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The increasing demand for wood with enhanced flame retardant characteristics in construction applications necessitates strategic interventions. This study explores the fire behaviour and chemical characterisation of Robinia pseudoacacia wood subjected to thermal modification and flame retardant treatments. Thermal modification was carried out at three different temperatures (160 oC, 180 oC and 240 oC). The fire properties of wood coated with Flame Gard (F), a commercial flame retardant, arabinogalactan (A), a natural flame retardant, melamine adhesive (MF) with ammonium polyphosphate (AP), nanosilica (NS), nanoclay (NC) (MF-AP-NS and MF-AP-NC) and arabinogalactan with AP, NS and NC (A-AP-NS and A-AP-NC), were assessed using cone calorimetry in terms of the weight loss rate, ignition time and heat release rate. The commercial flame retardant Flame Gard outperformed the natural and fortified flame retardants in terms of the weight loss rate, heat release rate (HRR) and ignition time (tig). Unmodified samples exhibited superior fire properties in terms of tig and HRR compared to thermally modified samples. The peak heat release rate (kW.mMINUS SIGN 2) and time to peak heat release rate (s) showed a moderate degree of dependency on the chemical constituents of the wood.

The increasing demand for wood with enhanced flame retardant characteristics in construction applications necessitates strategic interventions. This study explores the fire behaviour and chemical characterisation of Robinia pseudoacacia wood subjected to thermal modification and flame retardant treatments. Thermal modification was carried out at three different temperatures (160 oC, 180 oC and 240 oC). The fire properties of wood coated with Flame Gard (F), a commercial flame retardant, arabinogalactan (A), a natural flame retardant, melamine adhesive (MF) with ammonium polyphosphate (AP), nanosilica (NS), nanoclay (NC) (MF-AP-NS and MF-AP-NC) and arabinogalactan with AP, NS and NC (A-AP-NS and A-AP-NC), were assessed using cone calorimetry in terms of the weight loss rate, ignition time and heat release rate. The commercial flame retardant Flame Gard outperformed the natural and fortified flame retardants in terms of the weight loss rate, heat release rate (HRR) and ignition time (tig). Unmodified samples exhibited superior fire properties in terms of tig and HRR compared to thermally modified samples. The peak heat release rate (kW.mMINUS SIGN 2) and time to peak heat release rate (s) showed a moderate degree of dependency on the chemical constituents of the wood., info:eu-repo/semantics/openAccess

Robinia pseudoacacia L. (commonly known as black locust) is an economically and environmentally important plant, native to the eastern USA, and introduced into several European countries, including Hungary. An early successional leguminous tree, the black locust is characterized by tolerance to degraded sites, rapid growth rate, dense and rot-resistant wood, and heavy flowering. Due to its economic potential and environmental impact, the historic Hungarian breeding strategy targeted not only increased wood production but also in wood and honey-production quality. However, because many important features of the species are under polygenic control, genome-wide genetic data provided by high-throughput sequencing technology could make possible the identification of gene variants with identifiable functional effects on complex traits. Furthermore, the evaluation of the breeding efforts carried out so far would be also achievable, by comparing bred/selected genotypes with those from the original habitat. This paper provides a genomic dataset with highly variable SNP markers from native American and Hungarian Robinia pseudoacacia L. individuals. These SNP loci can be used to assess genetic differentiation, and to detect signatures of polygenic determination of economically important traits, providing a basis for further research into this species.

The cultivation of perennial biomass crops (PBCs) on marginal lands is necessary to provide feedstock for the bio-based EU economy and accrue environmental benefits through carbon (C) sequestration in soil. Short rotation coppice (SRC) species, e.g., willow, black locust, and poplar, and perennial rhizomatous grasses, e.g., miscanthus, switchgrass, and giant reed, have been tested in many EU projects in the last 10 years to investigate their productive potential and contribution to the mitigation of climate change. A major knowledge gap regarding PBCs is the fate of accumulated soil organic carbon (SOC), once PBC plantations are reverted to arable crops. In this study, the effects of PBCs reversion on SOC and carbon-dioxide emission (CO2) were monitored over a 2-year period in a long-term (11-year) multispecies trial of six PBCs: Three SRC species including poplar (Populus spp.), willow (Salix spp.), and black locust (Robinia pseudoacacia), and three herbaceous rhizomatous grasses including miscanthus (Miscanthus x giganteus), switchgrass (Panicum virgatum), and giant reed (Arundo donax). The SOC change and GHG emissions were then modeled with the ECOSSE model. Two years after the reversion, SOC increased significantly for all PBCs with no significant difference between them. During the PBC cultivation phase, 5.35 Mg SOC ha−1 was sequestered while 10.95 Mg SOC ha−1 was added by reversion, which indicated that 67% of SOC sequestration occurred after the reversion. The ECOSSE model was successfully used to simulate SOC sequestration trajectories (R2 = 0.77) and CO2 emission from soil (R2 = 0.82) after the reversion of the six PBCs. This indicated that the high SOC sequestration rate after the reversion was due to humification of belowground biomass (roots + rhizomes/stumps), which had been mulched and incorporated into the reversion layer (0–30 cm). This occurred in the first 2 months (on average 5.47 Mg SOC ha−1 y−1) and in the first year after the reversion (1.3–1.8

Black locust (Robinia pseudoacacia L.) is an alien species that is commonly planted in devastated lands, parks, residential gardens and is used as a nectar source for bees. However, the Japanese government has designated this species as an “Industrial exotic species under watch" because its rapid growth and reproductive capacity allows it to outcompete indigenous vegetation. Field surveys revealed that the back locust spreads through its sprouting roots and the elongation of its horizontal roots at soil depths between 0 and 10 cm. A practical method to regulate the spread of black locust would be to suppress the development of horizontal roots. Based on a nursery experiment, we propose the use of root-barrier panels to block and suppress the growth of horizontal roots. Monitoring the growth of roots in the field is labor-intensive, so we investigated the impact of root-barrier panels on shoot development by measuring the length of sprouting roots, the decrease in secondary flush, the increase in yellowed leaflets, and impact on plant height in a nursery setting. We concluded that root-barrier panels set at a depth of 30 cm effectively inhibited the growth of the horizontal roots of young black locust less than 3years old.

