Reproducible workflow in R for measuring ecological connectivity in urban areas.

Here you will find a collection of R scripts, functions and tutorials for calculating an ecological connectivity index based on "effective mesh size", a geometric measure of connectivity developed by Jochen Jaeger (2000), see also Spanowicz & Jaeger 2019. This method has also been used by (Deslauriers et al. 2017) in the development of the City Biodiversity Index #2.

Here we present a set of R functions that can be used to compute effective mesh size in urban areas. These functions all require installation of the sf package (more information about sf here). The functions were developed using sf version 0.9.3.

The workflow requires three main data inputs:

• A spatial polygon file that represents available habitat
• A spatial polygon file that repesents any barriers to movement
• A threshold distance (in metres) that represents how close habitat patches need to be to each other to be considered "connected"

For an example of how this method has been applied in a real-life urban planning scenario in the City of Melbourne you can download this report.

For scripts relating to the "Nature-based solutions for urban biodiversity: spatial targeting of retrofits can multiply ecological connectivity benefits" see the folder here. You can follow this workflow for an example of how to calculate the existing connectivity in a landscape and how to measure change in connectivity under different design scenarios.

All the main functions for calculating effective mesh size can be found in the connectFunctions file in the R folder

A demonstration workflow with a tutorial coming soon!