positive dynamics in all variants compared to the cultivation of this crop on bogar. Thus, its maximum value of 19,909 thousand m2/ha in the flowering phase was achieved with irrigation of the medium-ripened potato variety Grand, which is 2205 thousand m2/ha higher than when cultivating this variety on bogar. The maximum yield of 21.8 t/ha was obtained for the medium-ripened potato variety Grand, which is 9.28 t/ ha higher when cultivating this variety without watering. The medium–early potato variety Ariel also formed a fairly high yield - 20.94 t/ ha.

Сluster analysis of long-term crop yield data in crop rotation

Today, cluster analysis is one of the most effective tools for processing large amounts of information and is used wherever computing technology is used, since data and the results of their analysis play an increasingly important role in modern information society, and clustering allows for a better understanding of this data. Whenever it is necessary to classify a large amount of information of this kind and present it in a form suitable for further processing, cluster analysis turns out to be very useful and effective. The analysis of 48-year observations on 107 variables (crop yield, crop rotation by tillage techniques and means of intensification, crop contamination, soil moisture content under sowing during the growing season, the sum of non-vegetative precipitation, the sum of decadal precipitation and average decadal air temperatures during the growing season) using clustering by the Ward method allowed us to group observations into 6 clusters and use them to analyze the studied variables. An average positive relationship of soil moisture content before sowing with the amount of non-vegetative precipitation and a negative one with air temperature in May has been established. Linear regression equations of the positive relationship of yield with the consumption of soil moisture during the growing season, precipitation in June-July and negative clogging and average air temperature in May-July were selected.

ИЗМЕНЕНИЕ ТЕРМИЧЕСКИХ РЕСУРСОВ ВЕГЕТАЦИОННОГО ПЕРИОДА И УРОЖАЙНОСТЬ ЯРОВОЙ ПШЕНИЦЫ В УСЛОВИЯХ СРЕДНЕГО ПОВОЛЖЬЯ

The article presents the results of long-term studies (1982-2018) on the assessment of changes in thermal resources during the growing season and the indication of their impact on the yield of spring wheat. The work was carried out in the conditions of the northern part of the Middle Volga region on gray forest soils. The soil of the experimental site is gray forest medium loamy, the content of humus (according to Tyurin) is 2.8...3.2%, mobile phosphorus and potassium (according to Kirsanov) - 105...184 and 79...149 mg /100 g of soil, respectively, pH- 5.6...5.8. During the observation period, the highest temperature increase was recorded in July (2.4°C) and May (2.2°C), and the lowest in June (1.0°C). The sum of effective temperatures over 10°C increased by 500°C during the study period. The yield of spring wheat grown without fertilizers varied greatly in different years, ranging from 0.99 to 2.97 t/ha. The highest value of this indicator was observed at an average monthly air temperature of about 13 0C in May, 17 0C in June, 18 0c in July, and the sum of active temperatures was 1800 0c. The studied thermal resources, in accordance with the significance of the impact on the yield of spring wheat, can be arranged in the following descending order: average air temperature in June > average air temperature in July > the sum of effective temperatures above 10 °C > average air temperature in May. To describe the dependence of the yield of spring wheat grain on thermal resources, in three cases out of four, a polynomial equation of the second degree was better suited, and in one case, an exponential equation.

Analysis of long‐term trends and variations in extreme high air temperatures in May over Turkey and a record‐breaking heatwave event of May 2020

AbstractThis paper investigated the trends and variability in warmest daily maximum (TXx) and warmest daily minimum (TNx) air temperatures, and heatwave characteristics in Turkey in May during 1950–2020. It also analysed the climatological and synoptic meteorological evolutions of heatwave (HW) observed in May 2020. Trend analysis revealed significant increasing trends in TXx and TNx series and heatwave characteristics in May since 1950. Since the mid‐1980s, a continuously increasing trend in TXx and TNx series, and the number, frequency, and magnitude of the heatwaves were observed that accelerated with the mid‐1990s. The most severe heatwave in Turkey since 1950 in May was observed in 2020. The record‐breaking daily maximum (daily minimum) air temperatures were noted at 32 (23) of 96 stations in May 2020, mainly over Turkey's western and southern parts. Record‐high maximum (minimum) air temperature was 43.2°C (31.1°C) reached for the first time in May since 1950. The generalized extreme value model applied to the May TXx and TNx series revealed that the daily air temperatures in May 2020 exceeded 100 years' return periods at many stations of Turkey. This heatwave was linked to a regionalized strong anticyclonic blocking anomaly circulation and other associated atmospheric anomalies in May 2020. This also resulted in the centring of an unprecedented subsiding, calm, and stable warm air mass over Turkey. Adiabatic warming and drying developed very likely under subsidence control because of relatively weak circulation conditions. Such circumstances resulted in extremely hotter conditions in May 2020 compared to the long‐term averages.

