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In concurrent with global warming, precipitation regimes are predicted to change as well around the world. In this study, two experimental sites were selected with different nutrient availability along a slope to study the effects of simulated increased precipitation on soil β-glucosidase activities in an Inner Mongolian grassland. Soil samples were adjusted to 55% of water holding capacity and incubated at 22°C in the dark for 32 days. Soil β-glucosidase activities were measured prior to and after the incubation. Results showed that soil β-glucosidase activities had differential responses to increased precipitation with a significant increase in the downslope site, but not in the upslope site. Correlation analysis showed that the initial soil β-glucosidase activities exerted a significantly negative relationship with soluble organic nitrogen (N). Our results indicated that both water availability and soil soluble N availability played important roles in regulating β-glucosidase activities in this semiarid region.
The article contains descriptive statistics on rainfall in an area of the southern part of the last ice age in Europe, and which now comprises the north-eastern part of the Poland. The study covers the period of 1981-2010. The sums of the annual and monthly precipitation were calculated, while years and months were evaluated in relation to the multi-annual and monthly averages. The frequency of daily precipitations was also determined. Values of SPI (Standarized Precipitation Index) were calculated together with the values of the Selianinov Index, which measures the environmental aspect of precipitation. The average annual rainfall showed a spatial heterogeneity in the region from 700.1 mm (Elblag in the north-west) to 555.3 mm (Mława) in the east and south-east. The greatest precipitation occurred in the last decade of the analysed period of thirty years. However, statistical analysis shows no significant trend change in precipitation during this period. The number of years with sums of precipitation below 75% of the normal turned out to be very small. In the annual cycle, summer precipitation prevailed. On a monthly basis, the averages sometimes exceeded the multiyear averages by as much as 200%, while extreme lows in monthly precipitation reached levels below 25% of the long-term averages. The calculated value of the SPI indicated that the most common drought conditions occurred in May and June; such droughts did not occur in April and July. The Selianinov Index indicates that the least favorable hydrothermal conditions occur in April and May, while the most favorable conditions occur in August and September.
A method of forecasting rainfall and mean temperature is presented. It is based on plant phenology and probability distribution of both random variables. This method makes it possible to give a forecast for each recorded phenological stage; the time horizon of the longest of them exceeds 90 to 100 days. A verification test based on data from different regions of Poland proved the method to be very efficient comparing to prediction using simple climate averages. It was applied to a case of 1982 and potato phenology, as an example.
One of the manifestations of climate changes is the occurrence of a greater number of precipitation events, characterized by greater rain intensity that affects the economic stability of cities. Gdańsk is an example of a city in which such events have occurred since the beginning of the twenty-first century. Due to the altitude differences in the area of Gdańsk city (between –2 m and 180 m a.s.l.), the occurrence of extreme atmospheric precipitation almost immediately causes hydrological effects in the water network consisting of several streams of montane character, which flow eastwards from the plateau of the Kashubian Lakeland. Meteorological stations of the National Meteorological Service (IMGW-PIB) are located in the coastal zone (Port Północny/Northern Port, Świbno) and in the highest part of the city (the Rębiechowo airport). Because this is insufficient, the city of Gdańsk has been expanding the local rain monitoring network since 2001, currently having reliable 10-year observation data sequences. The said network is operated by the Gdańsk Water municipal company. Climate changes resulting in different characteristics of rainfall episodes in Gdańsk naturally influence the determination of the probability of their occurrence. According to the rainfall model developed by Bogdanowicz and Stachy at the turn of the 20th and 21st centuries, at least 4 rainfall events lasting for over 8 hours in the last 17 years should be classified as a 100-year rain event. One of these extended the parameters of a 300-year rain event; whereas we asses the rain in the year 2016, when even 170 mm of rainfall was recorded on July 14, as at least a 500-year rain event. During this period, several-minute events were also recorded, which also exceeded the parameters of a 100-year rain event. The paper presents precipitation models for the region of Gdańsk. Based on the maximum annual daily rainfall from Rębiechowo meteorological station from the years 1974–2017, an analysis of changes in precipitation values corresponding to certain probabilities of occurrence was conducted. An assessment was also made of the projected decrease in the value of precipitation in relation to hydro-technical constructions, road-engineering structures, and rainwater drainage systems in view of changing legal regulations, as well as the latest trends related to the management of rainwater.
Three types of alpine plant species,Carex montis-everestii,Quercus aquifolioidesandStipa capillacea, along an altitudinal gradient of 3005–5025 m on the Tibetan Plateau, were chosen to test the generality of the hypothesis that foliar carbon isotope composition (δ¹³C) of C3 plants increases significantly with altitude and to determine climate drivers shaping its altitudinal pattern. Temperature and relative humidity showed significantly negative correlations with altitude; however, precipitation and soil water potential remained unchanged with altitude. Foliar δ¹³C of C. montis-everestii,Q. aquifolioides,S. capillaceaalone or combined together did not significantly increase with altitude, which does not support the leading hypothesis of increased foliar δ¹³C with altitude. There was no difference in foliar δ¹³C among all three species. Multi-factor correlation analyses showed that temperature, precipitation and relative humidity alone did not affect foliar δ¹³C ofC. montis-everestiiandS. capillacea, but conferred significant effects on foliar δ¹³C of Q. aquifolioides.
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.
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