scholarly journals Managing Australia’s eucalypt gene pools: assessing the risk of exotic gene flow

2016 ◽  
Vol 128 (1) ◽  
pp. 25 ◽  
Author(s):  
Matthew J. Larcombe ◽  
Brad M. Potts ◽  
Rebecca C. Jones ◽  
Dorothy A. Steane ◽  
João Costa E. Silva ◽  
...  
Keyword(s):  
Gene Flow ◽  
Solid Wood ◽  
Biological Data ◽  
Wood Products ◽  
Gene Pools ◽  
Centre Of Origin ◽  
Eucalypt Species ◽  
Eucalypt Plantations ◽  
Plantation Species ◽  
The Many

Most eucalypts are endemic to Australia but they have been introduced into more than 100 countries and there are now over 20 million hectares of eucalypt plantations globally. These plantations are grown mainly for pulpwood but there is expanding interest in their use as a renewable source of solid wood products and energy. In Australia, the eucalypt plantation estate is nearing one million hectares, located mainly in temperate regions and dominated by Eucalyptus globulus and E. nitens (subgenus Symphyomyrtus), which are grown mainly outside their natural ranges. While eucalypt species from different major subgenera do not hybridise, hybrids within subgenera are often reported, including hybrids with plantation species. Concerns were raised in the late 1990s that pollen-mediated gene flow from locally exotic plantation eucalypts may affect the integrity of adjacent native eucalypt gene pools. As Australia is the centre-of-origin of most eucalypt species used in plantations around the world, exotic gene flow is one of the many issues that require management for industry sustainability and certification purposes. We here summarise over a decade of research aimed at providing the framework and biological data to help assess and manage the risk of gene flow from these plantations into native gene pools in Australia.

scholarly journals Silvicultura de plantaciones de Eucaliptos para productos de madera sólida de alto valor en el Sur de Australia = Silviculture of eucalypt plantations in Southern Australia for high-value solid wood products

2007 ◽  
Vol 13 (1) ◽  
pp. 43-57
Author(s):  
T.G. Baker ◽  
P.W. Volker
Keyword(s):  
Eucalyptus Globulus ◽  
Solid Wood ◽  
Wood Products ◽  
Eucalypt Plantations ◽  
El Sistema

La mayoría de las plantaciones de Eucalyptus han sido establecidas en la región templada de Australia (Australia Occidental, Australia Meridional, Victoria y Tasmania). Eucalyptus globulus es la principal especie en el área, con casi todas las plantaciones bajo el sistema de rotación corta para la producción de pulpa. En Tasmania y en Victoria, tal como en Chile, E. nitens ha sido utilizado como un sustituto de E. globulus, particularmente donde las bajas temperaturas son una limitante para esta última especie. La creciente reserva de bosques naturales, que han sido la fuente del tradicional recurso de la madera aserrada, ha despertado el interés en los productos de madera sólida de estas nuevas plantaciones de Eucalyptus. Hay resistencia a la utilización de la madera solida de Eucalyptus proveniente de plantaciones, principalmente de las industrias procesadoras debido a las dudas sobre la calidad de la madera y la idoneidad de las trozas para el procesamiento. Se requerirán muchas investigaciones para despejar estos temores. Este artículo describe algunos resultados de las investigaciones sobre las propiedades madereras y silvícolas de las plantaciones de Eucalyptus en el sur de Australia, además de las actuales prioridades y actividades de investigación.

scholarly journals The effect of time and site on incidence and spread of pruning-related decay in plantation-grown Eucalyptus nitens

2005 ◽  
Vol 35 (3) ◽  
pp. 495-502 ◽  
Author(s):  
Karen M Barry ◽  
Malcolm F Hall ◽  
Caroline L Mohammed
Keyword(s):  
Quantitative Information ◽  
Solid Wood ◽  
Fungal Species ◽  
Wood Products ◽  
Eucalyptus Nitens ◽  
Ongoing Research ◽  
Yield And Quality ◽  
Eucalypt Plantations ◽  
The Future ◽  
Over Time

