PhenoCaB: a new phenological model based on carbon balance in boreal conifers.

Abstract

Traditional phenological models use chilling and thermal forcing (temperature sum or degree-days) to predict budbreak. Because of the heightening impact of climate and other related biotic or abiotic stressors, a model with greater biological support is needed to better predict budbreak. Here, we present an original mechanistic model based on the physiological processes taking place before and during budbreak of conifers. As a general principle, we assume that phenology is driven by the carbon status of the plant, which is closely related to environmental variables and the annual cycle of dormancy-activity. The carbon balance of a branch was modelled from autumn to winter with cold acclimation and dormancy and from winter to spring when deacclimation and growth resumption occur. After being calibrated in a field experiment, the model was validated across a large area (> 34 000 km 2 ), covering multiple conifers stands in Québec (Canada) and across heated plots for the SPRUCE experiment in Minnesota (USA). The model accurately predicted the observed dates of budbreak in both Québec (±3.98 d) and Minnesota (±7.98 d). The site-independent calibration provides interesting insights on the physiological mechanisms underlying the dynamics of dormancy break and the resumption of vegetative growth in spring.

Plant phenotyping relevance

針葉樹の芽吹き時期という植物状態を予測する機 mechanistic phenology modelを開発し、野外実験と複数地域・加温プロットで較正および検証しており、方法が研究の中心である。

Code and data availability

The paper's Data availability section points to the public SPRUCE experiment dataset (used for model validation of black spruce budbreak under warming treatments) hosted on the mnspruce.ornl.gov site, which is an allowed URL. The Canadian sugar/phenology dataset (doi: 10.5683/SP3/MVRZMQ) is also public but its URL is不在