摘要:凋落物水解酶活性和环境要素对凋落物的分解有重要影响。为研究秋茄凋落叶分解过程中碳（C）、氮（N）、磷（P）元素动态特征及水解酶活性变化，采用凋落物分解袋法，以闽江口粗芦岛红树林湿地20年生秋茄（Kandelia obovata）为研究对象，探讨秋茄凋落叶在秋茄（主场）和互花米草（Spartina alterniflora Loisel.）（客场）生境分解的差异。结果表明：①整个分解期间，主场生境秋茄凋落叶累计质量损失率显著高于客场生境（P < 0.05），两生境下累计质量损失率和分解速率随分解时间变化差异性明显（P < 0.01）。主客场生境对比下，凋落叶C、N、P含量及其化学计量比没有显著性差异（P > 0.05），但均随分解时间推移发生显著性变化（P < 0.01）。②凋落物累计质量损失率与TC含量、C/N、酸性磷酸酶（AP）活性呈显著负相关关系（P < 0.01）、与TN显著正相关（P < 0.01），分解速率与TP呈显著正相关关系（P < 0.01）。③AP活性与凋落物C、N、P含量及C/N、C/P显著相关（P < 0.05），与土壤温度呈显著正相关关系（P < 0.01）。β-葡萄糖苷酶（βG）和β-N-乙酰氨基葡萄糖苷酶（NAG）均与N/P呈显著正相关关系（P < 0.01）、与土壤电导率负相关关系明显（P < 0.05），纤维素水解酶（CBH）与TC呈显著正相关关系（P < 0.05）。说明秋茄凋落叶的分解与部分水解酶活性和自身养分含量相关，并受到土壤环境因子的影响较大；凋落物分解过程中，水解酶活性会受到分解底物和土壤环境因子环境限制。



Abstract:Hydrolytic enzyme activities and environmental factors play important roles in litter decomposition. To better understand the changes in carbon (C), nitrogen (N), and phosphorus (P) dynamics and hydrolytic enzyme activities during litter decomposition of Kandelia obovata, the difference in decomposition between K. obovata population (local field) and Spartina alterniflora Loisel. population (away field) was measured; K. obovata population aged 20 years located in Culu Island of the Min River estuary was used. The results of the litter bag test revealed the following. 1) The accumulative mass loss rate in the local field was significantly higher than that in the away field throughout decomposition (P < 0.05), whereas the accumulative mass loss rate and decomposition rate exhibited significant difference with decomposition time (P < 0.01). In contrast, the total carbon content (TC), total nitrogen content (TN), total phosphorus content (TP), and stoichiometry were comparable between the local field and away filed (P > 0.05), but exhibited significant difference with decomposition time (P < 0.01). 2) The accumulative mass loss rate negatively correlated with the TC content, carbon/nitrogen ratio (C/N), and acid phosphatase (AP) activity (P < 0.01), whereas they exhibited a significant positive correlation with the TN content (P < 0.01). The decomposition rate positively correlated with the TP content (P < 0.01). 3) The activity of AP correlated with the TC, TN, and TP content, C/N ratio, and carbon/phosphorus ratio, whereas it positively correlated with soil temperature (P < 0.01). The activity of β-1,4-glucosidase and β-1,4-N-acetylglucosaminidase showed a significant positive correlation with the nitrogen/phosphorus ratio (P < 0.01), whereas they negatively correlated with soil electrical conductivity (P < 0.05). Cellobiohydrolase activity positively correlated with the TC content. The foliar litter decomposition of K. obovata correlated with the activity of some hydrolases and the content of nutrients. It was also significantly affected by soil environmental factors. The activity of hydrolase was affected by substrate concentration and soil environmental factors during litter decomposition.





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