The asynchronous rise of Northern Hemisphere alpine floras reveals general responses of biotic assembly to orogeny and climate change

Understanding how biotic assembly processes responded to past geo-climatic changes is key to explaining the origins of mountain biodiversity and the causes of regional disparities in species richness. Here, we jointly reconstructed geographic ranges and biome-niche evolution for 34 diverse plant clades across five major Northern Hemisphere mountain systems and quantified how late Neogene cooling increased arctic-alpine habitat connections across regions. We reveal that, while alpine floras originated asynchronously and were assembled through distinct evolutionary processes over the past 30 Ma, general biological responses to orogeny and environmental change are apparent. Across regions, in situ diversification was consistently elevated during heightened phases of tectonic activity. Over the past 5 Ma, enhanced arctic–alpine connectivity facilitated biotic interchange and positioned the boreal–arctic region as a major biogeographic crossroads linking Eurasia and North America.
, , # The asynchronous rise of Northern Hemisphere alpine floras reveals general responses of biotic assembly to orogeny and climate change

Dataset DOI: [10.5061/dryad.8931zcs30](10.5061/dryad.8931zcs30)

## Description of the data and file structure

The data archive comprises complementary components, including

* Curated GenBank accession tables organized by clade and gene region;
* Joint biogeographic and diversification analyses (geographic‐range & biome delimitations, RevBayes scripts);
* Cold-habitat connectivity assessments (paleoclimate-informed dispersal matrices and global connectivity metrics).

### Files and variables

#### File: Biogeographic_analysis.zip

**Description:** This folder contains the input data (delimitations of geographical range and biome, time-calibrated phylogenies), RevBayes scripts for the biogeographic model that jointly estimates the range and biome evolution, outputs from ancestral biogeographic reconstructions and bootstrap replicates.

The directory t...,