Temporal Change in Fragmentation in China’s Primary Forest Ecoregions

Forests are of interest from a wide range of perspectives simply because they serve many purposes, including timber products, watershed protection, wildlife habitat, carbon sequestration, recreational opportunities and aesthetic values. However, degradation or changes in forest ecosystem function and condition arise from changes in forest loss and fragmentation. In this study, based on the 1995 and 2005 land use/cover data for China, mathematical morphology coupled with the percolation theory was adopted to temporally assess changes in forest fragmentation patterns in 36 forest ecosystems of China through classifying each forest pixel into one of the six fragmentation components (interior, perforated, patch, edge, transitional and undetermined) by using the sliding window analysis technique to establish spatially explicit forest fragmentation maps. Additionally, landscape indices were also involved in the assessment of forest fragmentation status and trends. Results revealed that an accelerated fragmentation was observed in most forest ecoregions, especially in Daurian forest stepp, Hainan Island monsoon rain forests, and Northern Indochina subtropical forests with a sharp change in fragmentation patterns. The increased fragmentation was evidenced by a decreasing share of interior forest and an increasing trend of area share for perforated forest, patch forest and edge forest. In addition, derivations of geospatial indices from another three selected typical forest ecoregions also further confirmed the accelerated fragmentation. The increased fragmentation in most forest ecoregions of China was primarily driven by anthropogenic disturbances, including illegal logging, agricultural encroachment, infrastructure construction. Additionally, forest fragmentation maps provided valuable insights and implications regarding the development of land use strategies, habitat planning for rare and endangered species, and sustainable forest management. By utilizing the changes in fragmentation maps, such as the variation in location of the interior and perforated components, human can make effective risk assessments and crucial targets for protection and remediation.