海岸青皮林与木麻黄林养分动态及凋落物分解的比较

Nutrients and litter decomposition in Vatica mangachapoi forest versus Casuarina equisetifolia plantation

对海南岛东南部海岸生境相似的天然青皮Vatica mangachapoi林和人工木麻黄Casuarina equisetifolia林养分动态及凋落物分解(采用网袋法)进行比较研究,为营造青皮-木麻黄混交林,并逐渐过渡到天然青皮林的实施提供科学依据。结果表明:①青皮林土壤-植物系统各分室氮、磷、钾元素的质量分数均高于木麻黄林对应各分室(氮:P叶=0.008,P枝<0.001。磷:P叶=0.030,P枝<0.001,P根<0.021。钾:P叶<0.001,P枝<0.001,P根<0.001)。②2种林型土壤分室之间,氮和钾的质量分数呈现显著差异(P氮<0.001,P钾=0.028),磷的质量分数无显著性差异。③2种林型各分室中,除氮和磷元素在土壤分室随季节变化不明显外,其余均随季节变化而变化。④青皮和木麻黄凋落物分解周转期在青皮林下分别为3.53 a和1.83 a,在木麻黄林下分别为3.53 a和3.45 a,因而青皮林林下环境较木麻黄林利于凋落物的分解。可见青皮林比木麻黄林对氮、磷、钾元素有更高的积累能力,且青皮林林下环境更有利于凋落物的分解。

The aim of this study was to provide a scientific basis for constructing a mixed forest of Yatica mangachapoi and Casuarina equisetifolica Comparative biogeochemical and litter decomposition studies were conducted in similar environmental conditions on Shimeiwan Coast in Wanning City, Hainan Island. Results showed that （1） the concentration of N in leaf and branch compartments of V. mangachapoi forest was significantly higher （Pleaf = 0.008, Pbranch〈0.001）than that of C. equisetifolia plantation; the concentration of phosphorus in leaf, branch and root compartments of V. mangachapoi forest was significantly higher （Pleaf = 0.030, Pbcanch〈 0.001, Proot = 0.021） than that of C. equisetifolia plantation; the concentration of K in leaf, branch and root compartments of V. mangachapoi forest was significantly higher （Pleaf〈 0.001, Pbranch〈 0.001, Proot〈0.001） than that of C. equisetifolia plantation. （2） In the soil, N and K of the V. mangachapoi forest was significantly higher （PN〈0.001, PK = 0.028） than that of the C. equisetifolia plantation, but phosphorus was not significantly different. （3） Concentrations of N, P, and K in all compartments of both forest and plantation changed with the season, except for the concentration of N and P in soil compart- ments. Finally, （4） the turnovers of V. mangachapoi litter and C. equisetifolia litter were 3.52 and 1.83 years respectively under V. mangachapoi forest, whereas they were 3.53 and 3.45 years respectively underC. equisetifolia plantation. Thus, the Y. mangachapoi forests had a stronger N, P, and K accumulation capability than the C. equisetifolia plantation, and the microenvironment under V. mangachapoi was more conductive to litter decomposition. [Ch, 2 fig. 2 tab. 33 ref.]