Roads increase woody cover under varying geological, rainfall and fire regimes in African savanna

摘要: Roads extend throughout savannas, yet few studies have quantified their effects on adjoining woody vegetation structure. Airborne LiDAR imagery collected over 168 experimental fire plots in the Kruger National Park, all bounded by graded firebreak roads, provided an opportunity to study if, and what extent, roads influence structure under different rainfall, geologic conditions. In 91.7% of plots, canopy cover was higher edges compared areas farther away. The increase most pronounced within 5 m road edge, but detectable 10–15 m from edge. On average, area 15 m had approximately 6% 2% than further edge wetter granitic drier basaltic savanna landscapes, respectively. Increased were observed even exclusion suggesting that non-fire processes, likely altered hydrological regimes, may be underlying reason for encroachment. This illustrates cause selective plant thickening without management, therefore careful consideration should paid how are managed when planned.