Phenols in Leaves and Bark of Fagus sylvatica as Determinants of Insect Occurrences

Beech forests play an important role in temperate and north Mediterranean ecosystems in Greece since they occupy infertile montane soils. In the last glacial maximum, Fagus sylvatica (beech) was confined to Southern Europe where it was dominant and in the last thousand years has expanded its range to dominate central Europe. We sampled four different beech forest types. We found 298 insect species associated with beech trees and dead beech wood. While F. sylvatica and Quercus (oak) are confamilial, there are great differences in richness of the associated entomofauna. Insect species that inhabit beech forests are less than one fifth of those species living in oak dominated forests despite the fact that beech is the most abundant central and north European tree. There is a distinct paucity of monophagous species on beech trees and most insect species are shared between co-occurring deciduous tree species and beech. This lack of species is attributed to the vegetation history and secondary plant chemistry. Bark and leaf biophenols from beech indicate that differences in plant secondary metabolites may be responsible for the differences in the richness of entomofauna in communities dominated by beech and other deciduous trees

Current Wildland Fire Patterns and Challenges in Europe : A Synthesis of National Perspectives

Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by national representatives, supplemented by national fire statistics (2009-2018) across Europe. For each of the 31 countries included, we present a perspective authored by scientists or practitioners from each respective country, representing a wide range of disciplines and cultural backgrounds. The authors were selected from members of the COST Action "Fire and the Earth System: Science & Society" funded by the European Commission with the aim to share knowledge and improve communication about wildland fire. Where relevant, a brief overview of key studies, particular wildland fire challenges a country is facing, and an overview of notable recent fire events are also presented. Key perceived challenges included (1) the lack of consistent and detailed records for wildland fire events, within and across countries, (2) an increase in wildland fires that pose a risk to properties and human life due to high population densities and sprawl into forested regions, and (3) the view that, irrespective of changes in management, climate change is likely to increase the frequency and impact of wildland fires in the coming decades. Addressing challenge (1) will not only be valuable in advancing national and pan-European wildland fire management strategies, but also in evaluating perceptions (2) and (3) against more robust quantitative evidence.Peer reviewe

Limits to reproduction and seed size-number trade-offs that shape forest dominance and future recovery

International audienceThe relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundation for assessing fitness in forest trees. Four major findings emerged. First, seed production is not constrained by a strict trade-off between seed size and numbers. Instead, seed numbers vary over ten orders of magnitude, with species that invest in large seeds producing more seeds than expected from the 1:1 trade-off. Second, gymnosperms have lower seed production than angiosperms, potentially due to their extra investments in protective woody cones. Third, nutrient-demanding species, indicated by high foliar phosphorus concentrations, have low seed production. Finally, sensitivity of individual species to soil fertility varies widely, limiting the response of community seed production to fertility gradients. In combination, these findings can inform models of forest response that need to incorporate reproductive potential

Limits to reproduction and seed size-number tradeoffs that shape forest dominance and future recovery

The relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundation for assessing fitness in forest trees. Four major findings emerged. First, seed production is not constrained by a strict trade-off between seed size and numbers. Instead, seed numbers vary over ten orders of magnitude, with species that invest in large seeds producing more seeds than expected from the 1:1 trade-off. Second, gymnosperms have lower seed production than angiosperms, potentially due to their extra investments in protective woody cones. Third, nutrient-demanding species, indicated by high foliar phosphorus concentrations, have low seed production. Finally, sensitivity of individual species to soil fertility varies widely, limiting the response of community seed production to fertility gradients. In combination, these findings can inform models of forest response that need to incorporate reproductive potential

ECOPHYSIOLOGY OF THE POSTFIRE REGENERATION OF ALEPPO PINE (PINUS HALEPENSIS)

