Six hundred 7-year-old Eucalyptusnitens (Dean & Maid.) trees from 50 open-pollinated families were measured for wood density and Pilodyn penetration across two contrasting sites in eastern Victoria, Australia. Eight Pilodyn observations, two from each of four aspects, were made at a height of 1.3 m. Density was measured on whole disks cut from 1.3 m. Heritability of Pilodyn penetration and disk density at 1.3 m were 0.60 and 0.73, respectively. Phenotypic and genetic correlations between Pilodyn penetration and density at 1.3 m were −0.59 and −0.92, respectively. The high repeatability of Pilodyn penetration (0.90) suggests that only two observations per tree would be required for indirect selection of density. Direct index selection for density gave an expected 13% gain (assuming a selection intensity of 1%), compared with a 11% gain by using indirect Pilodyn selection, a selection efficiency of 84%. However, Pilodyn sampling is faster, cheaper, and not destructive, thus resulting in overall higher expected gains for selection of trees or culling of seedling seed orchards in comparison with the more destructive direct assessment of density.

-Wood discs were sampled from 6 heights up the stem of 248 trees representing 10 subraces and 116 families grown in an E. globulus base-population progeny trial. The lower stem had the least favourable wood properties for kraft pulpwood and most solidwood applications: bark was thickest, basic density was lowest and kino, decay and shrinkage traits were greatest at or below 12% of tree height. Significant genetic differences at the subrace level were revealed in diameter, bark thickness, basic density, decay and gross shrinkage and at the family within subrace level in diameter, basic density and decay. However, subrace-by-height-category interactions in bark thickness, basic density, decay and gross shrinkage indicated that differences among subraces were dependent on height in these traits. Examination of longitudinal trends revealed some evidence that the zone of thick basal bark extended further up the stem in thicker-barked subraces and that the Southern Tasmania subrace might be less effective than other subraces in restricting the longitudinal spread of decay after infection.wood properties / Eucalyptus globulus / longitudinal variation / within-tree variation / genetic variation Résumé -Les variations longitudinales intra-arbre des propriétés papetières et du bois varient entre les génotypes d'Eucalyptus globulus. Des disques de bois ont été prélevés à 6 hauteurs différentes dans 248 arbres représentant 10 provenances et 116 familles d'un dispositif de provenancedescendance d'E. globulus. La partie inférieure des troncs présente les propriétés du bois les moins bonnes pour la pâte Kraft et la plupart des utilisations du bois massif : l'écorce est plus épaisse, l'infradensité plus faible tandis que le lino, la dégradation biologique et les retraits sont plus importants jusqu'à 12 % de la hauteur des tiges. Des différences génétiques significatives ont été établies au niveau provenance pour le diamètre, l'épaisseur d'écorce, l'infradensité et la dégradation biologique et au niveau famille dans une provenance pour l'infradensité et la dégradation biologique. Cependant, pour ces propriétés, les interactions provenance par catégorie de hauteur, pour l'épaisseur d'écorce, l'infradensité, la dégradation biologique et le retrait total, indiquent que les différences entre provenances dépendent de la hauteur. L'analyse des variations longitudinales fait apparaître que la longueur de la bille de pied ayant une écorce plus épaisse est plus importante pour les provenances présentant des écorces épaisses et que les provenances de sud de la Tasmanie pourraient être moins efficaces que les autres pour limiter la diffusion des pourritures après infection.propriétés du bois / variation longitudinale / variation intra arbre / variation génétique / Eucalyptus globulus

