scholarly journals Photosynthetic activity of Fagus sylvatica L. and Quercus petraea (Matt) Liebl. in a mixed stand at Maljen mountain

2005 ◽  
Vol 57 (4) ◽  
pp. 305-306
Author(s):  
Zorica Popovic ◽  
Aleksandar Mijovic ◽  
Branko Karadzic ◽  
Miroslava Mijatovic ◽  
S. Skoric

Estimation of the photosynthetic performance of co-existing tree species with pronounced differences in ecophysiological context (Aranda et al. 1996 Leuschner et al. 2001) could provide insight into their vitality and competitive abilities at a particular site. Gas exchange, composition of photosynthetic pigments, and the water status of beech (Fagus sylvatica L) and sessile oak (Quercus petraea (Matt) Liebl) were studied in the present work. The investigation was performed on Mt. Maljen (Western Serbia, near the town of Mionica) at an altitude of 950 m, in an ecotope within the confines of the mountain's beech forest belt. Codominant samplings [three of each species, 30-years old (n=6), 10-12 m high] were selected for the measurements, which were conducted on fully developed leaves from the out?ermost branches and from the innermost canopy. Photosynthetic measurements were performed using an LI-6200 closed photo?synthesis system (LI-Cor. Inc, Lincoln, NE, USA), while irradiance was detected with a selenium cell mounted on the leaf chamber. Parameters of gas exchange are expressed on the basis of leaf area, using the AREAMETER software (Karadzic et al. 1999). Chlorophyll content was spectrophotometrically determined based on light absorption of the solution obtained after extraction with dMSO (Hiscox and Israelstam, 1979). The midday water saturation deficit was determined according to Turner (1981). For data analysis, we used the Statistic for Windows program package. The ANOVA one-way break?down was applied to compare differences within (leaves inside vs. leaves outside the surface of the tree canopy) and between species for all investigated parameters at the 0.05 level of significance.

2010 ◽  
Vol 56 (No. 12) ◽  
pp. 589-599 ◽  
Author(s):  
L. Dobrovolný ◽  
V. Tesař

Recently individually dispersed adult beech trees have regenerated in spruce monocultures and this fact could be used to manage the transformation of stands into a mixed forest. Three such cases in the fir-beech and spruce-beech forest zones were analyzed. Beech regeneration is dispersed to distances of several hundred meters regardless of the configuration of the terrain. Using a model we describe this process by a dispersion curve that can be broken up into three sections: (1) directly under the crown as the result of barochory; (2) from 15 to 30 m from the trunk, where the barochoric and zoochoric dispersal of beech nuts intersects; (3) from the "breakpoint" to farther away as a result of zoochory. Regeneration is utilizable as an optimal or at least acceptable method for creating the next economically valuable stands only in sections 1 and 2. In section 3 individual trees may be the central points for the transformation of the second successive forest generation. With spontaneous development without protection from game the density is in the range of hundreds of individuals; in protected groups density can be in the range of tens of thousands of individuals per hectare.


2019 ◽  
Vol 32 (2) ◽  
pp. 482-492
Author(s):  
GEOVANI SOARES DE LIMA ◽  
HANS RAJ GHEYI ◽  
REGINALDO GOMES NOBRE ◽  
LAURIANE ALMEIDA DOS ANJOS SOARES ◽  
JOÃO BATISTA DOS SANTOS

ABSTRACT Castor bean is an oilseed crop which is able to adapt to various edaphoclimatic conditions and has considerable contents of oil in its seeds, with potential for use in the castor oil industry. In this context, this study aimed to evaluate changes in membrane damage, water status and gas exchanges in castor bean plants (cv. ‘BRS Energia’) in response to irrigation water salinity and cationic composition. Randomized blocks were used to test six cationic compositions (S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Na+ + Ca2+; S5 - K+ and S6 - Na+ + Ca2+ + Mg2+), in four replicates. Plants in the control treatment were subjected to irrigation using water of low electrical conductivity (S1 - ECw = 0.6 dS m-1), whereas those in the other treatments were irrigated using 4.5 dS m-1 water prepared with different cations. Higher leaf succulence associated with lower water saturation deficit is an indication of tolerance to salt stress in castor bean plants irrigated with K+-rich water. The presence of Na+ in irrigation water caused the highest water saturation deficit in castor bean leaf blades. The lowest damage in cell membranes was observed in plants irrigated with Ca2+-rich water. The damaging effect of salt stress on castor bean gas exchanges depends on the cationic composition of water and occurred in the following order: Na+>Na++Ca2+>Ca2+> Na++Ca2++Mg2+>K+.


2004 ◽  
Vol 34 (11) ◽  
pp. 2340-2350 ◽  
Author(s):  
Gary Kerr

The effects of mixing ash (Fraxinus excelsior L.) with cherry (Prunus avium L.), oak (Quercus petraea (Matt.) Lieb., and Quercus robur L.), and beech (Fagus sylvatica L.) were investigated using a balanced two-component competition experiment. In general, two patterns of growth were observed. Firstly, in the ash–cherry experiment, two rapidly growing species altered their stem form and showed a plastic response to interspecific competition, and both species maintained a position in the upper canopy. Secondly, in the ash–oak and ash–beech experiments, a two-tier canopy formed with ash in the upper canopy, and interspecific competition resulted in an early nursing effect on the ash. In both patterns of growth, competition affected stem diameter and the shape of the tree with few, and only short-lived, effects on height. The maximum relative yield totals were 1.78 for ash–cherry, 1.77 for ash–oak, and 1.44 for ash–beech, indicating that the mixtures studied may be more productive in their early phase of growth than equivalent areas of pure species.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1128
Author(s):  
Alvaro Sánchez-Medina ◽  
Esperanza Ayuga-Téllez ◽  
Maria Angeles Grande-Ortiz ◽  
Concepción González-García ◽  
Antonio García-Abril

We present a new method for the classification of beech (Fagus sylvatica L.) forest plots based on discriminant and frequency analysis. This method can be used as a tool to allow experts to stratify beech forests in a simple and precise way. The method is based on discriminant analysis with cross-validation of 13 variables measured in 142 plots from the 2005 Second National Forest Inventory and 63 plots from an inventory installed in specific locations together with a frequency analysis of the qualifying variables. In the first stage, the method uses the results of a frequency analysis fitted with an iterative discriminant analysis that allows improving the subsequent classifications taking into account the results of the analysis and the correctly- and wrong-classified plots. This method is applied to beech forest in Burgos (Spain) where six structural groups were described. The discriminant functions show that forest structure depends basically on diameter distribution and almost 94% of the plots are correctly classified using this methodology. The high level of correctly assigned plots indicates an accurate classification of structure that can be used to stratify beech forests with only the diameter at breast height measurement.


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