The observed climate change determines the silvicultural and productive perspectives of the different species. The use of stand growth simulators, which are important tools for predicting future tree ...growth, requires verified and consistent data, such as length of forest growing season (FGS). The aim of this study is to determine the current and future FGS on the territory of Poland, which has a highly variable transition climate between maritime and continental types. The analysis is based on the WorldClim grid dataset corrected with the constructed model based on the FGS derived from 245 meteorological stations covering the whole territory of the country. In addition, predictions of changes in FGS depending on different climate scenarios were considered. The results show that the inclusion of geographical location components, i.e., longitude, latitude and especially altitude, is important for the correction of FGS calculated on the basis of raster datasets such as WorldClim. The prediction of climatic changes shows a significant increase in FGS duration in Poland, ranging from 18 to 52 days, mainly affecting the mountainous regions with the shortest actual FGS.
In this paper, changes in the duration of the meteorological vegetation period in Poland were analyzed for the three decade period: 1981–2010 as compared to the 1971–2000 period. The meteorological ...data regarding the monthly mean air temperature values from 53 weather stations distributed evenly across Poland were used. It was proved that the meteorological vegetation period in the years 1981–2010 increased by four days on average, as compared to the 1971–2000 period.
Genotype and weather conditions play crucial roles in determining the volume and stability of a soybean yield. The aim of this study was to identify the key meteorological factors affecting the ...harvest date (model M_HARV) and yield of the soybean variety Augusta (model M_YIELD) using a neural network sensitivity analysis. The dates of the start of flowering and maturity, the yield data, the average daily temperatures and precipitation were collected, and the Selyaninov hydrothermal coefficients were calculated during a fifteen-year study (2005–2020 growing seasons). During the experiment, highly variable weather conditions occurred, strongly modifying the course of phenological phases in soybean and the achieved seed yield of Augusta cultivar. The harvesting of mature soybean seeds took place between 131 and 156 days after sowing, while the harvested yield ranged from 0.6 t·ha−1 to 2.6 t·ha−1. The sensitivity analysis of the MLP neural network made it possible to identify the factors which had the greatest impact on the tested dependent variables among all the analyzed factors. It was revealed that the variables assigned ranks 1 and 2 in the sensitivity analysis of the neural network forming the M_HARV model were total rainfall in the first decade of June and the first decade of August. The variables with the highest impact on the Augusta soybean seed yield (model M_YIELD) were the mean daily air temperature in the second decade of May and the Seljaninov coefficient values calculated for the sowing–flowering date period.
The annual timing of leaf colouring of deciduous trees in temperate regions is not predictable using phenological models. In this analysis we show that commonly applied hypotheses of leaf colouring ...triggers have neither satisfactory explanatory power nor significant statistical proof. We tested meteorological parameters, such as monthly mean temperatures, threshold temperatures, monthly sums of precipitation and number of dry days per month of the year of the phenological event and of the previous year and the length of the vegetation period. Their influence on leaf colouring dates for 4 deciduous tree species (horse chestnut, beech, birch, oak) in Germany (1951–2003) was tested by Pearson's correlations. We created 3 different datasets: (A) phenological observations for single stations within 25 km of meteorological stations, (B) means of phenological observations around (<25 km) meteorological stations, and (C) phenological means for Germany. Only the mean temperature of September had a slight influence on the onset of leaf colouring (mean: rchestnut= 0.45; rbeech= 0.56; roak= 0.51; rbirch= 0.45). Taking all correlation coefficients r > |0.3| into account, we can deduce that a warm September (all species) and August (oak, birch) delayed leaf colouring while a warm June (horse chestnut, oak) and May (horse chestnut) advanced leaf colouring.
The aim of this study is a modern assessment of the agro-climatic resources of the semi-desert and desert landscapes of the North Caucasus. The methods of mathematical statistics used in ...agroclimatology have been used to analyze the changes in average monthly and annual air temperatures, the growing season, the amount of precipitation, and the hydrothermal coefficient according to the data of five weather stations with a long series of observations. Within the semi-desert and desert landscapes of the North Caucasus, there is an increase in annual air temperature over the period under review by an average of 0.86°С compared to the previous period. The sum of active temperatures increased by 9–11%. The duration of the period increased when passing through 0°C for 17 days, 5°C for 15 days, 10°C for 10 days, and 15°C for 8 days. An increase in precipitation is noted at all meteorological stations except Makhachkala. On average, precipitation increased by 36 mm. The hydrothermal coefficient of Selyaninov varies from 0.5 to 0.7 and is within the limits of natural fluctuation. Modern agro-climatic changes within the semi-desert and desert landscapes of the North Caucasus are characterized by an improvement in the conditions for heat and moisture supply to the territory. These conditions are favorable for the cultivation of melons and all types of grape varieties, with the exception of very late ones.
