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

Abstract

Ring width represents the total width of cells in a growing season. Relatively few studies have identified which of the parameters, cell number, size, or wall thickness is the greater contributor to variations in ring width. It is difficult to clearly explain the relationship between the climate in which a tree is located and the ring growth. In this study, the ring width and various tracheid characteristics (radial lumen diameter, double wall thickness, and number) in 298 rings of Picea crassifolia wood were investigated. Tree rings were quantitatively categorized based on their width into large, medium, and narrow classes. The tracheid number and lumen diameter were strongly correlated with annual ring width. The tracheid number had the strongest effect on the ring width. The effect of the tracheid number was three times larger than that of the lumen diameter. More earlywood cells were formed in larger rings, while larger earlywood cells were produced in years when narrow rings were formed. Wall thickness had no appreciable effect on ring width. The results of this study help to understand the relationship between the climate and the ring growth from the tree physiology perspective, when ring width is used as a climate proxy.

The genetics of drought tolerance in conifers

“…d), which limits responsiveness to precipitation pulses (Plaut et al ., ). Lumen width and cell wall thickness of tracheids are plastic, with those produced in moist seasons and years generally being wider, more numerous and thinner walled than those produced in dry periods (Eldhuset et al ., ; Xu et al ., ) (Fig. d).…”

“…d). Xylem is often functional for multiple years (Eilmann et al ., ; Mayr et al ., ; Xu et al ., ; Kimak & Leuenberger, ), and so current drought responses can affect water transport during future drought.…”

Fight or flight? Potential tradeoffs between drought defense and reproduction in conifers

“…Relationships among growth, xylem anatomy, and hydraulic safety are well established (Sperry et al 2003, Xu et al 2014, Venturas et al 2017, Barotto et al 2018. Hydraulic failurebreakage of the water column within xylem -can occur when air embolism blocks water flow (Sperry et al 1988, Cochard 2006, Barotto et al 2018, or when water potentials within the xylem become too negative and the xylem cell implodes (Hacke et al 2001, Pittermann et al 2006b).…”

“…We first review current understanding of C allocation to growth, tradeoffs between growth and hydraulic safety, and how drought modifies these allocation patterns. Tradeoffs between growth and hydraulic safety are well studied (Xu et al 2014, Venturas et al 2017, Barotto et al 2018, but often only with respect to tree growth and survival. Here we place these tradeoffs into a fitness context by reviewing the C budget implications of growth, hydraulic safety, and the interaction of the two for reproductive capacity.…”

Fire-scarred fossil tree from the Late Triassic shows a pre-fire drought signal

“…Growth releases are considered a reliable "fire indicator" 24 and are generally attributed to reduced competition for light, nutrients, and/or water caused by the mortality of nearby trees or other vegetation, and/or to an increase in available nutrients released from burned vegetation or litter 26,28 . In gymnosperms, where wood is mainly composed of tracheids, the formation of wide rings following fires results from an increase in tracheid size and/or tracheid number 22,29 .…”