Type of the wood used for the aging highly influences the quality of alcoholic beverages. In this research we explored the potential of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) to establish fingerprints characteristic for each wood and to enable determining the type of the wood used in the aging process. Eleven different wood samples were used to prepare three different types of spirits during 15 months. The highest extraction rate was obtained during the first month, while further aging was followed with almost constant amount of extracted polyphenols. Black locust, myrobalan plum, and mulberry extracts were discriminated from the spirits aged in oak and wild cherry wood when statistical analysis was applied. Although clear classification of all samples was not achieved, this long term study demonstrated a potential of both CV and DPV for differentiating wood species used in the aging, hence in the quality control of spirits. © 2020 Elsevier Ltd

Type of the wood used for the aging highly influences the quality of alcoholic beverages. In this research we explored the potential of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) to establish fingerprints characteristic for each wood and to enable determining the type of the wood used in the aging process. Eleven different wood samples were used to prepare three different types of spirits during 15 months. The highest extraction rate was obtained during the first month, while further aging was followed with almost constant amount of extracted polyphenols. Black locust, myrobalan plum, and mulberry extracts were discriminated from the spirits aged in oak and wild cherry wood when statistical analysis was applied. Although clear classification of all samples was not achieved, this long term study demonstrated a potential of both CV and DPV for differentiating wood species used in the aging, hence in the quality control of spirits. © 2020 Elsevier Ltd

The presence of trees in a grazing ecosystem increases edaphic populations and, therefore, symbiotic relationships. In the high Andean ecosystems of the northern part of Ecuador there is little research on this topic. The objective of this work is to determine the population growth of the edaphic fauna in the forest-pasture systems. For this case, this system has the following combinations: alder (Alnus acuminata) and forage mix, acacia (Acacia melanoxylon) and forage mix, and a control with forage mix. The count was carried out in two periods: July and December, in the years 2016, 2017 and 2018. For the statistical part, an analysis of variance and the Tukey’s test were carried out, which allowed showing probabilities and identifying the best response of species growth, depending on forest-pasture treatment. The statistical analyzes show the evolution of the system in the first year, in which there are no significant differences, due to the transplantation and growth of the trees; from the second year there are already edaphic changes between treatments due to an increase in organic matter, which influences the species in the soil. The statistical results conclude that the forest-pasture system with acacia has more edaphic population., A presença de árvores em um ecossistema de pastoreio aumenta as populações edáficas e, portanto, as relações simbióticas. Nos ecossistemas altos andinos do norte do Equador, existem poucas pesquisas sobre o assunto. O objetivo deste trabalho é determinar o crescimento populacional da fauna edáfica nos sistemas silvipastoris. Para este caso, o sistema silvopastoril conta com as seguintes combinações: mistura de amieiro (Alnus acuminata) e mistura de forragem, acácia (Acacia melanoxylon) e mistura de forragem, e uma testemunha com mistura de forragem. A contagem foi realizada em dois períodos: julho e dezembro, nos anos de 2016, 2017 e 2018. Para a parte estatística, foi realizada a análise de variância e o teste de Tukey, que permitiu evidenciar probabilidades e identificar a melhor resposta de crescimento das espécies, dependendo do tratamento silvopastoril. As análises estatísticas mostram a evolução do sistema no primeiro ano, no qual não há diferenças significativas, devido ao transplante e crescimento das árvores; a partir do segundo ano já ocorrem mudanças edáficas entre os tratamentos devido ao aumento da matéria orgânica, que influencia as espécies no solo. Os resultados estatísticos concluem que o sistema silvopastoril com acácia possui população mais edáfica., La presencia de árboles en un ecosistema de pastoreo aumenta las poblaciones edáficas y, por ende, las relaciones simbióticas. En los ecosistemas altoandinos de la zona norte del Ecuador existen escasas investigaciones sobre esta temática. El objetivo de esta investigación es determinar el crecimiento poblacional de la fauna edáfica en los sistemas silvopastoriles, para este caso, el sistema silvopastoril tiene las siguientes combinaciones: aliso (Alnus acuminata) y mezcla forrajera, acacia (Acacia melanoxylon) y mezcla forrajera, y un testigo con mezcla forrajera. El conteo se realizó en dos épocas, julio y diciembre, en los años 2016, 2017 y 2018. Para el análisis estadístico se realizó un análisis de varianza y la prueba de Tukey, que permitieron mostrar probabilidades e identificar la mejor respuesta de crecimiento de especies en función del tratamiento silvopastoril. Los análisis estadísticos muestran la evolución del sistema en el primer año, en el cual no existen diferencias significativas, debido al trasplante y crecimiento de los árboles; a partir del segundo año ya existen cambios edáficos entre tratamientos por aumento de materia orgánica, lo que influye sobre las especies en el suelo. Los resultados estadísticos concluyen que el sistema silvopastoril con acacia tiene más población edáfica.

The presence of trees in a grazing ecosystem increases edaphic populations and, therefore, symbiotic relationships. In the high Andean ecosystems of the northern part of Ecuador there is little research on this topic. The objective of this work is to determine the population growth of the edaphic fauna in the forest-pasture systems. For this case, this system has the following combinations: alder (Alnus acuminata) and forage mix, acacia (Acacia melanoxylon) and forage mix, and a control with forage mix. The count was carried out in two periods: July and December, in the years 2016, 2017 and 2018. For the statistical part, an analysis of variance and the Tukey’s test were carried out, which allowed showing probabilities and identifying the best response of species growth, depending on forest-pasture treatment. The statistical analyzes show the evolution of the system in the first year, in which there are no significant differences, due to the transplantation and growth of the trees; from the second year there are already edaphic changes between treatments due to an increase in organic matter, which influences the species in the soil. The statistical results conclude that the forest-pasture system with acacia has more edaphic population., A presença de árvores em um ecossistema de pastoreio aumenta as populações edáficas e, portanto, as relações simbióticas. Nos ecossistemas altos andinos do norte do Equador, existem poucas pesquisas sobre o assunto. O objetivo deste trabalho é determinar o crescimento populacional da fauna edáfica nos sistemas silvipastoris. Para este caso, o sistema silvopastoril conta com as seguintes combinações: mistura de amieiro (Alnus acuminata) e mistura de forragem, acácia (Acacia melanoxylon) e mistura de forragem, e uma testemunha com mistura de forragem. A contagem foi realizada em dois períodos: julho e dezembro, nos anos de 2016, 2017 e 2018. Para a parte estatística, foi realizada a análise de variância e o teste de Tukey, que permitiu evidenciar probabilidades e identificar a melhor resposta de crescimento das espécies, dependendo do tratamento silvopastoril. As análises estatísticas mostram a evolução do sistema no primeiro ano, no qual não há diferenças significativas, devido ao transplante e crescimento das árvores; a partir do segundo ano já ocorrem mudanças edáficas entre os tratamentos devido ao aumento da matéria orgânica, que influencia as espécies no solo. Os resultados estatísticos concluem que o sistema silvopastoril com acácia possui população mais edáfica., La presencia de árboles en un ecosistema de pastoreo aumenta las poblaciones edáficas y, por ende, las relaciones simbióticas. En los ecosistemas altoandinos de la zona norte del Ecuador existen escasas investigaciones sobre esta temática. El objetivo de esta investigación es determinar el crecimiento poblacional de la fauna edáfica en los sistemas silvopastoriles, para este caso, el sistema silvopastoril tiene las siguientes combinaciones: aliso (Alnus acuminata) y mezcla forrajera, acacia (Acacia melanoxylon) y mezcla forrajera, y un testigo con mezcla forrajera. El conteo se realizó en dos épocas, julio y diciembre, en los años 2016, 2017 y 2018. Para el análisis estadístico se realizó un análisis de varianza y la prueba de Tukey, que permitieron mostrar probabilidades e identificar la mejor respuesta de crecimiento de especies en función del tratamiento silvopastoril. Los análisis estadísticos muestran la evolución del sistema en el primer año, en el cual no existen diferencias significativas, debido al trasplante y crecimiento de los árboles; a partir del segundo año ya existen cambios edáficos entre tratamientos por aumento de materia orgánica, lo que influye sobre las especies en el suelo. Los resultados estadísticos concluyen que el sistema silvopastoril con acacia tiene más población edáfica.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation EU/2018/2019 as ‘High risk plants, plant products and other objects’. This Scientific Opinion covers plant health risks posed by bare rooted and potted plants of Robinia pseudoacacia that are imported from Turkey, taking into account the available scientific information, including the technical information provided by the Turkish NPPO. The relevance of any pest for this opinion was based on evidence following defined criteria. Three species, the EU‐quarantine pests Anoplophora chinensis and Lopholeucapsis japonica, and the EU non‐regulated pest Phocazia shantungensis fulfilled all relevant criteria and were selected for further evaluation. For these pests, the risk mitigation measures proposed in the technical dossier from Turkey were evaluated taking into account the possible limiting factors. For these pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The estimated degree of pest freedom varies among the pests evaluated, with L. japonica being the pest most frequently expected on the imported plants. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9,521 and 10,000 plants per 10,000 would be free of L. japonica.

