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Salix interior Rowlee (INT) is a wide-ranging North American willow from the small taxonomic group Salix section Longifoliae, notable for its ability to form multi-stemmed vegetative stem colonies arising via root sprouts (RS) from a shallow horizontal root network. This study quantifies biomass production for both 1-year-old coppiced plants and the original 4-year-old plants established from dormant, unrooted stem cuttings, as well as for the RS stems associated with each ortet (original mother plant) using eight selected INT clones established on two distinct site types. Significantly greater coppiced and uncoppiced ortet stem dry mass was recorded on coarse-textured, shale rock overburden (SO); possibly due to significantly greater fertility, compared to adjacent gravel outwash deposits (GD), which had greater RS stem mass. The total stem dry mass (ortet + associated RS) was comparable across the two different site types for both the 1-year-old coppiced plants and the 4-year-old uncoppiced plants, showing rapid recovery of biomass growth and yield in the year following coppicing. Significant clonal differences, as well as site type * clone interactions, were found for ortet stem dry mass, especially on SO sites, indicating that clonal selection might be useful to increase biomass production on different site types. When expressed as a fraction of total stem dry mass produced on 2 m * 2 m biomass plots, the RS component represented a significant 57% of total stem dry mass per plot (ortet + associated RS) on GD sites and only 18% on SO sites. The use of colony-forming willows such as INT minimizes the need for periodic replanting, providing a cost advantage over conventional short-rotation, coppice-based woody biomass plantations using species that do not have the ability to produce new stems via root sprouting. This root-sprouting trait enables INT to rapidly colonize and spread on difficult-to-manage sites, making it suitable for use in land reclamation. Key words: biomass partitioning, coppice biomass production, clonal variation, root sprout stem colony formation, Salix interior, site effects. Salix interior Rowlee (INT) est un saule nord-americain tres repandu appartenant au petit groupe taxonomique Salix section Longifoliae, qui est remarquable par sa capacite a former des colonies d'origine vegetative composees de nombreuses tiges provenant de drageons issus d'un reseau racinaire horizontal peu profond. La presente etude quantifie la production de biomasse par des plants recepes ages d'un an et des plants d'origine ages de quatre ans qui se sont etablis a partir de boutures dormantes sans racines, et par des drageons associes a chaque ortet (plante mere d'origine) a l'aide de huit clones de INT etablis sur deux types distincts de stations. La masse seche des tiges d'ortet recepees ou non etait significativement plus grande sur un sol recouvert d'un schiste argileux a texture grossiere (SA), peut-etre en raison de sa fertilite significativement plus elevee, que sur des depots adjacents composes de gravier d'epandage (DG) qui soutenaient une plus grande masse de drageons. La masse seche totale des tiges (ortet et drageons associes) etait semblable chez les plants recepes d'un an et les plants non recepes de quatre ans sur les deux types de stations, ce qui indique une recuperation rapide de la croissance en biomasse et de la production au cours de l'annee qui a suivi le recepage. Des differences significatives de masse seche de tige d'ortet ont ete observees entre les clones et entre les niveaux d'interaction entre le type de stations et les clones, en particulier sur les stations SA, ce qui indique que la selection clonale pourrait etre utile pour augmenter la production de biomasse sur differents types de stations. Lorsqu'elle etait exprimee en proportion de la masse seche totale des tiges produites sur des parcelles de 2 m * 2 m, la composante des drageons representait 57 % de la masse seche totale des tiges par parcelle (ortet et drageons associes) sur les stations DG et seulement 18 % sur les stations SA. L'utilisation de saules formant des colonies tel que le INT minimise le besoin de replantation periodique, ce qui constitue un avantage en matiere de cout par rapport aux plantations conventionnelles de biomasse ligneuse a courte rotation qui utilisent des especes qui n'ont pas la capacite de produire de nouvelles tiges a partir de drageons. Cette caracteristique de drageonnement permet a INT de s'etablir et de se propager rapidement sur les stations difficiles a amenager, ce qui rend ce saule approprie pour une utilisation visant la remise en etat des terres. [Traduit par la Redaction] Mots-cles : repartition de la biomasse, production de biomasse en taillis, variation clonale, formation de colonies de drageons, Salix interior, effets de la station., Introduction The genus Salix (willows) is a large taxonomic group consisting of approximately 350 species worldwide (Argus 2010). Canada has 76 native willow species (Argus 2010), some of which have [...]

Photosynthetic light response curves were parameterized for eight species in two genera, Pinus and Picea, grown in a 2 * 2 factorial of atmospheric C[O.sub.2] and soil moisture treatments. Four of the pines and three of the spruces are native to eastern North America, and the fourth spruce, Norway spruce (Picea abies (L.) Karst.), is native to Europe. There was a significant genus x C[O.sub.2] interaction in apparent quantum efficiency (AQE): spruce AQE was greater under ambient C[O.sub.2] (C[O.sub.2]) than elevated C[O.sub.2] (eC[O.sub.2]), but pine AQE were equal. Under drought treatment (DR), AQE declined for both genera. Assimilation at light saturation (Alsat) was greater for spruces than pines, and for both genera, Alsat decreased under eCO2 and DR. Water-use efficiency was greater for pines than spruces and greater for pines and unchanged for spruces under DR. Examining AQE and Alsat change (%) from aC[O.sub.2] to eC[O.sub.2], there was a significant positive relationship to biomass growth stimulation (%) across species. These relationships support the theory of sink (biomass growth) regulation of assimilation traits and also the importance of needle nitrogen. Our results in response to eC[O.sub.2] and DR suggest a shift toward increased use of pines in forest management for eastern North America. Key words: elevated C[O.sub.2], light efficiency traits, light response curves, pines and spruces, soil moisture stress. Les courbes de reponse photosynthetique a la lumiere ont ete parametrees pour huit especes appartenant a deux genres, Pinus et Picea, cultivees selon un plan factoriel comprenant deux traitements de C[O.sub.2] atmospherique et deux traitements d'humidite du sol. Les quatre especes de pins et trois especes d'epiceas sont des especes indigenes de l'est de l'Amerique du Nord et la quatrieme espece d'epicea, l'epicea commun (Picea abies (L.) Karst.), est originaire de l'Europe. Il y avait une interaction significative entre le genre et le C[O.sub.2] dans le cas du rendement quantique apparent (RQA): le RQA des epiceas etait plus eleve dans le traitement a la concentration ambiante de C[O.sub.2] (aC[O.sub.2]) que s'ils etaient exposes a une plus grande concentration de C[O.sub.2] (eC[O.sub.2]), mais le RQA des pins restait le meme. Dans le traitement emulant une secheresse (SE), le RQA diminuait chez les deux genres. L'assimilation a saturation lumineuse (Alsat) etait plus elevee chez les epiceas que chez les pins et elle diminuait chez les deux genres dans les traitements eC[O.sub.2] et SE. L'efficience de l'utilisation de l'eau etait plus elevee chez les pins que chez les epiceas et plus elevee chez les pins et inchangee chez les epiceas dans le traitement SE. L'examen de la variation (%) du RQA et de l'Alsat entre les traitements aC[O.sub.2] et eC[O.sub.2] suggere une relation positive significative avec la stimulation de la croissance de la biomasse (%) chez l'ensemble des especes. Ces relations supportent la theorie de la regulation par l'effet de puits (croissance de la biomasse) des caracteres associes a l'assimilation et aussi mettent en evidence l'importance de l'azote dans les aiguilles. Nos resultats en reaction aux traitements eC[O.sub.2] et SE suggerent d'evoluer vers une utilisation accrue des pins en amenagement forestier dans l'est de l'Amerique du Nord. [Traduit par la Redaction] Mots-cles : enrichissement en C[O.sub.2], caracteres d'efficacite lumineuse, courbes de reponse a la lumiere, pins et epiceas, stress hydrique dans le sol., Introduction Ecophysiological adaptations in carbon assimilation and growth are important for plant fitness and have significant growth and ecological implications for both intra- and inter-specific competition (Bazzaz 1979). Light utilization [...]