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Abstract• If selective breeding is to be successful, significant genetic variation must be present in the traits targeted for improvement (i.e. "objective traits").• This study aimed to quantify genetic variation in Eucalyptus globulus pulpwood and sawn-timber objective traits (rotation-age whole-tree volume, survival, whole-tree basic density, sawn-board Janka hardness and sawn-board internal checking) and estimate additive genetic correlations between these and inexpensively-assessed "selection traits".• Significant genetic variation was identified in all objective traits at the subrace and/or family within subrace level.• Selection-age diameter at breast height (1.3 m, DBH) was strongly genetically correlated with rotation-age volume (0.78) and survival (0.82). Subrace and additive genetic correlations of selectionage Pilodyn penetration with rotation-age 12-×-12-mm-sample basic density (-0.70 and -0.75 respectively) and whole-tree basic density (-0.83 and -0.91 respectively) were also strong.• No significant subrace or additive genetic correlation between wood-sample gross shrinkage and sawn-board internal checking was detected. However, subrace and additive genetic correlations of sawn-board Janka hardness with Pilodyn penetration (-0.75 and -0.58 respectively) and sample gross shrinkage (-0.77 and -0.73 respectively) were significantly different from zero.• These findings suggest that genetic improvement of the examined objective traits is possible through selective breeding, although none of the assessed selection traits were strongly correlated with internal checking. Mots-clés :volume / survie / infradensité / dureté Janka / contrôle Résumé -Corrélations génétiques entre traits objectifs de sélection pour le bois de pâte et le bois massif d'Eucalyptus globulus.• Pour qu'un programme d'amélioration soit couronné de succès, une variabilité génétique significative doit être présente dans les traits cibles de la sélection.• Cette étude visait à quantifier les variations génétiques des traits cibles du bois à pâte et du bois de sciage d'Eucalyptus globulus (âge de révolution, volume de l'arbre entier, survie, infradensité de l'arbre entier, indice de dureté de Janka des sciages et fissures internes des sciages) et à estimer les corrélations génétiques additives entre ces traits et une sélection de caractéristiques évaluées à peu de frais.• Des variations génétiques significatives ont été détectées pour tous les traits cibles au niveau de la provenance et/ou de la famille dans la provenance.• Le diamètre à hauteur de poitrine (1,3 m, DBH) présentait une forte corrélation génétique avec le volume en fin de révolution (0,78) et la survie (0,82). • Ces résultats suggèrent que l'amélioration génétique des traits-cibles examinés est possible par le biais d'une sélection bien qu'aucun des traits cibles évalués n'était fortement corrélé avec un contrôle interne.

-A system where carbon sequestration was directly dependent upon biomass production in a plantation was modelled to assess whether economic breeding objectives for the genetic improvement of Eucalyptus globulus were sensitive to potential revenues from carbon sequestration. Carbon dioxide equivalent accumulation in the biomass (CO 2 e) of the Australian E. globulus plantation estate established between 2004 and 2012 was estimated. Total carbon dioxide equivalent (CO 2 e) accumulation was in the order of ∼146 t CO 2 e ha −1 , of which 62 t CO 2 e ha −1 were tradable in 2012 (the 1st Kyoto Protocol commitment period) and a further 30 t CO 2 e ha −1 were tradable in 2016 (a hypothetical second Kyoto protocol commitment period). The correlated response of breeding objectives with and without carbon revenues (∆cG H1 ) never fell below 0.86 in sensitivity analysis, and the mean was 0.93. Where economic breeding objectives for the genetic improvement of Eucalyptus globulus for pulpwood plantations are based on maximizing net present value by increasing biomass production, the consideration of carbon revenues in economic breeding objectives will have no significant effect on the relative economic weights of the key economic traits, wood basic density and standing volume at harvest.Eucalyptus globulus / genetic improvement / economic breeding objectives / environmental services / carbon sequestration Résumé -Intégration des recettes de séquestration du carbone dans des objectifs d'amélioration économique pour la production de pâte à papier avec Eucalyptus globulus. Un système où la séquestration du carbone était directement dépendante de la production de biomasse en plantation a été modélisé pour déterminer si des objectifs d'amélioration économique pour l'amélioration génétique d'Eucalyptus globulus réagissaient sur des revenus potentiels à partir de la séquestration du carbone. Le dioxyde de carbone gaz équivalent de l'accumulation de biomasse (CO 2 e) par des plantations australiennes d'Eucalyptus globulus crées entre 2004 et 2012 a été estimé. L'accumulation de dioxyde de carbone (CO 2 e) était de l'ordre de ∼146 t CO 2 e ha −1 , dont 62 t CO 2 e ha −1 , étaient commercialisables en 2012 (période correspondant aux engagement du premier protocole de Kyoto) et 30 t CO 2 e ha −1 supplémentaires étaient commercialisables en 2016 (hypothétique second protocole de Kyoto). La réponse correspondant aux objectifs d'amélioration avec et sans recettes de carbone (∆cG H1 ) n'est jamais tombée sous 0,86 en analyse de sensibilité, et la moyenne était 0,93. Là où les objectifs d'amélioration économique pour l'amélioration génétique d'Eucalyptus globulus pour des productions de pâte à papier étaient basées sur maximalisation de la valeur actuelle nette par un accroissement de la production de biomasse, la prise en compte des recettes du carbone dans des objectifs d'amélioration économique n'aura pas d'effets significatifs sur le poids économique relatif de ces traits économiques, densité de base du bois et volume de bois su...

