Post-fire recovery of Abies cephalonica forest communities: the case of Mt Parnitha National Park, Attica, Greece

Abstract

Mountain coniferous forests of Southern Europe seem to be increasingly affected by large fires. Endemic Greek fir (Abies cephalonica) forests were among the most affected ecosystems by the 2007 extreme wildfires in Greece. The aim of this study is to investigate the pattern of post-fire regeneration of fir forest plant communities of Mount Parnitha National Park, in Attica (Greece), after a large wildfire. A network of 8 severely burned sites across the mountain ridge was established in order to monitor natural regeneration of A. cephalonica as well as post-fire floristic composition and species richness. Field campaigns took place in two distinct time periods, one close to the fire event and one 8 to 10 years after. Generalized linear models were used to explore the effects of distance and microhabitat variables on the post-fire regeneration of the Greek fir. Distance from the unburned patches, slope and cover of woody species significantly affected A. cephalonica seedling establishment and hence its natural post-fire regeneration. Floristic composition and plant species richness of the recovering fir communities changed through time. During the initial phase, high species richness was recorded, mainly because of the high contribution of herbaceous species. During the second period, species richness was lower and similar to that recorded in the unburned fir communities. It is during this period when the first seedlings of the Greek fir managed to establish, although their density is rather low to ensure full recovery of the forest.

Determination of the Environmental Factors that Affect the Growth and Survival of Greek Fir Seedlings

“…The species is susceptible to fire and natural regeneration cannot lead to a recovery of the forest [3][4][5]. Fir is shade tolerant and regenerates poorly in open sites.…”

Assessing the impact of different landscape features on post-fire forest recovery with multitemporal remote sensing data: the case of Mount Taygetos (southern Greece)

“…The nature of this transition depends on the dominant tree species before the fire event, as well as on the spatial configuration of the burned area. For both conifer species (Pinus nigra and Abies cephalonica), distance from unburned patches with mature trees that can contribute to the post-fire forest recovery through seed dispersal is of paramount importance after high-intensity crown fires (Ordóñez et al 2006;Christopoulou et al 2014Christopoulou et al , 2018Raftoyannis and Spanos 2015). Black pine, in contrast to Greek fir, can withstand low-intensity surface fires, owing to its thick bark (Tapias et al 2001(Tapias et al , 2004Pausas et al 2008).…”

“…These patches could contribute to post-fire Greek fir recovery through seed dispersal to the burned areas and subsequent seed germination (Arianoutsou et al 2010). In such cases, provided that the distance from the unburned mature Greek fir stands is less than 100 m, there is a chance of A. cephalonica regeneration (Christopoulou et al 2018). Nevertheless, even in these cases, post-fire recovery of Greek fir is expected to be a lengthy process (Ganatsas et al 2012;Christopoulou et al 2018).…”

“…In such cases, provided that the distance from the unburned mature Greek fir stands is less than 100 m, there is a chance of A. cephalonica regeneration (Christopoulou et al 2018). Nevertheless, even in these cases, post-fire recovery of Greek fir is expected to be a lengthy process (Ganatsas et al 2012;Christopoulou et al 2018). Another factor that may affect the total seed availability for the Greek fir is its masting behaviour, expressed with high interannual variability in the number of adult trees bearing cones, as well as in cones produced per tree and viable seeds per cone (Politi et al 2011), The lack of suitable microhabitats for seedling establishment in the post-fire open habitat may further limit Greek fir post-fire recovery (Ganatsas et al 2012;Raftoyannis and Spanos 2015;Christopoulou et al 2018), as has also been found for other fire-sensitive conifer species (e.g.…”

“…Ground-truth data for training remotely sensed vegetation classification were obtained from field measurements performed in June 2016. A field campaign was organised 8 years after the fire event, allowing enough time to detect any potential natural regeneration of A. cephalonica that might have taken place since the fire (Christopoulou et al 2018). Twenty-five sampling plots of 10 Â 10 m 2 were established in the forest vegetation types identified within the periphery of the 2007 fire event.…”