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Tree Physiology

Alexander W Cheesman, Lucas A Cernusak
No abstract text is available yet for this article.
October 18, 2016: Tree Physiology
Ayumi Shiraki, Wakana Azuma, Keiko Kuroda, H Roaki Ishii
Cupressoid (scale-like) leaves are morphologically and functionally intermediate between stems and leaves. While past studies on height acclimation of cupressoid leaves have focused on acclimation to the vertical light gradient, the relationship between morphology and hydraulic function remains unexplored. Here, we compared physiological and morphological characteristics between treetop and lower-crown leaves of 100-year-old Chamaecyparis obtusa Endl. trees (~27 m tall) to investigate whether height-acclimation compensates for hydraulic constraints...
October 15, 2016: Tree Physiology
Frank Sterck, Roman Zweifel
No abstract text is available yet for this article.
October 15, 2016: Tree Physiology
Justine Karst, Jacob Gaster, Erin Wiley, Simon M Landhäusser
How carbon (C) flows through plants into soils is poorly understood. Carbon exuded comes from a pool of non-structural carbohydrates (NSC) in roots. Simple models of diffusion across concentration gradients indicate that the more C in roots, the more C should be exuded from roots. However, the mechanisms underlying the accumulation and loss of C from roots may differ depending on the stress experienced by plants. Thus, stress type may influence exudation independent of NSC. We tested this hypothesis by examining the relationship between NSC in fine roots and exudation of organic C in aspen (Populus tremuloides Michx...
October 15, 2016: Tree Physiology
Christian Bianchi Strømme, Riitta Julkunen-Tiitto, Jorunn Elisabeth Olsen, Line Nybakken
The effects of warming on autumnal growth cessation and bud formation in trees remain ambiguous due to contrasting observations between a range of studies under controlled conditions and field experiments. High night temperature has been reported to advance growth cessation and bud formation in several tree species grown under controlled conditions. On the other hand, some recent field experiments have shown that autumn warming delays bud formation, although the temperature parameters that could account for this effect have not been identified...
October 13, 2016: Tree Physiology
Juan Chen, Zhi-Jun Shen, Wei-Zhi Lu, Xiang Liu, Fei-Hua Wu, Gui-Feng Gao, Yi-Ling Liu, Chun-Sheng Wu, Chong-Ling Yan, Hang-Qing Fan, Yi-Hui Zhang, Hai-Lei Zheng
Avicennia marina (Forsk.) Vierh is a widespread mangrove species along the southeast coasts of China. Recently, the outbreak of herbivorous insect, Phyllocnistis citrella Stainton, a leaf miner, have impacted on the growth of A. marina Little is reported about the responses of A. marina to leaf miner infection at the biochemical, physiological and molecular levels. Here, we reported the responses of A. marina to leaf miner infection from the aspects of leaf structure, photosynthesis, and antioxidant system and miner responsive genes expression...
October 13, 2016: Tree Physiology
Dominik Florian Stangler, Andreas Hamann, Hans-Peter Kahle, Heinrich Spiecker
A useful approach to monitor tree response to climate change and environmental extremes is the recording of long-term time series of stem radial variations obtained with precision dendrometers. Here, we study the impact of environmental stress on seasonal growth dynamics and productivity of yellow birch (Betula alleghaniensis Britton) and sugar maple (Acer saccharum Marsh.) in the Great Lakes, St Lawrence forest region of Ontario. Specifically, we research the effects of a spring heat wave in 2010, and a summer drought in 2012 that occurred during the 2005-14 study period...
October 13, 2016: Tree Physiology
Olga M Grant, Conor O'Reilly
Future limited water availability may reduce the potential of tree improvement to increase timber yields. We investigated ecophysiological variation between full-sibling families of Sitka spruce (Picea sitchensis (Bong.) Carr.) growing under contrasting water availability conditions: control (optimal) water availability and limited water availability. One-year-old seedlings of nine improved families plus an unimproved seed lot were grown in pots in a greenhouse and the two water availability treatments imposed via drip irrigation...
