Weak correlations among leaf thermal metrics, economic traits and damages under natural heatwaves.

The frequency and intensity of heatwaves are increasing around the world, causing severe damages to plants, but whether leaf thermal metrics is in line with leaf economic spectrum is still controversial. Here, we measured leaf damage ratio, leaf thermal metrics (tolerance and sensitivity) and economic traits of 131 woody species across five cities along the Yangtze River after a two-month natural extreme temperature event. We found that leaf thermal sensitivity but not thermal tolerance was correlated with leaf damage ratio, and the relationships between leaf thermal metrics and economic traits were weak, indicating that leaf thermal adaptation may be independent from leaf carbon construction. This study suggests a potential indicator for predicting plant survival under heatwaves, urging future research to explore more physiological traits to comprehensively understand plant heat responses and adaptations.

Comparative taxonomic variation in fruits and seeds' surface morphology among populations of alpine Rosa sericea complex (Rosaceae).

In this research, the fruits and seeds' surface morphological features and their taxonomic significance were determined. Additionally, useful traits for delimitation of taxa of Rosa sericea complex were studied. In this research, three taxa of the complex R. sericea, R. omeiensis, and R. sikangensis have been studied. A total of 41 populations and 130 specimens of seeds, and 35 populations and 168 specimens of fruits from 10 different geographical regions of southwest China have been examined. The surface micro-morphological characters of the seeds have been studied through scanning electron microscopy to distinguish important characteristics of the complex taxa. Forty-four different qualitative and quantitative characteristics were observed. Principal component analysis was used to simplify and elucidate the relationship between the studied characters of different population based on the morphology of fruits and seeds' features. Moreover, the numerical taxonomic characters and their variation with elevation have been studied in these species. The most interesting characters observed on the surface of the seeds were stomata, and trichomes, for which density was more at the dorsal and ventral parts, while rarely present on the lateral parts. The fruits and seeds' surface morphology of the studied species was complicated and some variation in the characters, that is, persistent calyx shape, the shape of fruits and seeds, stomata shape, and trichomes size were found significant for delimitation of taxa in the complex. The purpose of this study is to identify the taxa of R. sericea complex based on fruits and seeds' morphological characters, and identification keys.