Search results for "Robinia"
showing 10 items of 11 documents
Geometric analysis of intrusive growth of wood fibres in Robinia pseudoacacia
2018
ABSTRACT All cell types of the secondary xylem arise from the meristematic cells (initials) of the vascular cambium and grow under mechanical constraints emerging from the circular-symmetrical geometry that characterises many tree trunks. The course of intrusive growth of cambial initials has been elucidated, but is yet to be described in the case of xylem fibres. This study explains the geometry of intrusive growth of the secondary xylem fibres in the trunk of Robinia pseudoacacia. Long series of serial semi-thin sections of the vascular cambium and the differentiating secondary xylem were analysed. Since fibres grow in close vicinity to expanding cells of the derivatives of the vascular c…
Direct exposure to solar radiation causes radial growth eccentricity at the beginning of the growing season in Robinia pseudoacacia
2020
Abstract Our study investigated the effect of stem temperature increase on xylem formation in Robinia pseudoacacia tree-trunks, caused by direct exposure to solar radiation. It is important to determine factors which may improve the concentricity of deposited wood tissue and intensify xylogenesis because a strong irregularity of wood tissue deposited in the radial direction in mature trees of R. pseudoacacia reduces the commercial value of the wood. Samples of vascular cambium along with adjacent tissues were collected from the southern (illuminated) and northern (shaded) side of tree-trunks growing in the inner and peripheral (thus exposed to direct sunlight) zones of the research plot. Sa…
Regeneration of herbicide-tolerant black locust transgenic plants by SAAT
2003
A protocol based on SAAT (sonication-assisted Agrobacterium-mediated transformation) has been developed to obtain herbicide-resistant transgenic black locust (Robinia pseudoacacia L.) plants. Cotyledon explants were co-cultivated with Agrobacterium AGL1 strain carrying the pTAB16 plasmid (bar and gusA genes). The effects of bacterial concentration (OD550 of 0.3, 0.6, 0.8) and method of infection (sonication vs immersion) on bacterial delivery were determined by assaying cotyledons for transient beta-glucuronidase expression 3 days after infection. SAAT increases transient expression efficiency especially at an OD550 of 0.6. After determining bacterial concentration and infection method, oth…
Intrusive growth of initials does not affect cambial circumference in Robinia pseudoacacia
2021
AbstractThis study aimed to test the hypothesis whether intrusive growth of initial cells is related to the increase in circumference of Robinia pseudoacacia vascular cambium—both qualitatively and quantitatively. The mode of intrusive growth of cambial initial cells was also studied. Samples collected from tree trunks were examined using series of semi-thin transverse sections. Anatomical reconstructions of radial and tangential planes of analysed fragments of cambial tissue were made. Observations and measurements have shown that the intrusive growth of R. pseudoacacia initial cells does not contribute to an increase in tangential dimension of observed tissue fragments where cell rearrang…
Le principali specie arboree esotiche invasive e le categorie forestali più vulnerabili alla loro invasione nel territorio italiano
2022
In Italia, come in gran parte d’Europa, sono state introdotte numerose specie arboree esotiche che, in alcuni casi, si sono diffuse al di fuori delle aree di impianto e si sono naturalizzate, causando impatti alla biodiversità e al paesaggio. Studi recenti hanno definito la distribuzione degli alberi esotici invasivi in diversi habitat naturali e semi-naturali a scala nazionale. Sarebbe però utile soffermarsi sulla loro distribuzione tra categorie forestali, unità di classificazione dei boschi utili alla loro gestione. In questo lavoro sono state identificate le categorie forestali attualmente o potenzialmente più soggette all’invasione da parte delle specie arboree esotiche invasive, con l…
Effects of elevated ozone on physiological, anatomical and ultrastructural characteristics of four common urban tree species in China
2016
Fast urbanization has led to ozone (O3) being the main pollutant in summer in most of China. To assess future ground-level O3 effects on the service of urban greening species and clarify the underlying mechanism of O3 damage, four common urban greening species, Ailanthus altissima (AA), Fraxinus chinensis(FC), Platanus orientalis (PO) and Robinia pseudoacacia (RP) were exposed to non-filtered air (NF) and to elevated O3 (E-O3) in open-top chambers. E-O3 induced visible injury in all species as well as microscopic alterations such as collapse of the palisade parenchyma cells, callose accumulation, or chloroplast and mitochondrial accelerated senescence. E-O3 significantly reduced light-satur…
Comparison of neophyte communities of Robinia pseudoacacia L. and Acer negundo L. in the eastern Baltic Sea region cities of Riga and Kaunas
2015
Abstract In this study, we examined the species composition of neophyte communities of Robinia pseudoacacia and Acer negundo and compared the site conditions of the urban environment of two cities—Riga and Kaunas. Eighty-five plots of A. negundo and R. pseudoacacia communities were selected. Within each plot, all of the vascular plant species were recorded, and their abundance was estimated in 2014. Composite soil samples of the 0–10 cm mineral topsoil were collected for the estimation of the soil chemical properties at nine systematically distributed points in each sample plot. The soil pH KCL , exchangeable bases, total nitrogen, total organic matter, C/N ratio, and concentrations of the …
La diversité des communautés végétales des forêts alluviales de l’Allier est-elle affectée par l’invasion de l’Érable négundo, du Robinier faux-acaci…
2012
Identifiant ProdInra 270418 SPE EcolDur CT3; Master; L’objectif de notre étude a été d’analyser les effets de l’invasion de 3 espèces végétales (Érable négundo, Robinier faux-acacia, Renouée de Bohême) sur la diversité spécifique et fonctionnelle ainsi que sur la structure et la composition spécifique des communautés végétales des forêts alluviales de l’Allier. Des relevés de végétation ont été réalisés dans des paires de quadrats contiguës, envahis et non envahis par les 3 espèces invasives étudiées et dans 3 habitats envahis des forêts alluviales de l’Allier (Saulaie-peupleraie de niveau topographique haut et bas et Chênaie pédonculée-ormaie). Complémentairement à cette approche, un gradi…
Per una check-list delle specie legnose esotiche invasive nei tipi forestali italiani
2019
Le specie esotiche invasive rappresentano una delle principali minacce globali alla conservazione della biodiversità in diversi tipi di ecosistemi, tra cui quelli forestali, dove possono costituire un rischio per la conservazione di diversi valori sociali, economici e ambientali. Sebbene la maggior parte delle specie forestali invasive si rinvenga in habitat antropizzati o disturbati dalle attività umane, alcune di queste sono in grado di influenzare anche i processi ecosistemici delle foreste semi-naturali. In particolare, è stato osservato che le specie esotiche invasive possono entrare in diverse comunità vegetali lungo le successioni secondarie la cui vegetazione potenziale è forestale.…
L'espansione delle specie legnose esotiche negli habitat naturali e seminaturali: un problema di gestione forestale attuale
2018
Le specie esotiche invasive si diffondono soprattutto in aree antropizzate, dove riescono ad occupare spazi lasciati liberi dalle specie autoctone e dalle comunità da esse edificate. In questi ultimi anni, tuttavia, numerose specie arboree ed arbustive esotiche si stanno diffondendo in Italia, oltre che in ambienti disturbati, anche in aree naturali e semi-naturali. È questo il caso dell’ailanto (Ailanthus altissima (Mill.) Swingle), una delle specie arboree esotiche invasive più diffuse e dannose negli ecosistemi forestali temperati e mediterranei di tutto il mondo. Dal punto di vista ecologico, l’ailanto mostra tutti i caratteri tipici delle specie pioniere arboree: rapido accrescimento i…