亚热带6个典型树种吸收细根寿命与形态属性格局  

Lifespan and morphological traits of absorptive fine roots across six typical tree species in subtropical China

作　　者：王奕丹 李亮 刘琪璟[1] 马泽清[2,3] WANG Yi-Dan;LI Liang;LIU Qi-Jing;MA Ze-Qing(College of Forestry,Beijing Forestry University,Beijing 100083,China;Key Laboratory of Ecosystem Netw ork Observation and Modeling,Institute of Geographic Science and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;Qianyanzhou Ecological Research Station,Chinese Academy of Sciences,Ji'an,Jiangxi 343700,China)

机构地区：[1]北京林业大学林学院,北京100083 [2]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101 [3]中国科学院千烟洲亚热带森林生态系统观测研究站,江西吉安343700

出　　处：《植物生态学报》2021年第4期383-393,共11页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31822010和31971633);中国科学院基础前沿科学研究计划“从0到1”原始创新项目(ZDBS-LY-DQC023)。

摘　　要：根周转是地下生态过程的主要驱动力,根属性指征了物种生态策略,根寿命与属性是理解生态系统碳氮循环和群落多样性的关键。目前对亚热带常绿阔叶林根周转等生态过程的直接观测资料缺乏。该研究对中亚热带江西樟树试验林场6个树种吸收细根动态进行了2年观测,获取了2.8万张微根管照片,分析了吸收细根寿命年际和季节变化特征及其与根形态属性的关系。结果显示:1)亚热带6个树种间吸收细根寿命变异为4.6倍,变异系数可达73%。中值寿命排序为:红豆杉(Taxus wallichiana)(426天)>复羽叶栾树(Koelreuteria bipinnata)(155天)>竹柏(Nageia nagi)(145天)>樟(Cinnamomum camphora)(126天)>东京樱花(Cerasus yedoensis)(93天)>深山含笑(Michelia maudiae)(92天);2)树木吸收细根寿命年际、季节变异较大,可能是适应伏秋旱、雨热不同期、年际变化大的亚热带季风气候的结果;3)吸收细根寿命与直径呈显著正相关关系,与比根长呈显著负相关关系,表明根的构建成本可以在一定程度上预测寿命。这些结果为预测亚热带地下生态过程、揭示亚热带常绿阔叶林碳氮循环、物种共存机制提供依据。Aims Root turnover is a primary driver of belowground ecological processes,and root functional traits can indicate species ecological strategies,hence root lifespan and morphological traits are essential for understanding ecosystem carbon and nitrogen cycling as well as community diversity.Yet,data on root ecological processes in subtropical evergreen forest is very rare.Methods We observed root dynamics of six tree species across root orders for two years in an experimental forest farm in Zhangshu,Jiangxi Province.Based on 28000 minirhizotron photos,we analyzed interannual and seasonal changes of absorptive fine roots in relation to both lifespan and morphology.Important findings 1)The variation of root lifespan among the six species in subtropical forest was as high as 4.6-fold,the variation of coefficient was 73%,with median lifespan in the sequence of:Taxus wallichiana(426 d)>Koelreuteria bipinnata(155 d)>Nageia nagi(145 d)>Cinnamomum camphora(126 d)>Cerasus yedoensis(93 d)>Michelia maudiae(92 d);2)Absorptive fine root lifespan appeared remarkable in both seasonal and interannual variations,a pattern seemingly related to the monsoon climate which is characterized by summer-toautumn drought and the supplies of soil water resources;3)The lifespan of absorptive roots was positively associated with diameter,but negatively correlated with specific root length,suggesting that the root construction cost is a key predictor of lifespan.These results provide parameters for modeling belowground carbon and nitrogen cycling processes in subtropical evergreen broadleaf forest,and pave the way for exploring species coexistence mechanisms from belowground.

关 键 词：细根 吸收根 根周转 根生产 根死亡 地下生态过程 形态属性 净初级生产力 土壤有机碳 

分 类 号：Q948[生物学—植物学]