Fig. 3: Field sampling of typical high-Si (wheat and rice) and low-Si (weeping willow and winter jasmine) plants in China.
From: Convergent evidence for the temperature-dependent emergence of silicification in terrestrial plants
a The source of sampling for plant samples (wheat, n = 475 individuals; rice, n = 279 individuals; weeping willow, n = 140 individuals; winter jasmine, n = 80 individuals). The Chinese map data is sourced from DATAV.GeoAltas (http://datav.aliyun.com/portal/school/atlas/area_selector). b Correlation of phytolith/Si concentration with mean annual temperature. The Student’s t test for the regression coefficient is two-sided. c, d Coefficients of the multiple regression analysis of climatic variables and phytolith concentration in wheat (n = 475 individuals) and rice (n = 279 individuals) leaves. The climatic variables include mean annual air temperature (MAT), ground surface temperature (GST), evaporation (EVP), precipitation (PRE), pressure (PRS), relative humidity (RHU), wind speed (WIN), surface downwelling shortwave flux in air (RSDS), and vapor pressure deficit (VPD). The Student’s t test for the regression coefficient is two-sided, with no adjustments for multiple comparisons. The error bars represent the standard error of the regression coefficients. Solid rectangles indicate significant correlation (p < 0.05), while hollow rectangles indicate insignificant correlation. e, f The relative importance of various climate variables in explaining the phytolith concentration in wheat and rice leaves assessed by squared standardized coefficients (betasq).
