Response of Four Tree Species to Changing Climate in a Moisture-Limited Area of South Siberia

Abstract

The response of vegetation to climate change is of special interest in regions where rapid warming is coupled with moisture deficit. This raises the question of the limits in plants' acclimation ability and the consequent shifts of the vegetation cover. Radial growth dynamics and climatic response were studied in Scots pine (Pinus sylvestris L.), Siberian larch (Larix sibirica Ledeb.), and silver birch (Betula pendula Roth.) in the forest-steppe, and for Siberian elm (Ulmus pumila L.) in the steppe of South Siberia, as indicators of vegetation state and dynamics. Climate-growth relationships were analyzed by the following two approaches: (1) correlations between tree-ring width chronologies and short-term moving climatic series, and (2) optimization of the parameters of the Vaganov-Shashkin tree growth simulation model to assess the ecophysiological characteristics of species. Regional warming was accompanied by a slower increase of the average moisture deficit, but not in the severity of droughts. In the forest-steppe, the trees demonstrated stable growth and responded to the May-July climate. In the steppe, elm was limited by moisture deficit in May-beginning of June, during the peak water deficit. The forest-steppe stands were apparently acclimated successfully to the current climatic trends. It seems that elm was able to counter the water deficit, likely through its capacity to regulate transpiration by the stomatal morphology and xylem structure, using most of the stem as a water reservoir; earlier onset; and high growth rate, and these physiological traits may provide advantages to this species, leading to its expansion in steppes.

Do angiosperm tree species adjust intervessel lateral contact in response to soil drought?

“…Similar decreases of xylem areas were observed in many species experiencing soil drought (e.g. Babushkina et al, 2019; Hacke et al, 2017; Plavcová & Hacke, 2012). Furthermore, the decrease of xylem area in stems of tree seedlings was proportional to water deficit within the treatments applied (CD > PD; Table S1) indicating that the xylem development was sensitive to soil water availability.…”

Prospects of Using Tree-Ring Earlywood and Latewood Width for Reconstruction of Crops Yield on Example of South Siberia

“…Therefore, we can conclude that the observed weaker reaction of larch to temperature in comparison to crops might be explained by the low probability of thermal damage and heat stress for this species. It should be noted that other tree species (both coniferous and deciduous) also have a more pronounced reaction to precipitation than to temperature even in semiarid stands of the South Siberia [14,70]. Moreover, the semi-humid forests of the continental Asia respond positively to climate warming [71].…”

A Band Model of Cambium Development: Opportunities and Prospects

“…Significant limitations of those approaches have been shown, particularly with regards to estimating the processes that determines when cells transition from the cambial zone to the enlargement zone [23]. New quantitative approaches to the modelling of the cambial zone are also needed, in order to take into account a rapidly growing body of literature, observations, experimentation, and theory on xylogenesis measurements and the contributions of internal and external factors in influencing the production of new xylem cells [28][29][30][31][32][33][34][35][36].…”