Forests play an extremely important role in the formation of water circulation in a catchment. Despite numerous studies concerning the relations between forest and water, many problems still remain ...unexplained. Among them is the influence of the species composition in a stand on the water storage capacity of forest soils, especially of their surface horizons, whose physico-chemical properties are directly affected by the stand. The knowledge of those interactions is significant not only in the aspect of modelling of hydrological phenomena occurring in forest ecosystems but may also be helpful in indicating the directions of stand rebuilding aimed at extending the water-protective functions of forest.
The aim of the present research is to analyse the influence of the bulk density and the index of decomposition of organic matter on the water storage capacity of the surface layers of forest soils formed under beech (Fagus sylvatica L.) and fir (Abies alba Mill.) stands in southern Poland. The water storage capacity of individual forest soil horizons shows a distinct relationship with their bulk density. In beech and fir stands there is a critical value of bulk density, amounting to 0.48 and 0.51g·cm−3, which corresponds to culmination of the water storage capacity. A strong correlation has been shown between water storage capacity and the index of decomposition of beech and fir organic matter. It has also been found that the index of decomposition of organic matter and the degree of saturation, an indicator of water-filled voids in the soil, can constitute useful measures for describing and comparing the water storage capacity of the surface layers of forest soils formed under stands with a different species composition.
•The species composition of a stand affects the physical properties of organic horizons.•Capillary capacity is related to the bulk density of single soil horizons.•There is a relationship between capillary capacity and the index of decomposition.•A correlation has been shown between the degree of saturation and the index of decomposition.
In the context of global decline in old‐growth forest, historical ecology is a valuable tool to derive insights into vegetation legacies and dynamics and develop new conservation and restoration ...strategies. In this cross‐disciplinary study, we integrate palynology (Lago del Pesce record), history, dendrochronology, and historical and contemporary land cover maps to assess drivers of vegetation change over the last millennium in a Mediterranean mountain forest (Pollino National Park, southern Italy) and discuss implications in conservation ecology. The study site hosts a remnant beech–fir (Fagus sylvatica–Abies alba) mixed forest, a priority habitat for biodiversity conservation in Europe. In the 10th century, the pollen record showed an open environment that was quickly colonized by silver fir when sociopolitical instabilities reduced anthropogenic pressures in mountain forests. The highest forest cover and biomass was reached between the 14th and the 17th centuries following land abandonment due to recurring plague pandemics. This rewilding process is also reflected in the recruitment history of Bosnian pine (Pinus heldreichii) in the subalpine elevation belt. Our results show that human impacts have been one of the main drivers of silver fir population contraction in the last centuries in the Mediterranean, and that the removal of direct human pressure led to ecosystem renovation. Since 1910, the Rubbio State Forest has locally protected and restored the mixed beech–fir forest. The institutions in 1972 for the Rubbio Natural Reserve and in 1993 for Pollino National Park have guaranteed the survival of the silver fir population, demonstrating the effectiveness of targeted conservation and restoration policies despite a warming climate. Monitoring silver fir populations can measure the effectiveness of conservation measures. In the last decades, the abandonment of rural environments (rewilding) along the mountains of southern Italy has reduced the pressure on ecosystems, thus boosting forest expansion. However, after four decades of natural regeneration and increasing biomass, pollen influx and forest composition are still far from the natural attributes of the medieval forest ecosystem. We conclude that long‐term forest planning encouraging limited direct human disturbance will lead toward rewilding and renovation of carbon‐rich and highly biodiverse Mediterranean old‐growth forests, which will be more resistant and resilient to future climate change.
