Post‐fire regeneration inMediterranean reforested sites as affected by mechanical site preparation: lessons for restoration

Abstract

Question The importance of silvicultural site preparation techniques in determining vegetation succession is increasingly recognized. We studied the effects of mechanical site preparation (MSP) on post‐fire vegetation regeneration within reforested sites in Mediterranean Israel. Location Upper Galilee region, Israel. Methods Vegetation cover and composition, ruderal species colonization and pine regeneration were monitored in four reforested sites for 3 yr following wildland fires that burned mature Pinus brutia and P. halepensis plantations. In each reforested site, a 50 m × 50 m monitoring area was assigned and measurements were conducted within five subplots (2 m × 50 m) encompassing three MSP patch types: ploughed patches (P), unploughed patches (UP) and planting mounds (M) that combined ploughing, pit digging and wood‐chip mulching. Results Recovery of vegetation cover (excluding pines) was rapid. The MSP patch type significantly affected vegetation cover in the first spring following the fire: cover was lowest on M, intermediate on P and highest on UP. However, these differences became minor by the third spring following the fire. Total woody species richness was not affected by MSP patch type, although there were minor effects on relative abundance of woody species. Two ruderal species were found, but their abundance became untraceable by the third year. Patterns of MSP effects on pine regeneration were similar for P. halepensis and P. brutia. Density of emerging seedlings of both pine species during the first year following the fire was significantly affected by MSP patch type: lower in P and M than in UP by more than 50% and 90%, respectively. However, emergence and/or survival during the following 2 yr was higher in P and M than in UP, with overall outcome of pine regeneration still about 50% lower in P and M than in UP. Conclusions The MSP treatments had only a minor, short‐term effect on post‐fire regeneration and colonization of vegetation, except for pine recruitment, which was more severely affected.

Post-fire recovery of the plant community in Pinus brutia forests: active vs. indirect restoration techniques after salvage logging

“…Management decisions in favor of recruiting pine plantations, however, may lead to the disruption in the natural recovery process in such forests (Maestre & Cortina 2004, Gómez-Aparicio et al 2009). On the contrary, it is reported that plowing has minor and temporary effects on plant species richness and vegetation cover; however, it negatively affects pine regeneration in Mediterranean pine woodlands (Hibsher et al 2013). As the benefits of planting seedlings offset by its negative effect on the small mammal community in a pine woodland dominated by the non-serotinous species Pinus nigra, it has been suggested that a multi-criteria approach should be implemented before selecting post-fire management practices in such forests (Espelta et al 2003).…”

Managing cattle grazing and overstorey cover for the conversion of pine monocultures into mixedMediterranean woodlands

“…Particularly crucial is the capacity of young recruits to survive the long and dry hot season during the first few years following emergence (Hibsher et al. ; Osem et al. ).…”

“…, ; Hibsher et al. ) in the understorey of the pine plantations, the opportunity for converting these simply structured monocultures into mixed broad‐leaved–conifer woodlands is being seriously considered (Osem et al. ).…”

Vegetation dynamics of managed Mediterranean forests 16 yr after large fires in southeastern Spain

“…However for those variables that did not meet the assumptions of normality of residuals and homogeneity of variance, log‐transformed or rank‐transformed data were used (Conover & Iman ; Hibsher et al. ). The Tukey–Kramer HSD test was used for post‐hoc comparisons.…”