Data and code from: Temperature affects the relative importance of phenotypic plasticity and natural selection contributing to the niche breadth of invasive plants

Plant species adapt to changing climates through phenotypic plasticity and natural selection, affecting invasive plants’ niche breadth. However, our limited understanding of how temperature affects the relative importance of phenotypic plasticity and natural selection contributes to invasive plants' niche breadth across latitudes. Here, we used a model system, the salt marsh grass Spartina alterniflora, native to the United States but was introduced into China in 1979, spreading over 20° latitude. We collected seeds of S. alterniflora from nine locations across different latitudes in China, measured phenotypic plasticity, natural selection, and niche breadth of germination and post-germination traits in three greenhouse common garden experiments (low-latitude: 20.9° N, mid-latitude: 28.3° N, and high-latitude: 37.4° N) spread across the latitude in China. We found that germination time, germination percentage, germination index, and seedling survival all increased with latitude within t..., We selected nine field sites in the Hainan, Guangdong, Fujian, Zhejiang, Shanghai, Jiangsu, and Shandong provinces spanning the latitudinal gradient (19–38° N) of S. alterniflora in China. Seeds were collected from nine field sites along a latitudinal gradient from south to north at maturity between September and November 2019 . At each site, we sampled 10 quadrats (0.5 × 0.5 m) that were separated by > 30 m to avoid repeated collection of the same clone belongs to the same lineage with S. alterniflora occurred in monospecific stands. The filled seeds from each quadrate were placed into separate zip-lock bags and stored in 10 PSU seawater at 4 ºC. To standard the local climate and document the mechanisms of seed germination and seedling establishment in S. alterniflora at different latitudes, we established three greenhouse common gardens across the latitudinal gradient of the species in Dongying (37.46° N, 121.39° E), Taizhou (28.65° N, 121.41° E), and Zhanjiang (21.2..., # Temperature affects the relative importance of phenotypic plasticity and natural selection contributing to the niche breadth of invasive plants

**1.Germination traits raw data**: Cumulative germination, Germination index, Germination num, Germination rate, T50, Survival rate, GI plasticity, GR plasticity, GS plasticity, T50 Plasticity, Niche breadth.

* Garden_location: garden site name

- Provenance: field seed collection site name

* Garden_latitude: garden site latitude (N)

- Block_NO: block number

* Provenance_Latitude: field seed collection site latitude (N)

- Cumulative_per: germination rate per observation day

* Germination_day: day of observation

- T50: mean germiantion time (days)

* Germination_rate: germination percentage

- Germination_index: germination index

* Survival_rate: survival percentage

- Survival_num_mean: mean seeding survival number per provenance

* GI plasticity: germination index plasticity

- GR plasticity: germination rate plasticity

* GS plastic...,