scholarly journals Results of a phenological study of the European larch (Larix decidua Mill.) growing in a mixed stand

2013 ◽  
Vol 61 (5) ◽  
pp. 1239-1246 ◽  
Author(s):  
Emilie Bednářová ◽  
Kristýna Slovíková ◽  
Sabina Truparová ◽  
Lucie Merklová
Keyword(s):  
Correlation Coefficients ◽  
Early Spring ◽  
Larix Decidua ◽  
Climatic Conditions ◽  
Mixed Stand ◽  
European Larch ◽  
Phenological Stages ◽  
Air Temperatures ◽  
Soil Temperatures

This paper presents an evaluation of the onset and duration of phenological stages of the European larch (Larix decidua Mill.) growing in a mixed stand in Drahanská vrchovina highlands. It covers the period of 2007–2010 and refers to results obtained in the preceding study period of 1991–2006. In individual years of this study, beginnings and durations of individual phenological stages differed in dependence on climatic conditions. Temperature requirements of European larch regarding the onset of individual phenological stages were evaluated on the base of sums of air temperatures above 0° C and of effective air temperatures higher than +5° C. Obtained results indicate that the onset and duration of spring phenological stages are dependent on air and soil temperatures already in the early spring. As far as the European larch is concerned, the breaking of buds is dependent on temperatures of air and soil; the corresponding correlation coefficients were R2 = 0. 8684 (y = −3.788x + 97.165) and R2 = 0.7627 (y = −6.667x + 101.88), respectively. The obtained results indicate that recently the onset of spring phenological stages occurred earlier and earlier in the study area of Drahanská vrchovina highlands and that their course was also shorter and shorter. In spring months, higher temperatures influence the phenological stage of flushing at most while in the autumn individual phenological stages occur later and later so that the growing season is longer and longer. This finding was corroborated by results of long-term studies.

scholarly journals Evaluation of vegetative phenological stages in a spruce monoculture depending on parameters of the environment

2011 ◽  
Vol 59 (6) ◽  
pp. 31-36 ◽  
Author(s):  
Emilie Bednářová ◽  
Lucie Merklová
Keyword(s):  
Correlation Coefficients ◽  
Phenological Stages ◽  
Air Temperatures ◽  
Temperature Requirements ◽  
Sum Of Effective Temperatures ◽  
Soil Temperatures ◽  
Long Term Monitoring ◽  
Effective Temperatures ◽  
Term Monitoring

Vegetative phenological stages were evaluated in a spruce monoculture of the third age class in the region of the Drahanská vrchovina Upland. Methods of the ČHMÚ (Czech Hydro-Meteorological Office) were used. Temperature requirements of Norway spruce for the onset of particular phenological stages were evaluated on the basis of sums of air effective temperatures higher than 5 oC and at soil temperatures, values exceeding 1 oC were taken into account. In the paper, years 2005 to 2007 were evaluated. Results obtained were compared with long-term monitoring for the period 1991–2004. The onset and duration of phenological stages differed in particular years depending on the course of weather. Evaluation of the 17-year period shows that onsets of phenological stages in particular years differed markedly. An interval for the “onset of budbreak stage” was 13 days, at the “stage of 50% foliation” 14 days, the “stage of 100% foliation” 17 days. At the stage “full foliation”, the interval amounts to 33 days in the period 1991 to 2007. The start of budbreak and foliation is affected by air and soil temperatures, which was also proved by statistical evaluations. High dependence between the onset of budbreak and air temperatures is confirmed by statistically significant correlation coefficients R2 = 0.854 (2005–2007) and R2 = 0.754 (1991–2004). Dependence of the onset of budbreak and foliation on the soil temperature is proved by a correlation coefficient R2 = 0.658 (2005 to 2007) and R2 = 0.687 in the period 1991 to 2004. Results show that in recent years, the earlier onset of spring phenological stages occurs at the higher sum of effective temperatures. The length of their duration shortens.

scholarly journals Results of a phenological study at a young Norway spruce (Picea abies/L./Karst)

2010 ◽  
Vol 58 (5) ◽  
pp. 35-42
Author(s):  
Emilie Bednářová ◽  
Lucie Merklová ◽  
Sabina Truparová
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Meteorological Parameters ◽  
Correlation Coefficients ◽  
Early Spring ◽  
Phenological Stages ◽  
Air Temperatures ◽  
Sum Of Effective Temperatures ◽  
Soil Temperatures ◽  
The Mean

