抚育对长柄双花木叶枝氮磷钾生态化学计量的影响

    Effect of Tending on the Ecological Stoichiometry of Nitrogen, Phosphorus and Potassium in the Leaves and Branches of Disanthus cercidifolius var. Longipes

    • 摘要: 长柄双花木Disanthus cercidifoliusvar. longipes为国家Ⅱ级保护野生植物,有关抚育间伐对长柄双花木地径、树高生长及叶枝氮(N)、磷(P)、钾(K)的生态化学计量特征的影响尚未被认识。以钱江源国家森林公园长柄双花木群落为对象,建立未抚育(对照)、上层抚育、下层抚育、全抚育等4处理3重复的定位样地,监测了该植物地径、树高的年生长量,采样分析了叶片、枝条的N、P、K含量,并计算其化学计量。结果表明:抚育促进了长柄双花木的生长,与对照相比,地径、树高年生长量显著增加了20.0%~40.0%、20.0%~90.0%(P<0.05);全抚育叶片P含量显著下降(P<0.05),而K含量显著增加(P<0.05);枝条N含量在全抚育后显著下降(P<0.05),K含量在上层抚育后也显著降低(P<0.05);下层抚育和全抚育后叶片N∶P、K∶P显著升高(P<0.05),叶片N∶K显著下降(P<0.05),上层抚育显著提高了枝条N∶P、N∶K(P<0.05)。叶片中共有10对元素及化学计量比间的相关性达显著或极显著水平(P<0.05或P<0.01),枝条中仅有N∶P与N∶K具有显著性相关(P<0.05)。综上,抚育促进了长柄双花木的生长,改变了N、P、K在叶片、枝条中的积累与分配。

       

      Abstract: Disanthus cercidifolius var. longipes is a second-class protected wild plant in China. The effects of thinning and nurturing on the ground diameter, tree height growth, and the ecological stoichiometric characteristics of nitrogen (N), phosphorus (P) and potassium (K) in the leaves and branches of D. cercidifolius var. longipes have not been fully understood. By taking the community of D. cercidifolius var. longipes in Qianjiangyuan National Forest Park as the object of study, the four-treatment and three-replicate permanent plot was established, including no nurturing (control), upper nurturing, lower nurturing, and full nurturing. The annual growth of ground diameter and tree height of the plant was monitored. The N, P, and K contents in the leaves and branches were sampled and analyzed, and their stoichiometry was calculated. The results showed that nurturing promoted the growth of D. cercidifolius var. longipes. Compared with the control, the annual growth of ground diameter and tree height significantly increased by 20.0%−40.0% and 20.0%−90.0% (P<0.05). After full nurturing, the P content in the leaves significantly decreased (P<0.05), while the K content significantly increased (P<0.05). The N content in the branches significantly decreased after full nurturing (P<0.05), and the K content also significantly decreased after upper story nurturing (P<0.05). The N∶P and K∶P in the leaves of D. cercidifolius var. longipes plant significantly increased after lower and full nurturing (P<0.05), while the N∶K in the leaves significantly decreased (P<0.05). The upper story thinning significantly increased the N∶P and N∶K in the branches (P<0.05). There were 10 pairs of elements and stoichiometric ratios in the leaves that showed significant or extremely significant level correlations (P<0.05 or P<0.01), and only N∶P and N∶K in the branches showed significant correlations (P<0.05). In summary, nurturing promoted the growth of D. cercidifolius var. longipes, and changed the accumulation and distribution of N, P, and K in leaves and branches.

       

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