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.].
The last specimens of indigenous Eurasian lynx (Lynx lynx) in Croatia were exterminated around year 1903. Lynx dispersed back to Croatia after six animals were reintroduced to Slovenia from Slovakia in 1973. Considering the consequences of founder effect, genetic drift and expected high level of homozygosity, the goal of this paper was to determine variation in teeth number, teeth and skull disorders in Croatian lynx. It should also determine whether there has been a change in frequency of occurrence of developmental anomalies in relation to the population it originates from and in relation to other lynx populations. We studied 58 lynx skulls originating from the reintroduced lynx population. Changes on teeth and skull were found on 23 skulls (39.7%): supernumerary maxillary second premolar P2 (9 skulls, 15.5%), supernumerary mandibular second molar M2 (3 skulls, 5.2%), congenitally absent maxillary incisor (3 skulls, 6.9%), extra tooth between maxillary third incisor I3 and canine (1 skull, 1.7%) and acquired disorders of teeth and skull (9, 15.5%).
An experimental investigations on the effect of convergence of stream lines on the Darcy and non-Darcy parameters for different radial lines for different ratios of the radii was studied in a convergent flow permeameter. The applicability of a resistance law relating friction factor and Reynolds number using the square root of intrinsic permeability as the characteristic length is examined for flow with converging boundaries. In this study, crushed rock of size 3.25 mm and 4.73 mm were used as media and water as fluid, to develop curves relating friction factor and Reynolds number for different radial lines with different ratios of the radii. and V konvergentnom permeametri sme experimentálne skúmali vplyv konvergencie prúdnic na Darcyovské a nedarcyovské charakteristiky prúdenia. Pre prúdenie v pórovitom prostredí s konvergujúcimi hranicami sme zisťovali použiteľnosť zákona odporu, ktorý dáva do súvislosti súčiniteľ trenia a Reynoldsovo číslo, používajúc druhú odmocninu vnútornej priepustnosti ako charakteristickú dĺžku. Pre získanie kriviek závislostí medzi súčiniteľom trenia a Reynoldsovým číslom pre rôzne hydraulické polomery a rôzne pomery hydraulických polomerov sme použili drvenú horninu s veľkosťou zŕn 3,25 mm a 4,73 mm, tekutinou bola voda.
Variations in leaf gas-exchange characteristics, PSII activity, leaf pigments, and tuber yield were investigated in seven wild and one cultivated species of Dioscorea from Koraput, India, in order to find out their overall adaptability to the environment. The leaf photosynthetic rate, transpiration, stomatal conductance, water-use efficiency, carboxylation efficiency, and photosynthetic pigments were significantly higher in some wild species compared to the cultivated species. In addition, some wild species showed better photochemical efficiency of PSII, photochemical quenching, and electron transport rate in comparison to cultivated one. Furthermore, leaf dry matter accumulation and tuber yield was also higher in some wild species compared to the cultivated species. Taken together, the wild species, such as D. oppositifolia, D. hamiltonii, and D. pubera, showed the superior photosynthetic efficiency compared to the cultivated D. alata and they could be used for future crop improvement programs., B. Padhan, D. Panda., and Obsahuje bibliografii
In the present study changes of some blood parameters of wild female yellowfin seabream (Acanthopagrus latus) caught from Persian Gulf were assayed during reproductive cycle. Altogether, 120 female A. latus (15 each month) were captured monthly from October 2010 to May 2011 from the Mussa Creek in the north-west of Persian Gulf. Blood samples were collected from caudal vein; plasma was separated and kept at –80 °C till analysis. Total protein, glucose, cholesterol, triglyceride, electrolytes, calcium, sodium, chloride, magnesium, potassium plus hepatic enzymes, Alanine Amino Transferase (ALT) and Aspartate Amino Transferase (AST), were assayed in plasma sample. Total protein and calcium increased parallel to ovarian development and decreased after spawning time. Cholesterol and triglyceride had a peak during vitellogenesis and decreased after spawning but glucose had a peak during spawning time. Most of the electrolytes (sodium, magnesium and potassium) did not show any significant changes during the reproductive cycle in A. Latus. AST reached a peak during final
maturation of ovaries but ALT did not show any significant difference during differentsampling times.Our findings showed that biochemical parameters could be used as indicators of physiological status during differentmaturation stage in this species.
