油茶不同器官氮、磷、钾化学计量特征随年龄的变化

Ecological stoichiometry of N,P,and K with age in Camellia oleifera organs

油茶Camellia oleifera为中国特有的食用油料树种,但关于油茶不同器官氮、磷、钾的生态化学计量特征的认识还不够充分。以浙江省常山县油茶人工林为对象,通过测定不同年龄油茶叶片、枝条、主干、根系和果实中氮、磷、钾质量分数,探讨了油茶不同年龄各器官氮、磷、钾化学计量特征及在各器官中的分配规律。结果表明:油茶氮质量分数从大到小依次为叶片、枝条、根系、果实、主干,磷质量分数从高到低依次为叶片、枝条、果实、根系、主干,钾质量分数从高到低依次为果实、叶片、根系、枝条、主干;随年龄的增加,枝条中的氮、磷质量分数逐渐增大,而其他器官中氮、磷质量分数先增大后减小,钾质量分数先增高而后降低。油茶各器官氮磷比(N∶P)为3.91～10.68,氮钾比(N∶K)为0.33～1.31,钾磷比(K∶P)为3.71～19.08;随年龄的增长,油茶果实N∶P逐渐增高,而其他器官N∶P则先增高而后降低,叶片、枝条、根系和果实的N∶K逐渐增大,叶片、主干和果实K∶P先升高而后下降,枝条、根系的K∶P逐渐降低。油茶叶片的氮、磷平均分配比例为31.4%和28.6%,钾在根系中具有最高的分配比例,平均占比达30.5%。影响油茶生长的限制元素是氮,在生产经营程中,可适当增施氮。

To better understand the distribution of nitrogen(N),phosphorus(P),and potassium(K)over time in different organs of Camellia oleifera,a special edible oil tree species in China,samples of leaves,branches,stems,roots and fruits at different ages were collected from C.oleifera in Changshan County,Zhejiang Province.N,P and K content were measured to analyze the stoichiometry characteristics at different ages in the context of a distribution strategy.Results showed that average N content was leaf>branch>root>fruit>stem,average P content was leaf>branch>fruit>root>stem,and average K content was fruit>leaf>root>branch>stem.With an increase in age,in the branch the N and P content increased gradually;whereas,in the other organs,N and P content first increased and then decreased.For all organs,K content first increased and then decreased as time increased.The values for N∶P were 3.91-10.68;for N∶K were 0.33-1.31;and for K∶P were 3.71-19.08.With increased age in fruits,N∶P increased gradually,and in other organs N∶P first increased and then decreased;in leaves,branches,roots,and fruits,N∶K increased gradually;in leaves,stems,and fruits,K∶P first increased and then decreased;and in branches and roots,K∶P decreased gradually.In the leaves the average distribution ratio of N was 31.4%,and P was 28.6%.K had its highest proportion in the roots with an average ratio of 30.5%.Thus,the limiting element affecting the growth of C.oleifera was N;so in the process of production,N fertilizer should be properly added.[Ch,1 fig.4 tab.26 ref.]