Decomposition and Microbial Activity of Forest Floor Litter in the South of Espírito Santo

ABSTRACT The decomposition process of litter should be widely studied, as it is a key factor for nutrient maintenance and cycling in ecosystems. This study aimed to evaluate the decomposition, release of nutrients, and microbial activity of the forest floor litter of secondary forest, Acacia mangium, Sapindus saponaria, and Hevea brasiliensis in the south of Espirito Santo. The litter decomposition and nutrients release was measured by means of litter bags added to each forest cover. For the assessment of microbial activity, we quantified mineralizable carbon by CO2 evolution. The results showed that the forest covers behaved differently in terms of decomposition and microbial activity; particular emphasis is given to Sapindus saponaria, which presented a faster decomposition of litter. The cover of Sapindus saponaria also presented higher amounts of accumulated CO2 compared to other forest covers; whereas the cover of Acacia mangium presented the lowest values of accumulated CO2.

摘要
枯落物分解过程是生态系统养分维持与循环的关键环节，理应得到广泛研究。本研究旨在评估圣埃斯皮里图州南部次生林、马占相思（Acacia mangium）、无患子（Sapindus saponaria）以及橡胶树（Hevea brasiliensis）林下枯落物的分解、养分释放与微生物活性。本研究通过在各林分中布设枯落物袋的方式，测定枯落物分解与养分释放情况。在微生物活性评估方面，本研究通过CO₂释放量对可矿化碳进行定量分析。研究结果表明，不同林分的枯落物分解与微生物活性存在显著差异；其中无患子林的枯落物分解速率更快，是本次研究重点关注的对象。无患子林的累积CO₂释放量也高于其他林分；而马占相思林的累积CO₂释放量则为所有林分中最低。