Type of the wood used for the aging highly influences the quality of alcoholic beverages. In this research we explored the potential of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) to establish fingerprints characteristic for each wood and to enable determining the type of the wood used in the aging process. Eleven different wood samples were used to prepare three different types of spirits during 15 months. The highest extraction rate was obtained during the first month, while further aging was followed with almost constant amount of extracted polyphenols. Black locust, myrobalan plum, and mulberry extracts were discriminated from the spirits aged in oak and wild cherry wood when statistical analysis was applied. Although clear classification of all samples was not achieved, this long term study demonstrated a potential of both CV and DPV for differentiating wood species used in the aging, hence in the quality control of spirits. © 2020 Elsevier Ltd

Type of the wood used for the aging highly influences the quality of alcoholic beverages. In this research we explored the potential of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) to establish fingerprints characteristic for each wood and to enable determining the type of the wood used in the aging process. Eleven different wood samples were used to prepare three different types of spirits during 15 months. The highest extraction rate was obtained during the first month, while further aging was followed with almost constant amount of extracted polyphenols. Black locust, myrobalan plum, and mulberry extracts were discriminated from the spirits aged in oak and wild cherry wood when statistical analysis was applied. Although clear classification of all samples was not achieved, this long term study demonstrated a potential of both CV and DPV for differentiating wood species used in the aging, hence in the quality control of spirits. © 2020 Elsevier Ltd

The ageing process of alcoholic beverages in presence of wood is a significant label of their quality, in which important changes in aroma, color, taste and astringency occur due to the interaction between compounds present in the wood and beverages. In Balkan countries, several wood species such as oak, cherry, black locust, and mulberry can be used in that process. Cyclic voltammetry is simple, rapid and inexpensive method that could be used for measurement of antioxidant capacity. To our knowledge, cyclic voltammetry has not been implemented in characterization of wood extracts before. Therefore, the aim of our work was to characterize the 60% ethanolic extracts of different wood species commonly used in Balkan cooperage (reproducing the condition of ageing process) by cyclic voltammetry and to investigate differences among wood species. Our results showed that cyclic voltammetry can distinguish investigated wood species, which points to the phenolic profile unique for the wood specie. The same class of wood extract shows similar behavior (based on the peaks position) indicating the presence of the same phenolic compounds. Also, differences based on the current areas are strongly correlated with the geographical origin of the wood. Present study allows application of the rapid, reagentless and sensitive method for the monitoring of the phenolic profiles of the wood, and determination of geographical and botanical origin. Additionally, proposed approach, offers fast and reliable determination of the quality of the used wood barrel, as an important and beneficial fact for the producers of alcoholic beverages.

The ageing process of alcoholic beverages in presence of wood is asignificant label of their quality, in which important changes in aroma, color,taste and astringency occur due to the interaction between compoundspresent in the wood and beverages. In Balkan countries, several woodspecies such as oak, cherry, black locust, and mulberry can be used in thatprocess.Cyclic voltammetry is simple, rapid and inexpensive method that could beused for measurement of antioxidant capacity. To our knowledge, cyclicvoltammetry has not been implemented in characterization of woodextracts before. Therefore, the aim of our work was to characterize the 60%ethanolic extracts of different wood species commonly used in Balkancooperage (reproducing the condition of ageing process) by cyclicvoltammetry and to investigate differences among wood species.Our results showed that cyclic voltammetry can distinguish investigatedwood species, which points to the phenolic profile unique for the woodspecie. The same class of wood extract shows similar behavior (based onthe peaks position) indicating the presence of the same phenoliccompounds. Also, differences based on the current areas are stronglycorrelated with the geographical origin of the wood. Present study allowsapplication of the rapid, reagentless and sensitive method for themonitoring of the phenolic profiles of the wood, and determination ofgeographical and botanical origin. Additionally, proposed approach, offersfast and reliable determination of the quality of the used wood barrel, as animportant and beneficial fact for the producers of alcoholic beverages.

This study aims to quantify the potential contribution of nutrients derived from leaf litter in a short rotation coppice plantation which includes monocultures of the species Populus alba (PA) and Robina pseudoacacia (RP) as well as a mixture of 50PA:50RP, in the middle of the rotation. The P. alba monoculture was that which provided the most leaf litter (3.37 mg ha−1 yr−1), followed by the 50PA:50RP mixture (2.82 mg ha−1 yr−1) and finally the R. pseudoacacia monoculture (2.55 mg ha−1 yr−1). In addition to producing more litterfall, leaves were shed later in the P. alba monoculture later (December) than in the R. pseudoacacia monoculture (October) or the mix (throughout the fall). In terms of macronutrient supply per hectare, the contributions derived from leaf litter were higher for K, P and Mg in the case of P. alba and for N in R. pseudoacacia, the mix presenting the highest Ca content and intermediate concentrations for the rest of the nutrients. In addition, other factors such as C:N or N:MO ratios, as well as the specific characteristics of the soil, can have an important impact on the final contribution of these inputs. The carbon contribution derived from leaf fall was higher in the P. alba monoculture (1.5 mg ha−1 yr−1), intermediate in the mixed plot (1.3 mg ha−1 yr−1) and slightly lower for the R. pseudoacacia monoculture (1.3 mg ha−1 yr−1). Given these different strategies of monocultures with regard to the dynamism of the main nutrients, species mixing would appear to be suitable option to achieve a potential reduction in mineral fertilization in these plantations