DEPENDENCE OF SPRING WHEAT YIELD ON HYDROTHERMIC CONDITIONS IN THE SARATOV REGION

Using long-term stationary field studies on the phases of development of spring wheat, a prognostic equation for calculating the yield of a given crop depending on the duration of the growing season with a monthly lead time was derived. Taking into account the hydrothermic factors of the Saratov region, the prognostic equation of the multiple function of the yield of spring wheat from the amount of precipitation for April-May, the average air temperature in May, the amount of precipitation in June, the amount of precipitation in July, and the duration of the growing season was calculated.

Temperature Control of Spring CO2 Fluxes at a Coniferous Forest and a Peat Bog in Central Siberia

Climate change impacts the characteristics of the vegetation carbon-uptake process in the northern Eurasian terrestrial ecosystem. However, the currently available direct CO2 flux measurement datasets, particularly for central Siberia, are insufficient for understanding the current condition in the northern Eurasian carbon cycle. Here, we report daily and seasonal interannual variations in CO2 fluxes and associated abiotic factors measured using eddy covariance in a coniferous forest and a bog near Zotino, Krasnoyarsk Krai, Russia, for April to early June, 2013–2017. Despite the snow not being completely melted, both ecosystems became weak net CO2 sinks if the air temperature was warm enough for photosynthesis. The forest became a net CO2 sink 7–16 days earlier than the bog. After the surface soil temperature exceeded ~1 °C, the ecosystems became persistent net CO2 sinks. Net ecosystem productivity was highest in 2015 for both ecosystems because of the anomalously high air temperature in May compared with other years. Our findings demonstrate that long-term monitoring of flux measurements at the site level, particularly during winter and its transition to spring, is essential for understanding the responses of the northern Eurasian ecosystem to spring warming.

The effects of weather, harvest frequency, and rotation number on yield of short rotation coppice willow over 10 years in northern Japan

Under global warming, expectations for woody biomass as a renewable energy are increasing. Short rotation coppice willow is the most widely planted energy wood crop. In this study, we examined the effect of harvest frequency on willow yield across multiple harvest rotations, something which is poorly understood. We planted 18 clones of Salix pet-susu and S. sachalinensis at a density of 25,000 or 16,667 cuttings ha−1 in Hokkaido, northern Japan, and harvested either annually or biennially for 10 years (2009–2018). Annual variation in willow yield per stool was analyzed using five linear mixed-effect models incorporating the number of rotations, harvest interval, and weather parameters during the growing season with clones and plant density as random factors. Number of rotations had a significant negative effect on annual yield in all five models. We estimated that yield could be halved over 10 consecutive years of harvesting. In three out of the five models, biennial harvesting had a significant positive effect on yield in comparison with annual harvesting. In addition, we found that weather conditions, such as hours of sunshine during growing season, air temperature in May (when leaf flushing occurs), and precipitation in July (when vigorous height growth occurs) have significant positive effects on willow yield. These results suggest that, to maintain willow vigor for longer time periods biennial, or more than two-year-harvest, cycle is recommended rather than annual harvest.

Four-decadal series of dendrometric measurements reveals trends in Pinus sylvestris inter- and intra-annual growth response to climatic conditions

We analyzed a 42-year series (1976–2017) of Scots pine (Pinus sylvestris L.) tree-diameter data, obtained using band dendrometers, from our study site in Aukštaitija National Park, Lithuania. We evaluated the intra- and inter-annual growth dynamics of tree diameter and their response to meteorological forcing, as well as the long-term annual and monthly growth-rate changes in tree diameter in the study area. On average, the largest growth in tree diameter was found to have taken place in June (35% of the annual increase). After 24 June, the tree-diameter growth rate strongly decreased. Pine growth in May and August was mostly affected by the temperature during the previous month. Precipitation was the main driver that determined tree growth in June–August, with heavy precipitation events having the largest impact on short-term increases in tree diameter. We determined that the largest positive growth-rate changes in Scots pine tree diameter occurred as a result of higher air temperature in May and June between 1976 and 2017.

