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The aim of the study was to determine the impact of land relief on site index and growth parameters (height, diameter, slenderness) of Scots pine (Pinus sylvestris) stands on inland dunes in the Toruń Basin (N Poland). The study was conducted on 150 plots situated on north− and south−facing dune slopes (54 pairs of twin plots) as well as in intra−dune depressions (42 plots). Height and diameter of ten the thickest pines per 0.1 hectare was measured, and next site index as a potential height of a stand at the age of 100 years was calculated. As the results of the used equation, site index was strongly (R²=0.58) negatively biased to age, so the bias was removed using an elaborated regression model. For stands older than ca. 20 years, the clear higher site index values as well as higher heights and diameters were found for intra−dune depressions than for slopes of the two studied aspects. This was explained by the occurrence of much more fertile and moister soils in depressions. The only age class for which the advantage of site index and growth parameters was not stated for depressions was the youngest class (≤20 years old). This was likely caused by the competitive impact on young pines of Calamagrostis epigejos which prefers intra−dune depressions on inland dunes and forms in forest floor usually dense cover in this position. Impact of contrasting slope aspect was clearly related in the study to age of a stand. For the youngest studied age class both site index values as well as heights and diameters were lower on north− than on south−facing slopes. This was explained by the effect of weeds which form more dense cover on slopes of this aspect than on sunny slopes. For older stands; however higher site index values as well as heights and diameters were revealed for north−facing slopes, due to pines likely took advantage of higher moisture of soils occurring in this place. With reference to slenderness, regardless stand age the parameter was regularly the highest for north− than both for south−facing slopes and depressions. Because of the revealed distinct higher productivity of intra−dune depressions in normally dry and poor in nutrients dune landscape, it could be reasonable to use the depressions to introduce admixtures of broadleaved tree species into pine monocultures on inland dunes.
The objective of the study was to determine the dynamics of soil temperature on inland dunes in the Toruń Basin (N Poland) with reference to the two methods of site preparation: homogenization of belts with a forest mill (FR) and preparation of trenches with a double−mouldboard plough LPZ−75 (LPZ). The study was conducted in a young Scots pine (Pinus sylvestris) plantation on plots with soil prepared by a forest mill on north− and south−facing slopes of a dune (FR−N and FR−S respectively) and with soil prepared with a plough on the ridge of a small aeolian mound (LPZ). On each plot a soil pit was dug and soil samples were taken from distinguished horizons for laboratory analyses. Besides, from April to December of 2013, at interval of ca. two weeks, soil temperature was measured at the depths of 3, 10, 25 and 50 cm. To estimate daily amplitudes of temperature in topsoil on the studied plots, in a sunny summer day (23.08.2013) the temperature was additionally measured from 5 a.m. to 9 p.m. with an hourly interval. These measurements were taken at the two upper depths (3 and 10 cm). Despite the fact that soil surface was distinctly darker for belts prepared with a mill than in trenches prepared by a plough, soil temperatures were almost regularly lower in FR−N and in FR−S than in LPZ. This concerns all the investigated depths. The differences were explained by much higher moisture of soil material in belts what involves higher thermal capacity and with that slower heat of a soil, as well as causes higher losses of thermal energy for evaporation. Another agent explaining this was indicated to be related to high porosity of materials found in the belts. Namely, especially in dry periods, high volume of soil pores are filled on the FR plots with air what impedes heat transfer in a soil. It was concluded that stated in a previous study worse growth of pines planted in milled belts than in tranches prepared with a plough was unlikely related to differences in soil thermal conditions. Thus, differences in growth dynamics of young pines in plots with site prepared by the two studied methods are caused by other reasons rather as primarily other competitive impact of weeds and differences in soil water conditions occurring at root system of young trees.
Strojniś nadobny Philaeus chrysops Poda, 1761 jest kserofilnym i litobiontycznym pająkiem, zasiedlającym otwarte środowiska, głównie miejsca piaszczyste i naskalne. Pomimo iż gatunek ten jest rozprzestrzeniony w całej cieplejszej części Palearktyki, to jednak poza rejonem śródziemnomorskim jest rzadko notowany i uważany za zagrożony. Gatunek ten jest także wymieniany w Czerwonej liście zagrożonych gatunków w Polsce. W niniejszej pracy opisano nowe w Polsce stanowiska strojnisia nadobnego w Kotlinie Toruńskiej (UTM: CD36, CD37, CD46). Stanowiska te są prawdopodobnie jednymi z najbardziej na północ wysuniętych stwierdzeń gatunku w obrębie jego geograficznego zasięgu występowania.
The research was conducted in a young Scots pine (Pinus sylvestris) plantation located in a dune area of the Toruń Basin (N Poland). The aim of the study was to investigate differences in dynamics of soil water conditions followed different method used for site preparation. The three plots were investigated in the study: belt of soil prepared by a mill, north−facing slope of a dune (FR−N), belt of soil prepared with a mill, south−facing slope of a dune (FR−S) and soil prepared with a plough (furrows) on the ridge of a small aeolian mound (LPZ). On each plot soil samples were taken and soil moisture was regularly measured from April to December of 2013 (the TDR method). The measurements of soil moisture were taken at four depths (3, 10, 25 and 50 cm) at intervals of ca. 2 weeks. Additionally, soil moisture was also measured on 25.08.2015. It was done to determine soil water conditions for a deep summer drought (the measurements were taken twice this day – just before and after rain which turned to be the first since ca. a month). Reserves of soil moisture and shares of water unavailable to plants were calculated for every measure day for each study plot. As a result of higher organic carbon content, values of soil actual moisture as well as reserves of soil moisture were almost regularly higher for belts mixed with a mill than for furrows prepared with a plough (fig. 1, 3). Opposite relation was found, however for the summer drought (tab. 2). This was explained by the higher repellence of rich in organic mater, dried material occurring in belts. On 25.08.2015 much lower improvement of water conditions after rain was also stated for this material than for topsoil in LPZ. Unfavoured soil water conditions for plants occurring in belts in dry periods could explain relatively low dynamics of pine growth revealed for the variant of soil preparation in a previous study. However, it was concluded that a forest mill should be recommended for forestry, because the device much less disturbs topsoil than a plough. Besides, differences in growth parameters of pines followed different methods of soil preparation used before planting decline in next years of a stand growth.
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