ΣΚΟΠΟΣ ΤΗΣ ΔΙΔΑΚΤΟΡΙΚΗΣ ΔΙΑΤΡΙΒΗΣ ΕΙΝΑΙ Η ΟΙΚΟΦΥΣΙΟΛΟΓΙΚΗ ΜΕΛΕΤΗ ΤΗΣ ΦΥΣΙΚΗΣ ΑΝΑΓΕΝΝΗΣΗΣ ΤΩΝ ΠΕΥΚΟΔΑΣΩΝ (PINUS HALEPENSIS) ΜΕ ΕΜΦΑΣΗ ΣΤΑ ΠΡΩΤΑ ΣΤΑΔΙΑ ΤΗΣ ΜΕΤΑΠΥΡΙΚΗΣ ΔΙΑΔΟΧΗΣ. ΣΕ ΠΕΝΤΕ ΠΡΟΣΦΑΤΑ ΚΑΜΕΝΑ ΠΕΥΚΟΔΑΣΗ ΤΗΣ ΑΤΤΙΚΗΣ ΜΕΛΕΤΗΘΗΚΕ Η ΜΕΤΑΠΥΡΙΚΗ ΕΜΦΑΝΙΣΗ, Η ΠΥΚΝΟΤΗΤΑ, Η ΕΠΙΒΙΩΣΗ, Η ΘΝΗΣΙΜΟΤΗΤΑ, Η ΧΩΡΟΔΙΑΤΑΞΗ ΚΑΙ Η ΑΥΞΗΣΗ ΑΡΤΙΒΛΑΣΤΩΝ ΧΑΛΕΠΙΟΥ ΠΕΥΚΗΣ. ΕΠΙΣΗΣ ΔΙΕΡΕΥΝΗΘΗΚΕ Η ΕΔΑΦΙΚΗ ΚΑΙ Η ΥΠΕΡΓΕΙΑ ΣΠΕΡΜΑΤΙΚΗ ΤΡΑΠΕΖΑ ΣΕ ΚΑΜΕΝΑ ΚΑΙ ΑΚΑΥΤΑ ΠΕΥΚΟΔΑΣΗ, ΑΝΤΙΣΤΟΙΧΑ. Η ΕΜΦΑΝΙΣΗ ΤΩΝ ΑΡΤΙΒΛΑΣΤΩΝ ΠΕΥΚΟΥ ΠΡΑΓΜΑΤΟΠΟΙΗΘΗΚΕ ΚΑΤΑ ΚΑΝΟΝΑ ΣΕ ΕΝΑ "ΚΥΜΑ" (80-90% ΤΟΥ ΣΥΝΟΛΙΚΟΥ ΠΛΗΘΥΣΜΟΥ), ΧΡΟΝΙΚΗΣ ΔΙΑΡΚΕΙΑΣ 2-3 ΜΗΝΩΝ, ΑΜΕΣΩΣ ΜΕΤΑ ΤΗΝ ΕΝΑΡΞΗ ΤΗΣ ΠΡΩΤΗΣ ΜΕΤΑΠΥΡΙΚΗΣ ΒΡΟΧΕΡΗΣ ΠΕΡΙΟΔΟΥ. Η ΠΥΚΝΟΤΗΤΑ ΕΜΦΑΝΙΣΕ ΜΕΓΙΣΤΗ ΤΙΜΗ (3-5 ΑΤΟΜΑ/M2) ΤΟΥΣ ΠΡΩΤΟΥΣ ΜΕΤΑΠΥΡΙΚΟΥΣ ΧΕΙΜΕΡΙΝΟΥΣ ΜΗΝΕΣ ΕΝΩ "ΔΡΑΜΑΤΙΚΗ" ΗΤΑΝ Η ΕΛΑΤΤΩΣΗ ΤΗΣ ΤΟ ΑΚΟΛΟΥΘΟ ΘΕΡΟΣ. ΤΟ ΔΕΥΤΕΡΟ ΜΕΤΑΠΥΡΙΚΟ ΕΤΟΣ Η ΠΥΚΝΟΤΗΤΑ ΕΜΦΑΝΙΣΕ ΣΤΑΘΕΡΟΠΟΙΗΤΙΚΗ ΤΑΣΗ, ΦΘΑΝΟΝΤΑΣ ΤΑ 1.3-3 ΑΤΟΜΑ/M2, ΤΙΜΗ ΙΚΑΝΟΠΟΙΗΤΙΚΗΓΙΑ ΤΗ ΜΕΛΛΟΝΤΙΚΗ ΣΥΓΚΡΟΤΗΣΗ ΠΟΛΥ ΠΥΚΝΟΥ ΠΕΥΚΟΔΑΣΟΥΣ. Η ΘΝΗΣΙΜΟΤΗΤΑ ΤΩΝ ΑΡΤΙΒΛΑΣΤΩΝ ΕΜΦΑΝΙΣΕ ΔΥΟ ΜΕΓΙΣΤΑ: ΚΑΤΑ ΤΟΥΣ ΠΡΩΤΟΥΣ ΜΕΤΑΠΥΡΙΚΟΥΣ ΧΕΙΜΕΡΙΝΟΥΣ ΜΗΝΕΣ (ΚΡΙΣΙΜΟ ΣΤΑΔΙΟ ΤΗΣ ΕΓΚΑΤΑΣΤΑΣΗΣ ΑΡΤΙΒΛΑΣΤΩΝ) ΚΑΙ ΚΑΤΑ ΤΗ ΔΙΑΡΚΕΙΑ ΤΗΣ ΠΡΩΤΗΣ, ΜΕΤΑ ΑΠΟ ΤΗ ΦΩΤΙΑ, ΞΗΡΗΣ ΠΕΡΙΟΔΟΥ. Η ΧΑΛΕΠΙΟΣ ΠΕΥΚΗ ΣΥΓΚΡΟΤΕΙ ΜΟΝΙΜΗ ΥΠΕΡΓΕΙΑ ΤΡΑΠΕΖΑ ΣΠΕΡΜΑΤΩΝ ΣΤΗΝ ΚΟΜΗ ΤΩΝ ΔΕΝΔΡΩΝ, ΔΙΑΤΗΡΩΝΤΑΣ ΚΛΕΙΣΤΟ ΣΗΜΑΝΤΙΚΟ ΠΟΣΟΣΤΟ (35-85%) ΤΗΣ ΕΤΗΣΙΑΣ ΠΑΡΑΓΩΓΗΣ ΚΩΝΩΝ. ΑΝΤΙΘΕΤΑ Η ΕΔΑΦΙΚΗ ΣΠΕΡΜΑΤΙΚΗ ΤΡΑΠΕΖΑ ΕΜΦΑΝΙΣΕ ΠΑΡΟΔΙΚΟ ΧΑΡΑΚΤΗΡΑ. (ΠΕΡΙΚΟΠΗ ΠΕΡΙΛΗΨΗΣ)THE SUBJECT