【摘要】 [目的]探明亚热带不同森林类型的碳汇功能，为森林经营和针叶林改造中的树种选择提供指导。[方法]基于月动态监测，研究了罗卜岩自然保护区亚热带常绿阔叶林(米槠林)、常绿-落叶阔叶混交林(闽桦-闽楠林)和针叶林(马尾松林)3种森林类型的凋落物产量及碳氮归还动态变化。[结果](1) 3种林分中马尾松林的年总凋落量最高[9 815 kg/(hm~2·a)],其次为闽桦-闽楠林[9 207 kg/(hm~2·a)],米槠林最低[8 083 kg/(hm~2·a)],叶是闽桦-闽楠林和马尾松林凋落物的主要组分，而米槠林凋落物以碎屑等其他组分为主；3种森林的总凋落量、叶、花果和其他组分凋落量月动态均呈双峰型曲线，峰值分别出现在11—12月和次年的4—5月。(2) 3种林分总凋落物碳归还量为马尾松林[4 970 kg/(hm~2·a)]>闽桦-闽楠林[4 458 kg/(hm~2·a)]>米槠林[3 804 kg/(hm~2·a)],总凋落物氮归还量为闽桦-闽楠林[160 kg/(hm~2·a)]>马尾松林[128 kg/(hm~2·a)]>米槠林[113 kg/(hm~2·a)],3种林分凋落物碳氮归还的月变化与其总凋落物量的月变化一致。(3) 3种林分的凋落物质量差异显著，其中马尾松林的总凋落物碳氮比最高，闽桦-闽楠林最低；闽桦凋落物的木质素浓度最高，米槠最低；闽楠和马尾松凋落物的木质素/纤维素值最高，米槠最低。[结论]闽桦-闽楠林具有更高的年凋落物量和较快的潜在分解速率，可以更持续快速地为林地补充养分。更多还原

【Abstract】 [Objective] The aim of this study is to explore the carbon sink function of different forest types in subtropical China and better guide significance in tree species selection for forest management and coniferous forest transformation. [Methods] Based on monthly dynamic observation, the dynamic changes of litterfall and carbon(C) and nitrogen(N) return in three forest types including evergreen broad-leaved forest(the Castanopsis carlesii forest), evergreen and deciduous broad-leaved mixed forest(the Betula fujianensis and Phoebe bournei mixed forest) and coniferous forest(the Pinus massoniana forest) in Luoboyan Nature Reserve were studied from September 2018 to August 2019. [Results](1) The annual litterfall was highest in Pinus massoniana forest [9 815 kg/(hm~2·a)], followed by Betula fujianensis and Phoebe bournei mixed forest [9 207 kg/(hm~2·a)], and lowest in Castanopsis carlesii forest [8 083 kg/(hm~2·a)]. In terms of litter composition, the leaflitter of Betula fujianensis and Phoebe bournei mixed forest and Pinus massoniana forest was relatively high, while other components such as debris in Castanopsis carlesii forest accounted for the highest, followed by leaflitter. The monthly dynamics of total litterfall, leaf litter, flower, fruit and other components of three forests all showed double peak curve, and the peak appeared from November to December and from April to May in the next year, respectively.(2) The range of litter C return was Pinus massoniana forest [4 970 kg/(hm~2·a)]>Betula fujianensis and Phoebe bournei mixed forest [4 458 kg/(hm~2·a)]>Castanopsis carlesii forest [3 804 kg/(hm~2·a)], and the range of litter N return was Betula fujianensis and Phoebe bournei mixed forest [160 kg/(hm~2·a)]>Pinus massoniana forest [128 kg/(hm~2·a)]>Castanopsis carlesii forest [113 kg/(hm~2·a)]. The dynamic characteristics of litter C and N return of the three forests was consistent with that of total litterfall.(3) Significant differences were observed in litter quality among three forests, and the litter C∶N ratio was highest in Pinus massoniana forest, and lowest in Betula fujianensis and Phoebe bournei mixed forest, the litter lignin concentration was highest in Betula fujianensis, and the litter lignin: cellulose value was highest in Phoebe bournei and Pinus massoniana, and lowest in Castanopsis carlesii. [Conclusion] The Betula fujianensis and Phoebe bournei mixed forest has higher annual litterfall and faster potential decomposition rate, which can supplement nutrients more continuously and quickly.更多还原