Atmospheric CO2 levels have been increasing, and likewise, increasing drought events have been following increasing temperatures. There is very little literature on the effects of climate change factors on early-successional deciduous species used for ecological restoration. Thus, morphological and allometric variation in four coppiced early-successional deciduous species was examined in response to a 2 × 2 factorial of ambient CO2 (aCO2, 400 ppm) and elevated CO2 (eCO2, 800 ppm), as well as well-watered and drought treatments with 15%–20% and 5%–10% volumetric moisture content, respectively, grown in sandy soil with low soil nitrogen (N) under greenhouse conditions. The four species examined were as follows: green alder (Alnus viridis subsp. crispa (Ait.) Turrill), speckled alder (A. incana subsp. rugosa (Du Roi) R.T. Clausen), gray birch (Betula populifolia (Marshall)), and white birch (B. papyrifera (Marshall)), and all are from the same phylogenetic family, Betulaceae. Genus differences in morphological and growth traits were large, especially in response to the environmental treatments used. Alders upregulated all growth traits under eCO2 because of the strong coppicing sink effect and the additional foliar N provided by the actinorhizal ability of the genus, whereas birches remained the same or slightly decreased under eCO2. As a result, alders have a significantly greater foliar N than birches, with 2.8 and 1.0%, respectively. All species reduced growth under drought, and green alder had the greatest stem dry mass growth, followed by speckled alder and then the birches. Under drought, eCO2 not only mitigated the alder drought dry mass but, in fact, doubled the stem dm, whereas eCO2 only just mitigated the birches drought response. When corrected for size using stem height, alders allocated more to stem and leaf and less to root dry mass than birches. Atmospheric CO2 and soil moisture treatments changed organ biomass allocation. The tallest stem height was the best predictor of total (above and below) dry mass. With increasing atmospheric CO2, particularly on low nutrient sites, the results show alders are capable of sequestering far more carbon than birches. In addition, with more atmospheric CO2, alders can mitigate against drought conditions better compared to birches. [ABSTRACT FROM AUTHOR]

Barren sites that lack soil are exposed to some of the harshest elements, which include high temperatures, solar radiation, wind, extreme temperature changes, and low soil moisture and nutrient conditions. An ecological restoration experiment was conducted using three site-preparation treatments, straw (S), Meri-Crusher (MC), and coarse woody debris (CWD), in a site-/no site-preparation 2 × 2 × 2 factorial on sites that had been barren for 25 years. In addition, four early successional deciduous species, white birch (WB, Betula papyrifera Marshall), gray birch (GB, Betula populifolia Marshall), green alder (GA, Alnus viridis Vill. subsp. crispa Ait), and speckled alder (SA, Alnus incana L. subsp. rugosa Du Roi), were examined. The two- and three-way interactions were almost all magnitude effects and not rank changes. Gray birch had the greatest overall first-year height growth, followed by GA, SA, and WB, with 12.1, 9.7, 9.6, and 5.6 cm, respectively. Straw doubled first-year growth, while CWD and MC increased first-year height growth by 43 and 31%, respectively. Straw's ability to retain moisture in the dry summer provided the greatest benefit. In the second year, GA had the greatest height growth, followed by SA, GB, and WB, with 42.5, 30.5, 13.4, and 13.0 cm, respectively. Alders form symbiotic relationships with N-fixing bacteria and, although this was observed in some first-year roots, they did not fully express this advantage at these severely degraded sites until the second year, which allowed them to surpass birches in growth. Site-preparation treatments furthered their height growth affect, with S, and CWD doubling second-year height growth and MC, with an increase of 25%. Alders and birches had, on average, three and one stems, respectively, and the mean stem number of alders increased under S and CWD. After two years, overall stem dry mass had very large genus and species differences with GA, SA, GB, and WB, with 58.4, 30.3, 5.4, and 4.0 g, respectively. The N-fixing ability of alders under these conditions resulted in a 13-fold stem dry mass production increase compared with birches. Straw tripled, CWD doubled, and MC increased stem dry mass by 40%. For WB, site-preparation combinations had an additive effect, whereas GB, GA, and SA had several combined site-preparation treatments showing synergistic results, which were greater than the additive effects of single treatments. Under the control (no site prep.), second-year stem dry masses for WB, GB, GA, and SA were 0.7, 1.4, 17.8, and 0.5 g, respectively. Under the three combined treatments, MC × S × CWD, WB, GB, GA, and SA had 6.6, 12.3, 115.7, and 70.6 g stem dry masses, respectively. SA is ecologically a lowland species, hence the low 0.5 g under the control; however, the result under the three combined treatments demonstrates their combined effectiveness on these barren sites. Green alder seems to be the best adapted to the sites, having the greatest stem dry mass under control, although that was considerably magnified under the site-preparation treatments. This study using combinations of treatments with these early successional species introduces a novel research concept, and similar studies in the literature are currently lacking, creating an opportunity for future exploration. [ABSTRACT FROM AUTHOR]