Thermal requirements for flight in butterflies is determined by a combination of external factors, behaviour and physical constraints. Thorax temperature of 152 butterflies was monitored with an infra-red thermometer in controlled laboratory conditions. The temperature at take-off varied from 13.4°C, for a female Heteronympha merope to 46.3°C, for a female Junonia villida. Heteronympha merope, an understorey species, had the lowest recorded take-off temperatures, with females flying at a much lower thorax temperatures than males. Among the tested butterfly species, warming-up rate was positively correlated with take-off temperature and negatively with body mass. Wing loading is a major variable in determining the thorax flight temperature. Butterflies with the highest wing-loadings experienced the highest thorax temperatures at take-off. A notable exception to this rule is Trapezites symmomus, the only Hesperiidae of our data set, which had thorax flight temperatures of 31.5°C and 34.5°C, well within the range of the observed butterflies, despite a wing load ca. five times higher. The high thorax temperature recorded in J. villida is probably linked to its high flight speed. The results highlight the importance of physical constraints such as body size on the thermal requirements for flight across a range of butterfly species., Gabriel Nève, Casey Hall., and Obsahuje bibliografii
Carbon and water fluxes in a semiarid shrubland ecosystem located in the southeast of Spain (province of Almería) were measured continuously over one year using the eddy covariance technique. We examined the influence of environmental variables on daytime (photosynthetically active photons, FP >10 µmol m-2 s-1) ecosystem gas exchange and tested the ability of an empirical eco-physiological model based on FP to estimate carbon fluxes over the whole year. The daytime ecosystem fluxes showed strong seasonality. During two solstitial periods, summer with warm temperatures (>15 °C) and sufficient soil moisture (>10 % vol.) and winter with mild temperatures (>5 °C) and high soil moisture contents (>15 % vol.), the photosynthetic rate was higher than the daytime respiration rate and mean daytime CO2 fluxes were ca. -1.75 and -0.60 µmol m-2 s-1, respectively. Daytime evapotranspiration fluxes averaged ca. 2.20 and 0.24 mmol m-2 s-1, respectively. By contrast, in summer and early autumn with warm daytime temperatures (>10 °C) and dry soil (<10 % vol.), and also in mid-winter with near-freezing daytime temperatures the shrubland behaved as a net carbon source (mean daytime CO2 release of ca. 0.60 and 0.20 µmol m-2 s-1, respectively). Furthermore, the comparison of water and carbon fluxes over a week in June 2004 and June 2005 suggests that the timing-rather than amount-of spring rainfall may be crucial in determining growing season water and carbon exchange. Due to strongly limiting environmental variables other than FP, the model applied here failed to describe daytime carbon exchange only as a function of FP and could not be used over most of the year to fill gaps in the data. and P. Serrano-Ortiz ... [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
Young leaves of tropical trees frequently appear red in color, with the redness disappearing as the leaves mature. During leaf expansion, plants may employ photoprotective mechanisms to cope with high light intensities; however, the variations in anthocyanin contents, nonphotochemical quenching (NPQ), and photorespiration during leaf expansion are poorly understood. Here, we investigated pigment contents, gas exchange, and chlorophyll (Chl) fluorescence in Woodfordia fruticosa leaves during their expansion. Young red leaves had significantly lower Chl content than that of expanding or mature leaves, but they accumulated significantly higher anthocyanins and dissipated more excited light energy through NPQ. As the leaves matured, net photosynthetic rate, total electron flow through PSII, and electron flow for
ribulose-1,5-bisphosphate oxygenation gradually increased. Our results provided evidence that photorespiration is of fundamental importance in regulating the photosynthetic electron flow and CO2 assimilation during leaf expansion., S.-B. Zhang, J.-L. Zhang., and Obsahuje seznam literatury
Net photosynthetic rate (PN), transpiration rate (E), and stomatal conductance (gs) in an adult oil palm (Elaeis guineensis) canopy were highest in the 9th leaf and progressively declined with leaf age. Larger leaf area (LA) and leaf dry mass (LDM) were recorded in middle leaves. PN showed a significant positive correlation with gs and a negative relationship with leaf mass per area (ALM). The oil palm leaf remains photosynthetically active for a longer time in the canopy which contributes significantly to larger dry matter production in general and greater fresh fruit bunch yields in particular. and K. Suresh, C. Nagamani.