scl.subset: Create a subset for scale cells
In akeyel/spatialdemography: A Spatially Explicit Metacommunity Model

Select just a particular value of an environmental layer for evaluating biodiversity metrics

1	scl.subset(scale.cells.lst, landscape.identifiers, landscape)

`scale.cells.lst`	In this case, a text field with three parts. The first part is the word subset, the second part is the landscape.identifier to select the landscape layer, and the third part is the target value from that landscape layer
`landscape.identifiers`	A vector of landscape.identifiers
`landscape`	The landscape consisting of environmental layers