Atmospheric CO2 levels have been increasing, and these changes may result in differential adaptive responses in both genera and species and highlight the need to increase carbon sequestration. Ecophysiological and morphological responses of four early-successional deciduous species were examined under ambient CO2 (aCO2, 400 ppm) and elevated CO2 (eCO2, 800 ppm) treatments. The four species, all of which are used in restoration, were Alnus viridis subsp. crispa (Ait.) Turrill (green alder), A. incana subsp. rugosa (Du Roi) R.T. Clausen (speckled alder), Betula populifolia (Marshall) (gray birch), and B. papyrifera (Marshall) (white birch); all are from the same phylogenetic family, Betulaceae. We examined biochemical efficiencies, gas exchange, chlorophyll fluorescence, chlorophyll concentrations, foliar nitrogen (N), and growth traits. A general linear model, analysis of variance, was used to analyze the functional carbon efficiency and growth differences, if any, among genera, species, and provenances (only for growth traits). The alders had greater biochemical efficiency traits than birches, and alders upregulated these traits, whereas birches mostly downregulated these traits in response to eCO2. In response to eCO2, assimilation either remained the same or was upregulated for alders but downregulated for birches. Stomatal conductance was downregulated for all four species in response to eCO2. Intrinsic water use efficiency was greater for alders than for birches. Alders exhibited a consistent upregulation of stem dry mass and height growth, whereas birches were somewhat lower in height and stem dry mass in response to eCO2. Foliar N played an important role in relation to ecophysiological traits and had significant effects relative to genus (alders > birches) and CO2 (aCO2 > eCO2), and a significant genus × CO2 interaction, with alders downregulating foliar N less than did birches. Covariate analysis examining carbon efficiency traits in relation to foliar N showed clear functional responses. Both species in both genera were consistent in their ecophysiological and morphological responses to CO2 treatments. There was supporting evidence that assimilation was sink-driven, which is related to a plant organ's ability to continue to grow and incorporate assimilates. The alders used in this study are actinorhizal, and the additional available foliar N, paired with increased stem dry mass sink activity, appeared to be driving upregulation of the carbon efficiencies and growth in response to eCO2. Alders' greater carbon efficiencies and carbon sequestration in impoverished soils demonstrate that alders, as opposed to birches, should be used to accelerate ecological restoration in a world of increasing atmospheric CO2. [ABSTRACT FROM AUTHOR]

Barren, severely disturbed sites lacking soil, such as mine sites and waste deposit sites, present severe challenges to ecological service restoration because of high temperatures, solar radiation, and wind speeds; extreme temperature changes; and low soil moisture and nutrient availability. An ecological restoration experiment using three site preparation treatments was conducted. Straw (S), Meri-Crusher (MC), and coarse woody debris (CWD) were assessed in a site, no site preparation 2 × 2 × 2 factorial, including a control treatment, on sites barren for 25 years. In addition, four early-successional species: white birch (WB, Betula papyrifera Marsh), gray birch (GB, Betula populifolia Marsh), green alder (GA, Alnus viridis Vill. ssp. crispa Ait) and speckled alder (SA, Alnus incana L. ssp. rugosa Du Roi), were examined for mortality. Mortality was measured after three time periods, summer-related 2021, winter-related, and frost heave mortality (spring 2022). Summer-related mortality was predominantly influenced by S treatments (reduced mortality) and their interactions. Straw's ability to retain moisture strongly suggests it mitigated summer-related drought mortality. S interactions were not rank changes but magnitude effects. The species × straw interaction showed that SA had the greatest magnitude difference, with 25% and 3.6% summer-related mortality for NS and S treatments, respectively. SA, a hydrophilic species, accounted for nearly half the total summer-related mortality, and there were strong species effects and species interactions. The full combination of site preparation treatments had the lowest summer-related mortality, at 1%. Winter-related mortality only affected 1.9% of the total sample size, and there were no species effects or interactions, but contrary to other results, S was the leading cause of mortality due to fungal presence found on expired seedlings. For frost heave mortality, it was clear that the S treatment was effective, with 1.2% and 20.7% overall mortality for S and NS, respectively. MC alone had the greatest negative effect, with 46.9% frost heave mortality; however, when interacting with S or CWD, the mortality decreased substantially. Frost heave had no species interactions and only a species effect, with SA having the greatest mortality. Over the first full year, MC alone and control had the greatest mortality, with 60% and 38%, respectively, after one year. Overall, one-year mortality showed S reduced mortality by 27% and CWD by 19%, while MC increased mortality by approximately 4%. When treatments were combined in any way, mortality dropped significantly, showing an additive effect, with the three-combination treatment resulting in the lowest one-year mortality, of only 3.1%. Straw provided the strongest effect, both as an effective barrier to moisture evaporation, providing up to 10% more soil moisture under dry conditions and provided an effective thermal barrier that substantially reduced the frost heave mortality. Even early-successional species such as WB, GB, GA, and SA need site preparation treatments to establish and survive the first year on long-term barren lands. [ABSTRACT FROM AUTHOR]