Influence of meteorological conditions on ripening of grape shoots in south areas of Western Siberia

Introduced grape varieties were studied in the south of Western Siberia in order to identify the effects of unfavourable factors of the growing season on the ripening of grape shoots. Weather conditions in the south of Western Siberia during the vegetation periods 2012-2017 were characterized by large fluctuations in water and temperature conditions; there were sharp changes not only in different years, but also during one season. Compared with long-term average data, a significant increase of relative air humidity and the amount of precipitation was noted from May to September. In 2016-2017 sharp changes of the amount of precipitation by months were marked (dry June, over-moistened July). The most unfavorable weather conditions for grape crop were the conditions of the growing season of 2013 with excessive rainfall (410.3 mm), very low average monthly air temperatures in May, June, July, September and the sum of active temperatures (2031.7°C). Under the influence of meteorological conditions, the terms of the beginning of the studied phenological phase changed very significantly over the years (30-62 days). Shoots ripening in years with favourable weather conditions (2012, 2015) began from July 14-August 1, with unfavorable (2013, 2017) — September 11-15. In one grape variety, insignificant variability of the degree of the studied character was revealed by years, in two — medium, in eight — high. Shoots ripened better in warmer and less humid 2012 (66.8-94.1 %) and in 2015 (58.4-92.5 %). Varieties with very poor ripening (33.0-46.9 %) Arkady, Kodryanka, Tomaysky are unsuitable for cultivation under production conditions and recommended for cultivation in amateur gardens with additional shelter. Varieties with maximum ripening of shoots on average over the years were selected from the American group White Pearls, Latvian Pink (83.1-84.9 %), Amurian Adel, Vaskovsky Souvenir, Hasan Bousa (65.5-79.3 %).

It is not just a 'trade-off': indications for sink- and source-limitation to vegetative and regenerative growth in an old-growth beech forest.

Controls on tree growth are key issues in plant physiology. The hypothesis of our study was that the interannual variability of wood and fruit production are primarily controlled directly by weather conditions (sink limitation), while carbon assimilation (source limitation) plays a secondary role. We analyzed the interannual variability of weather conditions, gross primary productivity (GPP) and net primary productivity (NPP) of wood and fruits of an old-growth, unmanaged Fagus sylvatica forest over 14yr, including six mast years. In a multiple linear regression model, c. 71% of the annual variation in wood-NPP could be explained by mean air temperature in May, precipitation from April to May (positive influence) and fruit-NPP (negative influence). GPP of June to July solely explained c. 42% of the variation in wood-NPP. Fruit-NPP was positively related to summer precipitation 2yr before (R2 =0.85), and negatively to precipitation in May (R2 =0.83) in the fruit years. GPP had no influence on fruit-NPP. Our results suggest a complex system of sink and source limitations to tree growth driven by weather conditions and going beyond a simple carbon-mediated 'trade-off' between regenerative and vegetative growth.

Comparative evaluation of pea selection lines of different morphotypes

The results of a comparative study of samples of the garden pea (Pisum sativum L.) by the main economically valuable traits are presented. The objects of the research were 13 breeding lines of peas of various morphotypes (leafy, semi-leafl ess, chameleon). The experiment was conducted in 2016–2018 on leached chernozems in the northern forest-steppe of Western Siberia. The study period was characterized by contrasting weather conditions. Uneven precipitation was noted in 2016, which was higher than the norm in May, but below normal in June. In May 2017, the temperature and precipitation corresponded to the long-term average norm. Abundant rainfall from the period of sowing (the fi rst ten-day period of May) to full ripeness (July) and low average daily air temperature in May characterized the vegetation period of 2018. The best results in short-stalk characteristics and lodging resistance were reached by the line of the semi-leafl ess morphotype Nord × Az-318 (57.5 cm) and Orel × Yamal (57.7 cm). An average positive correlation was established between the height of the plant and the number of pods (r = 0.48 ± 0.20). By the mass of 1000 seeds the best results were shown by leafy lines (188.4 g) and the chameleon morphotype (181.1 g). Between the mass of 1000 seeds and the number of seeds in a pod, an average negative correlation was established (r = –0.63 ± 0.25). In terms of the yield, the chameleon morphotype lines (TM-1552, TM-1504) proved the most productive. The average yield of this morphotype was 280.0 g/m2, leafy lines – 271.4 g/m2 and the lines of the semi-leafl ess morphotype – 254.1 g/m2. A correlation was established between the yield and the studied traits. The yield is moderately positively affected by the number of seeds in a pod (r = 0.55 ± 0.20) and the number of pods in a plant (r = 0.50 ± 0.22). A signifi cant yield advantage was not found between the studied breeding lines. For sustainable production of pea seeds, it is advisable to have a system of varieties of different morphotypes.

