亚热带常绿阔叶林8种樟科树种细根化学计量特征

Stoichiometric Characteristics of Eight Lauraceae Species in a Subtropical Evergreen Broad-leaved Forest

为了研究亚热带常绿阔叶林樟科树种的细根化学计量特征,以福建省建瓯市万木林自然保护区天然常绿阔叶林中具有代表性的8种樟科树种(沉水樟Cinnamomum micranthum;浙江桂Cinnamomum chekiangense;黄绒润楠Machilus grijsii;桂北木姜子Litsea subcoriacea;闽楠Phoebe bournei;新木姜子Neolitsea aurata;香樟Cinnamomum camphora;黄毛润楠Machilus chrysotricha)为研究对象,分析细根C、N、P化学计量学特征随序级的变化规律及种间变异情况。结果表明:(1)树种、序级以及二者交互作用对细根C、N、P浓度及C/N、C/P和N/P均具有极显著影响(P<0.01)。(2)随序级增加,大部分树种的细根N和P浓度降低,而C/N和C/P比增大;随序级变化的变异系数C浓度最小,而P浓度最大。(3)不同序级的细根C浓度的种间变异系数均最低,而P浓度的则均最高,N/P比的种间变异系数亦低于C/N比和C/P比;不同序级细根的N、P浓度之间均具有显著的正相关。

In order to study the stoichiometric characteristics of fine roots of Lauraceae species in subtropical evergreen broad-leaved forest,eight representative Lauraceae species were selected in an evergreen broad-leaved forest species in Wanmulin Forest Nature Reserve,Jian ou City,Fujian Province,to investigate the variations in fine root C,N and P stoichiometry with branching order and across species.The results showed that tree species,branching order and their interactions had significant effects on fine root C,N,P,C/N,C/P and N/P(P<0.01).With increasing branching order,the N and P concentrations decreased and the C/N and C/P ratios increased in most of the species.The coefficient of variation with branching order was the lowest for C concentration and the highest for P concentration.For all root orders,the coefficient of variation across species was the lowest for C concentration and the highest for P concentration,and the coefficient of variation across species for N/P ratio was lower than that for both C/N and C/P ratios.Significant correlation was found between N and P concentrations for all root orders.