Leaf gas exchange, [Na.sup.+], and nutrient parameters were quantified under control (CTL), medium (MST), and high (HST) saline treatments for Salix discolor Muhl. (DIS), Salix eriocephala Michx. (ERI), and Salix interior Rowlee (INT). Net photosynthesis ([P.sub.n]) increased from CTL to MST for all species but remained unchanged between MST and HST for surviving INT plants in HST. Salix interior had greater water-use efficiency (WUE) than DIS and ERI. Under CTL, INT had 13x the leaf [Na.sup.+] concentration of DIS and ERI, but INT [Na.sup.+] only increased by 17% across each saline treatment, whereas DIS and ERI leaf [Na.sup.+] increased 6.0x from CTL to MST. Salix discolor and ERI had greater cation to [Na.sup.+] ratios than INT; however, INT ratios were stable across saline treatments, whereas the DIS and ERI ratios dropped precipitously. Across species and treatments, [P.sub.n] had a significant positive relationship to total aboveground dry mass, supporting the sink regulation of [P.sub.n] theory. Also, [P.sub.n] showed a significant positive relationship to WUE and leaf N and to leaf [Na.sup.+], which probably reflects greater energy expenditure required to mitigate the higher levels of [Na.sup.+]. The saline tolerance of INT may be due to natural selection pressure in the arid regions of the southwestern United States, where it is believed to have its evolutionary origins. Key words: leaf nutrients, net photosynthesis, salinity tolerance, water-use efficiency, willows. Nous avons quantifie les echanges gazeux foliaires, le [Na.sup.+] et les parametres nutritifs de Salix discolor Muhl. (DIS), Salix eriocephala Michx. (ERI) et Salix interior Rowlee (INT) soumis a des traitements salins d'intensites nulle (TEM), moyenne (TSM) et forte (TSF). La photosynthese nette ([P.sub.n]) a augmente de TEM a TSM pour toutes les especes, mais est demeuree inchangee entre TEM et TSF dans le cas des plants survivants de INT soumis au traitement TSF. L'efficacite d'utilisation de l'eau (EUE) de INT etait plus elevee que celles de DIS et ERI. Dans le cas du traitement TEM, la concentration foliaire en [Na.sup.+] de INT etait 13 fois plus elevee que celles de DIS et ERI, mais n'a augmente que de 17% pour chaque traitement de salinite alors que la concentration foliaire en [Na.sup.+] de DIS et de ERI du traitement TSM etait 6 fois plus elevee que celle du traitement TEM. Le rapport entre les cations et le [Na.sup.+] de DIS et ERI etait plus eleve que celui de INT. Toutefois, ce rapport etait stable entre les traitements de salinite pour INT alors que ceux de DIS et ERI ont chute de facon precipitee. Pour l'ensemble des especes et des traitements, la [P.sub.n] etait significativement et positivement reliee a la biomasse aerienne seche totale, ce qui appuie la theorie stipulant que [P.sub.n] est associee a une regulation par les puits. De plus, [P.sub.n] etait significativement et positivement reliee a l'EUE, au N foliaire et au [Na.sup.+] foliaire, ce qui reflete probablement la plus grande depense d'energie necessaire pour attenuer les plus hautes concentrations de [Na.sup.+]. La tolerance a la salinite de INT peut etre due a la pression de la selection naturelle des regions arides du sud-ouest des Etats-Unis d'ou on pense que cette espece tire ses origines evolutives. [Traduit par la Redaction] Mots-cles: nutriments foliaires, photosynthese nette, tolerance a la salinite, efficacite d'utilisation de l'eau, saules., Introduction Over the past 40 years, interest in the use of willows (Salix spp.) as a source of biomass for energy has increased concomitantly with the search for alternative energy [...]

Red spruce (RS; Picea rubens Sarg.)-black spruce (BS; Picea mariana (Mill.) B.S.P.) controlled crosses (100%, 75%, 50%, 25%, and 0% RS, balance BS) showed increasingly greater height with increasing proportion of BS in each successive year. Height growth of 4-year-old ambient C[O.sub.2] (aC[O.sub.2]) grown trees was highly correlated with height of 22-year-old field-grown trees of the same or similar crosses. Bud flush was earliest in BS and declined linearly with increasing proportion of RS with no significant C[O.sub.2] effect. Percent stem (stem + branches) mass increased under elevated C[O.sub.2] (eC[O.sub.2]), a quarter of which was due to ontogeny. Conversely, percent needle mass had a significant negative relationship with increasing tree size, and there was a C[O.sub.2] x tree size interaction. Shoot-to-root ratio was greatest for BS, whereas RS had among the lowest. Hybrid index (HI) 50 had the greatest root mass allocation, lowest shoot-to-root ratio, and among the greatest total mass under eC[O.sub.2]. Growth efficiency increased with tree size and eC[O.sub.2] but decreased with HI. Percent total biomass stimulation under eC[O.sub.2] was lowest for BS at 6.5%, greatest for HI 50 at 20.3%, and RS had 17.5%. Key words: allocation, black spruce, elevated C[O.sub.2], growth, fitness, interspecific hybridization, red spruce. Des croisements diriges entre l'epinette rouge (ER; Picea rubens Sarg.) et l'epinette noire (EN; Picea mariana (Mill.) B.S.P.) (composes a 100, 75,50, 25 et0% de ER et le reste de EN) ont produit des individus dont la hauteur augmentait avec la proportion grandissante de EN pour chaque annee consecutive. La croissance en hauteur a 4 ans des arbres sous des conditions de C[O.sub.2] ambiant (aC[O.sub.2]) etait fortement correlee a la hauteur a 22 ans d'arbres ayant pousse au champ et provenant des memes croisements ou de croisements similaires. Le debourrement des bourgeons etait le plus hatif chez EN et declinait lineairement avec une proportion grandissante de ER, sans effet significatif du C[O.sub.2]. La masse de la tige (tige + branches) en pourcentage augmentait sous des conditions d'enrichissement en C[O.sub.2] (eC[O.sub.2]) et le quart de cette augmentation etait du a l'ontogenie. A l'inverse, il y avait une relation negative significative entre la masse des aiguilles en pourcentage et l'augmentation de la taille des arbres, ainsi qu'une interaction entre le C[O.sub.2] et la taille des arbres. Le rapport entre la tige et les racines de EN etait le plus eleve, alors que celui de ER etait parmi les plus faibles. Les individus avec l'indice d'hybridation (IH) 50 allouaient le plus de masse aux racines, avaient le rapport le plus faible entre la tige et les racines et parmi la plus grande masse totale sous des conditions d'eC[O.sub.2]. L'efficacite de croissance augmentait avec la taille des arbres et l'eC[O.sub.2], mais elle diminuait avec l'IH. Le pourcentage de la biomasse totale attribuable a la stimulation par l'eC[O.sub.2] etait le plus faible chez EN avec 6,5 %, le plus eleve chez les individus d'IH 50 avec 20,3 % et atteignait 17,5 % chez ER. [Traduit par la Redaction] Mots-cles : allocation, epinette noire, enrichissement en C[O.sub.2], croissance, aptitude, hybridation interspecifique, epinette rouge., Introduction Red spruce (RS; Picea rubens (Sarg.)) is an important and characteristic component of the late-successional forest of the Acadian Forest Region in eastern Canada and the northeastern United States. [...]

