The anatomical and physiological response of Scots pine xylem formation to variable water availability

Study area

We sampled three Pinus sylvestris sites along a north-south gradient of increasing drought in southern Siberia (Krasnoyarsk Krai, Russia), from 56°N to 53°N. According to Köppen-Geiger climate classification, sampling sites belong to the Dfc zone (cold continental climate). The mean annual temperature along the gradient ranged from 0.1 °C at S2 to 1.5 °C at S3, and total annual precipitation from 308 mm at S3 to 668 mm at S2.

Tree growth modeling

The combination of dendrochronological methods, tree growth modeling (VS-model) and remote sensing (MODIS, EVI) allowed to evaluate changes in P. sylvestris phenology along the studied gradient. Simulated phenology series by the VS-model were validated by EVI-derived phenological metrics over a period of fourteen years with non-significant differences for the starting of the growing season, allowing the reconstruction of longer (six decades) phenological series by the VS-model. In this sense, results suggested an advance of the starting of growing season along the whole gradient, being faster (at a rate of 5.6 days/decade) at the southern site during the recent time.

Dominant vs suppressed trees

Tree-ring, earlywood and latewood width were measured, and IADFs and resin ducts visually identified on cross-dated cores from 40 trees per site (20 dominant and 20 suppressed). The analysis showed that suppressed trees have stronger and longer climatic signals, as well as a  higher occurrence of IADF and resin ducts than dominant trees. Moreover,   the occurrence of analyzed xylem traits was higher at the drier site. These results highlight that suppressed trees might be more sensitive to climate, having a lower threshold for growth activation.

Tree physiology

under construction

 

Published work linked to the project

(6) Dyachuk P, Arzac APeresunko P, Videnin S, Ilyn V, Assaulianov R, Babushkina EA, Zhirnova EA, Belokopytova L, Vaganov EA, Shishov VV (2020) AutoCellRow (ACR) – A new tool for the automatic quantification of cell radial files in conifer images. Dendrochronologia 60:125687.

(5) Arzac A, Popkova M, Anarbekova A, OIano JM, Gutiérrez E, Nikolaev A, Shishov V (2019) Increasing radial and latewood growth rates of Larix cajanderi Mayr. and Pinus sylvestris L. in the continuous permafrost zone in Central Yakutia (Russia). Ann. For. Sci. 76:96.

(4) Fajstavr M, Bednářová E, Nezval O, Giagli K, Gryc V, Vavrčík H, Horáček P, Urban J (2019) How needle phenology indicates the changes of xylem cell formation during drought stress in Pinus sylvestris L. Dendrochronologia 56:125600.

(3) Urban JRubtsov AV, Urban AV, Shashkin AV, Benkova VE (2019) Canopy transpiration of a Larix sibirica and Pinus sylvestris forest in Central Siberia. Agric. For. Meteorol. 271:64-72

(2) Safonova A, Tabik S, Alcaraz-Segura D, Rubtsov A, Maglinets Y, Herrera F (2019) Detection of Fir Trees (Abies sibirica) Damaged by the Bark Beetle in Unmanned Aerial Vehicle Images with Deep Learning. Remote Sensing 11(6): 643. 

(1) Urban JRubtsov AV, Shashkin AV, Benkova VE (2019) Growth, transpiration and water use efficiency of Larix sibiricaLarix gmelinii and Pinus sylvestris forest in Siberia (2019) SHS Acta Horticulturae 1222.

 

Siberian Federal University

Akademgorodok 50A-K2, room 503, Krasnoyarsk-Russia

©2020 by Laboratory for Complex Studies of Forest Dynamics in Eurasia. Siberian Federal University.

The laboratory is supported by the Ministry of Science and Education of the Russian Federation (project FSRZ-2020-0014).