The study looked at how using a single biome per species approach affects the detection of biome shifts and biome conservatism in plant lineages in New Zealand. They found that when only one biome is considered for each species, the estimated biome shift rates are significantly lower. This approach also detected fewer instances of biome conservatism compared to when multiple biomes per species were allowed. The results suggest that assuming species only occupy one biome can lead to inaccurate conclusions about biome shifts and conservatism. The researchers recommend analyzing data in a way that allows species to occupy multiple biomes for more accurate results.