OF THE PHD THESIS WAS THE ECOPHYSIOLOGICAL STUDY OF THE POSTFIRE REGENERATION OF ALEPPO PINE FORESTS (PINUS HALEPENSIS) WITH EMPHASIS AT THE FIRST STAGE OF THE POSTFIRE SUCCESSION. THE POSTFIRE EMERGENCE, DENSITY, SURVIVAL,MORTALITY, SPATIAL DISTRIBUTION AND GROWTH KINETICS OF ALEPPO PINE SEEDLINGS WERE INVESTIGATED IN FIVE RECENTLY BURNED PINE FORESTS OF ATTICA. IN ADDITION,THE DYNAMICS OF THE CANOPY AND SOIL SEED BANKS WERE STUDIED IN BURNED AND UNBURNED FORESTS, RESPECTIVELY. SEED GERMINATION AND SEEDLING EMERGENCE OCCURREDMASSIVELY IN A SINGLE "WAVE" (80-90% OF THE TOTAL COHORT), THAT LASTED 2-3 MONTHS, IMMEDIATELY AFTER THE ONSET OF THE FIRST POSTFIRE WINTER MONTHS. DURING THE FOLLOWING SUMMER MONTHS A "DRAMATIC" DECREASE OF SEEDLING DENSITY WAS OBSERVED. IN THE SECOND POSTFIRE YEAR ALEPPO PINE SEEDLING DENSITY TENDS TO STABILISE, REACHING AT 1.3-3 SEEDLINGS/M2, A SATISFACTORY VALUE FOR THE FUTURE ESTABLISHMENT OF A VERY DENSE FOREST. THE STUDY OF SEEDLING MORTALITY REVEALED TWOPEAKS: AT THE CRITICAL STAGE OF THE SEEDLING ESTABLISHMENT DURING THE FIRST POSTFIRE WINTER MONTHS AND DURING THE FIRST, CRITICAL FOR SEEDLING SURVIVAL, POSTFIRE SUMMER. PINUS HALEPENSIS CREATES A LONG LIVED SEED BANK ON THE TREE CANOPY. A SIGNIFICANT PERCENTAGE OF THE ANNUAL CONE PRODUCTION (35-85%) IS CHARACTERISED BY A DELAY IN CONE OPENING AND SEED DISPERSAL. ON THE CONTRARY, THE SOIL SEED BANK'S CHARACTER WAS FOUND TO BE TRANSIENT. (ABSTRACT TRUNCATED