Leaf chlorophyll pigment and macronutrient concentrations were quantified for four willow species (Salix cordata (COR), S. discolor (DIS), S. eriocephala (ERI) and S. interior (INT)) while growing under 2 × 2 factorial of ambient and elevated CO2 and well-watered and drought-stressed soil moisture treatments (Expt. 1). After the first year, we saw no difference in stem biomass between CO2 treatments. In the following year, a second experiment was conducted on a subset of well-watered willows as a 2 × 2 factorial of atmospheric CO2 and soil fertilization (FERT). For both years of Expt. 1, chlorophyll a, b, a + b (TCC) and carotenoids (CAR) significantly downregulated in response to elevated CO2 (eCO2) and upregulated in response to drought (DRT). In Expt. 2, FERT mitigated CO2 downregulation of TCC and CAR, and upregulated TCC and CAR. Across species, ERI had the greatest pigment concentrations followed by either COR or DIS. Except for one case, INT had the lowest pigment concentrations. A significant species x FERT interaction was due to magnitude effects. The CHLa:b ratio was not affected by CO2 or DRT but did increase in response to FERT. INT had the greatest CHLa:b ratio followed by DIS, then either ERI or COR. In the second year, TCC:CAR ratio decreased in response to eCO2 and increased in response to DRT and FERT. In Expt. 1, leaf N was the only nutrient to significantly downregulate in response to eCO2; whereas all other nutrient levels remained unchanged. In response to DRT, leaf N and Mg upregulated; whereas leaf P, K, and Ca were downregulated. In response to eCO2 in Expt. 2, again only leaf N downregulated; whereas all other nutrients remained unchanged. All leaf nutrients upregulated in response to FERT. Of the four species, INT had the greatest leaf N and K, and the lowest Ca. Species variation was important, but so to was clonal variation in response to change. Indeed, INT leaf chlorophyll and macronutrients are significantly different or segregated from the other three willow species and this may be related to the evolutionary origins of INT, and other species of the taxonomic section Longifoliae, in the arid southwest USA and Mexico. Furthermore, under low nutrient conditions, it may be necessary to fertilize the plants to see a biomass response to eCO2. [ABSTRACT FROM AUTHOR]

Total belowground biomass, soil C, and N mass were measured in plots of 32-year-old black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) from four full-sib families studied previously for drought tolerance and differential productivity on a dry and a wet site. Stump root biomass was greater on the wet than on the dry site; however, combined fine and coarse root biomass was greater on the dry than on the wet site, resulting in no site root biomass differences. There were no site differences in root distribution by soil depth. Drought-tolerant families had greater stump root biomass and allocated relatively less to combined coarse and fine roots than drought-intolerant families. Fine roots ( Resume: La biomasse souterraine totale ainsi que la masse de C et de N dans le sol ont ete mesurees dans des places echantillons ou croissaient des epinettes noires (Picea mariana (Mill.) Britton, Sterns & Poggenb.) agees de 32 ans. Quatre descendances biparentales etudiees precedemment pour leur tolerance a la secheresse et leurs differences de productivite selon qu'elles croissaient dans une station seche ou humide etaient representees. La biomasse des racines de souche etait plus importante dans la station humide que dans la station seche. Cependant, la biomasse combinee des racines fines et des grosses racines etait plus grande dans la station seche que dans la station humide, de telle sorte qu'il n'y avait pas de difference entre les stations dans la biomasse des racines. Il n'y avait pas de difference entre les stations dans la distribution des racines en fonction de la profondeur dans le sol. La biomasse des racines de souche etaient plus importante chez les descendances tolerantes a la secheresse qui allouaient relativement moins de ressources aux racines fines et aux grosses racines combinees que les descendances intolerantes. Les racines fines ( [Traduit par la Redaction], Introduction Efforts to reduce atmospheric [CO.SUB.2] are being explored both by reducing emissions and by sequestering more C. Forests are important C sinks because they sequester C both in situ [...]

Fine and coarse root biomass, C, and N mass parameters were assessed by root size and soil depths from soil cores in plots of 32-year-old black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) from four full-sib families studied previously for drought tolerance and differential productivity on a dry and wet site. All fine and coarse root size categories had greater root biomass on the dry than on the wet site. Most of the site differences resided in 0 -20 cm soil depth. The wet site had greater root N concentration than the dry site, despite the same soil N; thus, virtually no differences were observed in total fine and coarse root N mass between sites. Root N concentration declined with increases in both soil depth and root size. Fine roots ( Resume: La biomasse des racines fines et celle des grosses racines, ainsi que les parametres de masse du C et du N, ont ete evalues en fonction de la dimension des racines et de la profondeur dans le sol a partir de carottes de sol prelevees dans des places echantillons ou croissent des epinettes noires (Picea mariana (Mill.) Britton, Sterns & Poggenb.). Les arbres etaient ages de 32 ans et representaient quatre descendances biparentales etudiees precedemment pour leur tolerance a la secheresse et leurs differences de productivite selon qu'ils croissaient dans une station seche ou humide. La plupart des differences entre les stations ont ete observees dans les premiers 20 cm de sol. La concentration de N dans les racines etait plus elevee dans la station humide meme si la concentration de N dans le sol etait la meme dans les deux stations. Par consequent, pratiquement aucune difference entre les stations n'a ete observee dans la masse totale de N de l'ensemble des racines. La concentration de N dans les racines diminuait avec l'augmentation de la profondeur dans le sol et la dimension des racines. Les racines fines representaient respectivement 73% et 38% de la masse totale de N et C dans l'ensemble des racines. La masse d'aiguilles etait plus faible et la masse de racines fines plus elevee dans la station seche que dans la station humide, ce qui implique une adaptation au changement de stress hydrique via le reequilibrage des organes qui consomment des ressources. Les descendances tolerantes a la secheresse avaient la meme quantite de racines fines que les descendances intolerantes mais elles pouvaient supporter plus de feuillage et de masse aerienne par unite de masse de racines fines que les descendances intolerantes. [Traduit par la Redaction], Introduction Water availability is a predominant factor in determining the geographic distribution of vegetation, and water stress has long been known to decrease plant growth and gas exchange and change [...]

