Pirin Mountains in Bulgaria are refuge of endemic Pinus peuce and Pinus heldreichii forests. Due to the steep and long slopes the forests are affected by avalanches and many trees keep record of past avalanche activity in their tree rings.

In our study we use combination of dendrochronology, satellite images and historical aerophotos to study the effects of avalanches on forests in the Bunderitsa valley.

Our findings show that avalanches are the main shaping factor for the structure of forests in the valley followed by fires. Past avalanche activity is responsible for opened long-lasting avalanche tracks in the forests. About 60% of the potential forests (i.e. territories below treeline, outside of avalanche couloirs, streams, rock formations and screes) are strongly affected by avalanches. Of them almost 40% are in avalanche runout zones, 12% are in avalanche tracks in the forests and 48% are forests, which are periodically strongly affected by bigger avalanches. Comparisons of newer satellite images with older aerophotos showed that in the 1970s there were larger openings in the forests due to high frequency of avalanches in the very snowy 1950s and 1960s. Although recent avalanche activity has decreased, there are still years with larger avalanches, which affect forests. In addition, tourist development in vicinity has increased risk for human health and life due to avalanche accidents, including in forests.

Tree-ring analysis allowed reconstructing past avalanches that affected certain areas. The big couloirs are affected by smaller avalanches almost annually, while bigger avalanches have hit the neighboring forests almost every decade. Our findings demonstrate that avalanches in the valley are of high importance and require more attention by authorities both as risk factor for human health and life and as natural disturbance shaping the forest structure and dynamics.

Developing non-destructive indicators from leaf-level hyperspectral reflectance is the first step in mapping endangered tree species in the tropic. Therefore, hyperspectral reflectance at the leaf level was implemented to differentiate 15 tree species from Costa Rica's wet forests. Hyperspectral reflectance (310 to 1100 nm) was evaluated in six individuals per species (30 leaves per individual) in rainy season, in addition, specific leaf area (SLA) and leaf thickness (LT) were evaluated. The data were first analyzed with one-way ANOVA to identify differentiating bands between species. Then, linear discriminant analysis (LDA) was used to classify species and define the degree of similarity; the contribution of each narrow band to the classification was estimated with the absolute value of standardized coefficients associated with the discriminant function (kappa value). Subsequently, it was analyzed whether the SLA or LT correlated with species differentiation. The results showed that wavebands al 350, 700, 750, 780, 790, 800 and 1010 nm were key to differentiating the species, with an average kappa value of 0.88. Furthermore, the correlation of hyperspectral reflectance with SLA and LT was ruled out. Our results suggest differentiating tropical tree species with non-destructive methods, which will facilitate mapping endangered populations and the development of conservation strategies.

Deadwood is a basic component in forest ecosystems, since it supports many ecological and functional roles. The importance of deadwood is recognized by the pan-European criteria, identifying it as an index of sustainable forest management. Currently, its assessment is considered essential for the management of forest resources both in “wild” and in areas managed via “close-to-nature silviculture”, even if also for productive forests the deadwood dynamics are very interesting and more and more studied. Despite the importance of deadwood for assessing the sustainability of forest management, information on this fundamental parameter of forest ecosystems is documented mainly for protected areas, while for managed forests it is much scarcer. Too little is known of the influence that rights of use, by virtue of laws or customary law, have in close-to-nature forest management. The study aims to assess the deadwood in managed beech forests of the National Park of Abruzzo, Lazio and Molise. These forests have an important socio-economic function for inhabitants, that collect deadwood observing the park regulation. The deadwood gradient moving from logging roads was investigated. Three accessibility classes were established, and data analysis has been performed on this classification. The result showed that the accessibility to the forest affects the quantity and the decay class of the deadwood, thus influencing carbon storage. In conclusion, the deadwood removal influences the quantity of deadwood in the forest and the removal is influenced by the distance from the road. The results highlighted useful elements for the active management of the beech forests of the National Park aimed at the conservation and increase of the deadwood component of the mid-mountain forest ecosystems. These findings can also be considered in sustainable forest management, as the practice of collecting deadwood for fuelwood is a social aspect that cannot be forgotten.

