Spatial pattern dynamics of Cyclobalanopsis myrsinifolia in mixed broad-leaved forests on Tianmu Mountain, eastern China, 1996–2012

Studies of the spatial patterns of dominant plant species may provide significant insights into processes and mechanisms that maintain stand stability. This study was performed in a permanent 1 ha plot in evergreen and deciduous broad-leaved mixed forests on Tianmu Mountain. Based on two surveys (1996 and 2012), the dynamics of the spatial distribution pattern of the dominant population ( (Blume) Oersted) and the intra- and interspecific relationships between and other dominant species populations were analyzed using Ripley’s () function. We identified the importance value of a species in a community, which is the sum of the relative density, relative frequency, and relative dominance. The drivers of spatial distribution variation and the maintenance mechanisms of the forest were discussed. The results showed that the importance value of within the community decreased over the past 16 years. The population exhibited a significantly aggregated distribution within a spatial scale of 0–25 m in 1996 whereas it changed to a random distribution at scales larger than 5.5 m in 2012. From 1996 to 2012, the spatial distribution patterns between and (Batal.) Iljinsk. and between and (Lamb.) Hook did not change significantly. In 1996, and Miq. were positively associated at the scale of 0–25 m; this relationship was strongly significant at the scale of 6–10 m. However, there was no association between the populations of two species in terms of the spatial distribution at the scale of 0–25 m in 2012. Our findings indicate that the drivers of variation in the spatial distribution of the population were intra- and interspecific mutual relationships as well the seed-spreading mechanism of this species.Cyclobalanopsis myrsinifoliaC. myrsinifoliaKrC. myrsinifoliaC. myrsinifoliaC. myrsinifoliaCyclocarya paliurusC. myrsinifoliaCunninghamia lanceolataC. myrsinifoliaDaphniphyllum macropodumC. myrsinifolia

Cytotoxic neolignans from the traditional Chinese medicine Daphniphyllum macropodum Miq.

Four new neolignans (1–4) were isolated from the seeds of Daphniphyllum macropodum Miq. and the evaluated for their antiproliferative activity showed that 2 could induced the apoptosis in A549 cells through activating the mitochondrial pathway.