Effects of a 20-day-long dry period on cambial and apical meristem growth in Abies balsamea seedlings

Abstract

There is general agreement that in many regions additional precipitation with climate change will not be able to balance the increased evaporation rate induced by higher air temperatures, causing periods of intense drought. Although seedlings of Abies balsamea growing in the boreal forest are known for their resistance to harsh environmental conditions, the impact of water stress on their growth still remains largely unexamined. The aim of this study was to investigate growth responses of this species during and after a dry period by monitoring cambial and apical meristem activity at short time scale. Meristem growth was studied from May to October 2005 on seedlings of A. balsamea submitted to a 20-day-long dry period in June–July. Lower rates of shoot lengthening were observed in non-irrigated seedlings only in the first part of the growing season. Irrigated and non-irrigated trees showed the same trend of xylem formation and timings of cell differentiation. Cell production during cambial activity was estimated at about one xylem cell per day thus achieving in 100 days 108 tracheids in the tree ring and a width of 2 mm, with thinner tree rings observed in non-irrigated plants. A reduction of up to 50% in lumen area and cell diameter was observed for the cells produced during the dry period. Response of A. balsamea seedlings to a 20-day-long dry period consisted of good resistance of the cambial meristems during and after water stress, high sensitivity and rapid recovery of cell sizes during water depletion and slow but effective recovery of shoot growth after treatment

Climate Change Impact on Tree Architectural Development and Leaf Area

“…The variable response of traits in time and intensity may also be linked with phenology: secondary growth occurs longer than shoot extension in monocyclic species [58], but the opposite is observed in some polycyclic species when shoot growth occurs late in autumn and even in winter without cambial activity [20]. Early or late climate-related stresses may not have the same impact.…”

Relationship between Ring Width and Tracheid Characteristics In Picea crassifolia: Implication in Dendroclimatology

“…They demonstrated that the difference between narrow rings and large rings was mainly related to cell size, because larger earlywood tracheids were produced in years when larger rings were formed. Reductions in lumen area and cell diameter of up to 50% were observed in the cells produced during dry periods, and fewer cells with narrower rings were observed in non-irrigated Abies balsamea seedlings (Rossi et al 2009). The complex, largely unexplored relationship between cell characteristics (cell number and diameter) and ring width have permitted only vague explanations of the effects of climate on ring width.…”

effect of warming and water deficit on the non-structural sugars varations in picea mariana /

“…In 2011, T6D and T6N were warmer of 6 K than TO during the day or during the night, respectively (figure 1). For irrigation, control consisted in maintaining the soil water content over 80% of field capacity, while the other seedlings were submitted to a water deficit from mid-May to mid-June, when cambium was vigorously differentiating (Rossi et al, 2009b;Rossi et al, 2009a). (T5) 5 +6K during the day (T6D) and +6K during the night (T6N).…”