Wyniki wyszukiwania - Biblioteka Nauki

1

Oddziaływanie dwutlenku siarki na wybrane gatunki liściastych drzew leśnych

100%

Bęś A. , Baciak M.

|

tom Vol. 24, No. 2

155--166

PL

Działanie dwutlenku siarki na drzewa powoduje żółknięcie ich liści, ubytek chlorofilu, co ma przełożenie na zahamowanie procesu fotosyntezy. Rośliny są bardziej narażone na działanie SO2 w dzień, kiedy mają otwarte aparaty szparkowe, przez które wnika on do wnętrza komórek. Podwyższone stężenie SO2 powoduje rozkład chlorofilu, zakłócenie fotosyntezy, jak również zatrzymanie asymilacji, co w rezultacie prowadzi do zwiększonej wrażliwości drzew na czynniki klimatyczne, zmniejsza odporność drzewostanu na występowanie chorób oraz szkodników lasów. Celem prowadzonego eksperymentu było wykazanie wrażliwości olchy czarnej i dębu szypułkowego na zanieczyszczenia gazowe, podczas ekspozycji tych roślin w podwyższonych stężeniach dwutlenku siarki. Oddziaływanie dwutlenku siarki na liście określono poprzez oznaczenie zawartości chlorofili a i b metodą ekstrakcji chlorofilu dimetylosulfotlenkiem (DMSO). Olcha czarna wykazywała większą wrażliwość na działanie SO2 niż dąb szypułkowy. Działanie na rośliny dwutlenkiem siarki w znacznym stopniu obniżyło zawartości chlorofili a i b, a co za tym idzie intensywność fotosyntezy. Uszkodzenie wywołane przez SO2 na liściach olchy objawiało się w postaci nekroz, a w przypadku liści dębu uszkodzenia przyjmowały postać żółtych chloroz i pojedynczych brązowych nekroz.

EN

Exposure of plants to sulfur dioxide causes yellowing of the green portions of the leaf and chlorophyll destruction, which inhibits photosynthesis. Plants incur more damage from sulfur dioxide during daytime, when stomata are open in the presence of sunlight and sulfur dioxide can penetrate into leaf cells. High sulfur dioxide concentrations lead to chlorophyll degradation, photosynthesis disturbance and inhibition of assimilation in leaves, which increases the vulnerability of trees to climatic factors and decreases their resistance to diseases and pests. The aim of this study was to determine the sensitivity of black alder and English oak to gaseous air pollution. The trees were exposed to increased sulfur dioxide concentrations. The effect of sulfur dioxide on leaves was evaluated based on the concentrations of chlorophyll a and chlorophyll b extracted using dimethyl sulfoxide (DMSO). The black alder was more susceptible to sulfur dioxide than the English oak. Exposure of trees to sulfur dioxide considerably reduced the concentrations of chlorophyll a and chlorophyll b, and the rate of photosynthesis. Injury to foliage caused by sulfur dioxide appeared in the form of necrotic lesions in the black alder, and yellow chlorosis spots and individual brown necrotic patches in the English oak.

2

Evaluation of the effect of environmental variables on health condition of Quercus robur L. in parks

100%

Krzyżaniak M. , Świerk D. , Urbański P. , Walerzak M. T.

Ecological Chemistry and Engineering. S

|

2013

|

tom Vol. 20, nr 4

689--700

EN

Investigations concerned the effect of different environmental variables on health condition of English oak (Quercus robur L.). It was shown that in the public parks in the city of Poznan the health condition of the analysed species is good. It was stated that health condition of this species in the Poznan parks is influenced by the distance from the immediate city centre, vicinity of traffic arteries and gas emissions from the combustion of fossil fuels by households neighbouring with the parks. Although results recorded in this study confirm literature data concerning the effect of environmental variables on health condition of English oak (Quercus robur L.), it was shown that certain environmental variables have a greater effect on health condition of the analysed species in Poznan.