Genetic maps provide an important genomic resource of basic and applied significance. Spruce (Picea) has a very large genome size (between 0.85 x [10.sup.10] and 2.4 x [10.sup.10] bp; 8.5-24.0 pg/1C, a mean of 17.7 pg/1C). We have constructed a near-saturated genetic linkage map for an interspecific backcross ([BC.sub.1]) hybrid of black spruce (BS; Picea mariana (Mill.) B.S.P.) and red spruce (RS; Picea rubens Sarg.), using selectively amplified microsatellite polymorphic loci (SAMPL) markers. A total of 2284 SAMPL markers were resolved using 31 SAMPL-Msel selective nucleotide primer combinations. Of these, 1216 SAMPL markers showing Mendelian segregation were mapped, whereas 1068 (46.8%) SAMPL fragments showed segregation distortion at [alpha] = 0.05. Maternal, paternal, and consensus maps consistently coalesced into 12 linkage groups, corresponding to the haploid chromosome number (1n =1x = 12) of 12 in the genus Picea. The maternal BS map consisted of 814 markers distributed over 12 linkage groups, covering 1670 cM, with a mean map distance of 2.1 cM between adjacent markers. The paternal BS x RS map consisted of 773 markers distributed over 12 linkage groups, covering 1563 cM, with a mean map distance of 2.0 cM between adjacent markers. The consensus interspecific hybrid [BC.sub.1] map consisted of 1216 markers distributed over 12 linkage groups, covering 1865 cM (98% genome coverage), with a mean map distance of 1.5 cM between adjacent markers. The genetic map reported here provides an important genomic resource in Picea, Pinaceae, and conifers. Key words: genome map, spruce, backcross interspecific hybrid, SAMPL markers, segregation distortion. Les cartes genetiques constituent des ressources importantes pour des travaux fondamentaux et appliques. L'eepinette (Picea) possede un tres grand genome (0,85 x [10.sup.10] - 2,4 x [10.sup.10] pb; 8,5 - 24,0 pg/1C, 17,7 pg/1C en moyenne). Les auteurs ont produit une carte geenetique presque saturee pour un retrocroisement ([BC.sub.1]) interspeecifique entre l'epinette noire (BS ; Picea mariana (Mill.) B.S.P.) et l'epinette rouge (RS ; Picea rubens Sarg.), en employant des marqueurs SAMPL (<< selectively amplified microsatellite polymorphic loci >>). Au total, 2284 marqueurs SAMPL ont ete examineesa l'aide de 31 combinaisons d'amorces selectives SAMPL-Msel. De ce nombre, 1216 marqueurs SAMPL presentant une segregation mendelienne ont ete cartographies, tandis 1068 (48,6 %) des fragments SAMPL affichaient une distorsion de la segregation au seuil de a = 0,05. Les cartes maternelle, paternelle et consensus etaient toutes constitueees de 12 groupes de liaison, soit le nombre haploide de chromosomes (1n =1x = 12) chez le genre Picea. La carte maternelle BS comptait 814 marqueurs formant 12 groupes, de liaison s'etendant sur 1670 cM, pour une distance moyenne de 2,1 cM entre les marqueurs. La carte paternelle BS x RS totalisait 773 marqueurs sur 12 groupes, de liaison s'etendant sur 1563 cM, soit une moyenne d'un marqueur a tous les 2,0 cM. La carte consensus pour le retrocroisement [BC.sub.1] interspeecifique comptait 1216 marqueurs sur 12 groupes, de liaison couvrant 1865 cM (98 % de couverture genomique), pour une distance moyenne de 1,5 cM entre les marqueurs. La carte geenetique decrite dans ce travail represente une ressource genomique importante chez le genre Picea, les pinaceees ainsi que les coniferes. Mots-cles: carte du genome, epinette, hybride interspecifique retrocroise, marqueurs SAMPL, distorsion de la segregation. [Traduit par la Redaction], Introduction Genetic linkage maps provide crucial genomic resources of significant, basic, and applied importance, especially in those species whose genomes are not fully sequenced. Conifers are economically and ecologically important, [...]

Our goal was to quantify tree- and branch-level components of growth response to three silvicultural treatments (STs), and weevil incidence in white pine (Pinus strobus L.) from large, central populations in Ontario (ON) versus small, isolated populations in Newfoundland (NL). Light levels were 100%, 42.0%, and 20.4% transmittance for the full-sun, intermediate-shade, and high-shade STs. After 8 years, the overall incidence of weevil infestation was 42.1%, 23.4%, and 13.7% for the full-sun, intermediate-shade, and high-shade STs, respectively (P < 0.001). Weevil impact on total height and volume averaged -13.2% and -11.8%. Analysis of dominant lateral shoots showed that ON populations had 32% longer shoots than the NL populations. Bud set difference was a primary determinant of shoot-length growth differences between regions: Julian days 171 and 184 for the NL and ON populations, respectively. The primary determining factors related to shoot length were the number of needle bundles and region, driven by light levels and day length, respectively, and the internode length, probably through inbreeding effects. Total height and diameter showed a positive curvilinear relationship to light level. To maximize fitness, NL conservation strategies should also now consider introducing adaptive trait variation in the context of anticipated climate change. Resume : Notre objectif consistait a quantifier les composantes de la reaction en croissance au niveau de l'arbre et des branches du pin blanc (Pinus strobus L.) a trois traitements sylvicoles et l'incidence du charancon chez de vastes populations centrales en Ontario (ON) comparativement a de petites populations isolees a Terre-Neuve (TN). Les traitements sylvicoles consistaient a creer des conditions de plein soleil, moyennement ombragees et tres ombragees dont les niveaux de luminosite correspondaient respectivement a 100 %, 42,0 % et 20,4 % de transmittance. Apres 8 ans, l'incidence de l'infestation du charancon etait respectivement de 42,1 %, 23,4 % et 13,7 % pour les traitements sylvicoles associes a des conditions de plein soleil, moyennement ombragees et tres ombragees (P < 0,001). L'impact du charancon sur la hauteur totale et le volume etait en moyenne de -13,2 % et -11,8 %. L'analyse des pousses laterales dominantes a montre que les populations de l'ON avaient des pousses 32 % plus longues que les populations de TN. La difference dans le moment ou apparaissent les bourgeons etait le principal facteur responsable des differences de croissance en longueur des pousses entre les regions : les jours juliens 171 et 184 respectivement pour les populations de TN et de l'ON. Les principaux facteurs qui determinaient la longueur des pousses etaient le nombre de faisceaux d'aiguilles et la region, par l'intermediaire respectivement du degre de luminosite et de la duree du jour, ainsi que la longueur des entrenoeuds, probablement par l'intermediaire d'effets de consanguinite. La hauteur totale et le diametre avaient une relation curviligne positive avec le degre de luminosite. Pour maximiser la sante du pin blanc a TN, les strategies de conservation devraient aussi a partir de maintenant envisager l'introduction d'une variabilite chez les caracteres adaptatifs dans le contexte des changements climatiques anticipes. [Traduit par la Redaction], Introduction Eastern white pine (Pinus strobus L.) is one of the most valuable softwood lumber species in eastern North America and has historically been a very important economic resource. It [...]

Abstract: Ecophysiological traits related to light-energy processing and freezing tolerance are important adaptive traits in plants. Our goal was to investigate the pattern of inheritance of these traits in hybrids [...]

Author(s): Chad Nusbaum (corresponding author) [1]; Tarjei S. Mikkelsen [1]; Michael C. Zody [1]; Shuichi Asakawa [2]; Stefan Taudien [3]; Manuel Garber [1]; Chinnappa D. Kodira [1]; Mary G. Schueler [...]

