Mapping temporal changes in landscape spatial heterogeneity using the contrast weighted edge density index

Abstract

The aim of this study is to map and analyze the temporal changes in the landscape structural heterogeneity over the past 40 years in a brutian pine (Pinus brutia Ten.) dominated forest area in the Mediterranean region of Turkey. The change detection analysis was done based on two forest stand maps belonging to 1966 and 2006 years. We used the Contrast Weighted Edge Density Index (CWEDI) for quantifying landscape structural heterogeneity. The study area was converted to 500 x 500 m grid cells and then a CWEDI value was calculated for each cell. The temporal differences were determined by subtracting the cell values in the heterogeneity map of 2006 year from the corresponding cell values in the map of 1966 year. In the change map, we perceived that the changes in 24% of the area (2364.93 ha) resulted from the management activities. The changes in the rest of study area (7471.75 ha) might occur due to other factors except management activities such as the natural growth in the stands or the photo-interpretation differences between the two measurement times. The study results show that the even-aged management has promoted the artificial edges between brutian pine stands with different ages while it has reduced the natural edges. Although the patchiness generated by the wood-oriented management may positively affect edge-dwelling species, it may have negatively influences on edge-sensitive species. As a result, a biodiversity-friendly forest management strategy should be developed to maintain a good balance between wood production and non-wood forest values in the brutian forests.