The paper deals with results of phenological studies of Norway spruce (Picea abies/L./ Karst.) in a mixed stand. This broad range was important in spring phenological stages. High correlations were determined between the mean air temperature, soil temperature and the start of phenological stages. Relationships between the onset of phenological stages and changes in meteorological parameters were expressed by the sum of effective air temperatures exceeding 0 and 5 °C. To evaluate the relationships by means of the sum of effective temperatures >5 °C, the stage of budbreak was most important.The onset of budbreak in Norway spruce occurred on average in the 125th day in the period 2005 to 2008. First, the stage of budbreak in spruce began the 121st day and at the latest the 128th day in 2005. The most often budbreak was in 2007. The onset of foliage in spruce began between the 128th day and the 136th day. Full 100% foliage occurred in 2007, viz. the 159th day, i.e. 12 day earlier than in the previous year. In 2005, full foliage occurred the 171st day. The air and soil temperatures affected spring phenological stages during the early spring, which was demonstrated by high correlation coefficients.

scholarly journals Monitoring the spring phenological stages in a spruce monoculture in the Drahanská vrchovina upland in 2005–2011

2012 ◽  
Vol 60 (6) ◽  
pp. 15-20 ◽  
Author(s):  
Emilie Bednářová ◽  
Sabina Truparová ◽  
Lucie Merklová
Keyword(s):  
Statistical Processing ◽  
Climatic Conditions ◽  
Phenological Stages ◽  
Factors Affecting ◽  
Air Temperatures ◽  
Temperature Requirements ◽  
Long Term Monitoring ◽  
Effective Temperatures ◽  
Term Monitoring

The paper evaluates the onset and duration of spring vegetation phenological stages in a spruce monoculture of the third age class in relation to changing parameters of the environment in the region of the Drahanská vrchovina Upland. Temperature requirements of Norway spruce necessary for the onset particular phenological stages were evaluated on the basis of sums of effective temperatures > 5 oC. The period of 2005–2011 is processed in relation to long-term monitoring since 1991. Based on results obtained, there is considerable variability owing to changing climatic conditions in the onset of spring phenological stages in the course of monitored years. In recent years, the earlier onset of spring phenological stages occurs and their duration gets shorter. This phenomenon is caused by higher air temperatures in spring months. The statistical processing of results obtained demonstrated the high dependence of the onset of particular phenological stages on the temperature of air and soil. Particular factors affecting budbreak and foliation cannot be detached and thus, it is necessary to be evaluated as a complex of influences. Long-term phenological studies of forest trees can serve as the bioindicator of climatic changes.

scholarly journals Pollination success and full seed percentage in European larch (Larix decidua MILL.)

2019 ◽  
Vol 48 (No. 6) ◽  
pp. 271-280 ◽  
Author(s):  
B. Slobodník
Keyword(s):  
Correlation Analysis ◽  
Correlation Coefficients ◽  
Critical Value ◽  
Larix Decidua ◽  
European Larch ◽  
Seed Formation ◽  
Pollination Success ◽  
Empty Seed ◽  
Linear Correlation Analysis ◽  
The Mean

A relationship between the success of pollination and the percentage of full seeds of European larch (Larix decidua MILL.) was studied using several models of non-linear correlation analysis. Although the proportion of pollinated ovules was high in most cases (especially in the middle parts of open-pollinated conelets), the mean percentage of full seeds was extraordinarily low (after the controlled self-pollination even close to zero) and most of the calculated correlation coefficients are lower than the corresponding critical value. This fact gives an evidence for the strong effect of additional important factors causing the empty seed formation in Larix even after the successful pollination of ovules.

scholarly journals Changes in the hydrochemical regime of Onegо Lake since the early 1990s

2019 ◽  
pp. 62-72 ◽  
Author(s):  
N. M. Kalinkina ◽  
E. V. Tekanova ◽  
A. V. Sabylina ◽  
A. V. Ryzhakov
Keyword(s):  
Organic Matter ◽  
River Water ◽  
Ph Value ◽  
Correlation Coefficients ◽  
Climatic Conditions ◽  
Allochthonous Organic Matter ◽  
Hydrochemical Regime ◽  
First Time ◽  
Liquid Precipitation