Assimilation to the internal CO2 (ACi) response curve and gas exchange parameters were quantified for four North American willows ((Salix cordata (COR), S. discolor (DIS), S. eriocephala (ERI), and S. interior (INT)) grown in a 2 × 2 factorial of atmospheric CO2 and soil moisture treatments to see how they would respond to climate change factors. After the first year of greenhouse growth under said treatments, we saw no difference in the aboveground stem biomass between CO2 treatments. Thus, in the second year, a second experiment on a subset of well-watered, coppiced willows was conducted in a 2 × 2 factorial of atmospheric CO2 and soil fertilization (FERT) treatments. In both experiments, the maximum rate of carboxylation (Vcmax) significantly declined for all four species in response to elevated CO2 (eCO2). In response to a drought treatment (DRT), Vcmax declined, except for INT, which increased Vcmax. In both experiments, INT had the greatest Vcmax, maximum rate of electron transport (Jmax), and triose phosphate utilization, followed by COR and ERI, with DIS having the lowest values. FERT resulted in a strong increase in assimilation (A) and stomatal conductance (Gwv) by 92 and 119%, respectively. Gwv is the primary driver and A is a minor driver of water use efficiency (WUE) under DRT. FERT mitigated the Vcmax and A downregulation in eCO2, but eCO2 did not mitigate the DRT downregulation effect. Differences between INT and the other three willows in a number of adaptive traits and responses related to drought may reflect the evolutionary origins of INT and the taxonomic group Longifoliae in the arid southwest USA and Mexico. [ABSTRACT FROM AUTHOR]

Key message: Large differences were detected between genera and among species in chlorophyll pigment and macronutrient concentrations. Pines have greater variances than spruces and showed less downregulation of chlorophyll pigment concentrations than spruces in response to eCO2 and DRT. There was strong genetic control of chlorophyll pigments and most macronutrients. Chlorophyll pigment and needle macronutrient concentrations were quantified for eight tree species in two commercially important genera, Pinus and Picea grown in a 2 × 2 factorial of atmospheric CO2 (370 and 740 ppm) and soil moisture stress (− 0.1 to − 0.5 and − 0.7 to − 1.0 MPa) treatments. Four of the pines and three of the spruces are native to eastern North America, while a fourth spruce, Norway spruce (NS: Picea abies), is from Europe but has been widely used for reforestation in northeastern North America. Overall, spruces had significantly greater chlorophyll a, b, (CHLa, CHLb), and total chlorophyll concentration (TCC) and carotenoid concentration (CAR) than pines. Ambient CO2 (aCO2) had significantly greater TCC than in response to elevated CO2 (eCO2), and TCC and CAR was significantly downregulated more in spruces than in pines in response to eCO2. Pines had equal or greater TCC and CAR in response to drought treatment (DRT) than well-watered treatment, whereas spruces had significantly lower values in response to DRT. Needle N, P and Ca concentrations were greater for spruces than pines. Needle N concentrations declined in response to both eCO2 and DRT. Needle P increased in response to eCO2 but declined in response to DRT. Using total biomass as a covariate, needle N showed no response in pines; whereas spruces showed a slight positive response to increasing total biomass. Covariate analysis showed that TCC had a significant positive relationship to needle N and Mg, with greater TCC in spruces than in pines for a given needle N. Photosynthetic quantum efficiency (QE), derived from light response curves, had a significant positive relationship to TCC that was greater in pines than in spruces for a given TCC. Photosynthetic light convexity had a significant positive relationship to TCC that was also greater in pines than in spruces for a given TCC, indicating a sharper curvature compared to a more progressive curve for spruce. Pine species have greater variances than spruce species. While Pinus strobus (white pine, subgenus Strobus) stands out as having greater chlorophyll and nutrient concentrations than the other three pines (subgenus Pinus). Overall, pines showed less downregulation of chlorophyll pigment concentrations than spruces in response to eCO2 and DRT. There was strong genetic control for chlorophyll pigments and most macronutrients. [ABSTRACT FROM AUTHOR]

Abstract Background Genetic maps provide an important genomic resource for understanding genome organization and evolution, comparative genomics, mapping genes and quantitative trait loci, and associating genomic segments with phenotypic traits. Spruce (Picea) genomics work is quite challenging, mainly because of extremely large size and highly repetitive nature of its genome, unsequenced and poorly understood genome, and the general lack of advanced-generation pedigrees. Our goal was to construct a high-density genetic linkage map of black spruce (Picea mariana, 2n = 24), which is a predominant, transcontinental species of the North American boreal and temperate forests, with high ecological and economic importance. Results We have developed a near-saturated and complete genetic linkage map of black spruce using a three-generation outbred pedigree and amplified fragment length polymorphism (AFLP), selectively amplified microsatellite polymorphic loci (SAMPL), expressed sequence tag polymorphism (ESTP), and microsatellite (mostly cDNA based) markers. Maternal, paternal, and consensus genetic linkage maps were constructed. The maternal, paternal, and consensus maps in our study consistently coalesced into 12 linkage groups, corresponding to the haploid chromosome number (1n = 1x = 12) of 12 in the genus Picea. The maternal map had 816 and the paternal map 743 markers distributed over 12 linkage groups each. The consensus map consisted of 1,111 markers distributed over 12 linkage groups, and covered almost the entire (> 97%) black spruce genome. The mapped markers included 809 AFLPs, 255 SAMPL, 42 microsatellites, and 5 ESTPs. Total estimated length of the genetic map was 1,770 cM, with an average of one marker every 1.6 cM. The maternal, paternal and consensus genetic maps aligned almost perfectly. Conclusion We have constructed the first high density to near-saturated genetic linkage map of black spruce, with greater than 97% genome coverage. Also, this is the first genetic map based on a three-generation outbred pedigree in the genus Picea. The genome length in P. mariana is likely to be about 1,800 cM. The genetic maps developed in our study can serve as a reference map for various genomics studies and applications in Picea and Pinaceae.

