Influence of Temperature on Cambial Activity and Cell Differentiation in Quercus Sessiliflora and Acer Pseudoplatanus of Different Ages

Abstract

We evaluated the response of active cambium of sessile oak (Quercus sessiliflora) and sycamore maple (Acer pseudoplatanus) to experimentally increased (20–22 °C) and decreased (9–11 °C) temperatures. Heating and cooling experiments on 150-year old Q. sessiliflora were performed during the growth season of 2007 and on 30-year old A. pseudoplatanus in 2008. In 2009, heating experiment was carried out on 30-year old Q. sessiliflora. For each treatment, two trees were selected of each species and sampled at 21-day intervals during the vegetation period and investigated by means of light microscopy. Continuously elevated temperatures slightly promoted the development of xylem cells in old Q. sessiliflora trees in the first month of cambial activity. However, no effect of elevated or decreased temperature was detected in the timing and dynamics of wood and phloem formation. The applied treatments, therefore, had no visible impact on the structure or width of the xylem or phloem increments in 2007. On the other hand, heating young A. pseudoplatanus trees provoked the development of epicormic shoots two months after the onset of the experiment and finally the death of trees. The cambium of those trees did not reactivate in 2008; xylem and phloem increments were consequently not formed. Low temperature treatments slowed down cell production at the very beginning of the growing season, but no alterations in wood or phloem formation dynamics or structure were observed later. The heating of young Q. sessiliflora trees caused the development of epicormic shoots and the death of trees four months after the experiment. The pattern of their dying was similar as in A. pseudoplatanus but with a two month delay. The observations indicate that tree age, thickness of dead bark and duration of the applied treatments influence the response of cambium. The development of dead bark is species specific and it occurs earlier in Q. sessiliflora than in A. pseudoplatanus. Thick dead bark acts as a very good insulation layer for the sensitive internal, living tissues of bark and cambium and therefore protects them against external abiotic and biotic factors

Potential for a New Multimillennial Tree-Ring Chronology from Subfossil Balkan River Oaks

“…This means that where the last ring under the bark is not preserved to provide an exact cutting date, if any sapwood is present it is possible to improve on a terminus post quem date for the last measured year by making an informed estimate as to the likely number of missing sapwood rings (see Kuniholm 2001). Where the last ring under the bark (terminal ring or "waney edge") is present, dating precision with oaks can be exact to a particular season depending on the degree of cell formation observed (Eckstein 2007;Gričar 2010Gričar , 2013. Unfortunately, in the abrasive context of our riverine burial environments, sapwood preservation is extremely rare.…”

Phenology and Tree Radial Growth of Schinus terebinthifolius in a Subtropical Forest

“…Tree growth is controlled by endogenous factors such as the plant genotype (Anderson et al, 2012) and physiological processes (Pallardy, 2006), as well as exogenous factors which are regulated by the availability of water and light (Gričar, 2013). Growth can usually be measured by repetitive measurements of the tree dimensions, which is most commonly performed by monitoring the stem diameter increment (Turner, 2001).…”

Cambial dormancy lasts 9 months in a tropical evergreen species

“…Marcati, personal communication). Various studies on cambial growth (Gričar et al 2006;Pumijumnong and Wanyaphet 2006;Rajput et al 2008;Pumijumnong and Buajan 2012;Gričar 2013;Morel et al 2015) described the beginning of xylem production by recording the number of cells in radial files in the cambial zone to determine cambial activity. However, cambial activity might be initiated before the already produced cells are visible.…”