The role of whole-genome duplication (WGD) in facilitating shifts into novel biomes remains unknown. Focusing on two diverse woody plant groups in New Zealand, Coprosma (Rubiaceae) and Veronica (Plantaginaceae), we investigate how biome occupancy varies with ploidy level, and test the hypothesis that WGD increases the rate of biome shifting. Ploidy levels and biome occupancy (forest, open and alpine) were determined for indigenous species in both clades. The distribution of low-ploidy (Coprosma: 2x, Veronica: 6x) versus high-ploidy (Coprosma: 4–10x, Veronica: 12–18x) species across biomes was tested statistically. Estimation of the phylogenetic history of biome occupancy and WGD was performed using time-calibrated phylogenies and the R package BioGeoBEARS. Trait-dependent dispersal models were implemented to determine support for an increased rate of biome shifting among high-ploidy lineages. We find support for a greater than random portion of high-ploidy species occupying multiple biomes. We also find strong support for high-ploidy lineages showing a three- to eightfold increase in the rate of biome shifts. These results suggest that WGD promotes ecological expansion into new biomes.

全基因组复制（WGD）在促进向新生物群落转变中的作用仍然未知。我们专注于新西兰的两个不同的木本植物群，Coprosma（茜草科）和Veronica（车前草科），研究生物群落占有率如何随倍性水平变化，并检验 WGD 增加生物群落转移率的假设。确定了两个进化枝中本地物种的倍性水平和生物群落占有率（森林、开阔和高山）。低倍性 ( Coprosma : 2 x , Veronica : 6 x ) 与高倍性 ( Coprosma : 4–10 x , Veronica : 12–18 x的分布) 对跨生物群落的物种进行了统计测试。使用时间校准的系统发育和 R 包 BioGeoBEARS 对生物群落占有率和 WGD 的系统发育历史进行估计。实施了依赖于性状的扩散模型，以确定对高倍性谱系之间生物群落转移率增加的支持。我们发现了对占据多个生物群落的高倍性物种的更大随机部分的支持。我们还发现对高倍体谱系的强有力支持，表明生物群落变化率增加了三到八倍。这些结果表明，WGD 促进了向新生物群落的生态扩张。