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In natural systems, litter typically undergoes decomposition as species mixtures, with litter species composition and richness affecting decomposition processes and ecosystem functioning. In this study, we collected and measured leaf litter samples from 25 litter traps within a 1 ha permanent forest dynamics plot and 396 litter traps in three forest sites. Our objective was to investigate the temporal and spatial pattern of leaf litterfall in an old-growth evergreen broad-leaved forest. Mean annual leaf litterfall in the study area was 4.31 ± 0.46 Mg/ha. A total of 61 tree species were recorded in the leaf litter mixtures collected in the 1-ha forest plot, and 39, 48, and 37 tree species were found in the three forest sites. We noted that the abundance of the tree species in the leaf litter mixtures was best fitted as the preemption model. We observed a significant difference in litter species composition between the rain season and the dry season, as well as among the three forest sites, caused by the relative abundance of litterfall from evergreen and deciduous tree species in the two seasons, and the varying proportion of litterfall from dominant tree species in three forest sites. The species diversity of leaf litterfall also varied across different levels. Our study highlights the importance of the dominant tree species in producing leaf litters and determining the litter composition, and indicates that the studies on the leaf litter mixing effects in subtropical forests should be conducted at a high level of species richness, taking into account the relative abundance of litter species.

As an important hydrological ecosystem component, the glacier basin has great significance for climate and environment, and it is also linked to regional water sustainability. In this paper, the sampling and isotope analysis of glacial ice, ice-melt water, river water (river midstream and river downstream), groundwater (spring), and precipitation were carried out in a hydrological year of the Mingyong Glacier basin, which is located at the Meili Snow Mountains, Southeastern Tibetan Plateau. At the same time, the hydrograph separation of the recharge sources of the lower mountain pass is studied. The results show that the range of δD, δ18O, and d-excess (deuterium excess) in natural water bodies are significantly different, and the precipitation is the most obvious. The high values of δD and δ18O in the water samples all appeared in spring and summer, and the low values appeared in autumn and winter, while glacial ice showed opposite trends. Meanwhile, the local meteoric water line (LMWL) of the Mingyong Glacier basin is δD = 8.04δ18O + 13.06. The End-Member Mixing Analysis (EMMA) was adopted to determine the sources proportion of river water (river downstream) according to the δD, δ18O, and d-excess ratio relationships. The results showed that the proportion of ice-melt water, groundwater, and precipitation in the ablation period was 80.6%, 17.2%, and 2.2% as well as 19.2%, 73.1%, and 7.7% in the accumulation period, respectively. Ice-melt water has a higher conversion recharge rate to groundwater and indirectly recharges river water, especially in nonmonsoon seasons. In other words, the main recharge source of river water in the lower reaches of the Mingyong Glacier basin during the ablation period is ice-melt water. In the accumulation period, the main recharge source of river water in the lower reaches of the Mingyong Glacier basin is groundwater, while nearly half of the recharge of groundwater comes from ice-melt water. Therefore, regardless of the ablation period or the accumulation period, ice-melt water is sustainable and important to this region.