Leaf litter and its breakdown products represent an important input of organic matter and nutrients to mangrove sediments and adjacent coastal ecosystems. It is commonly assumed that old-grown stands with mature trees contribute more to the permanent sediment organic matter pool than younger stands. However, neither are interspecific differences in leaf decay rates taken into account in this assumption nor is our understanding of the underlying mechanisms or drivers of differences in leaf chemistry sufficient. This study examines the influence of different plant species and ontogenetic stage on the microbial decay of mangrove leaf litter. A litterbag experiment was conducted in the Matang Mangrove Forest Reserve, Malaysia, to monitor leaf litter mass loss, and changes in leaf litter chemistry and microbial enzyme activity. Four mangrove species of different morphologies were selected, namely the trees Rhizophora apiculata and Bruguiera parviflora, the fern Acrostichum aureum and the shrub Acanthus ilicifolius. Decay rates of mangrove leaf litter decreased from A. ilicifolius to R. apiculata to B. parviflora to A. aureum. Leaf litter mass, total phenolic content, protein precipitation capacity and phenol oxidase activity were found to decline rapidly during the early stage of decay. Leaf litter from immature plants differed from that of mature plants in total phenolic content, phenolic signature, protein precipitating capacity and protease activity. For R. apiculata, but not of the other species, leaf litter from immature plants decayed faster than the litter of mature plants. The findings of this study advance our understanding of the organic matter dynamics in mangrove stands of different compositions and ages and will, thus, prove useful in mangrove forest management.

落叶及其分解产物是向红树林沉积物和邻近沿海生态系统输送有机物质和养分的重要输入。通常认为，具有成熟树木的老林比年轻林对永久性沉积物有机物库的贡献更大。然而，在这个假设中既没有考虑到叶子腐烂率的种间差异，我们对叶子化学差异的潜在机制或驱动因素的理解也不够充分。本研究考察了不同植物种类和个体发育阶段对红树林凋落物微生物腐烂的影响。在马来西亚马当红树林保护区进行了垃圾袋实验，以监测凋落物质量损失、凋落物化学和微生物酶活性的变化。Rhizophora apiculata和Bruguiera parviflora、蕨类植物Acrostichum aureum和灌木Acanthus ilicifolius。从A. ilicifolius到R. apiculata再到B. parviflora到A. aureum，红树林凋落物的腐烂率下降。发现凋落物质量、总酚含量、蛋白质沉淀能力和酚氧化酶活性在腐烂的早期迅速下降。未成熟植物的凋落物在总酚含量、酚类特征、蛋白质沉淀能力和蛋白酶活性方面与成熟植物不同。对于R. apiculata，但不是其他物种，未成熟植物的凋落物比成熟植物的凋落物腐烂得更快。这项研究的结果增进了我们对不同组成和年龄的红树林中有机物质动态的理解，因此将被证明对红树林管理很有用。