Arefyev (2025) Dendrochronological Reconstruction of Waterlogging of Birch Forests in Steppe Watersheds in Southern Omsk Oblast

Identification

• Journal: Arid Ecosystems
• Year: 2025
• Date: 2025-12-01
• Authors: S. P. Arefyev
• DOI: 10.1134/s2079096125700374

Research Groups

• Institute of Northern Development Problems, Tyumen Science Center, Siberian Branch, Russian Academy of Sciences

Short Summary

This study dendrochronologically reconstructed the timing and causes of waterlogging in insular steppe birch forests in the Odessa district of Omsk Oblast, Western Siberia, revealing that warm, snowy winters leading to anaerobic root rotting are the primary cause of extreme stress and mortality since 2007.

Objective

• To perform a dendrochronological reconstruction of the timing and causes of waterlogging in insular steppe birch forests, using the Odessa district of Omsk Oblast as an example.

Study Configuration

• Spatial Scale: Odessa district, southern Omsk Oblast, Western Siberia, specifically the rural settlement of Zhelannoye (54°09′45″ N, 72°34′42″ E). Data collected from three similar areas of silver birch (Betula pendula Roth) within a 5-kilometer radius, located in saucer-shaped depressions (1–2 hectares).
• Temporal Scale: Dendrochronological data from 1947 to 2024 (trees approximately 80 years old). Analysis period for climate-stress relationships: 1950–2024. Meteorological data from 1938–2024.

Methodology and Data

• Models used: Dendroclimatic analysis methods, chronologies of standardized radial increment (indexed using an exponential spline), year-by-year variability (v-series) as an indicator of ecological and physiological stress, sliding response function (22-year window, 1-year step) using Pearson correlation coefficient (R), Fisher’s t-test, precipitation and air temperature indices, and stress correlation C(v,p) and C(v,t).
• Data sources: Wood cores (20 cores from 10 living silver birch trees, Betula pendula Roth), monthly precipitation amounts and average monthly air temperatures from the Odessa meteorological station (Vserossiiskii… , 2025; http://meteo.ru/).

Main Results

• Extreme ecological and physiological stress on birch trees was recorded in 1952, 2007, 2014, and 2020–2024.
• Since 2007, these stress peaks coincided with extremely high groundwater levels and warm, snowy winters (December and January), which created anaerobic conditions conducive to root intoxication and rotting.
• The average annual air temperature in the study area showed a linear increase trend of 0.33 °C per decade. Annual precipitation averaged 336 mm.
• Three distinct periods were identified based on birch responses to climate and groundwater trends: (1) typical steppe zone responses before 1983, (2) a transitional period, and (3) a period of extreme atypical responses since 2007, characterized by the influence of a nemoral dendroclimatic pattern.
• Birch trees were found to be less resistant to winter rotting caused by warm, snowy conditions than to temporary spring–summer flooding or droughts, which historically characterized the region.

Contributions

• Provided the first dendrochronological reconstruction of waterlogging timing and causes for steppe island birch forests in the southern Omsk Oblast.
• Identified warm, snowy winters leading to anaerobic root rotting as the primary and most maladaptive cause of extreme birch stress and mortality in the 21st century, distinguishing it from traditional drought or temporary flooding impacts.
• Differentiated the influence of various dendroclimatic patterns (steppe, tundra–steppe, taiga, and nemoral forests) on birch stress, highlighting the increasing and detrimental role of the nemoral pattern since 2007.
• Established a detailed chronology of birch stress events and linked them to regional climate warming and rising groundwater levels, offering a long-term perspective where direct groundwater monitoring data are scarce.

Funding

• State Assignment from the Ministry of Science and Higher Education of the Russian Federation, topic no. FWRZ-2021-0006.

Citation

@article{Arefyev2025Dendrochronological,
  author = {Arefyev, S. P.},
  title = {Dendrochronological Reconstruction of Waterlogging of Birch Forests in Steppe Watersheds in Southern Omsk Oblast},
  journal = {Arid Ecosystems},
  year = {2025},
  doi = {10.1134/s2079096125700374},
  url = {https://doi.org/10.1134/s2079096125700374}
}