2 Introduction
2.1 What is connectivity?
Landscape connectivity represents the degree to which landscape composition (including both native (i.e., natural) and anthropogenic (i.e., human-caused) disturbances) and configuration impact the ability of organisms to move between suitable habitat patches (Taylor et al. 1993; Blake 2018).
2.2 How can it be measured?
There are three main approaches for quantifying landscape connectivity (Calabrese and Fagan 2004):
Structural connectivity: This can be determined from physical attributes in the landscape, and based on maps alone (i.e., without reference to movement behaviour of a single species).
Potential functional connectivity: This is determined using assumptions on organismal movement behaviour (e.g., by mapping a single species’ habitat and setting dispersal thresholds).
Actual functional connectivity: This is determined using observed data (e.g., species occupancy, radio tracking, mark-recapture, or molecular genetic data), which reflect actual rates of the exchange of organisms (or genes) among habitat patches.
The Equivalent Connected Area (ECA; structural connectivity) index was selected as the metric for the Landscape Connectivity indicator. Landscape connectivity was calculated for three broad habitat types: Upland Forest, Lowland Forest, and Grass-Shrub. We also aggregated the three habitat classes to create a composite indicator of landscape connectivity.