LEAF DYNAMICS AND SHOOT PHENOLOGY OF 11 WARM-TEMPERATE EVERGREEN BROAD-LEAVED TREES NEAR THEIR NORTHERN LIMIT IN CENTRAL JAPAN

Dynamic features of shoot phenology including leaf emergence and leaf fall, and leaf life span for eleven evergreen broad-leaved tree specie s were investigated in a warm-temperate rain forest in Mount Kiyosumi, central Japan. All species had periodic leaf emergence or flushing pa ttern, and were classified into two types; single and multiple flush a nd only one species, Eurya japonica, represented the latter type and t he rest had single flush in spring. The single Bush type can further b e subdivided into two groups according to their duration of shoot grow th; short and long flush. Seasonal patterns of leaf fall were categori zed into four; unimodal, bimodal, broad unimodal, and multimodal type though they were not fixed pattern. The leaf emergence and leaf fall p atterns were correlated for the eleven species, and five phenological types were categorized. Four of them were the single flush types, i.e. , short flush of leaf emergence with unimodal leaffall (SSU) type of C astanopsis sieboldii and Quercus salicina, short flush with bimodal le af fall (SSB) type of Quercus acuta, Machilus thunbergii, Neolitsea se ricea, and Cinnamomum japonicum, long flush with bimodal leaffall (SLB ) type of Myrsine seguinii, and long flush with broad unimodal leaffal l (SLR) type of Symplocos prunifolia, Cleyera japonica, and Illicium a nisatum. The multiple flush type is only one species, Eurya japonica, and it had multimodal leaffall pattern (MM type). The phenological pat tern varied in relation to leaf life span, leaf size, and tree habit. Leaf life span ranged from 1.1 to 5.8 yr. The short flush species or S SU and SSB types were all canopy or subcanopy trees, and the former ha d short and the latter had long leaf life spans. The long flush specie s were all microphyllous small trees, and SLB type had a relatively lo ng leaf life span in understory, SLR type had a long leaf life span in understory or in open habitat and/or forest gap as a pioneer tree. MM type had a long leaf life span and colonizing species in open habitat but they can survive in understory as well. The phenological attribut es of evergreen trees were well corresponded to the ecological guild o f the tree in both forest structure and successional stage, and were a lso constrained by phylogenetic groups.