CONTEXT : In the Mediterranean area, numerous decline and mortality processes have been reported during recent decades, affecting forest dynamics. They are likely due to increases in summer drought ...severity and therefore especially affect drought-sensitive species, such as silver fir (Abies alba Mill.). AIMS AND METHODS : To understand the relationships between tree growth, crown condition and mortality probability, radial growth trends of healthy, declining (showing crown damages) and dead trees were compared using tree-ring analysis. Factors involved in determining this mortality were also examined at the plot and tree level using altitudinal gradients on three contrasted sites in southeastern France. RESULTS : Individuals with higher inter-annual variability in growth were more prone to dieback. At two sites, dead trees displayed lower growth rates over their entire lifetime, while, on the last site, their juvenile growth rate was higher. Trees with crown damage had higher growth rates than healthy trees on one site, and their radial growth trends over time always differed from those of dead trees. Mortality and crown damage were little related to altitude, but strongly differed between sites and among plots underlining the importance of local edaphic and topographic conditions. CONCLUSION : These results suggest that the relationships among mortality probability, crown condition and growth can differ among sites, and highlight the impact of soil conditions and the need to assess them in tree mortality studies.
•The roof beams of the Romanesque-Gothic church of San Francesco in Prato have been analysed through dendrochronology.•The main roof structure is made of silver fir, except for two struts made of ...spruce. Chestnut, silver fir, spruce and deciduous trees, including pear, were used for the brackets.•-Dendrochronology has identified the oldest material, dating back to the original construction of 1284, and the material resulting from later replacements, which mainly took place around the middle of the 19th century.•Similarities with the basilica of Santa Croce in Florence were recognized and the most probable origin of the timber used for the construction of the roof was identified.
The church of San Francesco was built on terrain donated by the city of Prato to the Franciscan Friars just 2 years after the saint's death. In addition to worship, the building is of extreme historical and architectural interest and preserves valuable medieval artwork inside. The roof structures show modern features combined with ancient decorations and elements, which do not allow to precisely define its chronology. In particular, it is not clear whether the current roof structure dates back to the original construction or is the result of repeated subsequent interventions. The dendrochronological investigation involved 49 structural elements collected from 14 of the 16 trusses. The results obtained from silver fir samples separated the material into two groups: an older one, with a terminus post quem dating back to 1278, and a more recent one, which is the result of interventions of the mid-nineteenth century. The oldest elements are essentially the tie-beam of the trusses, while the replacement interventions have affected the rafters and some prostheses of the tie beams. The dendrochronological analysis showed marked analogies between the oldest roof structure of the church of Prato and that of the Basilica of Santa Croce in Florence, suggesting that the timber could comes from the large silver fir forests of Casentino, in Tuscany.
Key message
Conventional methods for estimating the current annual increment of stand volume are based on the uncertain assumption that height increment decreases with tree age. Conversely, size, ...rather than age, should be accounted for the observed senescence-related declines in relative growth rate and, consequently, implemented in silvicultural manuals. Results stem from a study on
Abies alba
Mill. at its southern limit of distribution.
Context
Many factors limit height increment when age and size increase in large-statured tree species. Height–diameter allometric relationships are commonly used measures of tree growth.
Aims
In this study, we tested if tree age was the main factor affecting the reduction in height increment of silver fir trees (
Abies alba
Mill.), verifying also whether tree size had a significant role in ecophysiological-biomechanical limitations to tree growth.
Methods
The study was carried out in a silver fir forest located in Southern Italy, at the southernmost distribution limit for this species. Through a stratified random sampling, 100 trees were selected. All the selected trees were then felled and the total tree height, height increments (internode distances), diameter at breast height, and diameter increments (ring widths) were measured.
Results
The analyses of allometric models and scaling coefficients showed that the correlation between tree age and height increment was not always significant.
Conclusion
We may conclude that tree age did not statistically explain the decrease in height increment in older trees. Instead, the increase in tree size and related physiological processes (expressed as product between diameter at breast height and tree height) explained the reduction in height increment in older trees and was the main factor limiting height growth trends in marginal population of silver fir.