Assessment of Herbaceous Plant Composition, Diversity, and Indicator Species in the <i>Juniperus drupacea</i> Forest Openings of the Mountain Parnonas in Greece

A significant challenge in community ecology is the establishment of ecological baselines, which permit the evaluation of the variations in ecological dynamics at different temporal and spatial scales. To our best knowledge, few studies have been conducted in the forest openings of Mt. Parnon to establish a baseline for future monitoring. Hence, a floristic study of the herbaceous plant species composition, diversity, cover, and biomass was conducted in the forest openings of the Mt. Parnon-Natura 2000 Site in Greece to develop an ecological baseline that could be utilized in decision making for conservation and the sustainable use of forest biodiversity and ecosystem services in the forest ecosystem of Mt. Parnon. In the spring season, a thorough floristic survey was performed on Mt. Parnon for two consecutive years, 2021 and 2022. Herbaceous plant composition, diversity, cover, biomass, and plant indicator species (indicator value analysis) in the forest openings of Mt. Parnon were assessed. In the studied area, 63 plant species belonging to 58 genera from 20 families were recorded. The most numerous families were Asteraceae and Poaceae, followed by Fabaceae. Variable plant diversity, herbaceous plant cover, and produced biomass were recorded in different sites. It is noteworthy that some plant species could be regarded as indicators of the sites in the study area [Geranium molle L., Cerastium candidissimum Correns, Vicia villosa Roth, Euphorbia myrsinites L., Odontarrhena muralis (Waldst. & Kit.) Endl., Medicago lupulina L., Lotus corniculatus L., Crepis fraasii Sch. Bip., Bellis sylvestris Cirillo, and Trifolium stellatum L.], and information about these indicators, including Ellenberg type indicator values, is also provided. This study contributes to the understanding of the relevant ecological topics and provides key elements that could be utilized in decision making for the conservation and sustainable use of forest biodiversity and ecosystem services on Mt. Parnon

Impact of regional climatic conditions on tree growth on mainland Greece

Forest growth is commonly used to explore tree vitality and ability to resist to environmental changes or climatic fluctuations. This paper illustrates and examines how regional climatic conditions can be related to the decline of tree growth, which were found to be more distinct in Quercus frainetto Ten. (Hungarian oak) and Fagus sylvatica L. (European beech) and less pronounced in Abies borissi-regis Matt f. (Bulgarian fir) on three long-term intensive monitoring plots (ICP Forests-Level II) in Greece during the period 1996–2009. Relative basal area increment and volume increment were calculated, expressing tree growth in terms of mean relative annual periodic increment. A decline in the growth of basal area and volume was observed after hot and dry periods, where annual temperatures and precipitation were far from the mean of the analyzed period. This observation was statistically confirmed in oak and beech plots regarding summer precipitation only and are in agreement with the findings of previous studies in Europe. The representativeness of the results at a national scale needs further investigation, although our results provide a good basis for further and more intensive monitoring programs to address various forest management scenarios against the background of potential climatic changes in the Mediterranean area

Effect of Seedling Provenance and Site Heterogeneity on Abies cephalonica Performance in a Post-Fire Environment

