What are the key factors influencing the dynamics of forest edge? An application of a new forest edge index in the southeast of China

Abstract

Recent reforestation programs have led to significant increases in forest cover in China; however, they have not been able to halt the process of forest fragmentation. The dynamics of forest fragmentation are still unknown, especially the transitions among forest core (FC), forest edge (FE), and non-forest areas. Taking Fujian Province in southeast China as a case, a new FE index (FEI) was proposed to identify FE, FC, forest patch (FP), matrix edge (ME), matrix core (MC), and forest perforation (FPe) as well. Then the transitions among FC, FE, and non-forest areas was explored; a series of logistic regression models were developed to examine the internal and external, static and dynamic driving patterns of the FE dynamics. The results revealed that the FEI outperforms conventional landscape metrics in identifying FE areas. During the period from 2000 to 2020, FE constituted approximately 41% of the study area. Frequent transition dynamics were observed between FE and other landscape types, accounting for 22% and 19% of the study area during 2000–2010 and 2010–2020, respectively. The internal driving models demonstrated that various landscape types exerted a negative influence on FE expansion. Among these, FPe emerged as a dominant factor, followed by MC, FC, and ME. The external models highlighted the significant influence of elevation, average annual temperature, distance from road, and slope on the mutual transition between FC and FE, while aspect and GDP influenced greatly on the transition from matrix to FE. These findings deepen the understanding of forest fragmentation dynamics and provide valuable insights for forest management.