Table 1. Comparison of three PLC indices

Index	What it measures	Analytical level	Value range	Variables in this study	Interpretation
Aggregation index (AI)	Degree to which cells of the same land cover class are spatially adjacent	Class level	0%–100%	AI_G, AI_Y, AI_Gr, AI_B	Higher = clumped; Lower = fragmented
Mean contiguity index (CONTIG_MN)	Internal connectedness and form coherence of cells within each patch	Patch level, averaged to class	0–1	CONTIG_MN_G, CONTIG_MN_Y, CONTIG_MN_Gr, CONTIG_MN_B	Higher = compact, coherent patches; Lower = elongated or fragmented
Contact length (CL)	Length of shared boundary between two land cover classes	Class-pair level	≥ 0 m	CL_GY, CL_GG, CL_GB	Longer = more extensive contact between cover types