This study aims to quantify the potential contribution of nutrients derived from leaf litter in a short rotation coppice plantation which includes monocultures of the species Populus alba (PA) and Robina pseudoacacia (RP) as well as a mixture of 50PA:50RP, in the middle of the rotation. The P. alba monoculture was that which provided the most leaf litter (3.37 mg ha−1 yr−1), followed by the 50PA:50RP mixture (2.82 mg ha−1 yr−1) and finally the R. pseudoacacia monoculture (2.55 mg ha−1 yr−1). In addition to producing more litterfall, leaves were shed later in the P. alba monoculture later (December) than in the R. pseudoacacia monoculture (October) or the mix (throughout the fall). In terms of macronutrient supply per hectare, the contributions derived from leaf litter were higher for K, P and Mg in the case of P. alba and for N in R. pseudoacacia, the mix presenting the highest Ca content and intermediate concentrations for the rest of the nutrients. In addition, other factors such as C:N or N:MO ratios, as well as the specific characteristics of the soil, can have an important impact on the final contribution of these inputs. The carbon contribution derived from leaf fall was higher in the P. alba monoculture (1.5 mg ha−1 yr−1), intermediate in the mixed plot (1.3 mg ha−1 yr−1) and slightly lower for the R. pseudoacacia monoculture (1.3 mg ha−1 yr−1). Given these different strategies of monocultures with regard to the dynamism of the main nutrients, species mixing would appear to be suitable option to achieve a potential reduction in mineral fertilization in these plantations.

The ageing process of alcoholic beverages in presence of wood is a significant label of their quality, in which important changes in aroma, color, taste and astringency occur due to the interaction between compounds present in the wood and beverages. In Balkan countries, several wood species such as oak, cherry, black locust, and mulberry can be used in that process. Cyclic voltammetry is simple, rapid and inexpensive method that could be used for measurement of antioxidant capacity. To our knowledge, cyclic voltammetry has not been implemented in characterization of wood extracts before. Therefore, the aim of our work was to characterize the 60% ethanolic extracts of different wood species commonly used in Balkan cooperage (reproducing the condition of ageing process) by cyclic voltammetry and to investigate differences among wood species. Our results showed that cyclic voltammetry can distinguish investigated wood species, which points to the phenolic profile unique for the wood specie. The same class of wood extract shows similar behavior (based on the peaks position) indicating the presence of the same phenolic compounds. Also, differences based on the current areas are strongly correlated with the geographical origin of the wood. Present study allows application of the rapid, reagentless and sensitive method for the monitoring of the phenolic profiles of the wood, and determination of geographical and botanical origin. Additionally, proposed approach, offers fast and reliable determination of the quality of the used wood barrel, as an important and beneficial fact for the producers of alcoholic beverages.

The ageing process of alcoholic beverages in presence of wood is asignificant label of their quality, in which important changes in aroma, color,taste and astringency occur due to the interaction between compoundspresent in the wood and beverages. In Balkan countries, several woodspecies such as oak, cherry, black locust, and mulberry can be used in thatprocess.Cyclic voltammetry is simple, rapid and inexpensive method that could beused for measurement of antioxidant capacity. To our knowledge, cyclicvoltammetry has not been implemented in characterization of woodextracts before. Therefore, the aim of our work was to characterize the 60%ethanolic extracts of different wood species commonly used in Balkancooperage (reproducing the condition of ageing process) by cyclicvoltammetry and to investigate differences among wood species.Our results showed that cyclic voltammetry can distinguish investigatedwood species, which points to the phenolic profile unique for the woodspecie. The same class of wood extract shows similar behavior (based onthe peaks position) indicating the presence of the same phenoliccompounds. Also, differences based on the current areas are stronglycorrelated with the geographical origin of the wood. Present study allowsapplication of the rapid, reagentless and sensitive method for themonitoring of the phenolic profiles of the wood, and determination ofgeographical and botanical origin. Additionally, proposed approach, offersfast and reliable determination of the quality of the used wood barrel, as animportant and beneficial fact for the producers of alcoholic beverages.

Black locust (Robinia pseudoacacia L.), a species native to the eastern North America, was introduced to Europe probably in 1601 and currently extends over 2.3 × 106 ha. It has become naturalized in all sub-Mediterranean and temperate regions rivaling Populus spp. as the second most planted broadleaved tree species worldwide after Eucalyptus spp. This wide-spreading planting is because black locust is an important multipurpose species, producing wood, fodder, and a source of honey as well as bio-oil and biomass. It is also important for carbon sequestration, soil stabilization and re-vegetation of landfills, mining areas and wastelands, in biotherapy and landscaping. In Europe, black locust is drought tolerant so grows in areas with annual precipitation as low as 500–550 mm. It tolerates dry, nutrient poor soils but grows best on deep, nutrient-rich, well-drained soils. It is a fast-growing tree and the height, diameter and volume growth peak before the age of 20. It mostly regenerates vegetatively by root suckers under a simple coppice system, which is considered the most cost-effective management system. It also regenerates, but less frequently, by stool sprouts. Its early silviculture in production forests includes release cutting to promote root suckers rather than stool shoots, and cleaning-respacing to remove low-quality stems, reduce the number of shoots per stool, and adjust spacing between root suckers. In addition, early, moderate and frequent thinning as well as limited pruning are carried out focusing on crop trees. The species is regarded as invasive in several European countries and its range here is expected to expand under predicted climate changes.

Introduced in 1750 as an ornamental tree and then in 1852 as a forest tree species, black locust occupied nowadays 250,000 ha in Romania. The tree species is important for its wood (lumber, poles, firewood, etc.), its honey-related production as well as its environmental role (afforestation of sand dunes and sterile dumps). One of the most important activities in the middle basin of Jiu River is coal mining. After 1956 this activity has developed very quickly and two power plants were built in Rovinari and Turceni. As a result, sterile dumps and coal ash dumps have established so it was necessary to restore the area by afforestation. This activity started with the sterile dump Viaduct Rovinari, using Austrian pine and black locust, and continued with others such as Cocoreni and Moi. The most used tree species for ecological restoration was black locust. In order to express the stand structure, diameter at breast height (DBH), total height (H) and crown diameter were measured. The soil analysis were performed and showed differences in the content of heavy metals and radionuclides for both location. The study revealed positive correlations between DBH and H, a stronger one for Moi plantation. Our research highlights the capacity of black locust to establish and grow under very difficult site conditions.

Introduced in 1750 as an ornamental tree and then in 1852 as a forest tree species, black locust occupied nowadays 250,000 ha in Romania. The tree species is important for its wood (lumber, poles, firewood, etc.), its honey-related production as well as its environmental role (afforestation of sand dunes and sterile dumps). One of the most important activities in the middle basin of Jiu River is coal mining. After 1956 this activity has developed very quickly and two power plants were built in Rovinari and Turceni. As a result, sterile dumps and coal ash dumps have established so it was necessary to restore the area by afforestation. This activity started with the sterile dump Viaduct Rovinari, using Austrian pine and black locust, and continued with others such as Cocoreni and Moi. The most used tree species for ecological restoration was black locust. In order to express the stand structure, diameter at breast height (DBH), total height (H) and crown diameter were measured. The soil analysis were performed and showed differences in the content of heavy metals and radionuclides for both location. The study revealed positive correlations between DBH and H, a stronger one for Moi plantation. Our research highlights the capacity of black locust to establish and grow under very difficult site conditions.