PL

Badania dotyczyły wpływu różnych zmiennych środowiskowych na stan zdrowotny dębu szypułkowego (Quercus robur L.). Wykazano, że na terenie parków publicznych Poznania stan zdrowotny omawianego gatunku jest dobry. Stwierdzono, że wpływ na stan zdrowotny tego gatunku w parkach Poznania mają: oddalenie od ścisłego centrum miasta, bliskość arterii komunikacyjnych oraz emisja gazów ze spalania paliw kopalnych przez sąsiadujące z parkami gospodarstwa domowe. Mimo że wyniki uzyskane w pracy potwierdzają dane literaturowe dotyczące wpływu zmiennych środowiskowych na stan zdrowotny dębu szypułkowego (Quercus robur L.), to wykazano, że niektóre zmienne środowiskowe mają większy wpływ na stan zdrowotny badanego gatunku w Poznaniu.

3

Temperature effects performance of Lymantria dispar larvae feeding on leaves of Quercus robur

100%

Karolewski P. , Grzebyta J. , Oleksyn J. , Giertych M. J.

Dendrobiology

|

2007

|

tom 58

43-49

EN

Future climatic warming may modifyinsect development, sex ratio, quantitative changes in populations that could affect the frequency of outbreaks. Here we analyzed the influence of temperature on larval growth and development in the gypsy moth (Lymantria dispar L.). The larvae were reared at three constant temperatures: 15, 20 or 25°C, and fed with leaves of the English oak (Quercus robur L.). Larval mortality, duration of development (DD), relative growth rate (RGR), total mass of food eaten (TFE), and pupal mass (PM) were estimated. Larval mortality was lowest at 20°C, higher at 25°C, and highest at 15°C. DD significantly decreased with increasing temperature and depended on sex. The influence of temperature on the shortening of DD was stronger in males than in females. RGR significantly depended on temperature and was the highest at 25°C, and lowest at 15°C. At 15°C, RGR did not change markedly with time. In contrast, RGR at 20°C was characterized bya continuous decreasing trend. At 25°C, RGR was very high for 2 weeks but quickly declined afterwards. Temperature did not affect the TFE. PM was significantly correlated with temperature and sex. PM of females was higher at 20°C than at 15 and 25°C, in contrast to that of males, which was similar at 20 and 25°C, and higher than at 15°C. For larval growth and development, the most favourable was the medium temperature (20°C). The least favourable temperature for females was 25°C, for males 15°C. The results suggest that global warming may modifythe future sex ratio of gypsy moths that may affect insect development and outbreaks.

4

The growth ring structure effect on moisture content in green wood of English oak [Quercus robur L.] and Northern red oak [Quercus rubra L.]

100%

Raczkowski J. , Helinska-Raczkowska L. , Molinski W.

Folia Forestalia Polonica. Series B - Drzewnictwo

|

2003

|

nr 34

5

Effects of temperature on larval survival rate and duration of development in Lymantria monacha [L.] on needles of Pinus sylvestris [L.] and in L.Dispar [L.] on leaves of Quercus robur [L.]

100%

Koralewski P. , Grzebyta J. , Oleksyn J. , Giertych M. J.

|

nr 3

EN

This study assessed the effects of temperature on survival rate and duration of development (DD), i.e., time needed by larvae to reach the pupal stage, in nun moth (Lymantria monacha L.) and gypsy moth (L. dispar L.). The larvae were raised at 15, 20 or 25°C, and fed with current-year-needles of Scots pine (Pinus sylvestris L.) and leaves of English oak (Quercus robur L.), respectively. With increasing temperature 15, 20 and 25°C, larval survival rate (LSR) declined in L. monacha (for 35th day LSR was 0.44, 0.31 and 0.21, respectively), but increased in L. dispar (0.50, 1.00 and 0.94). In contrast, the duration of development decreased with increasing temperature in larvae of both moth species (67, 52 and 39 days for L. monacha, and 66, 43 and 33 days for L. dispar, respectively). The differences in larval survival rate between those species at higher temperatures can affect significantly their growth and development in warmer years. Therefore, it is possible that under global climate change these differences may lead to changes in distribution of both insect species.