Climate change alters the future of natural floristic regions of deep evolutionary origins

Biogeographic regions reflect the organization of biotas over long evolutionary timescales but face alterations from recent anthropogenic climate change. Here, we model species distributions for 189,269 vascular plant species of the world under present and future climates and use this data to generate biogeographic regions based on phylogenetic dissimilarity. Our analysis reveals declines in phylogenetic beta diversity for years 2040 to 2100, leading to a future homogenization of biogeographic regions. While some biogeographic boundaries will persist, climate change will alter boundaries separating biogeographic realms. Such boundary alterations will be determined by altitude variation, heterogeneity of temperature seasonality, and past climate velocity. Our findings suggest that human activities may now surpass the geological forces that shaped floristic regions over millions of years, calling for the mitigation of climate impacts to meet international biodiversity targets., Distribution data and species distribution modeling
We explored shifts in plant biogeographic regions under climate change using species distribution modeling under alternative climate change scenarios. Our models were constructed based on the standard protocol for reporting species distribution models using the ODMAP (Overview, Data, Model, Assessment and Prediction) protocol54 (Supplementary Note 1), along with open-source data and codes for scientific reproducibility (see Data Availability). We used maximum entropy (MaxEnt v.3.4.3)55 to model plant species distributions. MaxEnt is not computationally expensive56 and has been shown to outperform other algorithms in modeling species distributions for computational efficiency especially when dealing with a huge number of species spanning hundreds of thousands of species as in this study and is robust for modelling distributions for species with relatively few occurrence records57. Predictor variables for the modeling were downloaded fro..., , # README: Climate change alters the future of natural floristic regions of deep evolutionary origins

## General Information
This repository contains datasets and R scripts used in the analysis of Climate change alters the future of natural floristic regions of deep evolutionary origins. The dataset includes geographic distance calculations, optimal clustering, spatial correlations, and other supporting files.

## Data Structure
The dataset is organized into the following directories:

### 1. **CODES/**
This directory contains all the R scripts used in the analyses.
- **DATA_ANALYSIS/**
- Contains R scripts for computing various biogeographic indices (Sørensen and Simpson).
- Includes scripts for mapping, clustering, boundary determination, spatial correlations, and statistical models (HGLM).
- Example scripts:
- `2a_mapping_phyloregions_present.R`: Maps present-day phyloregions.
- `12a_optimal_clusters_present.R`: Determines optimal clusters for present conditions.
-...,