Indian sandalwood (Santalum album Linn.), an evergreen tree, indigenous to the Indian peninsula is known for its fragrant heartwood worldwide. Sandalwood plantations are gaining importance throughout the Indian subcontinent demanding large-scale production and the establishment of nurseries with Quality Planting Material (QPM). However, sandalwood seedlings succumb to devastating diseases at nurseries leading to high mortality of the planting stock. Therefore, there is a dire need for the effective management of these diseases. In our study, we isolated and identified phytopathogenic fungi such as Fusarium solani causing wilt disease with seedling mortality of 25 % and Colletotrichum siamense causing anthracnose disease with a disease incidence of 75 %.We identified and characterized a total of 90 fungal endophytic isolates from leaf, stem, and root tissues of disease escaped or apparently healthy seedlings of sandalwood. Total fungal endophytes isolated from the disease escaped sandalwood seedlings comprised 33.3 % Colletotrichum siamense, 26.6% Diaporthe melonis, 13.3% Aspergillus sclerotiorum, 13.3% Fusarium oxysporum, 13.3 Paraphoma radicina, 6.6% Alternaria alternata and 6.6% Pestalotiopsis microspora. Molecular identification using the nuclear ribosomal DNA internal transcribed spacer (ITS) sequences were performed and those species which could not be resolved with ITS sequence were subjected to multi-locus gene (beta-tubulin (TUB2), glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) gene, chitin synthase 1 gene (CHS‐1), actin gene (ACT) and glutamine synthetase (GS) genes) analysis and the sequences were deposited to GenBank. Dual culture test assay revealed that the fungal endophytes Aspergillus sclerotiorum and Diaporthe melonis showed the highest percent inhibition of 63.08% and 61.54%, respectively against Fusarium solani and Diaporthe melonis and Fusarium oxysporum showed highest percent inhibition of 55.38 % and 67.69 % in case of the pathogen Colletotrichum siamense. This study will be useful for the management of seed, soil and airborne pathogens of Indian sandalwood.

Invasive non-native trees (INNTs) are increasingly recognized to have negative effects on biodiversity and ecosystem services in protected areas. The management of INNTs is one of the major challenges to preserving native species and ecosystems, to which more and more efforts and resources are bound to be destined in the coming decades. Indeed, the combining effect of climate change and increasing disturbance factors (e.g. wildfires) is likely to aid the spread of many INNTs in the Mediterranean protected areas, as well as favouring their competitive relationships with native species. However, the effective implementation of control measures is far from being fully achieved. I assessed how the problem of INNTs is currently addressed within the Natura2000 sites in Sicily, designed according to the Habitats Directive (92/43/EEC). In particular, I will check the management plans of some selected Special Areas of Conservation searching for the activities provided for the management and control of INNTs. My research will be focused on the most widespread INNTs occurring on the island, such as Ailanthus altissima and Acacia saligna, along with taxa characterized by a very recent spread such as Parkinsonia aculeata and Vachellia karroo. Furthermore, some of these non-native trees are included in the list of Invasive Alien Species of Union concern pursuant to Regulation (EU) 1143/2014 on invasive alien species. The study will address some main questions: 1) Are invasive non-native trees well managed in protected sites in Sicily?; 2) Do different protected sites deal with the same non-native species in the same way?; 3) Are planned activities effectively implemented and successful? The result of the study could be used to favour the cooperation and exchange of information about the control of INNTs between the managing bodies of different protected sites, thus increasing the efficacy of the necessary interventions.

Mycorrhizas are considered bio-fertilizers that could improve plant growth when seedlings are inoculated. This study assessed how the interactions between chemical fertilization levels and arbuscular mycorrhizal fungus species (AMF) affected the seedling's morphology and physiology traits. In addition, we evaluated the subsequent effect on plant quality of Prosopis alba. The impact on the seedling's growth in the nursery was evaluated by applying different chemical fertilization concentrations (0, 30, 60 and 100%). Subsequently, the seedlings were inoculated or not with a mixture of native AMF from two origins of contrasting sites in the Chaco Region. We measured biochemical traits (chlorophylls and carotenoid contents) and morphological parameters (stem neck diameter, shoot height, root dry weight, aerial dry weight). The mycorrhizal response on P. alba seedlings was calculated from these variables. Our results suggest that mycorrhizal response on stem neck diameter was significantly higher in the treatment inoculated with both AMF at 60% fertilizer concentration. In inoculated treatments, the shoot height was significantly higher (p <0.0001) than in control treatments. The aerial dry weight exhibited no differences between treatments. The root dry weight exhibited differences between inoculated and control treatments, showing higher values in control seedlings. We found a negative mycorrhizal response on the biochemical parameters, as control treatments showed higher pigments concentration than inoculated plants. Preliminarily, we observed a positive mycorrhizal response to the AMF in interaction with chemical fertilization (at 60% fertilizer concentration). These results were reflected mainly over some morphological parameters than over biochemical parameters. The lack of a clear answer is probably since the benefits of the symbiosis on the host plant could be observed in the establishment phase in the field.

