Phylogeny, habitat together with biological and ecological factors can influence germination of 36 subalpine Rhododendron species from the eastern Tibetan Plateau.

Yongji Wang,Fei Wang,Chao Zhang,Lianhe Jiang,Yuanrun Zheng,Hui Du,Liming Lai,Ping Zhuang

doi:10.1002/ece3.3874

Yongji Wang, Fei Wang + Show 6 more

Open Access

https://doi.org/10.1002/ece3.3874

Copy DOI

Abstract

The reproductive stages of the life cycle are crucial in explaining the distribution patterns of plant species because of their extreme vulnerability to environmental conditions. Despite reported evidence that seed germination is related to habitat macroclimatic characteristics, such as mean annual temperature, the effect of this trait in controlling plant species distribution has not yet been systematically and quantitatively evaluated. To learn whether seed germination can predict species distribution along altitude gradients, we examined germination data of 36 Rhododendron species in southeastern Tibet originating from contrasting altitudes, habitats, plant heights, seed masses, and phylogenies. Germination varied significantly with altitude, habitat, plant height, and phylogeny and was higher in the light than in the dark. Germination percentage was highest at 10:20°C in the light and 15:25°C in the dark. As altitude increased, germination percentages first rose and then decreased, being highest at 3,500–4,000 m. Germination percentage and rate were highest on rocky slopes, increasing as seed mass and plant height rose. Variations in germination percentage and rate were not significant at subgenera, section, and subsection levels, but they were significant at species level. The results suggested that the relationship between germination and altitude may provide insights into species distribution patterns. Further, germination patterns are a result of long‐term evolution as well as taxonomic constraints.

Highlights

To learn whether seed germination can predict species distribution along altitude gradients, we examined germination data of 36 Rhododendron species in southeastern Tibet originating from contrasting altitudes, habitats, plant heights, seed masses, and phylogenies
2.3 | Attribute groups used to explore the effect of altitude, habitat, seed mass, taxonomic level, and plant height on seed germination
Poschlod (2015) found that seed size had no effect on seedlings and altitudes might have started the stratification period earlier than that seed germination was mainly driven by exterior environmental seeds from lower sites because of the reduced temperature as altifactors and not by internal factors including seed size

Summary

Funding information

National Natural Science Foundation of China, Grant/Award Number: 41401105 terns of plant species because of their extreme vulnerability to environmental conditions. To learn whether seed germination can predict species distribution along altitude gradients, we examined germination data of 36 Rhododendron species in southeastern Tibet originating from contrasting altitudes, habitats, plant heights, seed masses, and phylogenies. Germination varied significantly with altitude, habitat, plant height, and phylogeny and was higher in the light than in the dark. Germination percentage was highest at 10:20°C in the light and 15:25°C in the dark. Germination percentages first rose and decreased, being highest at. Germination percentage and rate were highest on rocky slopes, increasing as seed mass and plant height rose. The results suggested that the relationship between germination and altitude may provide insights into species distribution patterns. KEYWORDS altitude, habitat, phylogeny, plant height, Rhododendron, seed germination, seed mass, Tibet

| INTRODUCTION

| MATERIALS AND METHODS

| RESULTS

| DISCUSSION

Findings

| CONCLUSIONS