In the production of some alcoholic beverages one of the most important practices is the ageing process in a presence of wood. This process contributes to improved sensory characteristics such as aroma, color, taste and astringency. Although oak heartwood is the most used material in cooperage, other species such as chestnut, cherry, and mulberry can be also considered. Currently, limited published data are available on the mineral content of the wood extract from cooperage industry, although some research was done to investigate the content of heavy metals in alcoholic beverages1, especially in wine2. Daily consumption of the wine and brandy with an elevated content of heavy metals might cause chronical poisoning. To avoid this issue, the maximum allowable concentration (MAC, mg L–1) in fruit brandies were established for lead, zinc, arsenium, and copper.1 The aim of this research was to investigate elemental composition of ethanolic extracts, obtained from alternative wood species used in Balkan cooperage, such as mulberry (Morus alba L.), Myrobalan plum (Prunus cerasifera Ehrh.), black locust (Robinia pseudoacacia L.), and wild cherry (Prunus avium (L.) L.). Elements were determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results indicated that the elemental composition of wild cherry extract was much lower than in other nonoak wood extracts, and all investigated wood extracts have lower content of trace elements than maximum allowable concentration in fruit brandies.

In the production of some alcoholic beverages one of the most important practices is theageing process in a presence of wood. This process contributes to improved sensorycharacteristics such as aroma, color, taste and astringency. Although oak heartwood isthe most used material in cooperage, other species such as chestnut, cherry, and mulberrycan be also considered. Currently, limited published data are available on the mineralcontent of the wood extract from cooperage industry, although some research was doneto investigate the content of heavy metals in alcoholic beverages1, especially in wine2.Daily consumption of the wine and brandy with an elevated content of heavy metalsmight cause chronical poisoning. To avoid this issue, the maximum allowableconcentration (MAC, mg L–1) in fruit brandies were established for lead, zinc, arsenium,and copper.1The aim of this research was to investigate elemental composition of ethanolic extracts,obtained from alternative wood species used in Balkan cooperage, such as mulberry(Morus alba L.), Myrobalan plum (Prunus cerasifera Ehrh.), black locust (Robiniapseudoacacia L.), and wild cherry (Prunus avium (L.) L.). Elements were determined byinductively coupled plasma-optical emission spectroscopy (ICP-OES). Results indicatedthat the elemental composition of wild cherry extract was much lower than in other nonoakwood extracts, and all investigated wood extracts have lower content of traceelements than maximum allowable concentration in fruit brandies.

In the production of some alcoholic beverages one of the most important practices is the ageing process in a presence of wood. This process contributes to improved sensory characteristics such as aroma, color, taste and astringency. Although oak heartwood is the most used material in cooperage, other species such as chestnut, cherry, and mulberry can be also considered. Currently, limited published data are available on the mineral content of the wood extract from cooperage industry, although some research was done to investigate the content of heavy metals in alcoholic beverages1, especially in wine2. Daily consumption of the wine and brandy with an elevated content of heavy metals might cause chronical poisoning. To avoid this issue, the maximum allowable concentration (MAC, mg L–1) in fruit brandies were established for lead, zinc, arsenium, and copper.1 The aim of this research was to investigate elemental composition of ethanolic extracts, obtained from alternative wood species used in Balkan cooperage, such as mulberry (Morus alba L.), Myrobalan plum (Prunus cerasifera Ehrh.), black locust (Robinia pseudoacacia L.), and wild cherry (Prunus avium (L.) L.). Elements were determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results indicated that the elemental composition of wild cherry extract was much lower than in other nonoak wood extracts, and all investigated wood extracts have lower content of trace elements than maximum allowable concentration in fruit brandies.

In the production of some alcoholic beverages one of the most important practices is theageing process in a presence of wood. This process contributes to improved sensorycharacteristics such as aroma, color, taste and astringency. Although oak heartwood isthe most used material in cooperage, other species such as chestnut, cherry, and mulberrycan be also considered. Currently, limited published data are available on the mineralcontent of the wood extract from cooperage industry, although some research was doneto investigate the content of heavy metals in alcoholic beverages1, especially in wine2.Daily consumption of the wine and brandy with an elevated content of heavy metalsmight cause chronical poisoning. To avoid this issue, the maximum allowableconcentration (MAC, mg L–1) in fruit brandies were established for lead, zinc, arsenium,and copper.1The aim of this research was to investigate elemental composition of ethanolic extracts,obtained from alternative wood species used in Balkan cooperage, such as mulberry(Morus alba L.), Myrobalan plum (Prunus cerasifera Ehrh.), black locust (Robiniapseudoacacia L.), and wild cherry (Prunus avium (L.) L.). Elements were determined byinductively coupled plasma-optical emission spectroscopy (ICP-OES). Results indicatedthat the elemental composition of wild cherry extract was much lower than in other nonoakwood extracts, and all investigated wood extracts have lower content of traceelements than maximum allowable concentration in fruit brandies.

Robinia pseudoacacia L. occupies large areas of Mediterranean riparian zones of the northeast of the Iberian Peninsula. This study investigates the influence of the invasive alien nitrogen-fixing R. pseudoacacia on leaf litter nitrogen (N) inputs and soil N availability in a mixed riparian forest in NE Spain. We measured annual leaf litter N inputs, decomposition rates, soil N processes, and soil N concentrations at three sections (near-stream, intermediate, and hillslope) across a riparian forested zone. Moreover, we explored changes in soil N availability associated with the presence of R. pseudoacacia by means of an empirical forest floor model. Leaf litter N content was higher for R. pseudoacacia than for the native non-fixing species. Although the contribution of R. pseudoacacia to annual leaf litter N inputs increased from the near-stream to the hillslope section, soil N mineralization, nitrification, and N availability were similar among sections. Simulations suggest that soil N availability was higher at the near-stream than at the hillslope section without the presence of R. pseudoacacia. However, this pattern smoothed down as R. pseudoacacia spread across the riparian forest. Overall, our results suggest that the spreading of R. pseudoacacia across the riparian zone contributed to homogenize soil N availability over time, and highlight that an integrated spatiotemporal view of the invasive process is needed to assess its impact on soil N biogeochemistry.