Reforestation constitutes a challenge in post-fire ecosystem restoration, although there are limitations such as species and genotype selection, planting and management design, and environmental conditions. In the present study, the basic issue is the longevity of Abies cephalonica Loudon—the Greek fir seedlings planted extensively in Parnitha National Park (Central Greece), located near the metropolitan city of Athens, following the large-scale wildfire of 2007. Seedling performance was assessed for a 3-year monitoring period (2013–2015) through the establishment of 8 permanent transects, including 400 seedlings at the burned, reforested sites. According to the long-term reforestation project, two seedling provenances were used: (a) from Mt. Mainalon (South Greece, Vytina provenance) and (b) the local one from Mt. Parnitha. Both provenances showed a relatively successful survival rate reaching, in average, 73.8%, with the first summer after planting being crucial for seedling survival. The overall mean seedling height was 39.2 ± 1.1 cm, with a mean crown diameter of 47.3 ± 1.4 cm in the last monitoring survey. Although Parnitha seedlings seem to perform better in terms of growth, seedling performance in both provenances was affected by reforestation site characteristics, mainly altitude and aspect. Approximately one third of seedlings exhibited damage in their crown architecture (29.8%), while apical bud damage was less extensive (12.2%) in the final field measurement. Data indicate that seedling performance has proved to be quite promising for post-fire restoration, although long-term monitoring data should be considered

Potential and Constraints on In Vitro Micropropagation of <i>Juniperus drupacea</i> Labill.

Juniperus drupacea Labill. (Cupressaceae) is a species with ecological and medicinal value. In Europe, it is native only in southern Greece, and is listed as endangered. Due to its uniqueness, this study attempted, for the first time, an in vitro propagation effort of Syrian juniper. Explants of the lateral shoot tips were surface-sterilized and cultured on Murashige and Skoog (MS) medium. The cultures were subcultured on MS, woody plant medium (WPM), and Driver and Kuniyaki Walnut (DKW) supplemented with different concentrations of 6-benzylaminopurine (BA), thidiazuron (TDZ), or meta-topolin [6-(3-hy-droxybenzylamino)purine] for shoot induction. Explants derived from female trees exhibited 54.17% bud proliferation on DKW medium with 4 μM meta-topolin or 4 μM TDZ and on WPM with 4 μM meta-topolin or 4 μM BA. A total of 62.50% of the male tree derived explants produced multiple shoots on DKW with 4 μM BA. The maximum average number of shoots per explant were 1.17 per explant in both cases. The length of the shoot derived from explants of female origin was 2.94 mm compared to 2.69 mm of the in vitro shoots from the explants of male trees. Overall, the best medium and plant growth regulator combination for the explants derived from both female and male trees, for the traits under study, was proven to be DKW + 4 µM TDZ. Our experiments show that Juniperus drupacea, under in vitro conditions, shows recalcitrance in rooting, as the applications of IBA, NAA, and IAA concentrations were proven to be ineffective treatments. Although the results show low values, this avant-garde study provides a foundation for further research on the in vitro regeneration of Juniperus drupacea

Current Wildland Fire Patterns and Challenges in Europe : A Synthesis of National Perspectives

Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by national representatives, supplemented by national fire statistics (2009–2018) across Europe. For each of the 31 countries included, we present a perspective authored by scientists or practitioners from each respective country, representing a wide range of disciplines and cultural backgrounds. The authors were selected from members of the COST Action “Fire and the Earth System: Science & Society” funded by the European Commission with the aim to share knowledge and improve communication about wildland fire. Where relevant, a brief overview of key studies, particular wildland fire challenges a country is facing, and an overview of notable recent fire events are also presented. Key perceived challenges included (1) the lack of consistent and detailed records for wildland fire events, within and across countries, (2) an increase in wildland fires that pose a risk to properties and human life due to high population densities and sprawl into forested regions, and (3) the view that, irrespective of changes in management, climate change is likely to increase the frequency and impact of wildland fires in the coming decades. Addressing challenge (1) will not only be valuable in advancing national and pan-European wildland fire management strategies, but also in evaluating perceptions (2) and (3) against more robust quantitative evidence