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Pinus nigra (black pine) is an ecologically and economically important species widely distributed around the Mediterranean Basin. P. nigra ecosystems have recently been affected by high severity fires occurring over the mountainous forest ecosystems of Southern Europe. The aim of this study is to investigate the post-fire regeneration patterns of black pine after a high severity crown fire which occurred on Mt Taygetos in Southern Greece. A network of 18 sites was selected to study black pine natural post-fire regeneration. Regeneration density was higher at the edges of patches that have remained unburned within the periphery of fire (0.406 individuals/m2) as compared to isolated burned areas (0.007 individuals/m2) although a significant between sites heterogeneity was recorded. Boosted regression trees analysis was used to explore the effects of environmental and microhabitat variables on black pine post-fire regeneration. The number of fires a site has experienced had a negative effect on regeneration density, while the presence of recovering ferns had a positive effect. The most important variable related to the black pine post-fire regeneration was distance from unburned patches. The result of the current study substantiates the importance of maintaining fire-resistant stands with large trees that are more likely to survive after a surface fire and which can also serve as seed sources for the recolonization of the burned area after severe crown fires.

In the past few decades there is an increasing trend of both fire activity and area burned in many regions of the world. Moreover, there is a worldwide concern regarding the increasing presence of crown fires in forest types that were historically prone to surface fires. Among the recently affected mountainous forest ecosystems are those of Pinus nigra, an ecologically and economically important species that is widely distributed around the Mediterranean Basin. Mount Taygetos, a mountainous landscape in Peloponnese, Greece, that was severely burned in 2007, was selected to carry out the first landscape-scale fire history reconstruction in P. nigra of the eastern Mediterranean. The aims of the study were to investigate whether fire-regime attributes can be reconstructed from fire-scarred trees and also to examine the consistency of fire occurrence and spatial extent through time within the area selected. Partial cross-sections were sampled within the perimeters of the more recent known large fires in the region, those of 2007 and 1998. The overall mean fire interval between 1845 and 2007 was 4.9 years, while for the larger fires this time window was 16.2 years. Even at the individual-sample scale, with the sample mean fire interval equaling 29.5 years, the fire frequency still falls within the range of the ‘‘predictable stand-thinning fire’’ regime. The majority of fire scars recorded were dated to the warm and dry season of summer to fall. During the last 165 years of fire reconstruction, neither fire frequency nor percentage of trees scarred by fires varied significantly. Nevertheless, the size of the area burned as well as the type of fire seem to have changed, with the 2007 event being the most extended crown fire encountered so far. Our study has provided additional evidence that P. nigra is indeed a fire-resistant tree species provided that it is exposed to surface fires, even if they are recurrently occurring. Shifts from this pattern may lead to local extirpation of the species, as in the case of severe and extended crown fires.

Patterns of Abies cephalonica Loudon seedling recruitment at its westernmost geographical limit (western Greece), were studied by monitoring their emergence, survival, and establishment for up to four years in the microhabitats to which seeds are dispersed. Seedlings were monitored on 200 permanent sampling plots established in 11 different locations covering the entire strictly protected Mount Aenos National Park (Cephalonia). Annual seedling mortality rate was estimated in relation to habitat characteristics as well as to their number of cotyledons. A. cephalonica presented the typical behaviour of a masting species in the number of seedlings produced over the four years of study. Of the habitat characteristics studied, ground cover, elevation, soil depth, slope and canopy openness were the main parameters that classified seedling habitat with respect to their emergence. Seedling survival was higher in years of low seedling production. Seedlings with higher cotyledon numbers exhibited higher survival. Our data indicate that A. cephalonica is characterized by remarkable reproductive plasticity, which is expressed in the number of seedlings produced each year and those surviving with respect to its habitat characteristics. Preserving the species implies preserving its habitat. In this sense, Mount Aenos National Park may be the most important protected area for the endemic fir in view of preserving its integrity through pre-emptive management, in the light of current and future threats.

The long-term post-fire development of evergreen sclerophyllous shrub biomass was studied along a chronosequence of Pinus halepensis stands. These shrubs are regarded as the most important component of the understorey vegetation concerning the Mediterranean coniferous forests in question. Eighteen (18) forest stands of different post-fire age were selected for sampling in the Attica region (Central Greece) and the neighbouring island of Evia. Most of the forest stands were re-sampled for two to four consecutive years, depending on their post-fire age, since younger stands change more rapidly, and on the time available for this task. In every stand, the total cover and maximum height of evergreen sclerophyllous shrubs were recorded. Measurements were carried out within three 10x1 m randomly established plots. Each plot was divided into ten (10) 1x1 m quadrats. Thus, there were 30 quadrats per forest stand. Using two published regression equations, with the product of shrub height with the square of cover as the independent variable, the total understorey fuel load (TLOAD) and the “active” fuel load (ALOAD) for fire modelling purposes were calculated. It was shown graphically and through regression analysis that, at least in Central Greece, there are two distinct types of Pinus halepensis forest stands in regard to the understorey vegetation. The first (type 1) is characterized by the dominance of evergreen sclerophyllous shrubs in the understorey, with a shrub cover of 50-80%. In the other (type 2), the cover of such shrubs is much lower, usually

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