In the production of some alcoholic beverages one of the most important practices is theageing process in a presence of wood. This process contributes to improved sensorycharacteristics such as aroma, color, taste and astringency. Although oak heartwood isthe most used material in cooperage, other species such as chestnut, cherry, and mulberrycan be also considered. Currently, limited published data are available on the mineralcontent of the wood extract from cooperage industry, although some research was doneto investigate the content of heavy metals in alcoholic beverages1, especially in wine2.Daily consumption of the wine and brandy with an elevated content of heavy metalsmight cause chronical poisoning. To avoid this issue, the maximum allowableconcentration (MAC, mg L–1) in fruit brandies were established for lead, zinc, arsenium,and copper.1The aim of this research was to investigate elemental composition of ethanolic extracts,obtained from alternative wood species used in Balkan cooperage, such as mulberry(Morus alba L.), Myrobalan plum (Prunus cerasifera Ehrh.), black locust (Robiniapseudoacacia L.), and wild cherry (Prunus avium (L.) L.). Elements were determined byinductively coupled plasma-optical emission spectroscopy (ICP-OES). Results indicatedthat the elemental composition of wild cherry extract was much lower than in other nonoakwood extracts, and all investigated wood extracts have lower content of traceelements than maximum allowable concentration in fruit brandies.

In the production of some alcoholic beverages one of the most important practices is theageing process in a presence of wood. This process contributes to improved sensorycharacteristics such as aroma, color, taste and astringency. Although oak heartwood isthe most used material in cooperage, other species such as chestnut, cherry, and mulberrycan be also considered. Currently, limited published data are available on the mineralcontent of the wood extract from cooperage industry, although some research was doneto investigate the content of heavy metals in alcoholic beverages1, especially in wine2.Daily consumption of the wine and brandy with an elevated content of heavy metalsmight cause chronical poisoning. To avoid this issue, the maximum allowableconcentration (MAC, mg L–1) in fruit brandies were established for lead, zinc, arsenium,and copper.1The aim of this research was to investigate elemental composition of ethanolic extracts,obtained from alternative wood species used in Balkan cooperage, such as mulberry(Morus alba L.), Myrobalan plum (Prunus cerasifera Ehrh.), black locust (Robiniapseudoacacia L.), and wild cherry (Prunus avium (L.) L.). Elements were determined byinductively coupled plasma-optical emission spectroscopy (ICP-OES). Results indicatedthat the elemental composition of wild cherry extract was much lower than in other nonoakwood extracts, and all investigated wood extracts have lower content of traceelements than maximum allowable concentration in fruit brandies.

Research Highlights: Plant cover drives the activity of the microbial decomposer community and affects carbon (C) sequestration in the soil. Despite the relationship between microbial activity and C sequestration in the soil, potential inhibition of soil microbial activity by plant cover has received little attention to date. Background and Objectives: Differences in soil microbial activity between two paired stands on soil at a very early stage of formation and a common story until afforestation, can be traced back to the plant cover. We hypothesized that in a black locust (Robinia pseudoacacia L.) stand the high-quality leaf litter of the tree, and that of the blackberry (Rubus fruticosus L.) understory had an inhibitory effect on soil microbial community resulting in lower mineralization of soil organic matter compared to the paired black pine (Pinus nigra Arn.) stand. Materials and Methods: We estimated potential mineralization rates (MR), microbial (MB), and active fungal biomass (AFB) of newly-shed litter, forest floor, and mineral soil. We tested the effects of litters' water extracts on soil MR, MB, AFB and its catabolic response profile (CRP). Results: Newly-shed litter of black locust had higher MR than that of blackberry and black pine; MR, MB, and AFB were higher in forest floor and in mineral soil under black pine than under black locust. Water extracts of black locust and blackberry litter had a negative effect on the amount, activity of microorganisms, and CRP. Conclusions: The results demonstrate the potential for black locust and blackberry litter to have a marked inhibitory effect on decomposer microorganisms that, in turn, reduce organic matter mineralization with possible consequences at the ecosystem level, by increasing C sequestration in mineral soil.

The possibility of using mixtures of species in an attempt to increase biomass yield in plantations managed in short rotation coppice (SRC) has received little attention in scientific literature. The hypothesis is that mixtures of two complementary species under SRC are more productive than monocultures. The objective of this study was to compare the growth and yield of mixtures and monocultures at the tree and stand levels. A mixed plantation of Populus alba L. genotype ‘111’ (P) and the nitrogen-fixing species Robinia pseudoacacia L. genotype ‘Nyirsegi’ (R) was established in 2012 in the centre of Spain, at a density of 10,000 trees per hectare (spacing 0.4m×2.5 m). The experimental design included pure as well as mixtures with different proportions of the species (100P:0R; 75P:25R; 50P:50R; 25P:75R and 0P:100R) following a completely randomized block design with 64 trees per plot. There was a positive effect of the mixture 75P:25R in terms of biomass yield, achieving a total yield of 13.66 Mg ha−1 yr−1 (26.83% higher than that of the P. alba monoculture and 89.99% higher than the R. pseudoacacia monoculture), with both species achieving a greater biomass yield per tree. In the other mixture treatments there was no significant positive effect of the nitrogen (N) fixing species on the non-N-fixing species. Within-row interactions were more important than between row-interactions. There was a positive effect on the yield of R. pseudoacacia when the neighbouring trees (within a row) on both sides were P. alba, while P. alba responded better with a P. alba tree on one side and a R. pseudoacacia tree on the other. The results point to the presence of competitive reduction or facilitation as the mechanisms for increased biomass yield under certain mixture ratios, and indicates the importance of mixing within the same row rather than row-by-row, in this type of plantation.

In this version 13 new plots of White elder and 13 new plots of Sitka spruce were added, both from the collection of the former Stichting Industriehout. This database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures.

