机构地区:[1]东北林业大学林学院生态研究中心,森林生态系统可持续经营教育部重点实验室,黑龙江哈尔滨150040
出 处:《南京林业大学学报(自然科学版)》2021年第4期159-166,共8页Journal of Nanjing Forestry University:Natural Sciences Edition
基 金:中央高校基本科研业务费专项资金项目(2572019CP14,2572018BA05)。
摘 要:【目的】针叶树种和阔叶树种木质部孔性特征的分化,导致两个功能类群在水力学结构上存在显著差异,分析针叶与阔叶树种枝条及其组分间导水率对比特征,了解树木枝-叶水力传导机制。【方法】以东北温带森林中常见的3种针叶树种红松(Pinus koraiensis)、红皮云杉(Picea koraiensis)、兴安落叶松(Larix gmelinii)和4种阔叶树种白桦(Betula platyphylla)、五角槭(Acer mono)、春榆(Ulmus japonica)、蒙古栎(Quercus mongolica)为研究对象,利用高压流速仪(HPFM)的准稳态法,测定枝条的整枝(K_(wb))、茎段(K_(b))、叶片(K_(lb))和叶柄导水率(K_p),并分别计算基于叶面积和叶质量的整枝(K_(wb-area)和K_(wb-mass))、茎段(K_(b-area)和K_(b-mass))、叶片导水率(K_(lb-area)和K_(lb-mass))。比较同一树种枝条水力阻力分配以及不同树种同一组分间导水率差异,并探索标准化后的枝条及其组分导水率与叶性状[包括比叶质量(LMA)和叶干物质含量(LDMC)]的关系。【结果】(1)红松的K_(lb)约是K_(b)和K_(wb)的4倍,针叶阻力(R_(lb))仅占枝条总水力阻力(R_(wb))的20%;其余树种K_(lb)和K_(wb)差异不显著,并显著低于K_(b),R_(lb)占R_(wb)的61%~80%,茎段阻力(R_(b))占R_(wb)的20%左右,叶柄阻力(R_p)占R_(wb)不足10%。(2)不同材性树种K_(lb-area)表现为无孔材最高、散孔材和环孔材树种相似,阔叶K_(lb-area)显著低于针叶。不同材性或叶习性树种间K_(wb-area)或K_(b-area)均无显著差异。(3)K_(lb-area)、K_(wb-area)和K_(b-area)与比叶质量(LMA)、干物质含量(LDMC)均正相关,其中K_(lb-area)与两者相关极显著(P<0.01);K_(lb-mass)、K_(wb-mass)和K_(b-mass)与LMA、LDMC均为负相关,K_(lb-mass)与两者相关不显著。【结论】除了红松,其余6个树种均可采用枝条或带叶柄的叶片代替叶片导水率数据。针叶导水率高于阔叶,一定程度上弥补了针叶树种木质部输水效率低的限制。对针叶树种采用枝条代替K_(lb-area)【Objective】The divergence in wood types between coniferous and broadleaved tree species is expected to lead to significantly different hydraulic architectures between these two functional groups.Despite extensive research on branch xylem,the hydraulic conductance of the whole branch and its parts between the two groups are not well understood.【Method】In the present study,the hydraulic conductance and the hydraulic relative resistance(the inverse of conductance)of the whole branch(Kwb),leafless branch(K_(b)),leaf blades(K_(lb)),and petioles(KP)as well as the above values normalized by leaf area(Kwb-area,K_(b)-area,K_(lb-area))and dry mass(Kwb-mass,K_(b)-mass,K_(lb)-mass),were determined in the quasi-steady-state mode using a high-pressure flow meter(HPFM).This was performed on three conifers(Pinus koraiensis,Picea koraiensis,Larix gmelinii)and four deciduous broadleaved tree species(Betula platyphylla,Acer mono,Ulmus japonica,Quercus mongolica)commonly found in the eastern region of northeast China.We analyzed the hydraulic resistance distribution of the whole branch,compared hydraulic conductance values within the same part of the branch among the different tree species,wood properties,or leaf habits,and established the relationship between the hydraulic conductance and leaf traits(leaf mass per area-LMA and leaf dry mass content-LDMC).【Result】The K_(lb) for Pinus koraiensis was approximately four times as much as the Kwb and K_(b),whereas the K_(lb) and Kwb for the remaining six species were similar,and significantly lower than those of the K_(b).The leaf-blade relative resistance(R_(lb))in Pinus koraiensis accounted for 20%of the total hydraulic resistance(Rwb)in the branch,whereas the relative resistance contribution of R_(lb),leafless branch(R_(b)),and petiole(R_(p))to the Rwb ranged from 61%to 80%,about 20%,and lower than 10%,respectively,for the remaining tree species.The K_(lb-area) of the non-porous species was higher than those of the diffuse-and ring-porous species.The latter two functional
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...