Leaf traits have long been recognized as influential factors in the acquisition and processing of resources by plants. However, there is less knowledge of between-species variations in seasonal changes in leaf traits and trait interrelationships. Therefore, we examined variations in leaf area (LA), dry biomass (DM), specific leaf area (SLA), and leaf gas-exchange parameters in one non-native and seven native tree species under field environmental conditions, in a karst area in China subjected to desertification. Measurements were taken three times during the growing season. The results show that the seven native trees had higher LA, DM, and water-use efficiency (WUE) than the non-native Cinnamomum camphora. In contrast, all the native tree species except Ligustrum lucidum had lower photosynthetic rates (PN) than the non-native species. In all species, the relationship between LA and DM was less variable than the relationship between SLA and LA. However, leaves of the non-native C. camphora and native species Sterculia lanceolata, Cleidiocarpon cavalerei and Cyclobalanopsis glauca were highly sensitive to seasonal conditions, leaves of Sapindus mukorossi and Ligustrum lucidum were less sensitive to seasonal changes, and leaves of Syzygium cumini and Cephalomappa sinensis were insensitive. An understanding of leaf traits will aid the selection of suitable species for land restoration. and L.-Y. Wei ... [et al.].
Leaf respiration (R L) of evergreen species co-occurring in the Mediterranean maquis developing along the Latium coast was analyzed. The results on the whole showed that the considered evergreen species had the same R L trend during the year, with the lowest rates [0.83 ± 0.43 μmol(CO2) m-2 s-1, mean value of the considered species] in winter, in response to low air temperatures. Higher R L were reached in spring [2.44 ± 1.00 μmol(CO2) m-2 s-1, mean value] during the favorable period, and in summer [3.17 ± 0.89 μmol(CO2) m-2 s-1] during drought. The results of the regression analysis showed that 42% of R L variations depended on mean air temperature and 13% on total monthly rainfall. Among the considered species, C. incanus, was characterized by the highest R L in drought [4.93 ± 0.27 μmol(CO2) m-2 s-1], low leaf water potential at predawn (Ψpd = -1.08 ± 0.18 MPa) and midday (Ψmd = -2.75 ± 0.11 MPa) and low relative water content at predawn (RWCpd = 80.5 ± 3.4%) and midday (RWCmd = 67.1 ± 4.6%). Compared to C. incanus, the sclerophyllous species (Q. ilex, P. latifolia, P. lentiscus, A. unedo) and the liana (S. aspera), had lower R L [2.72 ± 0.66 μmol(CO2) m-2 s-1, mean value of the considered species], higher RWCpd (91.8 ± 1.8%), RWCmd (82.4 ± 3.2%), Ψpd (-0.65 ± 0.28 MPa) and Ψmd (-2.85 ± 1.20 MPa) in drought. The narrow-leaved species (E. multiflora, R. officinalis, and E. arborea) were in the middle. The coefficients, proportional to the respiration increase for each 10°C rise (Q10), ranging from 1.49 (E. arborea) to 1.98 (A. unedo) were indicative of the different sensitivities of the considered species to air temperature variation., R. Catoni, L. Varone, and L. Gratani., and Obsahuje bibliografii
V této práci sumarizujeme data o výskytu invazních druhů řas a sinic v České republice a mapujeme reálná či potenciální rizika jejich rozšíření. Seznam invazních druhů v ČR obsahuje 10 druhů sinic, 9 rozsivek, 1 obrněnku, 1 zástupce třídy Ulvophyceae, 2 zelené řasy třídy Chlorophyceae a jednu krásivku., This paper summarizes data on alien species of algae and cyanobacteria in the Czech Republic; we identified actual or potential risks resulting from their spread. The list of aliens contains 10 species of Cyanobacteria (Cyanophyta), 10 species of Bacillariophyceae, one species of Dinophyta, one species of Ulvophyceae, two species of Chlorophyceae, and one species of Desmidiales., and Jan Kaštovský ... [et al.].
Vřeckovýtrusná houba druhu Hymenoscyphus pseudoalbidus s anamorfou Chalara fraxinea způsobuje onemocnění známé jako nekróza jasanu na různých druzích jasanů v Evropě. Onemocnění se objevilo v Polsku na počátku 90. let po introdukci patogenu z Východní Asie. Následně se epidemie rozšířila do celého areálu přirozeného rozšíření hostitelských druhů a zasáhla i umělé výsadby a školky. Článek shrnuje historii a současný stav našeho poznání od objevu patogenu až po nejnovější poznatky., The ascomycete Hymenoscyphus pseudoalbidus with its anamorph Chalara fraxinea causes a disease known as ash dieback on various ash (Fraxinus) species in Europe. The disease emerged in Poland in the early 1990s after introduction of the pathogen from East Asia. The epidemic spread across the entire native distribution range of the host trees also affected artificial plantations and nurseries. This review presents the history and the state of research from the discovery of the pathogen to the most recent findings., and Ondřej Koukol, Ludmila Havrdová.
Ačkoli jsou elektrické signály typičtější pro neurony živočichů, také rostliny jsou schopné vytvářet tento druh signálů. Rozeznáváme u nich dva základní typy - variační a akční potenciály. Ty se od sebe odlišují určitými vlastnostmi, ale oba typy mají významný dopad na fyziologické procesy v rostlinách, např. na pohyb listů, fotosyntézu, dýchání, opylování, zavírání průduchů, syntézu hormonů nebo trávení hmyzu u masožravých rostlin., Although electrical signals are more typical for animal neurons, plants also have the ability to generate these signals. Two different types are recognized: action and variation potentials. They differ in certain characteristics, however both have significant impact on physiological processes in plants; e.g. on leaf movement, photosynthesis, respiration, pollination, stomata closure, hormone synthesis and insect digestion in carnivorous plants., Andrej Pavlovič., and Obsahuje seznam literatury