Испитиван је утицај повећаних концентрација тешких метала, кадмијума, никла и олова, на метаболизам и биопродукцију различитих генотипова (фамилија) багрема (Robinia pseudoacacia L. 1753) у циљу дефинисања њиховог физиолошког и биохемијског одговора на различити степен загађења. Биолошки ефекат тешких метала испитиван је на биљкама гајеним на воденим хранљивим растворима и у земљишним културама. Истраживања су обухватила одређивања степена биопродукције (свежа маса корена, изданака и листова; висина биљака; укупна лисна површина), интензитет размене гасова (фотосинтеза и транспирација), садржаја фотосинтетичких пигмената (каротеноиди, хлорофил а и б), садржаја макроелемената у биљном ткиву (N, P и К) и акумулираних тешких метала, биохемијске физиолошке параметре (активност ензима нитрат-редуктазе, каталазе, аскорбат-пероксидазе, гвајакол-пероксидазе, интензитет липидне пероксидације (садржај MDA), садржај пролина) у ткивима коренова, изданака и листова. Токсични ефекти примењених метала су зависили од испитиване фамилије багрема (генотипа) и врсте метала, а испољили су се у редукцији интензитета фотосинтезе и транспирације, као и у променама активности ензима укључених у антиоксидативне механизме заштите. Изразитити симптоми токсичности били су евидентни код биљака гајених методом водених култура, где је присуство метала у раствору довело до значајних поремећаја водног биланса у виду смањенетранспирације и проводљивости стома. Регистровано је такође сигнификантно смањење интензитета фотосинтезе биљака гајених на третману никлом. Активност ензима укључених у антиоксидативне механизме заштите показала се као поуздан индикатор стреса изазваног тешким металима. Хидропоним тестовима утврђен потенцијал испитиваних фамилија багрема за фитоекстракцију метала класификује их у категорију хиперакумулатора. Поред тога, значајна акумулација тешких метала у корену биљака указује на велики потенцијал ових фамилија у процесу фитостабилизације полутаната у земљишту. Поред наведеног, Ispitivan je uticaj povećanih koncentracija teških metala, kadmijuma, nikla i olova, na metabolizam i bioprodukciju različitih genotipova (familija) bagrema (Robinia pseudoacacia L. 1753) u cilju definisanja njihovog fiziološkog i biohemijskog odgovora na različiti stepen zagađenja. Biološki efekat teških metala ispitivan je na biljkama gajenim na vodenim hranljivim rastvorima i u zemljišnim kulturama. Istraživanja su obuhvatila određivanja stepena bioprodukcije (sveža masa korena, izdanaka i listova; visina biljaka; ukupna lisna površina), intenzitet razmene gasova (fotosinteza i transpiracija), sadržaja fotosintetičkih pigmenata (karotenoidi, hlorofil a i b), sadržaja makroelemenata u biljnom tkivu (N, P i K) i akumuliranih teških metala, biohemijske fiziološke parametre (aktivnost enzima nitrat-reduktaze, katalaze, askorbat-peroksidaze, gvajakol-peroksidaze, intenzitet lipidne peroksidacije (sadržaj MDA), sadržaj prolina) u tkivima korenova, izdanaka i listova. Toksični efekti primenjenih metala su zavisili od ispitivane familije bagrema (genotipa) i vrste metala, a ispoljili su se u redukciji intenziteta fotosinteze i transpiracije, kao i u promenama aktivnosti enzima uključenih u antioksidativne mehanizme zaštite. Izrazititi simptomi toksičnosti bili su evidentni kod biljaka gajenih metodom vodenih kultura, gde je prisustvo metala u rastvoru dovelo do značajnih poremećaja vodnog bilansa u vidu smanjenetranspiracije i provodljivosti stoma. Registrovano je takođe signifikantno smanjenje intenziteta fotosinteze biljaka gajenih na tretmanu niklom. Aktivnost enzima uključenih u antioksidativne mehanizme zaštite pokazala se kao pouzdan indikator stresa izazvanog teškim metalima. Hidroponim testovima utvrđen potencijal ispitivanih familija bagrema za fitoekstrakciju metala klasifikuje ih u kategoriju hiperakumulatora. Pored toga, značajna akumulacija teških metala u korenu biljaka ukazuje na veliki potencijal ovih familija u procesu fitostabilizacije polutanata u zem, The influence of increased concentrations of heavy metals, cadmium, nickel and lead on the metabolism and bioproduction of different genotypes (half-siblings) of black locust (Robinia pseudoacacia L. 1753) was investigated in order to define their physiological and biochemical responses to different pollution levels. The biological effect of heavy metals was tested on plants grown in aquatic nutrient solutions and in soil cultures. Тhe investigations included determination of biological production degree (fresh weight of roots, stems and leaves, plant height, total leaf area), the rate of gas exchange (photosynthesis and transpiration), the photosynthetic pigments content (carotenoids, chlorophyll a and b), the contents of major macronutrients in plant tissue (N, P and K) and the accumulated heavy metals, physiological biochemical parameters (activity of the enzymes: nitrate reductase, catalase, ascorbate peroxidase, guaiacol peroxidase, lipid peroxidation (MDA content), the content of proline) in tissues of roots, stems and leaves. Toxic effects of applied treatments differed between tested plant genotypes and applied metal, resulting with depletion of the photosynthetic and transpiration rate, and further altering the activity of antioxidative enzymes. Major influence of applied metals were observed on plants grown in nutrient solution where the presence of heavy metals had caused water status disbalance, resulting with decrease in transpiration rate and stomatal conduction. Results related to the activity of enzymes involved in antioxidative protection indicated significance and relevance of these metabolic parametars in research of heavy metals stress in plants. Besides aforementioned , the potential forphytoextraction purposes was confirmed through hydroponic trials. Obtained results for heavy metal accumulation in plant tisuess have determined these families as heavy metal hyperaccumulators. Likewise, significant accumulation of metals in root tissues might be

Field trials were conducted in 2010 and 2011 to evaluate floristic composition of weeds and the efficacy of pre herbicides in black locust (Robinia pseudoacacia L.) nurseries. The weed population in both years was consisted mainly of annual spring and summer weeds, and some perennial weeds. The weediness in both years was relatively high. Weed density in the untreated control plots was 106.5 plants per m2 in 2010 and 87.4 plants per m2 in 2011. The most dominant weeds were Chenopodium album, Polygonum aviculare and Amaranthus retroflexus in 2010 and Polygonum aviculare, Tribolus terestris and Cynodon dactilon in 2011. By taxonomic aspect, the weed flora was distributed in 11 families. 15 weed species were dicotyledons and 2 weed species were monocotyledons. Terophytes were the dominant life form weed category in black locust nurseries. Efficacy of herbicides 28 days after treatment (DAT) ranged from 91.0% (pendimethalin) to 95.3% (linuron) in 2010, and 74.5% (linuron) to 88.0% (pendimethalin) in 2011, respectively. Efficacy of herbicides 56 DAT ranged from 93.6% (pendimethalin) to 98.3% (linuron) in 2010, and from 74.8% (linuron) to 83.1% (pendimethalin) in 2011, respectively. Prevailing weed control by herbicides was not consistent over the years. However, efficacy of herbicides in control of prevailing weeds 28 and 56 DAT ranged from 88% to 100% in 2010 and 7% to 86% in 2011, respectively. Lower herbicide efficacy in 2011 was most likely due to high precipitation occurred immediately after herbicide application and domination of perennial weeds, particularly Cynodon dactilon.

Field trials were conducted in 2010 and 2011 to evaluate floristic composition of weeds and the efficacy of pre herbicides in black locust (Robinia pseudoacacia L.) nurseries. The weed population in both years was consisted mainly of annual spring and summer weeds, and some perennial weeds. The weediness in both years was relatively high. Weed density in the untreated control plots was 106.5 plants per m2 in 2010 and 87.4 plants per m2 in 2011. The most dominant weeds were Chenopodium album, Polygonum aviculare and Amaranthus retroflexus in 2010 and Polygonum aviculare, Tribolus terestris and Cynodon dactilon in 2011. By taxonomic aspect, the weed flora was distributed in 11 families. 15 weed species were dicotyledons and 2 weed species were monocotyledons. Terophytes were the dominant life form weed category in black locust nurseries. Efficacy of herbicides 28 days after treatment (DAT) ranged from 91.0% (pendimethalin) to 95.3% (linuron) in 2010, and 74.5% (linuron) to 88.0% (pendimethalin) in 2011, respectively. Efficacy of herbicides 56 DAT ranged from 93.6% (pendimethalin) to 98.3% (linuron) in 2010, and from 74.8% (linuron) to 83.1% (pendimethalin) in 2011, respectively. Prevailing weed control by herbicides was not consistent over the years. However, efficacy of herbicides in control of prevailing weeds 28 and 56 DAT ranged from 88% to 100% in 2010 and 7% to 86% in 2011, respectively. Lower herbicide efficacy in 2011 was most likely due to high precipitation occurred immediately after herbicide application and domination of perennial weeds, particularly Cynodon dactilon.