Extracts from parts of coniferous trees have received increased interest due to their valuable bioactive compounds and properties, useful for plenty of experimental and consolidated applications, in ...fields comprising nutraceutics, cosmetics, pharmacology, food preservation, and stimulation of plant growth. However, the variability of the bioactive properties, the complexity of the extraction methods, and the use of potentially harmful synthetic chemicals, still represent an obstacle to the spreading of such valuable natural compounds. Hydrodynamic cavitation is emerging as a promising innovative technique for the extraction of precious food components and by-products from waste raw material of the agro-food production chain, which can improve processing efficiency, reduce resource consumption, and produce healthy, high-quality products. In this study, a process based on controlled hydrodynamic cavitation was applied for the first time to the production of aqueous solutions of silver fir (
Mill.) needles with enhanced antioxidant activity. The observed levels of the in vitro antioxidant activity, comparable or higher than those found for reference substances, pure extracts, and other water extracts and beverages, highlight the very good potential of the hydrodynamic cavitation (HC) process for the creation of solvent-free, aqueous solutions endowed with bioactive compounds extracted from silver fir needles.
The modification of wood and its surface is one of the challenges that is being perfected with the aim of transitioning to sustainable management. This study investigated the dynamic mechanical and ...thermal behaviour of unmodified and styrene modified fir wood (
Mill.). Styrene monomer was chosen and impregnated into the porous structure of fir wood by reversible addition-fragmentation chain transfer (RAFT) polymerisation. Attenuated total reflection Fourier-transform infrared spectroscopy (FTIR-ATR), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA) were employed to characterise the chemical structure, viscoelastic properties, and thermal stability of unmodified and modified (surface-modified) wood. All tests have to be regarded as being preliminary due to the small number of specimens. Fourier transform infrared analysis showed evidence of the phenyl group from styrene at 700 cm
. DMA results showed that the modified wood caused an increase in the glass transition temperature relative to the unmodified wood. In addition, modification with styrene improves thermal stability, as revealed by thermogravimetric analysis (TGA).
This study investigated the physicochemical properties of fir (Abies alba Mill.) honeydew honey (FHH) and its biological activity against the leading foodborne bacterium Campylobacter jejuni. ...Antibacterial activity, bacterial growth and anti-adhesion tests were performed in Mueller Hinton (MH) broth and cow’s milk used as a food model. FHH from the mountainous region of Croatia showed antibacterial activity against C. jejuni in MH broth and milk, with the minimal inhibitory concentration (MIC) values ranging from 12.5 to 50 mg/mL. A transmission electron microscopy (TEM) analysis of C. jejuni cells showed severe cellular damage after exposure to the tested honeydew honey. FHH in concentrations of 3 and 5% (w/v) inhibited growth and prevented adhesion to the polystyrene surface at a concentration of 25 mg/mL or lower of the bacterium C. jejuni in MH broth and milk. The anti-adhesion effect was more pronounced in the milk than in the MH broth. These results suggest that FHH has potent antibacterial activity against C. jejuni due to its particular physicochemical properties.
Many buildings are being restored in the city of Aix-en-Provence, southeastern France and allowed systematic dendrochronological analyses. 144 fir timbers (Abies alba Mill.) were examined and dated ...between 1303 and 1933. They highlight three felling phases (Medieval period, 17th-18th century, and 19th century). The best documented one corresponds to the 17th-18th centuries and coincides with significant building activity connected to the status of Aix, which is the parliamentary capital of Provence. Around Aix-en-Provence, it is difficult to find timbers with good dimensions. Our results show that timbers were transported from the Alps to Aix’s buildings. Potential testimonies of this timber trade have been found, such as raft assemblage marks, and carved signs and letters. A dendroprovenancing case study shows that between 1810 and 1890, some of Aix’s timbers could have come from the Northern French Alps or the Verdon-Durance region. Finally, the lack of timbers with good dimension and the difficulties of timber supply contributed to the development of reuse economy and technical innovation. These results are the foundation of a future well-established dendroprovenancing approach in the Southern Alps.
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