Relationship Between Climate Trends and Grassland Yield Across Contrasting European Locations.

We investigated climatic trends in two contrasting locations in Europe at a regional level and at two specific sites, and we analysed how these trends are associated with the dry matter yield (DMY) of agriculturally improved grasslands. Trends of different meteorological variables were evaluated for Wielkopolska province, central Poland (1985-2014) and Troms county, northern Norway (1989-2015), as well as for two research stations located in these regions. Significant trends of increased mean air temperatures annually, and in April, June, July, August and November were identified both at the regional and site levels in Wielkopolska. In addition, growing degree days were increasing in Wielkopolska. In Troms, the common trends for the region and site studied were increase in mean air temperature in May and decrease in January. Grassland DMY was subsequently regressed against those meteorological variables for which significant trends were detected. In the Wielkopolska region, yields were negatively associated with the increase in air temperature in June, August, and the annual air temperature. The last relationship was also detected at the site level. We did not find any significant effects of climate trends on grassland DMY in the Norwegian study site or region.

THE USE OF PEA GENE POOL FOR BREEDING OF MODERN VARIETIES OF PEAS IN WESTERN SIBERIA

The work presents the results of evaluation of 150 varieties of sowing peas (Pisum Sativum L.) of different ecological and geographical origin that have not lost their breeding value in recent years by a number of economically valuable signs from the world collection of The N.I. Vavilov All Russian Institute of Plant Genetic Resources. The purpose of the research was to identify promising varieties of sowing peas from the collection to create modern varieties of peas for grain use. The experiment was conducted in 2014–2016. on leached chernozem of the northern foreststeppe of Western Siberia. The weather conditions during the years of research were contrasting. So, in May and July of 2014, precipitation was above the average rainfall, which caused the formation of tall pea plants, especially in the varieties of leafy morphotype. In 2015, the air temperature was above the long-term average annual rate with uneven precipitation. In 2016, the air temperature in May generally corresponded to the long-term average annual rates, but August was characterized by precipitation deficit. The maximum yield for the years of research was noted in the varieties of leafy morphotype group: Bogatyr (625 g/m2), Kemchug (510 g/m2), and the group with the modified morphotype: Az-318 and Orel (480 g/ m2). Varieties with the modified morphotype Az-318, Sprut-2, Orel, Demos, Yamal proved to be highly resistant to lodging and easy to harvest, due to being adapted to the soil and climatic conditions of Western Siberia. The correlation analysis conducted in 2016 revealed a reliable positive relationship (r = 0.63) between the mass of 1000 grains and the yield. A closer positive relationship was found during all the years of the study between the yield and the number of peapods on the plant (r = 0.48–0.67). A negative dependence was observed between the length of the plant and the yield.

Жирнокислотный состав масла семян селекционных линий ярового рапса (<i>Brassica napus</i> L.) в условиях Ленинградской области

Отмечена роль Н. И. Вавилова в организации исследований исходного и селекционного материала по биохимическим признакам, определяющим пищевые, кормовые и технологические качества сельскохозяйственной продукции. Выделен перспективный материал для создания сортов рапса с улучшенными пищевыми, кормовыми и технологическими характеристиками; выявлен характер зависимости признаков качества масла от погодных условий (температура, количество осадков и др.). Изучены 50 высокоэруковых (ВЭ) и 40 низкоэруковых (НЭ) линий ярового рапса (Brassica napus L.), выращенных в условиях Ленинградской области в 2012 – 2015 гг. Содержание масла и влажность в семенах определяли методом инфракрасной спектрометрии. Жирнокислотный состав (ЖКС) масла изучали с помощью газожидкостной хроматографии с масс-спектрометрией. Установлено содержание доминирующих жирных кислот для ВЭ и НЭ образцов, а также характер влияния погодных условий на ЖКС масла, в том числе на состав его отдельных фракций. Для ВЭ образцов установлена достоверная отрицательная корреляция (r = –0,96) между содержанием эруковой кислоты и температурой воздуха и достоверная положительная (r = 0,96) с количеством осадков в первую декаду июля. Для НЭ образцов установлена достоверная отрицательная зависимость между содержанием эруковой кислоты и средней температурой воздуха в мае. Выделенные образцы с высоким содержанием олеиновой (61,4 %) и низким линолевой (7,4 %) кислот можно рекомендовать для получения безэруковых сортов рапса, масло которых пригодно для длительного хранения. Контрастные по содержанию эруковой кислоты образцы будут использованы для создания сортов ярового рапса пищевого и кормового назначения, а также для производства биодизеля.