The hygroscopicity and the dimensional changes of black locust heartwood were investigated in relation to the progressive removal of hot-water extractives. Extraction in the original specimen form removed only part of the total 8.434 % hot-water extractives, 3.601 % in first extraction and 4.642 % in second extraction. As a result, the adsorption and desorption behaviour of black locust wood was little affected by the extraction and only a small increase was observed in dimensional changes at every RH from 0 % to 97 %. The mean hysteresis coefficient was also little affected by extraction and increased from 0.75 at the unextracted stage to 0.77 at the second extraction. The initial dimensional change 3.76 % of unextracted black locust wood corresponding to RH changes between 43 % and 80 % increased after the first and second extraction to the respective values of 3.96 % and 3.97 %. Extraction had no effect on the significant, very strong linear relationships between swelling or shrinkage and equilibrium moisture content (EMC).

This article defines age of transition from juvenile to mature wood in two ring-porous species, black locust (Robinia pseudoacacia L.) and chestnut (Castanea sativa Mill.). A logistic function was proposed using fiber length and ring width data of three black locust trees, aged 35-37 yr, and five chestnut coppice trees, aged 25-27 yr, from Sithonia Peninsula, Chalkidiki, Greece. The approach proved to be practical and objective in delineating maturity zones, and it was based on rate of change of yearly fiber length. The juvenile wood zone spread to the sixth growth ring from the pith in both species, whereas the demarcation of juvenile and mature wood was at age 12 and 14 yr in chestnut and black locust, respectively. Transition zone width comprised rings 7-12 in chestnut and rings 7-14 in black locust.

Disregarding shear effects is a principal defect in predicting the bending strengths of small clear specimens of timber according to standards. The present study proposes a method to determine spans of 2 x 2 cm wood specimens of black locust and chestnut for shear free deformations in static bending. It was found that for both ring-porous species, spans of at least 40 cm in a bending test would ensure a negligible influence of shear on modulus of elasticity.

Cross-sectional discs were cut at breast height from 19 black locust trees aged 18–39 years of different clones and origin (Greece, Bulgaria and Hungarian clones J, U and NY). Ring width, latewood proportion and dry density were measured according to standard laboratory techniques in order to examine their relationships. Latewood proportion was found to increase (except for one tree from Bulgaria) with increasing ring width and logarithmic equations were calculated with relatively high correlation coefficients. A positive relation between dry density and latewood proportion was found in black locust of Bulgarian origin and in the Hungarian clone NY while in all other cases no meaningful relationship was observed. In mature wood, improved positive linear correlations were observed between dry density and latewood proportion with the exception of the Hungarian clone U. Regression analysis revealed low correlations between dry density and ring width and only black locust from Bulgaria had a high positive correlation. The positive correlations between dry density and ring width were slightly improved in mature wood with the exception of clone J from Hungary.

The relationship between wood density (WD) and fibre length (FL) with cambium age (CA) and ring width (RW) was studied in two ring-porous species, black locust and coppice-grown chestnut, collected in the Sithonia Peninsula, Chalkidiki, Greece. Using regression analysis methods, models of WD and FL in relation to CA and RW were obtained. It was found that the effect of CA and RW on WD and FL was similar for both species examined. WD of black locust and chestnut was predicted better through a model using CA and RW. A model for FL variations was also obtained with CA and RW and was more accurate than the simple models based on the two factors, CA and RW, separately. The multiple regression models suggested that the use of cambial age of growth rings together with their width might explain better their effects on WD and FL of black locust and chestnut.

This study was undertaken to investigate the strength properties of juvenile and mature wood in black locust (Robinia pseudoacacia L.). Wood specimens were prepared from various stem heights, up to 9 m, of five naturally-grown black locust trees, 21-37 years old. Mechanical properties tested included moduli of rupture (MOR) and elasticity (MOE), and pure modulus of elasticity (PMOE) in static bending, stress wave modulus of elasticity (SWMOE) in dynamic strength, axial compression, and toughness. Comparisons between juvenile and mature wood specimens of similar densities (0.667-0.894 g/cm3 and 0.682-0.892 g/cm3, respectively) showed that juvenile wood had a statistically significant lower mean MOR (138.78 N/mm2), MOE (13,936 N/mm2), PMOE (18,125 N/mm2), SWMOE (16,813 N/mm2) and toughness strength (155.25 KJ/m2) than the mature wood (148.29 N/mm2, 14,747 N/mm2, 19,498 N/mm2, 17,635 N/mm2 and 181.27 KJ/m2, respectively). On the contrary, no statistically significant differences were found for the mean strength in axial compression among juvenile (63.75 N/mm2) and mature wood (66.65 N/mm2). Fractured surfaces of juvenile and mature wood specimens in static bending and toughness were classified into the "splintering tension" type of failure, while compression failures were of the "shearing type" according to ASTM D 143-83 standards. Lower strength of juvenile wood in most of the properties examined may be attributed to anatomical and chemical properties rather than density of wood specimens. The adverse influence of juvenile wood on strength properties should be considered for effective management (e.g. longer rotation age and other genetic and forest or plantation management measures that reduce juvenile wood content) and utilization of the species.

Black locust (Robinia pseudoacacia L.) is regarded as an important natural resource almost throughout the world but relatively little is known about the within-tree variability of the anatomical characteristics of its wood. Discs 2 cm thick were cut at 2.25 m intervals, from the ground level to the top from ten black locust trees, 18–37-years-old, from the University Forest of Taxiarchi, Chalkidiki, Greece. The discs were used for the determination of growth rate and cell dimensions (fiber length and vessel member length and diameter) and their withintree variability (radial, oblique, vertical). Growth rate increased within the first 5–9 growth rings from the pith and then gradually decreased. Oblique variation of growth rate did not exhibit any clear tendency but a decrease at the top. In the case of vertical variation, growth rate decreased gradually with the year of cambium formation. Radial variability curves were found to be typical for the dimensions of cells (fibers, vessel members) especially for the fiber length. A rapid increase in cell dimensions was observed in the first 7–11 growth rings, the juvenile zone. Oblique and vertical variation of cell dimensions did not exhibit any clear tendencies.

Common throughout the mesic upland woods

Wooded hillside