jessa-porifera / species-distribution-ml-maxent

R Script for investigating past and present species distribution using MaxEnt (machine learning algorithm) and Environmental PCA (PCA-env) for niche dynamics of the species

Master thesis

<The impact of climate change on plant distribution and niche dynamics over the past 250 years in Switzerland>

file created by Jessica Wang, 05.12.2022, last edit 05.12.2022

R Script for investigating past and present species distribution using MaxEnt (machine learning algorithm). As a part of my master thesis, I analyzed past (1768-1950) and present (1950- mid 2022) plant species distribution to investigate the relationship between climatic changes and species distribution in Switzerland.

Table of contents

<The data and scripts attached here are for everyone's use. Do not hesitate to contact Jessica Wang via E-Mail ([email protected]) if there are any questions.>

• "README.txt" : this file

• scripts : Two scripts are available. One for the distribution mapping with MaxEnt (name: MaxEnt_Script), the other for the niche dynamics using PCA-env (name: nichedyn_Script). They are two independent, separate analyses using the same dataset.

• data :

  • all_data_every_century.txt : herbarium records from Jessica Wang and InfoFlora (see "origin" column)
  • climate data from Noemi Imfeld and Stefan Brönnimann from the Institute of Geography at University of Bern. Please ask them directly. It is an unpublished data set that they are currently working on (last update June 2022).

• Remarks: the data set "all_data_every_century.txt" has been split into two time periods (before 1950 and after 1950) for the MaxEnt analysis and for the niche dynamics plots using PCA-env.

• dataset

• all_data_every_century : all herbarium records (from Jessica and Infoflora)