Changes in smolt traits of Atlantic salmon (Salmo salar Linnaeus, 1758) and linkages to parr density and water temperature

Smolt traits (length, age) and timing of smolt migration of wild Atlantic salmon, Salmo salar L., were investigated in the Simojoki River, northern Baltic Sea. The aim was to determine whether they responded to changes in parr length, parr density and temperature from 2000 to 2014. Annual electrofishing surveys and smolt numbers determined parr densities by springtime trapping in the river mouth. During the smolt trapping period captured parr and smolts were aged from scales. Water temperature was measured daily. Mean length decreased from 137 mm (TL) to 129 mm among 2-year-old smolts, and from 150 mm to 139 mm among 3-year-olds. Median date of the smolt migration was 10 days earlier, from early June to late May during the study period, linked to the rise in air temperature in May at the nearby Kemi-Tornio airport. However, the median day temperature and the mean daily water temperatures during the second (Q2) and third (Q3) migration quartiles did not change. This implied that migration began when a suitable water temperature was reached, independent of the date.

Diurnal and seasonal variations of soil respiration rate under different row-spacing in a Panicum virgatum L. field on semi-arid Loess Plateau of China

Soil respiration (SR) in crop field is affected by environmental factors, agronomic practices and crop types. To clarify how planting density affects the SR dynamics in switchgrass (Panicum virgatum L.) field on the semi-arid Loess Plateau, this research investigated diurnal and seasonal changes of soil respiration rate (RS) under three different row-spacing treatments (20, 40 and 60 cm) in the fourth growing year of switchgrass. Results showed that RS presented a pronounced seasonality under all row-spacing treatments. The highest daily average RS values appeared in August, while the lowest (P<0.05) were in September for each row-spacing. Diurnal variations of RS exhibited single-peak curves in each month. Daily average RS increased significantly as row-spacing enlarged during May and August but there was no significant difference among row-spacing treatments in September. Soil water storage in the depth of 0–100 cm had no significant difference (P>0.05) among the row-spacing treatments, and similar results were found for soil temperature in 0–15 cm soil depth. Soil respiration temperature sensitivity (Q10) values were 1.0–3.7 during the growing months, which were strongly correlated with air temperature in May and June and the soil temperature at 15 cm depth in August. Higher aboveground biomass production and lower RS in most growth months indicated that 20 cm row-spacing treatment was beneficial for increasing the carbon fixation in switchgrass field. Results also implied that it is necessary to take into account the influence of phenology and root growth of switchgrass on soil respiration for accurately evaluating the carbon cycle in the region.

Relationships of Pinus koraiensis Cone Production with Stand and Climate Factors

In order to analyze the relationship of Pinus koraiensis cone production with stand and climate factors,6 plots were set in a broad-leaved P. koraiensis forest at Liangshui nature reserve,Heilongjiang province in China. The cone production,diameter at breast height( DBH),and tree height( H) for each individual were investigated. The monthly climate factors( eg.,temperature,relative humidity and precipitation) were also measured. At a scale of individual,cones yield decreased with the DBH and H increasing. At a scale of stand,mean cone production per tree was not significantly related to forest age,and there was not significant difference between the stands at forest edge and the stands far away from forest edge. Between years,the cone production per tree significantly correlated with the mean air temperature in May and June,and precipitation in last June.

Influence of meteorological conditions on the yield of winter oilseed rape in Lower Silesia