The supply of allochthonous organic matter with river water to the lakes rises in the new climatic conditions of Karelia (mild winters, an increase in the amount of liquid precipitation, less freezing of the soil). In connection with the geochemical peculiarities of Fennoscandia, more quantity of humic substances in a complex with iron and phosphorus enter the water bodies. These processes can lead to a change in the hydrochemical regime, water quality and habitat of the biota. For the first time for lakes of Karelia, long-term changes (1963–2017) of parameters, which are markers of allochthonous organic matter, were estimated on the example of Petrozavodsk Bay of Onego Lake. It was found that since the 1990s, the following characteristics significantly increase in Petrozavodsk Bay water: the color of water (from 56 to 73 degrees), the content of suspended matter (from 1.6 to 3 mg/l), iron (from 0.12 to 0.42 mg/l), phosphorus (from 12 to 22 μg/l). This leads to changes in the carbonate system of the bay water. The concentration of carbon dioxide increases significantly (from 1.2 to 3.0 mg/l), the pH value drops (from 7.22 to 7.12) and the oxygen content diminishes (from 101 to 92% of saturation). The Spearman correlation coefficients between the chemical characteristics and the year of study were the highest for the spring period, when the bay is separated from the open part of the lake by thermal bar and is strongly influenced by river water. Simultaneously with the change in the hydrochemical regime, there is an increase in the amount of iron in the upper layer of silts (from 0.65 to 4.8% of the air-dry sample). This led to a decrease in the number of macrozoobenthos 6–7 times.

A novel approach for the operational production of hybrid larch seeds under northern climatic conditions

2008 ◽  
Vol 84 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Fabienne Colas ◽  
Martin Perron ◽  
Denise Tousignant ◽  
Carol Parent ◽  
Monique Pelletier ◽  
...  
Keyword(s):  
Wood Quality ◽  
Time Lag ◽  
Seed Orchard ◽  
Larix Decidua ◽  
Climatic Conditions ◽  
Snow Accumulation ◽  
Japanese Larch ◽  
Larix Kaempferi ◽  
Hybrid Larch ◽  
European Larch

Hybrid larch ([Larix × marschlinsii Coaz], HL) is sought after by the forest industry because of its growth characteristics, excellent wood quality and disease resistance. However, the difficulty in obtaining HL seeds limits the production of seedlings for reforestation. Both European larch (Larix decidua Mill.) and Japanese larch (Larix kaempferi [Lamb.] Carrière) produce few seeds and the time lag in their flowering phenology complicates their natural pollination. We have developed a novel type of sheltered seed orchard, dedicated to the production of HL seeds from grafts grown in pots. Inverting the arches of a conventional tunnel provides a sturdy structure which is easy to maintain. Because of its height, the tunnel can accommodate the rapid growth of the trees, which reduces the need for pruning. The tunnels are covered in the winter and spring. In the winter, the covers prevent snow accumulation. In the spring, they create a "greenhouse effect" inside the tunnels, accelerating flower development, preventing pollen contamination from trees outside the tunnels and protecting the flowers from late spring frosts. Over the past five years, flowering has been regular and abundant. Bagging the crowns for pollen harvest is cost-effective and yields large quantities of high quality pollen. Pollination operations are conducted using an electrostatic pistol. Because of the large number of available clones, large quantities of seeds with a high genetic variability can be produced at a competitive cost. In 2006, this seed orchard concept was implemented operationally at the Berthier forest nursery (Québec, Canada). Key words: Japanese larch (Larix kaempferi [Lamb.] Carrière), European larch (Larix decidua Mill.), seed production, electrostatic pollination, indoor seed orchard

scholarly journals Miniature (dwarf) daff odils in the collection of Federal Research Center “Subtropical Scientifi c Center of the Russian Academy of Sciences”

2020 ◽  
pp. 25-31
Author(s):  
A. V. Ryndin ◽  
N. A. Slepchenko
Keyword(s):  
Research Area ◽  
Early Spring ◽  
Climatic Conditions ◽  
Open Ground ◽  
Experimental Base ◽  
The 1960S ◽  
Rip Van Winkle ◽  
Humid Subtropics ◽  
C Center

The Subtropical Scientifi c Center has a large collection of bulbous plants, including daff odils, dating back to the 1960s. The purpose of this work was to study miniature daff odils attracted to the collection. The research was carried out at the experimental base of the Center in Sochi (Razdolnoye village) in 2013-2019. As the collection was replenished with dwarf varieties, the work was begun on developing a methodology for evaluating this group. Climatic conditions of the research area are typical for the zone of humid subtropics, characterized by a large amount of precipitation, mainly in winter and early spring, and mild winters. During the research, it was noted that the meteorological parameters in the years of research diff ered both from the average long-term indicators and between themselves. When introducing and studying varieties, much attention was paid to both phenological observations and biometric measurements, as well as to varieties’ reproduction ability. It is established that all these parameters largely depend not only on variety characteristics, but also on climatic conditions during the growth and development of plants. Insuffi cient precipitation in some years and relatively cold winters contributed to the later phenophases, reducing their terms and biometric parameters. In general, as a result of long-term observations, it was found that in the humid subtropics of Russia, dwarf daff odils begin their vegetation in the fi rst or second ten-day period of January, which lasts from 118 to 135 days, depending on a variety. Early blooming (in the third ten-day period of February) was recorded in ‘Tete-a-Tete’ and ‘Jetfi re’ cvs. Later blooming was recorded in ‘Jack Snipe’ and ‘Canaliculatus’ cvs. in the second ten-day period of March. As a result of the research, the following miniature varieties with a plant height of less than 20 cm were selected from the daff odils collection: ‘Canaliculatus’, ‘Jack Snipe’, ‘Jetfi re’, ‘Rip van Winkle’, ‘Tete-a-Tete’ and ‘Topolino’. The studied varieties have high ornamental qualities, are resistant to biotic factors and can be used in pot culture and landscaping of open ground.

