The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Abstract. We tested the hypothesis that hydraulic conductance per unit leaf surface area of plant shoots (KSL) determines the maximum diurnal stomatal conductance (gL) that can be reached by plants growing in the field. A second hypothesis was tested that some xylem cavitation cannot be avoided by transpiring plants and might act as a signal for regulating gL. Eleven woody species were studied, differing...
Abstract. The terminal (1-year-old) shoot of dormant, 2-year-old Abies balsamea (L.) Mill. seedlings was ringed with 0 or 10mg Ethrel g1 lanolin. After 5weeks of culture under environmental conditions favorable for growth, some of the treated shoots were harvested to measure tracheid number by microscopy and ethylene evolution by gas chromatography-flame ionization detection. The remaining shoots...
Abstract. Stems of plane tree seedlings were cytologically investigated regarding the involvement of tyloses and gels in defense reactions to Ceratocystis fimbriata f. sp platani, the canker stain disease agent. In the lumen of infected xylem vessels, cytochemical tests revealed the occurrence of compounds labeled for cellulose and which seem to be involved in gel formation. Immunogold methods indicated...
Abstract. Shoot architecture was quantified by measuring the "maximum silhouette area ratio" (Rmax). Rmax was calculated from the maximum silhouette area (or projected area) of the intact shoot, divided by the silhouette area of the leaves or phylloclades (leaf-like flattened stems) when they are removed from the shoot and laid out flat. Like conifers of the Northern Hemisphere (NH) with...
Abstract. This review examines the ecological traits and ecophysiological characteristics of the common ash (Fraxinus excelsior L.) that help to explain the current spread of ash communities in Europe. As a consequence of anthropogenic disturbance, the common ash has experienced new environmental conditions and the frequency of the species has fluctuated over space and time. Owing to its ubiquity,...
Abstract. The effects of cold-induced photoinhibition on Eucalyptus globulus and Eucalyptus nitens seedlings were assessed between planting and age 23weeks. The seedlings were subjected to four treatments before planting: non-hardened (NH) E. globulus and E. nitens, cold-hardened (CH) E. nitens, and nutrient-starved (NS) E. nitens. Seedlings were planted alongside established 1-year-old E. nitens...
Abstract. Changes in the stem radius of young Norway spruce [Picea abies (L.) Karst.] were related to changes in stem water content in order to investigate the relationship between diurnal stem size fluctuations and internally stored water. Experiments were performed on living trees and on cut stem segments. The defoliated stem segments were dried under room conditions and weight (W), volume (V),...
Abstract. We present a technique to measure the simultaneous sway of a group of trees and reconstruct the frequency of crown collisions and sway dynamics of individual or groups of trees. We placed a biaxial clinometer (tiltmeter) at the live crown base in each of ten neighboring 15-m-tall lodgepole pine trees in Alberta, Canada. Tree bole rotation at tiltmeter mount height was recorded during windy...
Abstract. Although the processes governing photosynthesis are well understood, scaling from shoot to canopy in coniferous forests is complex. Development of different sap-flow techniques has made it possible to measure transpiration of whole trees and thereby also of whole canopies. There is a strong link between photosynthesis and transpiration, for which reason it would be interesting to test whether...
Abstract. In conifers, attacks by bark beetles and associated pathogenic fungi cause an induced wound response, which is characterized by accumulation of antifungal compounds and morphological changes that aid wound healing. In this article the stilbene and terpene concentrations of Norway spruce phloem were monitored as symptoms of induced wound responses in relation to changed nutrient conditions...
Abstract. The development of tap root anatomical features was investigated in seedlings of loblolly pine (Pinus taeda L.) under both pot and pouch growth regimes. The roots possessed the three anatomical zones previously observed in jack pine (Pinus banksiana Lamb) and Eucalyptus pilularis Sm. white, condensed tannin (CT), and cork suggesting that this developmental sequence is preserved over species...
Abstract. Hydraulic properties and gas exchange were measured in branches of two tropical tree species (Simarouba amara Aubl. and Tapirira guianensis Aubl.) in a moist lowland forest in Panama. Branch-level sapflow, leaf-level stomatal conductance, and water potential measurements, along with measurements of specific hydraulic conductivity of stems in crown tops, were used to relate hydraulic parameters...
Abstract. Variation in the wood and bark anatomy of the dominant species of a mangrove forest community in Mexico was evaluated in relation to some environmental factors, and their physiological adaptations to salinity and flooding period are discussed. The forest is characterized by three zones according to the presence of dominant tree species and flooding periodicity. Vessel arrangement and wood...
Abstract. Beech seedlings (Fagus sylvatica L.) were exposed to episodes of O3 in environmentally controlled growth chambers during one growing season. Three treatments were applied: charcoal-filtered air, charcoal-filtered air with the addition of 40ppb O3 for seven episodes of 5days' duration (90001700hours), and charcoal-filtered air with the addition of 100ppb O3 for seven episodes of 5days' duration...
Abstract. Because of the harsh environments in boreal clearcuts, it is necessary to plant only stress-tolerant seedlings. To test the use of antioxidants to enhance stress tolerance, Ambiol (2-methyl-4-dimethylaminomethyl-5-hydrohybenzimidazole dihydrochloride) was applied to jack pine (Pinus banksiana Lamb.) and black spruce [Picea mariana (Mill.) BSP], using a 24-h seed soak. For seedlings treated...
Abstract. We investigated the chemistry of xylem sap as a marker of red spruce metabolism and soil chemistry at three locations in northern New England. A Scholander pressure chamber was used to extract xylem sap from roots and branches cut from mature trees in early June and September. Root sap contained significantly greater concentrations of K, Ca, Mg, Mn, and Al than branch sap. Sap collected...
Abstract. Source water utilized by four families of loblolly pine (Pinus taeda L.) was assessed by comparing the H isotope composition (D) of xylem sap and of soil water from four depths (020cm, 2040cm, 1.2m, and 2.1m) across 1year. Soil water D values varied with soil moisture content in the well-drained, sandy site and at each of the four soil depths. In September and November 1997 and May through...
Abstract. The cell wall architecture of bamboo at various developmental stages of culm growth was investigated by rapid-freezing and deep-etching (RFDE) electron microscopy. The unlignified primary wall (ULP) was characterized by the narrow spacing between the cellulose microfibrils in fibres, but not in parenchyma cells. The unlignified secondary wall (ULS) largely consisted of dense cellulose microfibrils...
Abstract. This study was undertaken to determine how the results from lipid, moisture, and differential scanning calorimetry analyses conducted on silver maple (Aceraceae: Acer saccharinum L.) and red buckeye (Hippocastanaceae: Aesculus pavia L.) compared with those obtained from previous studies on white and water oaks (Fagaceae: Quercus alba and Q. nigra), and the tropical zone species American...
Abstract. Bark necrosis and resin flows in Norway spruce have increased in southern Sweden over the last few decades. Frost damage late in spring has been suggested as a possible cause, but other factors besides the climate may have contributed to the damage. The nutrient status influences the hardening processes and plants with poor nutritional conditions have an increased sensitivity to frost. In...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.