COS 128-4 - CANCELLED - Phenotypic plasticity and natural selection shape the niche breadth of the invasive salt marsh grass Spartina alterniflora in China

Tuesday, August 8, 2023

4:15 PM – 4:30 PM PDT

Location: B116

Presenting Author(s)

WL

Wenwen Liu

Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, China (People's Republic)

Coauthor(s)

LL

Lin Li

Xiamen University, China (People's Republic)
CY

Congting Ye

Xiamen University, China (People's Republic)
XC

Xincong Chen

Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, China (People's Republic)
YZ

Yihui Zhang

Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, China (People's Republic)

Abstract: Background/Question/Methods

Phenotypic plasticity and natural selection have major effects on the ecological niches of invasive plants. However, the relative roles of phenotypic plasticity and natural selection in driving the niche breadth of invasive plants across latitudes remain unclear. We collected seeds of Spartina alterniflora, an invasive salt marsh grass, from nine locations across latitude in China. We further measured phenotypic plasticity and phenotypic selection on Spartina alterniflora germination and post-germination traits in four greenhouse common garden experiments established along the latitudinal gradient of the species in China.

Results/conclusions

Germination time, germination rate, and seedling survival increased with latitude within common gardens, with a higher slope at higher-latitude common garden sites, indicating natural selection for later germination, higher germination rate, and higher seedling survival with higher fitness at high latitudes. In contrast, the phenotypic plasticity of germination and post-germination traits decreased with the increasing latitude of origin, which compensates for the lower fitness at low latitudes. Furthermore, we found the germination niche breadth decreased with increasing latitude. The climate is a primary selective force driving the divergence of germination and post-germination traits, which strongly correlate with temperature. Overall, our study supports the hypothesis that climate-driven selection favors sexual reproduction at higher latitudes and higher phenotypic plasticity at lower latitudes, which together explains why the germination niche breadth of S. alterniflora decreased with increasing latitude in China.