September 27, 2016: Tree Physiology
Sanna Sevanto, Chonggang Xu
No abstract text is available yet for this article.
September 26, 2016: Tree Physiology
Mark E De Guzman, Louis S Santiago, Stefan A Schnitzer, Leonor Álvarez-Cansino
In tropical forest canopies, it is critical for upper shoots to efficiently provide water to leaves for physiological function while safely preventing loss of hydraulic conductivity due to cavitation during periods of soil water deficit or high evaporative demand. We compared hydraulic physiology of upper canopy trees and lianas in a seasonally dry tropical forest to test whether trade-offs between safety and efficiency of water transport shape differences in hydraulic function between these two major tropical woody growth forms...
September 26, 2016: Tree Physiology
A G Quentin, T Rodemann, M-F Doutreleau, M Moreau, N W Davies
Near-infrared reflectance spectroscopy (NIRS) is frequently used for the assessment of key nutrients of forage or crops but remains underused in ecological and physiological studies, especially to quantify non-structural carbohydrates. The aim of this study was to develop calibration models to assess the content in soluble sugars (fructose, glucose, sucrose) and starch in foliar material of Eucalyptus globulus A partial least squares (PLS) regression was used on the sample spectral data and was compared to the contents measured using standard wet chemistry methods...
September 26, 2016: Tree Physiology
Krõõt Aasamaa, Pedro José Aphalo
Stomatal anatomical traits and rapid responses to several components of visible light were measured in Tilia cordata Mill. seedlings grown in an open, fully sunlit field (C-set), or under different kinds of shade. The main questions were: (i) stomatal responses to which visible light spectrum regions are modified by growth-environment shade and (ii) which separate component of vegetational shade is most effective in eliciting the acclimation effects of the full vegetational shade. We found that stomatal opening in response to red or green light did not differ between the plants grown in the different environments...
September 26, 2016: Tree Physiology
Jan-Peter George, Michael Grabner, Sandra Karanitsch-Ackerl, Konrad Mayer, Lambert Weißenbacher, Silvio Schueler
Assessing intra-specific variation in drought stress response is required to mitigate the consequences of climate change on forest ecosystems. Previous studies suggest that European larch (Larix decidua Mill.), an important European conifer in mountainous and alpine forests, is highly vulnerable to drought. In light of this, we estimated the genetic variation in drought sensitivity and its degree of genetic determination in a 50-year-old common garden experiment in the drought-prone northeastern Austria. Tree ring data from larch provenances originating from across the species' natural range were used to estimate the drought reaction in four consecutive drought events (1977, 1981, 1990-1994, and 2003) with extremely low standardized precipitation- and evapotranspiration-index values that affected growth in all provenances...
September 26, 2016: Tree Physiology
Wen Lin, Asko Noormets, John S King, Ge Sun, Steve McNulty, Jean-Christophe Domec
Stable isotope ratios (δ(13)C and δ(18)O) of tree-ring α-cellulose are important tools in paleoclimatology, ecology, plant physiology and genetics. The Multiple Sample Isolation System for Solids (MSISS) was a major advance in the tree-ring α-cellulose extraction methods, offering greater throughput and reduced labor input compared to traditional alternatives. However, the usability of the method for resinous conifer species may be limited by the need to remove extractives from some conifer species in a separate pretreatment step...
September 26, 2016: Tree Physiology
Marco Borghetti, Tiziana Gentilesca, Stefano Leonardi, Twan van Noije, Angelo Rita
The objectives of this study were to provide a quantitative description of the long-term effects of environmental variability on xylem functional traits, in order to better assess xylem capacity to change in response to climate change. Twenty-six sites throughout the world, primarily in Europe, were chosen where results from long-term measurements of anatomical traits were previously published. Published data on long-term xylem anatomy (conduit size and density) and ring width variability were compiled across a range of tree species, which was subsequently related to variability in temperature, precipitation and nitrogen deposition rates across the study sites using generalized additive models and Bayesian methods...