Quantitative information on stem decay in eucalypt plantations grown for solid wood products, with consideration of the effect of site, pruning, and spread of decay with time, is required for the prediction of harvest yield and quality. A trial at three Eucalyptus nitens (Dean & Maiden) Maiden plantations in Tasmania revealed that the effect of time on the number and size of decay columns was substantially greater than the effect of site or of whether trees were pruned or not. Length of decay columns was 3.4-fold greater on average for the trees assessed 5.5 years after pruning than at 1 year. All decay columns in pruned trees were restricted to the knotty core, and the amount of decay-free clearwood increased over time. A controlled wounding trial showed that decay in sapwood was not significantly different in length with site but was mainly determined by the fungal species used. Ongoing research to monitor the spread of decay in pruned plantation-grown E. nitens will be important to enable prediction of the future impact of decay on harvest yields of solid wood products.

scholarly journals Physico-mechanical properties of thermally modified Eucalyptus nitens wood for decking applications

2019 ◽  
Vol 70 (3) ◽  
pp. 235-245 ◽  
Author(s):  
Maximilian Wentzel ◽  
Óscar González-Prieto ◽  
Christian Brischke ◽  
Holger Militz
Keyword(s):  
Brinell Hardness ◽  
Good Alternative ◽  
Solid Wood ◽  
Thermal Modification ◽  
Wood Products ◽  
Added Value ◽  
Eucalyptus Nitens ◽  
Plantation Species ◽  
The Moment ◽  
Quality Material

Eucalyptus nitens is a fast growing plantation species that has a good acclimation in Spain and Chile. At the moment it is mainly used for pulp and paper production, but there is a growing market for solid wood products made from this species. Thermal modification offers a good alternative to produce high quality material to manufacture products with high added value. This study used unmodified and thermally modified E. nitens wood from Spanish and Chilean plantations to elaborate external decking and examine if it complies with the necessary properties to be a competitive product. A process similar to ThermoWood® was applied at the following temperatures: 185 °C, 200 °C and 215 °C. For each modification and for an unmodified specimen mass loss, volumetric swelling, anti-swelling efficiency (ASE) and equilibrium moisture content (EMC) were determined. Brinell hardness, dynamic hardness, screw and nail withdrawal resistance, and abrasion resistance according to the Shaker method and the Taber Abraser method were also determined. According to this study, thermally modified E. nitens from both countries showed high potential to be used as decking material, particularly when modified at 200 °C.

Genetic pollution of native eucalypt gene pools—identifying the risks

2003 ◽  
Vol 51 (1) ◽  
pp. 1 ◽  
Author(s):  
B. M. Potts ◽  
R. C. Barbour ◽  
A. B. Hingston ◽  
R. E. Vaillancourt
Keyword(s):  
Related Species ◽  
Native Species ◽  
Management Strategies ◽  
Pollen Dispersal ◽  
Rapid Expansion ◽  
Gene Pools ◽  
European Settlement ◽  
Genetic Pollution ◽  
Plantation Species ◽  
Eucalypt Woodlands

The contamination of native-eucalypt gene pools via exotic pollen is of concern as (i) pollen dispersal is believed to be much more widespread than seed dispersal, (ii) reproductive barriers are often weak between closely related species, (iii) European settlement has already had a major impact on Australia's eucalypt woodlands and mallee, (iv) there has been a rapid expansion of eucalypt plantations and restoration plantings in Australia and (v) Australia is the custodian of an internationally important genetic resource. Pollen flow between plantation and native eucalypt species has already been reported and implementation of strategies to minimise the risk and consequences of genetic pollution is important if Australian forestry is to be considered sustainable. The risks associated with the introduction of non-native species, provenances and hybrids include direct effects on the gene pool through genetic pollution as well as indirect effects on dependent biodiversity. In many cases, the risk of genetic pollution will be small due to strong barriers to hybridisation between distantly related species, differences in flowering time or poor fitness of hybrids. There is no risk of hybridisation between species from the different major eucalypt genera and/or subgenera (e.g. symphyomyrts, monocalypts, eudesmids, bloodwoods and angophora). The main plantation species are symphyomyrts and within this subgenus, the probability of successful hybridisation generally decreases with increasing taxonomic distance between species. The planting of non-local provenances or improved material within the range of native populations has the potential to have an impact on local gene pools to varying degrees, indicating the requirement for the adoption of management strategies to reduce this risk. Naturally small or remnant populations are at particular risk. A framework for assessment of the risk of genetic pollution is developed herein.

