Temperature responses of cambial reactivation and xylem differentiation in hybrid poplar (Populus sieboldii x P. grandidentata) under natural conditions

Abstract

Several studies have demonstrated that localized heating of tree stems induces localized cambial reactivation. We analyzed by light microscopy the effects of early spring increases in ambient temperature in 2005 and 2007 on the timing of cambial reactivation and xylem differentiation in stems of two trees of a cloned deciduous hardwood hybrid poplar (Populus sieboldii Miquel. x P. grandidentata Michx.) growing under natural conditions. Meteorological data at the study site showed that temperatures in late winter and early spring differed markedly between 2005 and 2007, with trends toward higher temperatures starting around April 3 in 2005 and around March 20 in 2007. Cambial reactivation occurred about 17 days earlier in 2007 than in 2005. The cumulative daily maximum temperature in excess of 15 degrees C (maximum daily temperatures minus 15 degrees C) in late winter and early spring before cambial reactivation was defined as the cambial reactivation index (CRI(15)). Cambial reactivation, which began when the minimum temperature rose above 0 degrees C, occurred when the CRI(15) was 93 and 96 degrees C in 2005 and 2007, respectively. The differentiation of secondary xylem started earlier in 2007 than in 2005. On May 27, we found a wider current-year band of xylem and a higher frequency of small-diameter vessel elements in 2007 than in 2005. We propose that the timing of cambial reactivation is controlled by air temperature and that earlier cambial reactivation induces earlier differentiation of xylem in hybrid poplar under natural conditions. Our results indicate that the CRI might be a useful indicator of the timing of cambial reactivation.

Intra-Annual Xylem Growth of Larix principis-rupprechtii at Its Upper and Lower Distribution Limits on the Luyashan Mountain in North-Central China

“…At high altitudes/latitudes, temperature (mean daily/heat sum) is regarded as the major determinant for the cambial reactivation in spring [9,10]. However, the influence of temperature weakens during the course of the growing season and wood formation ends within a wider range of time [11].…”

Wood Density-Climate Relationships Are Mediated by Dominance Class in Black Spruce (Picea mariana (Mill.) B.S.P.)

“…In boreal and temperate forests, temperature is an important factor controlling cell differentiation [17,56]. For example, the minimum daily temperature is thought to determine the onset of cambial activity [18,57].…”

“…These anatomical changes result from variation in cambial activity triggered by crown processes [15][16][17], which are under a degree of climatic control, at least for the onset of growth and dormancy [18,19].…”

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

“…The effect of specifi c climatic factors on the mechanism of xylem and phloem growth ring formation can be studied on trees growing in their natural environment or under experimentally controlled conditions (e.g., Oribe et al, 2001; Gričar et al, 2006;Begum et al, 2008Begum et al, , 2010. Additionally, many controlled experiments have been performed on growing seedlings or saplings, allowing simulation of different growing conditions on the growth and adaptivity of young trees (e.g.…”

“…It has been demonstrated that the application of temperature in the period of either cambial activity or dormancy can cause alterations in its regular rhythm of periodicity and cell differentiation (e.g., Denne and Dodd, 1981;Mellerowicz et al, 1992; Barnett and Miller, 1994; Oribe and Kubo, 1997; Oribe et al, 2001; Gričar et al, 2006Gričar et al, , 2007Begum et al, 2007Begum et al, , 2008. The application of heat has revealed differences in the response of dormant cambium to treatments among different species of evergreen and deciduous habit (e.g., Oribe et al, 2003;Gričar et al, 2006;Begum et al, 2010); however, in all cases, temperature has been proven to be crucial for the onset of cell division and SAŽETAK • U radu je istraživan utjecaj grijanja (20-22 °C) i hlađenja (9-11 °C) The stem portion of the two trees of each species were heated with a 15 m long electric heat cable (FSM-17, 17W/+5°C, 11W/25°C, 230V) wrapped around 1 meter of the stem length.…”