[M-IS05] Environmental, Socio-economic, and Climatic Changes in Northern Eurasia

[MIS05-04] Potential distributions of major conifers and their seed mass across Siberia in the twenty-first century warming climate

*Nadezhda Tchebakova¹, Elena I. Parfenova¹, Elena V. Bazhina¹, Sergei R. Kuzmin¹, Nina A. Kuzmina¹, Galina V. Kuznetsova¹, Vera A. Senashova¹, Susan G. Conard², Pavel Y. Groisman³ (1.Institute of Forests, FRC KSC of Siberian Branch, Russian Academy of Sciences, 2.George Mason University, 3.NC State University Research Scholar at National Centers for Environment Information)

Keywords:bioclimatic envelope and regression models, six major Siberian conifers, ranges and seed mass, twenty general circulation models CMIP5 and spp126 and spp585 climate change scenarios for the 2100

At the turn of the 21st century, there were more forest territories found disturbed by both natural processes (climate change, wildfires, insect outbreaks, permafrost thawing, etc.) and anthropogenic interferences (air pollution, clearcuts, etc.). Our goals were to construct bioclimatic models of ranges and seed mass of major Siberian forest-forming conifers to restore lost forest areas after disturbances and predict their potential change in a warming climate by the end of the century. The major Siberian conifers are Siberian pine, Siberian fir, Siberian spruce, Siberian larches (Siberian larch, Gmelin larch and Cajander larch) and Scots pine. Multi-year seed mass data were derived from the literature, seed station data, and were collected in the field. Contemporary climate data (January and July data and annual precipitation) were derived from published Russian reference books and websites on climate. The future 2100 (2070-2100) climate data (January and July temperatures and annual precipitation) were calculated using the ensemble of twenty general circulation models and two climate change scenarios, ssp126 and ssp585 of CMIP5. Our bioclimatic range envelope-type models and regression seed mass models for major conifers were built based on three bioclimatic indices (Growing degree-days, base 5 C, GDD; Negative degree-days; Annual Moisture Index, the ratio of GDD/annual precipitation). Additionally, the ranges of the conifers were divided by the permafrost border for five conifers in the permafrost-free zone and only one conifer, Dahurian larch, in permafrost zone, where is able to survive. Under warmed climates, the ranges of all Siberian conifers would expand 1.5-fold due to the decrease in the permafrost zone, except Dahurian larch, which would lose 5–20% of its coverage due to permafrost retreat. Conifers shifting northward would be slower than predicted only by warmed climates because permafrost would thaw slower than climates would warm. Scots pine may expand by up to 60%, covering dryer lands in the south. Future climates were found to favor seed mass increase for major Siberian conifers and for heavier seed to shift northward. Warmed climates would favor the expansion of the ranges of major Siberian conifers and their seed mass to be heavier, which would support the high-quality seed production for forest well-being and its restoration in Siberia.

We acknowledge the Basic project FWES-2024-0023 of the Forest Institute of FRC KSC SB RAS for the administrative and technical support.