scholarly journals   Influence of injection nitrogen fertilization on yield and seed composition of winter oilseed rape (Brassica napus L.)

2012 ◽  
Vol 58 (No. 11) ◽  
pp. 508-513 ◽  
Author(s):  
L. Peklová ◽  
J. Balík ◽  
O. Kozlovský ◽  
O. Sedlář ◽  
K. Kubešová
Keyword(s):  
Soil Surface ◽  
Vegetation Period ◽  
Early Spring ◽  
Climatic Conditions ◽  
Seed Composition ◽  
Winter Rape ◽  
Brassica Napus L ◽  
Nitrogen Injection ◽  
Ammonium Nutrition

Influence of the nitrogen injection fertilization ‘controlled uptake long term ammonium nutrition’ (CULTAN) on winter rape yield and seed composition was studied in 2009 and 2010 at two sites with different soil-climatic conditions in the Czech Republic. Two conventional treatments consisted of fertilization using the system of divided doses applied on soil surface. Two CULTAN treatments used injection fertilization with the whole dose of nitrogen applied once in the vegetation period, in early spring at the BBCH 26 stage (6 side shoots detectable). The trial compared conventional and CULTAN treatments. The overall dose of nitrogen was 200 kg N/ha in each treatment. The seed yield in a two-year average was 4.83 t/ha at conventional and 4.80 t/ha at the CULTAN treatment. This difference was not statistically significant. The higher nitrogen content in seed was recorded mainly at CULTAN treatments at the Hněvčeves site in 2009. An inconclusively higher phosphorus content was recorded in winter rape seed fertilized with the CULTAN method at both sites in 2010. Content of K, Ca, Mg and S did not show statistically significant differences between the two treatments during both experimental years. In oiliness no differences between conventional and CULTAN methods were observed.    

scholarly journals Shallowing of the Svityaz Lake in the context of regional climate change

2020 ◽  
Vol 29 (4) ◽  
pp. 673-683
Author(s):  
Vitalina Fedoniuk ◽  
Maria Khrystetska ◽  
Mykola Fedoniuk ◽  
Ihor Merlenko ◽  
Serhiy Bondarchuk
Keyword(s):  
Climate Change ◽  
Regional Climate ◽  
Correlation Coefficients ◽  
Regional Climate Change ◽  
Water Levels ◽  
Climatic Data ◽  
Ecological Stability ◽  
Air Temperatures

The paper analyzes the dynamics of the main climatic indicators in order to reveal the role of regional and local factors in the current changes in the water content of the Svitiaz Lake (NW Ukraine). The current state of study of the water balance of the lake and the factors that form it are estimated. The main trends for changes in the levels and regime of surface water, groundwater and artesian water in the territory of the Shatsk National Nature Park are identified. Quantitative data characterizing long-term and modern changes in water levels in the lake are presented. Shallowing of 2019 is characterized (the lowest water level over the last 50 years, reduction of the water mirror area by 8%). Based on statistical mathematical and cartographic analysis of climatic data provided by 17 meteorological stations in the region the dynamics of average annual, monthly and seasonal precipitation, evaporation and their spatial distribution were estimated. A significant increase in evaporation during the warm period of the year over the last decades (2000-2018) has been revealed. Changes in the amount and mode of precipitation over 2 long-term periods are estimated. The peculiarities of the dynamics of the main meteorological indicators in 2019 (average monthly and average annual air temperatures, relative humidity, precipitation amounts) were separately analyzed. Values of humidity coefficients and hydrothermal coefficients were calculated. The parts of the region with the lowest values of these indicators, including the catchment area of Lake Svityaz, are outlined and visualized on the map. The significant role of evaporation growth was confirmed given the consistent increase in air temperatures over the last 20 years. Given the Svityaz station data it is also calculated the correlation coefficients of water levels in the lake with the same indicators for the period since 1970. During the period of 2000-2018, a significant increase in the dependence of water levels on the hydrothermal coefficient of Selyaninov was established, which may indicate a decrease in the ecological stability of the lake and its increasing vulnerability to climate change.

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