Ecological requirements of the threetoed woodpecker (Picoides tridactylus L.) in boreal forests of northern Sweden

The three-toed woodpecker (Picoides tridactylus L.) is a forest specialist bird, highly dependent on dead and decaying trees for foraging. I investigated the occurrence of the three-toed woodpecker in relation to vegetation characteristics including dead wood in the boreal forests of northern Sweden. Forty old forest stands were studied, were I collected data on living and dead trees, and related them to the occurrence of the three-toed woodpecker during the breeding season. Logistic regression was used to model the occurrence of the three-toed woodpecker in relation to habitat variables. I found that of all variables taken in consideration, the amount of freshly dead Norway spruce (Picea abies L.) contributed most to explaining the occurrence of three-toed woodpecker. The probability to find three-toed woodpecker in a stand increased with the basal area of freshly dead spruce, the size of the stand, the basal area of living deciduous trees and that of dying Scots pines. A probability of occurrence of 0.5 corresponded to 1.8 m²/ha of freshly dead spruce. The results refined the knowledge about three-toed woodpecker requirements, underlying the importance of spruce for foraging, and adding information on which decay stage is more preferable for the species. Taking in consideration the fact that the species is declining and included in the Swedish Red List, this study will help defining future targets for conservation management for the three-toed woodpecker

Wood properties characterisation of thermo-hydro mechanical treated plantation and native tasmanian timber species

Thermo-hydro mechanical (THM) treatments and thermo-treatments are used to improve the properties of wood species and enhance their uses without the application of chemicals. This work investigates and compares the effects of THM treatments on three timber species from Tasmania, Australia; plantation fibre-grown shining gum (Eucalyptus nitens H. Deane and Maiden), plantation saw-log radiata pine (Pinus radiata D. Don) and native-grown saw-log timber of the common name Tasmanian oak (which can be any of E. regnans F. Muell, E. obliqua L’Hér and E. delegatensis L’Hér). Thin lamellae were compressed by means of THM treatment from 8 mm to a target final thickness of 5 mm to investigate the suitability for using THM-treated lamellas in engineered wood products. The springback, mass loss, set-recovery after soaking, dimensional changes, mechanical properties, and Brinell hardness were used to evaluate the effects of the treatment on the properties of the species. The results show a marked increase in density for all three species, with the largest increase presented by E. nitens (+53%) and the smallest by Tasmanian oak (+41%). E. nitens displayed improvements both in stiffness and strength, while stiffness decreased in P. radiata samples and strength in Tasmanian oak samples. E. nitens also displayed the largest improvement in hardness (+94%) with respect to untreated samples. P. radiata presented the largest springback whilst having the least mass loss. E. nitens and Tasmanian oak showed similar dimensional changes, whilst P. radiata timber had the largest thickness swelling and set-recovery due to the high water absorption (99%). This study reported the effects of THM treatments in less-known and commercially important timber species, demonstrating that the wood properties of a fibre-grown timber can be improved through the treatments, potentially increasing the utilisation of E. nitens for structural and higher quality timber applications