Luzula sylvatica

Abstract: Determinations of the NH(3) compensation point for the understory plant of semi-natural woodlands Luzula sylvatica (Huds.) Gaud. were carried out by measurements of gas exchange and by calculation from the NH(4)(+) concentration and pH of extracts of the foliar apoplast. Compensation points determined by gas exchange measurements were among the lowest yet reported (0.51-1.10 microg NH(3) m(-3)) and those calculated from apoplast extracts were lower than any yet reported (0.017-0.54 microg NH(3) m(-3)). Those determined by gas exchange were consistently found to be between 2 and 30 times higher than those determined from apoplast extracts. Consideration of possible causes of this discrepancy, which is not confined to this investigation, showed that all likely errors would result in an increase in the discrepancy, or were insufficient to account for observed differences. It is suggested that spatial variability of pH and NH(4)(+) concentration within the foliar apoplast represents the most promising line for further investigation. It is also shown that the foliar apoplast of L. sylvatica is sufficiently buffered to eliminate the need for correction of H(+) concentration for dilution during extraction, but that it is necessary to correct the NH(4)(+) concentration of apoplast extracts for dilution.

Abstract: This study reveals which temperature range is favoured or avoided by 156 forest plant species and how the distribution of potential suitable habitats of species in beech forests may change in the future. We performed 140 phytosociological releves along a temperature gradient (4.1 to 9.8 °C) in Bavaria, southern Germany, on south exposed slopes. One half of the plots were located on acidic substrate, the other half on base-rich substrate. Generalized linear models (GLM) were used to analyse species occurrence along the temperature gradient and to model habitats for species in beech forests under a present (1971-2000) and a future climate (2071-2100) scenario assuming a temperature increase of 1.8 °C. Herb species of beech forests are more adapted to lower temperatures and tree species more to higher temperatures. Current habitats will clearly change under increasing temperatures. We found large habitat losses for Luzula sylvatica (Huds.) Gaudin, Maianthemum bifolium (L.) F. W. Schmidt, Picea abies (L.) H. Karst., Prenanthes purpurea L. and large habitat gains for Carpinus betulus L., Impatiens parviflora DC., Prunus avium (L.) L. and Quercus petraea (Matt.) Liebl. on both substrates. Forestry will be affected positively as well as negatively with a change in tree cultivation. Losses in biodiversity might be strong for mountainous forests and must also be considered in future conservation plans.

Abstract: The aim of this study was to evaluate the effects of different in situ light regimen on ecophysiological parameters of Luzula sylvatica leaves Plants of L sylvatica grown under natural sunny and shade conditions in arcto-alpine tundra were analyzed with respect to their leaf anatomy, content of photosynthetic pigments, UV absorbing compounds and phenanthrenoid compounds Relationship between chlorophyll concentrations (Chla+b) and SPAD values was determined for sun and shade leaves measured repeatedly within summer and autumn seasons 2019 and 2020 Pooled data showed curvilinear Chla+b to SPAD relationship with the highest Chla+b and SPAD values found for shade leaves Sun leaves had higher UV-B absorbing compounds contents than shade ones The HPLC-DAD analysis revealed significant amount of soluble flavonoids in Luzula sylvatica leaves, amongst others the flavone-luteolin and its derivatives (eg tentatively identified luteolin-methyl-glucoside and luteolin-glucoside) The accumulation of luteolin based compounds in sun acclimated leaves is also plausible explanation for the higher antioxidant activity determined in sun leaf extraxts Such response of flavonoid metabolism may help LS to cope with excessive-light stress through UV-attenuation mechanism and ROS scavanging Additionally, phenanthrenoid compounds contents in L sylvatica leaves were determined Altogether, 9 phenanthrenoid compounds were identified by HPLC-HRMS Their content was markedly different (up to the factor of 5) between sun and shade leaves of Lsylvatica

Abstract: Understorey plant communities are crucial to maintain species diversity and ecosystem processes including nutrient cycling and regeneration of overstorey trees. Most studies exploring effects of elevated CO2 concentration ([CO2]) in forests have, however, been done on overstorey trees, while understorey communities received only limited attention. The hypothesis that understorey grass species differ in shade-tolerance and development dynamics, and temporally exploit different niches under elevated [CO2], was tested during the fourth year of [CO2] treatment. We assumed stimulated carbon gain by elevated [CO2] even at low light conditions in strongly shade-tolerant Luzula sylvatica, while its stimulation under elevated [CO2] in less shade-tolerant Calamagrostis arundinacea was expected only in early spring when the tree canopy is not fully developed. We found evidence supporting this hypothesis. While elevated [CO2] stimulated photosynthesis in L. sylvatica mainly in the peak of the growing season (by 55%-57% in July and August), even at low light intensities (50 mu mol m(-2) s(-1)), stimulatory effect of [CO2] in C. arundinacea was found mainly under high light intensities (200 mu mol m(-2) s(-1)) at the beginning of the growing season (increase by 171% in May) and gradually declined during the season. Elevated [CO2] also substantially stimulated leaf mass area and root-to-shoot ratio in L. sylvatica, while only insignificant increases were observed in C. arundinacea. Our physiological and morphological analyses indicate that understorey species, differing in shade-tolerance, under elevated [CO2] exploit distinct niches in light environment given by the dynamics of the tree canopy.