Parameter values of spring warming model (SW), temperature-precipitation based leafing model (TP), and alternating model (AM) for plant leafing in Northeast China.

m: parameterized starting date (t0); n: fixed starting date (t0); Tb: base temperature; F*: temperature sum critical threshold; k1: efficiency of precipitation in the previous year in affecting leafing in the current year; k2: efficiency of precipitation in the current year (prior to leafing) in affecting leafing; CU: chilling unit; Pcrit: water threshold; C*: critical value of state of chilling for the transition from rest to quiescence; a and b: constants. PSM=Salix matsudana; PUP=Ulmus pumila; PAV=Armeniaca vulgaris; PPS=Populus simonii; PSO=Syringa oblate; PPNK=Pinus koraiensis; PLD=Larix dahurica; PPCK=Picea koraiensis; XLC=Leymus chinensis in Xilinhot; XSK=Stipa krylovii; ELC=Leymus chinensis in Ewenki; ESB=Stipa baicalensis; HAC=Agropyron cristatum; HED=Elymus dahuricus. The fixed parameters from Chuine et al. (1998) are in bold.