Litter usually drops to the ground, but some is retained within the canopy. Mass and CO₂ efflux from retained litter may play a significant role in carbon cycling in tropical rainforests where emergent trees with complicated canopy structures are observed. This study aimed to show vertical variation in the mass and CO₂ efflux (R_litter) of the retained litter and examined its contribution to carbon cycling in a Bornean tropical rainforest. The retained litter was collected from six 40 m tall columns with a radius of 1.6 m using an 85 m tall crane at six subplots. Dry mass and R_litter were measured in the laboratory. The mass of the retained litter from the sampling points ranged from 0.35 g to 187.0 g, and R_litter of the retained litter (42.4 ± 43.4 mg CO₂ kg⁻¹ h⁻¹) was significantly lower than that of the soil surface litter (85.9 ± 39.2 mg CO₂ kg⁻¹ h⁻¹) because of the lower water content in the retained litter. The mean mass of the retained litter measured from the ground to the canopy was 40.6 ± 22.2 g m⁻². The greatest mass was observed at a height of 0–2 m. The ratio of the retained litter mass to the soil surface litter mass ranged from 1.0% to 11.5% with a mean of 5.2%, suggesting that litter retained within the canopy can contribute to carbon storage in this forest. On the other hand, R_litter did not differ with height, and the ratio of R_litter to aboveground autotrophic respiration was less than 1%. This study is the first to show that the litter retained within the canopy can sporadically be a moderate hot spot for C storage, but it is not a significant source of released CO₂.

垫料通常会掉到地上，但有些会保留在树冠内。来自保留凋落物的质量和 CO ₂流出可能在热带雨林中的碳循环中发挥重要作用，在热带雨林中观察到具有复杂冠层结构的挺水树木。本研究旨在显示保留凋落物的质量和 CO ₂流出（R_凋落物）的垂直变化，并检查其对婆罗洲热带雨林中碳循环的贡献。使用 85 m 高的起重机在六个子地块从半径为 1.6 m 的六个 40 m 高的柱子上收集保留的垃圾。干质量和R_凋落物在实验室中测量。采样点残留垃圾的质量范围为 0.35  g至 187.0 g，滞留凋落_物的R_凋落物（42.4 ± 43.4 mg CO ₂ kg ^-1 h ^{- 1}）显着低于土壤表层凋落物（85.9 ± 39.2 mg CO ₂ kg ^-1 h ^{- 1}），因为保留的垫料中较低的水含量。从地面到树冠测量的保留凋落物的平均质量为 40.6 ± 22.2 g m ^{- 2}。在 0-2 m 的高度处观察到最大质量。保留的凋落物质量与土壤表面凋落物质量的比率范围为 1.0 %到 11.5%，平均值为 5.2%，这表明保留在树冠内的枯枝落叶有助于该森林的碳储存。另一方面，R_凋落物不随高度变化，R_凋落物与地上自养呼吸的比值小于 1%。这项研究首次表明，保留在树冠内的凋落物偶尔会成为 C 储存的中等热点，但它不是释放 CO ₂的重要来源。