Parameter values of sequential model (SM) and parallel model (PM) for plant leafing in Northeast China.

m: all parameters estimated; n: section parameters estimated; Tlow: the lowest temperature of the rate of chilling; CU: chilling unit; FU: forcing unit;Thigh: the highest temperature of the rate of chilling; va, vb and vc: constants; Tb: base temperature; C*: critical value of state of chilling for the transition from rest to quiescence; F*: temperature sum critical threshold; To: optimal temperature of the rate of chilling; Km: minimum potential of unchilled buds to respond to forcing temperature. 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.