September 26, 2016: Tree Physiology
Oliver Binks, Patrick Meir, Lucy Rowland, Antonio Carlos Lola da Costa, Steel Silva Vasconcelos, Alex Antonio Ribeiro de Oliveira, Leandro Ferreira, Maurizio Mencuccini
Dry periods are predicted to become more frequent and severe in the future in some parts of the tropics, including Amazonia, potentially causing reduced productivity, higher tree mortality and increased emissions of stored carbon. Using a long-term (12 year) through-fall exclusion (TFE) experiment in the tropics, we test the hypothesis that trees produce leaves adapted to cope with higher levels of water stress, by examining the following leaf characteristics: area, thickness, leaf mass per area, vein density, stomatal density, the thickness of palisade mesophyll, spongy mesophyll and both of the epidermal layers, internal cavity volume and the average cell sizes of the palisade and spongy mesophyll...
September 10, 2016: Tree Physiology
J J Camarero, G Guada, R Sánchez-Salguero, E Cervantes
Continental Mediterranean forests face drought but also cold spells and both climate extremes can impair the resilience capacity of these forests. Climate warming could amplify the negative effects of cold spells by inducing premature dehardening. Here we capitalize on a winter drought-induced dieback triggered by a cold spell which occurred in December 2001 affecting Scots pine forests in eastern Spain. We assessed post-dieback recovery by quantifying and comparing radial growth and xylem anatomy of non-declining (ND, crown cover >50%) and declining (D, crown cover ≤50%) trees in two sites (VP, Villarroya de los Pinares; TO, Torrijas)...
September 10, 2016: Tree Physiology
Antonio José Barotto, María Elena Fernandez, Javier Gyenge, Ariel Meyra, Alejandro Martinez-Meier, Silvia Monteoliva
The relationship between hydraulic specific conductivity (ks) and vulnerability to cavitation (VC) with size and number of vessels has been studied in many angiosperms. However, few of the studies link other cell types (vasicentric tracheids (VT), fibre-tracheids, parenchyma) with these hydraulic functions. Eucalyptus is one of the most important genera in forestry worldwide. It exhibits a complex wood anatomy, with solitary vessels surrounded by VT and parenchyma, which could serve as a good model to investigate the functional role of the different cell types in xylem functioning...
September 10, 2016: Tree Physiology
Tai-Jie Zhang, Wah Soon Chow, Xiao-Tao Liu, Peng Zhang, Nan Liu, Chang-Lian Peng
The presence of anthocyanins in young leaves plays an important role in mitigation against photodamage and allows leaves to grow and develop normally. Many studies have reported that foliar anthocyanins are distributed within the vacuoles of mesophyll cells, so we explored the novel defence style of anthocyanin-coated young leaves of Castanopsis fissa, a dominant subtropical forest tree species, via removable trichomes. Anthocyanins were distributed in C. fissa leaf trichomes, which produced a red coating for the young leaves...
September 10, 2016: Tree Physiology
Milan Balaz, Radek Jupa, Steven Jansen, Alexander Cobb, Vít Gloser
Vessels with simple perforation plates, found in the majority of angiosperms, are considered the evolutionarily most advanced conduits, least impeding the xylem sap flow. Nevertheless, when measured, their hydraulic resistivity (R, i.e., inverse value of hydraulic conductivity) is significantly higher than resistivity predicted using Hagen-Poiseuille equation (RHP). In our study we aimed (i) to quantify two basic components of the total vessel resistivity - vessel lumen resistivity and end wall resistivity, and (ii) to analyze how the variable inner diameter of the vessel along its longitudinal axis affects resistivity...
September 8, 2016: Tree Physiology
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