Table 2 Selection of landscape pattern indices and their ecological significance

Patch type level

Patch Number

(NP)

Indicates the total number of patches in the landscape, related to landscape fragmentation; higher values indicate higher fragmentation

Patch Density

(PD)

Reflects fragmentation of the landscape and the fragmentation degree of a certain type; higher density indicates more severe fragmentation

Largest Patch Index (LPI)

Indicates the influence of the largest patch on the entire type or landscape; its value change can reflect the variation in human disturbance intensity

Landscape Shape Index (LSI)

Reflects the complexity of patch shapes in the landscape pattern; higher values indicate greater complexity

Aggregation Index (AI)

Reflects the aggregation degree of each attribute grid in raster format data, assessing the connectivity between patches of each landscape type

Patch Density

(PD)

Reflects the overall heterogeneity and fragmentation of the landscape; higher density indicates more severe fragmentation

Interspersion & Juxtaposition Index

(IJI)

Measures the overall distribution and adjacency of patch types

Division Index

(DIVISION)

Assesses the degree of separation of the same patch type, with smaller values indicating greater dispersion

Landscape type

level

Total Edge Contrast Index

(TECI)

Describes the contrast of landscape boundaries, with higher contrast approaching

Contagion Index (CONTAG)

Describes the degree of non-randomness or aggregation of different patch types in a landscape

Fragmentation Degree

(SPLIT)

Quantifies the fragmentation level of a landscape, with values ≥ 1. Higher values indicate greater fragmentation

Shannon's Evenness Index

(SHEI)

Represents the evenness of distribution across different landscape types

Shannon's Diversity Index

(SHDI)

Reflects landscape diversity, where higher values indicate richer diversity