Mycorrhizae and biostimulants are among the most innovative biological techniques used in large-scale food production. Positive effect son plant growth have been reported. However, the use of these "biofertilizers" in afforestation is limited. This study aimed to evaluate the synergy between arbuscular mycorrhizal fungi (AMF) and foliar biostimulant applications (phytoextracts) on an important Chaco native species (Prosopis alba) during the nursery stage. We tested biochemical parameters (MDA, malondialdehyde, an oxidative stress biomarker, and photosynthetic pigments) on P. alba seedlings sprayed with three different phytoextracts and inoculated with mycorrhizal strains of different local origins. Even though the statistical model was not significant at the preliminary level, our results showed that inoculated plants with one of the mycorrhizal strains (M2) could exhibit better results than other plants. For example, plants inoculated with M2 in combination with foliar applications of Larrea divaricata at 3% w/v showed a lower accumulation of the oxidative stress biomarker, MDA (p>0.5). Besides, M2 treated plants in combination with a phytoextract mixture (L. divaricata 1% w/v and Ilex paraguariensis 1% w/v) exhibited a higher biosynthesis of photosynthetic pigments (p>0.5). However, apparently, M2 showed better results in interaction with a biostimulant (M2 without a biostimulant is the treatment with the highest accumulation of MDA, p>0.5). Although there were no significant differences, trends indicate positive relationships between neck diameter and mycorrhizal response in plants treated with M1 with foliar applications of Larrea divaricata at 3% w/v. However, height does not consistently respond to mycorrhizae interacting with biostimulants. Consequently, deeper analysis is needed to understand the effect of the interaction between AMF with biostimulants for improving the plant's physiological status. Deepening research in this regard will result in significant benefits for restoration activities.

The study presents the growth response of Scots pine to long-term the application of potato industry sewage. The research was carried out in a fresh pine forest in northern Poland, where organic wastewater from the Potato Industry Plant in Iława (FWTP) was sprinkled for over 25 years. Our research sought to determine (i) the direction, extent, and duration of changes in the trees’ growth caused by the application of the fertiliser and (ii) the influence of climatic conditions on radial growth in those trees.

The extent of and changes in the growth were estimated by changes in annual ring widths and earlywood and latewood widths using dendrochronological methods. The research was carried out in different-aged pine stands located within the FWTP site and control stands located outside that area. Core samples were collected from 15 trees in each stand. The last sewage application took place ten years before core sampling.

We found a two-way impact of potato sewage on radial growth of Scots pine, with a stimulatory effect (27–30%) in the first decade of fertiliser application followed in the subsequent years by a strong reduction in growth (30–45%, depending on the age of the trees). Over the entire period during which the fertiliser was applied, changes occurred in the structure of the wood as manifested in the increased share of earlywood. The sprinkler application of potato starch wastewater and the accompanying irrigation caused a shift in dendroclimatic relationships of Scots pine in comparison to the pine from control plots. Surface irrigation and the resulting changes in water balance reduced the drought susceptibility of the pines under study. At the same time, trees weakened by the excessive concentration of toxic nitrates became more sensitive to thermal conditions in winter.

Platanus orientalis L. var. cretica is the ever-growing mutant of Platanus orientalis L. (plane tree) and its population consists of few trees, growing isolated in the island of Crete, Aegean Archipelago,Greece, while the typical plane tree form is ubiquitous to the island mainly present in streams and ravines. In the present study, 23 mutant and adjacent typical plane tree pairs were studied. Four leaf morphometry parameters were measured using the ImageJ software to derive five independent of size leaf shape ratios. Paired comparisons using Kruskal-Wallis tests were conducted via the SPSS software. The analyses showed no general tendency of statistically significant differences regarding studied parameters between pairs. Statistically significant differences (p<0.05) in the majority of the analyzed ratios were detected in 35% of the studied pairs. Our results show that leaf morphometrics present notable phenotypic variation which can be valuable in diversity studies. Nevertheless, they are not particularly useful in distinguishing P. orientalis L. and the ever - growing P. orientalis L. var. cretica.

The Zagros forest in West Iran is one of the most important livestock centers for animal husbandry. Overgrazing has depleted forest biodiversity, regeneration, and forest structure. We aimed to investigate the plasticity of the leaf traits under grazed and ungrazed treatments in semi-arid areas, Ilam. Therefore, three forest stands and three species as Amygdalus orientalis, Cerasus incana, and Acer monspessulanum were selected. The statistical analyses showed that leaf right vein (RV), leaf width (LW), blade length (BL), specific gravity (SG), wet weight of leaf (WWL), dry weight of leaf (DWL), and leaf internode length (LIN) (P < 0.05) significantly differed among two treatments. Furthermore, significant differences were determined in tree species as well as the interaction between trees × treatments in the measured traits. The Principle Components Analysis (PCA) presented a significant positive correlation among RV, LW, BL, WWL, DWL, and LIN. Consequently, the traits of grazed leaves were well separated from ungrazed. The traits in grazed leaves of C. incana, and A. monspessulanum were differentiated from another tree, so showing more similarities related to the measured traits. There was a negative correlation between leaf SG and other traits in ungrazed treatment. This was predictable due to correlation between SG and the leaf area in grazed trees. It was concluded that all leaf traits were impacted by the grazing and that in the long term this could influence the forest structure and survival. The results will help to better management of the forests and preservation of high-value trees.