scholarly journals Low Genetic Connectivity of Strongly Inbred Ruppia brevipedunculata in Aquaculture Dominated Lagoons (Viet Nam)

2021 ◽  
Vol 2 ◽  
Author(s):  
Ludwig Triest ◽  
Jasper Dierick ◽  
Thi Thuy Hang Phan ◽  
Quang Doc Luong ◽  
Nguyen Quang Huy ◽  
...  
Keyword(s):  
Water Surface ◽  
Ecological Factors ◽  
Survival Strategies ◽  
Genetic Connectivity ◽  
Spatial And Temporal Variability ◽  
Gene Pools ◽  
Aquaculture Ponds ◽  
Genetic Differentiation Of Populations ◽  
The Many ◽  
Private Alleles

Lagoonal environments exhibit high levels of instability depending on hydrological, climatic and ecological factors, thereby influencing the distribution and structure of submerged plant communities. Conditions typically fluctuate widely due to the interaction of freshwater from rivers with saltwater from the sea, as well as from aquaculture activities that together influence submerged hydrophyte community spatial and temporal variability depending on plant survival strategies. Ruppia species feature either underwater pollination mediated by an air bubble or by the release of pollen floating at the water surface, the former promoting self-pollination. Tropical Asian Ruppia brevipedunculata Yu and den Hartog was assumed to pollinate below the water surface and identified as a separate lineage among selfed Ruppia taxa. We used nine nuclear microsatellites to estimate inbreeding levels and connectivity of R. brevipedunculata within a large SE Asian lagoon complex. Ruppia brevipedunculata meadows were strongly inbred as could be derived from the many monomorphic or totally fixed loci for unique alleles in different parts of the lagoon, which appears consistent with selfing behavior. Those from aquaculture ponds were highly inbred (FIS = 0.620), though less than open lagoon sites that showed nearly total inbreeding (FIS = 0.942). Ruppia brevipedunculata from two major lagoon parts were highly differentiated with spatially structured gene pools and a strong barrier between parts of the lagoon over a 30 km distance. Migration-n analysis indicated unidirectional though limited gene flow and following potential hydrological connectivity. Overall, private alleles under homozygote conditions explained a stronger genetic differentiation of populations situated inside aquaculture ponds than of open lagoon populations. Kinship values were only relevant up to 5 km distance in the open lagoon. Within a confined area of aquaculture ponds featuring dense vegetation in stagnant water, there would be opportunity for mixed pollination, thereby explaining the higher diversity of unique multilocus genotypes of aquaculture pond habitats. Low connectivity prevents gene pools to homogenize however promoted sites with private alleles across the lagoon. Complex hydrodynamic systems and human-made habitats enclosed by physical structures impose barriers for propagule dispersal though may create refugia and contribute to conserving regional genetic diversity.

scholarly journals Improving the accuracy of wood moisture content estimation in four European softwoods from Spain

2021 ◽  
Vol 30 (1) ◽  
pp. e002
Author(s):  
Juan I. Fernández-Golfín ◽  
Maria Conde Garcia ◽  
Marta Conde Garcia
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Electrical Resistance ◽  
Solid Wood ◽  
Wood Products ◽  
Wood Moisture Content ◽  
Accurate Estimation ◽  
Wood Moisture ◽  
Mathematical Functions ◽  
Measured Moisture Content

