Landform and lithospheric development contribute to the assembly of mountain floras in China.

Although it is well documented that mountains tend to exhibit high biodiversity, how geological processes affect the assemblage of montane floras is a matter of ongoing research. Here, we explore landform-specific differences among montane floras based on a dataset comprising 17,576 angiosperm species representing 140 Chinese mountain floras, which we define as the collection of all angiosperm species growing on a specific mountain. Our results show that igneous bedrock (granitic and karst-granitic landforms) is correlated with higher species richness and phylogenetic overdispersion, while the opposite is true for sedimentary bedrock (karst, Danxia, and desert landforms), which is correlated with phylogenetic clustering. Furthermore, we show that landform type was the primary determinant of the assembly of evolutionarily older species within floras, while climate was a greater determinant for younger species. Our study indicates that landform type not only affects montane species richness, but also contributes to the composition of montane floras. To explain the assembly and differentiation of mountain floras, we propose the 'floristic geo-lithology hypothesis', which highlights the role of bedrock and landform processes in montane floristic assembly and provides insights for future research on speciation, migration, and biodiversity in montane regions.

[Continuous XRF Element Characteristics and Significance of Sedimentary Facies Indication of the Quaternary Core from Fuzhou Basin].

This paper focuses on the study on continuous XRF (X-Ray Fluorescence) scanning elements of a 39 m core from Fuzhou Basin. The XRF scanning result is used to recognize the different sedimentary environment before the discussion of the element variation of different deposit in transitional zone between land and ocean. There are five sedimentary facies in the study area from the late Pleistocene: lacustrine-fluvial-estuary (mud tidal flat)-mixed tidal flat-fluvial. The XRF result from the 5 sedimentary stages shows that the high concentration of Co, Fe, Ti, Si are controlled largely by grain size. The average element intensity of layers with similar grain size indicates that Ca, Ti, Mn, Fe and Co from the marine (tidal flat) deposit is 3~10 times bigger than those from terrestrial (fluvial) deposit, with higher content of Si coinciding with terrestrial deposit. It is indicated that except grain size, the deposit environment is an important factor for element concentration. In this study, Ca, Ti, Mn, Fe and Co are relatively better indicator elements for marine sediments while Si is good and K, Rb and Sr have some indication for terrestrial sediments. The study result shows XRF continuous scanning can help to identify the subtle variation of elements, as to the determination of the sediment facies. Thus, XRF scanning is an important supplement to sediment facies identification. This study also provides an application example of XRF in a typical transitional zone between land and ocean.