Abstract Influence of meteorological conditions on the yield of winter oilseed rape in Lower Silesia. This work uses the results of Post-registration Cultivar and Agricultural Experimentation conducted in 1999-2011 in Lower Silesia, on soils of very good and good wheat complex. The rape vegetation season was divided into five periods that approximately corresponded to the phenological phases of the plant, namely: September-November (from sowing to stemming the growing season in the autumn), December-March (stunted vegetation - renewal of vegetation), April (renewal of vegetation - the beginning of flowering), May (flowering), June (end of flowering - technical maturity). In the constructed regression model the following factors were included: the average air temperature and total precipitation in the periods, the content of phosphorus, potassium and pH of soil and fertilization with nitrogen, phosphorus and potassium. Comparing the impact of meteorological conditions in different growing periods of winter rape, it was found that the weakest impact on the yield had temperature and precipitation from September to November. During this period, the optimum for yield are the following conditions: average temperature 10.4°C and precipitation total 145 mm. The winter period (December- March) has the strongest impact on the yield of rape. The yield is conspicuously higher with lower average air temperatures. Optimal for yield is precipitation of 171 mm (highest tested) and a relatively low average air temperature (-0.9°C). In April, the decisive factor is rainfall. Its lower values (12 mm) favour higher yield. The optimum weather in this period is 12 mm precipitation and average temperature of 9.1°C. Rape yield increases with increasing average air temperature in May and is highest when its value is 15°C and rainfall in this month is above average (73 mm). The weather in June has less impact on rape crop than in the three previous periods. The optimal layout is: 27 mm precipitation and temperature 16°C, these values being the smallest tested

Influence of Meteorological Elements on Changes in Active‐Layer Thickness in the Bellsund region, Svalbard

ABSTRACTMeasurements of active‐layer thickness (ALT) at seven locations on Calypsostranda, Svalbard (CALM Site P1), over 1986–2009, are used to estimate the influence of cloudiness, precipitation, air temperature, the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO). Between 1986 and 2002, ALT amounted to 118 ± 14 cm and did not show any significant trend. During 2002–06, ALT increased rapidly (12.6 cm yr‐1) to a maximum of ~ 174 cm in 2006 and 2007. In 2008 and 2009, ALT decreased. No statistically significant correlations were determined between ALT and monthly precipitation and cloudiness at Barentsburg, Hornsund and Svalbard Airport stations. There were, however, very strong and highly significant (p &lt; 0.001) relationships with air temperatures in May and June (the strongest association being with Svalbard Airport). The influence of air temperature in May and June on ALT is indirect; it regulates the time of the melt of snow cover, which determines the duration of the ground‐warming period. Using statistical relationships between ALT and air temperature at Svalbard Airport, the time series of ALT at Calypsostranda is reconstructed from 1911 to 2010. It was also found that the AO and the NAO did not significantly affect ALT and air temperature on western Spitsbergen. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Inundating contrasting boreal forest soils: CO2 and CH4 production rates

Flooding boreal forest ecosystems for hydroelectric power generation may release substantial amounts of carbon (C) to the atmosphere, contributing to global warming. The objectives of this study were to evaluate CO2 and CH4 production rates using spring/fall (14 °C) and summer (21 °C) temperatures under non-flooded and flooded conditions. incubation temperatures represented the mean annual air temperature in May and September (14 °C), and in July (21 °C). Greenhouse gas production rates were quantified using laboratory incubations of 2 contrasting soil types (Humo-Ferric Podzol [very dry, mineral] and a Histic Folisol [moist, organic]) collected at the experimental lakes area in northwestern Ontario, Canada. The mean production rate of CO2 and CH4 in the headspace of the incubation jars was significantly influenced by temperature, flooding and soil type. results showed that the mean CO2 (65 [Podzol]; 43 [Folisol]) and CH4 (0.06 [Podzol]; 0.06 [Folisol]) production rates (μg·g−1·−1) were significantly higher (P < 0.05) at 21 °C and in flooded treatments from both soil types. The greatest CO2 and CH4 production rates (μg·g−1·d−1) occurred from the Folisol (110 [CO2]; 0.03 [CH4]) and the L and FH horizons of the Podzol (250 [CO2]; 0.05 [CH4]). Q10 values showed that decomposition of soil organic matter was more temperature dependent in non-flooded treatments, with values ranging from 1.57 to 5.03, than in flooded treatments (1.31 to 3.58). The greatest loss of soil organic carbon relative to the original C content (g-m−2) occurred in the Ah horizon of the Podzol in non-flooded (0.01% [14 °C]; 0.02% [21°C]) and flooded (0.02% [14 °C]; 0.03% [21 °C]) treatments and at both temperatures. Information presented in this paper helps to evaluate how 2 contrasting soil types (Podzol and Folisol) responded to flooding and provided further insight into the dynamics of greenhouse gas (GHG) production rates as a result of hydroelectric reservoir creation. This will aid in future planning, construction, and management of hydroelectric reservoirs to help minimize GHG emissions and boreal forest disturbance.