During the last decade, the popularity of hemp products has been rising rapidly. Products containing cannabidiol (CBD) are of predominant interest. Traditional hemp products are frequently enriched ...by CBD due to their potential therapeutic effects. Cannabidiol occurs naturally in hemp juice together with other biologically active substances, such as terpenes, flavonoids, and stilbenoids. These constituents act synergistically. This study aimed to observe the influence of the hemp plant developmental stage on its chemical composition and antioxidant activity. The hemp plants were analyzed during three vegetative stages, i.e., before, during, and after flowering. The collected samples were evaluated using the following analyses: total polyphenolic content and profile, terpenoid and cannabinoid contents, and ferric reducing antioxidant power. The results revealed statistically significant differences between the samples in almost all set parameters. The optimal period for hemp harvest depends on desirable compounds, i.e., phenolic content is the highest before flowering, while the levels of cannabinoids and terpenoids are the highest during the flowering period.
Aim
Assessing the relationship between a spatial process and environmental variables as a function of spatial scale is a challenging problem. Therefore, there is a need for a valid and reliable tool ...to examine and evaluate scale dependencies in biogeography, macroecology and other earth sciences.
Location
Central Europe (latitude 43.99°–54.22° N, longitude 4.79°–15.02° E).
Methods
We present a method for applying two‐dimensional wavelet analysis to a generalized linear model. This scale‐specific regression is combined with a multimodel inference approach evaluating the relative importance of several environmental variables across different spatial scales. We apply this method to data of climate, topographic and land cover variables to explain variation in annual greening of vegetation (i.e. phenology) in Central Europe.
Results
Land use is more important to explain the variation in greening than climate at smaller resolution while climate is more important at larger resolution with a shift at c. 1000 km2.
Main conclusions
To the best of our knowledge, this is the first study analysing the scale dependency of an ecosystem process, clearly distinguishing between the different components of scale, namely grain, focus and extent. The obtained results demonstrate that our newly proposed method is particularly suitable for studying scale dependencies of various spatial processes on environmental drivers keeping grain and extent constant and changing focus (i.e. resolution).
Key message
The change in forest productivity was simulated in six stands in Wallonia (Belgium) following different climate scenarios using a process-based and spatially explicit tree growth model. ...Simulations revealed a strong and positive impact of the CO
2
fertilization while the negative effect of the transpiration deficit was compensated by longer vegetation periods. The site modulated significantly the forest productivity, mainly through the stand and soil characteristics.
Context
Forest net primary production (NPP) reflects forest vitality and is likely to be affected by climate change.
Aims
Simulating the impact of changing environmental conditions on NPP and two of its main drivers (transpiration deficit and vegetation period) in six Belgian stands and decomposing the site effect.
Methods
Based on the tree growth model HETEROFOR, simulations were performed for each stand between 2011 and 2100 using three climate scenarios and two CO
2
modalities (constant vs time dependent). Then, the climate conditions, soils and stands were interchanged to decompose the site effect in these three components.
Results
In a changing climate with constant atmospheric CO
2
, NPP values remained constant due to a compensation of the negative effect of increased transpiration deficit by a positive impact of longer vegetation periods. With time-dependent atmospheric CO
2
, NPP substantially increased, especially for the scenarios with higher greenhouse gas (GHG) emissions. For both atmospheric CO
2
modalities, the site characteristics modulated the temporal trends and accounted in total for 56 to 73% of the variability.
Conclusion
Long-term changes in NPP were primarily driven by CO
2
fertilization, reinforced transpiration deficit, longer vegetation periods and the site characteristics.
Relevance.
One of the types of agricultural raw materials for the food industry is the root chicory, the product from the roots of which is produced in pure form, as well as is an important component ...in the production of tea and coffee drinks, confectionery. Its value is determined by the content in the roots of inulin, fructose, intibin and chicory. Despite the great economic importance and economic profitability of chicory cultivation, in recent years, the local processing industry is not provided with this type of raw material and is forced to buy the product from dried root crops in other countries, such as Ukraine, Italy and India. Modern agricultural production is in dire need of new varieties of root chicory, combining high yields and chemical and technological qualities, having the form of a root crop suitable for mechanized harvesting, and adapted to cultivation in soil and climatic conditions of the Non-chernozem zone. Purpose of work: to assess the nature of the impact of ultraviolet radiation in the time mode on watermelon seeds using cytogenetic analysis.
Material and methods
. The article describes the results of the test in the control nursery of a new sample of chicory root with 0428 selection of Rostov OSC.
Results
. As a result of breeding work, a promising sample of root chicory. It was isolated early maturing, with high yields and economically valuable properties, root crop truncated, suitable for mechanized harvesting by commercially available machines.
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