Aim of study: To obtain improved models to predict, with an error of less than ± 2.0%, the gravimetric moisture content in four different softwoods commonly present in the Spanish and European markets, based on electrical resistance measurements. This improved moisture content estimation is useful not only for assessing the quality of wood products, especially in the case of laminated products, during the transformation and delivery process, but also for accurately monitoring the evolution of moisture in wood present in bridges and buildings, which is of great importance for its maintenance and service life improvement.Area of study: The study was carried out on samples of Scots, laricio, radiata and  maritime pines of Spanish provenances.Material and methods: On 50x50x20 mm3 solid wood samples (36 per species, 9 per condition), conditioned at 20ºC (±05ºC) and 40±5%, 65±5%, 80±5% or 90±5% Relative Humidity (RH), electrical resistance and oven-dry moisture content was measured. The Samuelsson's model was fitted to data to explain the relationship between the two variables. The accuracy of the model was evaluated by the use of an external sample.Main results: With the proposed mathematical functions the wood moisture content can be estimated with an error of ±0.9% in the four species, confirming the effectiveness of this nondestructive methodology for accurate estimation and monitoring of moisture content.Research highlights: our results allow the improvement of the moisture content estimation technique by resistance-type methodologies.Keywords: Resistance-type moisture meter; species correction.Abbreviations used: MC: Moisture content; RH: relative Humidity; R: electrical resistance; RP: wood electrical resistance measured parallel to the grain; RT: electrical resistance measured perpendicular (transversally) to the grain; GM-MC: gravimetrically measured moisture content.

scholarly journals Studi Perbandingan Analisis Struktur Rumah 2 Lantai Menggunakan Kayu Glulam dan Kayu Solid Terhadap Beban Gempa. (Hal. 85-94)

2019 ◽  
Vol 5 (1) ◽  
pp. 85
Author(s):  
Ramdhan Taufik ◽  
Erma Desmaliana ◽  
Amatulhay Pribadi
Keyword(s):  
Construction Material ◽  
Pushover Analysis ◽  
Solid Wood ◽  
Wood Products ◽  
Basic Material ◽  
Class Iii ◽  
Base Shear ◽  
Non Linear ◽  
The Difference ◽  
Immediate Occupancy

ABSTRAKKondisi geografis Indonesia memiliki struktur tektonik kompleks. Kondisi ini membuat perencanaan rumah tinggal 2 (dua) lantai membutuhkan pertimbangan khusus dari segi kekuatan dan kekakuan. Penggunaan material kayu sebagai bahan konstruksi di Indonesia masih jarang digunakan. Kayu glulam adalah suatu produk kayu rekayasa yang dibuat dari beberapa bilah kayu yang direkatkan dengan arah sejajar serat menggunakan perekat berupa lem. Penelitian ini bertujuan untuk mengidentifikasi respon struktur pada rumah tinggal menggunakan material kayu glulam dan solid dengan bantuan program ETABS 2016. Berdasarkan analisis yang telah dilakukan, diperoleh nilai periode struktur, gaya geser dasar, dan simpangan antar lantai antara seluruh model menunjukan hasil yang berbeda, perbedaan diakibatkan dari hasil konversi berat jenis dan modulus of elastisity berdasarkan BS EN 1194:1999. Berdasarkan analisis non-linier pushover didapatkan bahwa kayu glulam Nyatoh (kayu kelas III) berada pada level pada kinerja B to IO (Immediate Occupancy), dimana hasil tersebut tidak berbeda jauh dengan kayu solid Bangkirai (kayu kelas I).Kata Kunci: rumah tinggal, kayu glulam, non-linier pushover ABSTRACTGeographical condition of Indonesia has a complex tectonic structure. These conditions create  2-storyhome-planning that require special consideration in terms of strength and rigidity. The use of wood as a construction material in Indonesia is still rarely used. Glulam wood is a wood products engineering made from wooden slats several glued with the direction of the parallel fibers using adhesives. This research aims to identify the structure of the response at home using basic material glulam and solid wood with the help of ETABS 2016 programs. Based on the analysis that has been done, obtained the value of the structure periode, base shear force, and interstory drift between all models show different results, the difference is due to the results of specific gravity conversion and modulus of elasticity base on BS EN 1194:1999. Based on non-linear pushover analysis, it shows that Nyatoh glulam wood (class III wood) was at the level of the B to IO (Immediate Occupancy) performance, where the results were not much different from Bangkirai solid wood (class I wood).Keywords: home livingstructure, glulam wood, non-linear pushover

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