SEM Analysis of Glued Joints of Thermally Modified Wood Bonded with PUR and PVAc Glues.

This study deals with the scanning electron microscopy (SEM) analyses of the phase interfaces in the glued joints between Norway spruce wood elements thermally modified at 160, 180, 200, and 220 °C/4 h and polyurethane (PUR) and polyvinyl acetate (PVAc) glues with the aim of evaluating various anatomical influences of wood on the quality of joints. Due to cracked regions created in the surface of spruce wood at severe thermal modifications, the penetration depth of glues doubled from 140 to 241 μm for PUR glue, and from 100 to 200 μm for PVAc glue. The thickness of glue lines in joints was apparently higher for PVAc glue, mainly in earlywood regions; however, in joints from thermally modified (TM) woods it increased more apparently for PUR glue from 16.

Different Responses in Vascular Traits between Dutch Elm Hybrids with a Contrasting Tolerance to Dutch Elm Disease.

The ascomycetous fungus is the causative agent of the current Dutch elm disease (DED) pandemic, which has ravaged many tens of millions of European and North American elm trees. Host responses in vascular traits were studied in two Dutch elm hybrids, 'Groeneveld' and 'Dodoens', which show different vascular architecture in the secondary xylem and possess contrasting tolerances to DED. 'Groeneveld' trees, sensitive to DED, possessed a high number of small earlywood vessels.

Distinguishing the Signs of Fungal and Burial-Induced Degradation in Waterlogged Wood from Biskupin (Poland) by Scanning Electron Microscopy.

A scanning electron microscopy (SEM) investigation of pine (Pinus sylvestris) and oak (Quercus sp.) wood samples exposed to various types of natural degradation is presented with the aim of discussing the correct identification of multiple degradation signs in waterlogged wood. This is part of an experiment performed at the archeological site of Biskupin (Poland) to evaluate the dynamics of short-term wood degradation during reburial and the suitability of excavated wood as substrate for the fungal attack.

Physiological, vascular and nanomechanical assessment of hybrid poplar leaf traits in micropropagated plants and plants propagated from root cuttings: A contribution to breeding programs.

Micropropagated plants experience significant stress from rapid water loss when they are transferred from an in vitro culture to either greenhouse or field conditions. This is caused both by inefficient stomatal control of transpiration and the change to a higher light intensity and lower humidity. Understanding the physiological, vascular and biomechanical processes that allow micropropagated plants to modify their phenotype in response to environmental conditions can help to improve both field performance and plant survival.

Anatomical and morphological spine variation in Gymnocalycium kieslingii subsp. castaneum (Cactaceae).

Although spine variation within cacti species or populations is assumed to be large, the minimum sample size of different spine anatomical and morphological traits required for species description is less studied. There are studies where only 2 spines were used for taxonomical comparison amnog species. Therefore, the spine structure variation within areoles and individuals of one population of Gymnocalycium kieslingii subsp.