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Abstract. Ozone depletion and climate change are causing the Southern Annular Mode (SAM) to become increasingly positive, driving stronger winds southward in the Southern Ocean (SO), with likely effects on phytoplankton habitat due to possible changes in ocean mixing, nutrient upwelling, and sea ice characteristics. This study examined the effect of the SAM and 12 other environmental variables on the abundance of siliceous and calcareous phytoplankton in the seasonal ice zone (SIZ) of the SO. A total of 52 surface-water samples were collected during repeat resupply voyages between Hobart, Australia, and Dumont d'Urville, Antarctica, centred around longitude 142∘ E, over 11 consecutive austral spring–summer seasons (2002–2012), and spanning 131 d in the spring–summer from 20 October to 28 February. A total of 22 taxa groups, comprised of individual species, groups of species, genera, or higher taxonomic groups, were analysed using CAP analysis (constrained analysis of principal coordinates), cluster analysis, and correlation. Overall, satellite-derived estimates of total chlorophyll and measured depletion of macronutrients both indicated a more positive SAM was associated with greater productivity in the SIZ. The greatest effect of the SAM on phytoplankton communities was the average value of the SAM across 57 d in the previous austral autumn centred around 11 March, which explained 13.3 % of the variance in community composition in the following spring–summer. This autumn SAM index was significantly correlated pair-wise (p<0.05) with the relative abundance of 12 of the 22 taxa groups resolved. A more positive SAM favoured increases in the relative abundance of large Chaetoceros spp. that predominated later in the spring–summer and reductions in small diatom taxa and siliceous and calcareous flagellates that predominated earlier in the spring–summer. Individual species belonging to the abundant Fragilariopsis genera responded differently to the SAM, indicating the importance of species-level observation in detecting SAM-induced changes in phytoplankton communities. The day through the spring–summer on which a sample was collected explained a significant and larger proportion (15.4 %) of the variance in the phytoplankton community composition than the SAM, yet this covariate was a proxy for such environmental factors as ice cover and sea surface temperature, factors that are regarded as drivers of the extreme seasonal variability in phytoplankton communities in Antarctic waters. The impacts of SAM on phytoplankton, which are the pasture of the SO and principal energy source for Antarctic life, would have ramifications for both carbon export and food availability for higher trophic levels in the SIZ of the SO.

&lt;p&gt;&lt;strong&gt;Abstract.&lt;/strong&gt; Ozone depletion and climate change are causing the Southern Annular Mode (SAM) to become increasingly positive, driving stronger winds southward in the Southern Ocean (SO), with likely effects on phytoplankton habitat due to changes in ocean mixing, nutrient upwelling, and sea ice. This study examined the effect of the SAM and other environmental variables on the abundance of siliceous and calcareous phytoplankton in the seasonal ice zone (SIZ) of the SO. Samples were collected during repeat transects between Hobart, Australia, and Dumont d'Urville, Antarctica, centred around longitude 142&amp;#176;&amp;#8201;E, over 11 consecutive austral spring-summers (2002&amp;#8211;2012). Twenty-two taxa, comprised of species, genera or higher taxonomic groups, were analysed using CAP analysis, cluster analysis and correlation. The SAM significantly affected phytoplankton community composition, with the greatest influence exerted by a SAM index averaged across 57 days centred on 11th March in the preceding autumn, explaining 13.3&amp;#8201;% of the variance of taxa composition during the following spring&amp;#8211;summer, and showing correlation with the relative abundance of 12 of the 22 taxa resolved. The day through the spring-summer that a sample was collected exerted the greatest influence on phytoplankton community structure (15.4&amp;#8201;% of variance explained), reflecting the extreme seasonal variation in the physical environment in the SIZ that drives phytoplankton community succession. The response of different species of &lt;i&gt;Fragilariopsis&lt;/i&gt; spp. and &lt;i&gt;Chaetoceros&lt;/i&gt; spp. differed over the spring&amp;#8211;summer and with the SAM, indicating the importance of species-level observation in detecting subtle changes in pelagic ecosystems. This study indicated that higher SAM favoured increases in the relative-abundance of large &lt;i&gt;Chaetoceros&lt;/i&gt; spp. that predominated later in the spring&amp;#8211;summer and reductions in small diatom taxa and siliceous and calcareous flagellates that predominated earlier in the spring&amp;#8211;summer. Such changes in the taxonomic composition of phytoplankton, the pasture of the SO and principal energy source for Antarctic life, may alter both carbon sequestration and composition of higher tropic levels of the SIZ region of the SO.&lt;/p&gt;