Photosynthetic light response curves were parameterized for eight species in two genera, Pinus and Picea, grown in a 2 × 2 factorial of atmospheric CO2 and soil moisture treatments. Four of the pines and three of the spruces are native to eastern North America, and the fourth spruce, Norway spruce (Picea abies (L.) Karst.), is native to Europe. There was a significant genus × CO2 interaction in apparent quantum efficiency (AQE): spruce AQE was greater under ambient CO2 (CO2) than elevated CO2 (eCO2), but pine AQE were equal. Under drought treatment (DR), AQE declined for both genera. Assimilation at light saturation (Alsat) was greater for spruces than pines, and for both genera, Alsat decreased under eCO2 and DR. Water-use efficiency was greater for pines than spruces and greater for pines and unchanged for spruces under DR. Examining AQE and Alsat change (%) from aCO2 to eCO2, there was a significant positive relationship to biomass growth stimulation (%) across species. These relationships support the theory of sink (biomass growth) regulation of assimilation traits and also the importance of needle nitrogen. Our results in response to eCO2 and DR suggest a shift toward increased use of pines in forest management for eastern North America. [ABSTRACT FROM AUTHOR]

Highlights • Four pines and four spruces in a 2 × 2 factorial of CO 2 and soil moisture. • Overall, pines respond better to eCO 2 and soil moisture stress. • Shade-tolerant spruces perform better in eCO 2 than shade-intolerant spruces. • Greater the mass, greater the response to eCO 2 and soil moisture. • Supports shift toward increased use of pines in NE N. America. Abstract Growth, components of growth, and biomass allocation were quantified for eight species in two commercially important genera, Pinus and Picea , grown in a 2 × 2 factorial of atmospheric CO 2 and soil moisture stress. Four of the pines and three of the spruces are native to eastern North America; a fourth spruce, Norway spruce (NS: P. abies), is native to Europe but is used for reforestation in northeastern North America. Height, basal diameter (BD), and total biomass response of pines were often more than two times greater than that of spruces under elevated CO 2 (eCO 2). A significant species × CO 2 interaction for total biomass was a result of species' differential response to eCO 2 : Pinus rigida had the greatest biomass stimulation (59%), followed by P. resinosa (39%), P. strobus (26%), and P. banksiana (19%). Among spruces, Picea glauca showed the greatest response (30%), and P. mariana the least response under eCO 2 (5%). Overall, soil moisture stress reduced total productivity by 12%. Most pines did have greater growth under moisture stress, and NS and BS grew well. Percent needle mass was lower under eCO 2 , but this was not due directly to eCO 2 but to ontological changes. Controlling for size, pines had 20% greater needle biomass than spruces, while having a negative relationship to total biomass. A comparison of total biomass under eCO 2 in relation to aCO 2 by species showed that overall, the greater the species mass, the greater the mass gain under eCO 2, and the greater the mass loss under drought conditions. In addition, our results for spruces lend strong support to the theory that late-successional species have greater growth response under eCO 2 than early to mid-successional species. A diverse portfolio of tree species for artificial reforestation would help forest management adapt to the many uncertainties over future environments and markets, but our results on responses in spruces and pines to eCO 2 and soil moisture stress support a shift toward increased use of pines in forest management and artificial reforestation. [ABSTRACT FROM AUTHOR]

Key message: After 3 years of elevated CO2 treatments, spruce Pn regulation from aCO2 to eCO2 was strongly related to total dry mass change (%), whereas pines displayed the same trend, but the relationship was not statistically significant.Abstract: Assimilation to internal CO2 (ACi) response curve parameters were grown and quantified under ambient (aCO2) and elevated (eCO2) CO2 treatments for two commercially important tree genera, Pinus and Picea spp. The species include Pinus strobus (WP), P. resinosa (RP), P. banksiana (JP), P. rigida (PP), Picea glauca (WS), P. rubens (RS), P. mariana (BS), and P. abies (NS). Seedlings were 4 years old and dosed for 3 years at the time of measurements. Overall, pines had greater maximum rates of carboxylation (Vcmax) and maximum assimilation (Amax) values than spruces, and there was a significant downregulation in Vcmax and Amax for both genera in eCO2, but more so for the spruces. For the maximum rate of electron transport (Jmax) and the rate of triose phosphate utilization (TPU), there was no significant genus effect, but there was a significant downregulation in eCO2. For these four traits, all spruces downregulated, whereas each pine species responded quite differently. White pine downregulated the most, followed by RP; no change for JP, and PP traits increased under eCO2. At an intermediate CO2 level, net photosynthesis @570 ppm CO2 (Pn570) was 13.0% greater for pines and 9.0% lower for spruces under eCO2 compared with aCO2. Comparing responses under eCO2 to aCO2, Pn570 was equal for WS but lower for the other spruces; however, WP declined, RP showed no difference, JP had greater Pn570, and PP had substantially greater Pn570. For pines, there appears to be a consistent enhanced sink effect on Pn across all species. Corresponding Pn570 change from aCO2 to eCO2 across spruce species showed a strong positive and statistically significant correlation to biomass stimulation that supports the theory of sink regulation of Pn. [ABSTRACT FROM AUTHOR]

Plants regularly experience suboptimal environments, but this can be particularly acute on highly-disturbed mine sites. Two North American willows--Salix discolor Muhl. (DIS) and S. eriocephala Michx. (ERI)--were established in common-garden field tests on two adjacent coal mine spoil sites: one with high clay content, the other with shale overburden. The high clay content site had 44% less productivity, a pH of 3.6, 42% clay content, high water holding capacity at saturation (64%), and high soil electrical conductivity (EC) of 3.9 mS cm-1. The adjacent shale overburden site had a pH of 6.8, and after removing 56.5% stone content, a high sand content (67.2%), low water holding capacity at saturation (23%), and an EC of 0.9 mS cm-1. The acidic clay soil had significantly greater Na (20x), Ca (2x), Mg (4.4x), S (10x), C (12x) and N (2x) than the shale overburden. Foliar concentrations from the acidic clay site had significantly greater Mg (1.5x), Mn (3.3x), Fe (5.6x), Al (4.6x), and S (2x) than the shale overburden, indicating that these elements are more soluble under acidic conditions. There was no overall species difference in growth; however, survival was greater for ERI than DIS on both sites, thus overall biomass yield was greater for ERI than DIS. Foliar concentrations of ERI were significantly greater than those of DIS for N (1.3x), Ca (1.5x), Mg (1.2x), Fe (2x), Al (1.5x), and S (1.5x). There were no significant negative relationships between metal concentrations and growth or biomass yield. Both willows showed large variation among genotypes within each species in foliar concentrations, and some clones of DIS and ERI had up to 16x the Fe and Al uptake on the acidic site versus the adjacent overburden. Genetic selection among species and genotypes may be useful for reclamation activities aimed at reducing specific metal concentrations on abandoned mine sites. Results show that, despite having a greater water holding capacity, the greater acidity of the clay site resulted in greater metal mobility--in particular Na--and thus a greater EC. It appears that the decline in productivity was not due to toxicity effects from the increased mobility of metals, but rather to low pH and moisture stress from very high soil Na/EC. [ABSTRACT FROM AUTHOR]

Red spruce (RS; Picea rubens Sarg.) - black spruce (BS; Picea mariana (Mill.) B.S.P.) controlled crosses (100%, 75%, 50%, 25%, and 0% RS, balance BS) showed increasingly greater height with increasing proportion of BS in each successive year. Height growth of 4-year-old ambient CO2 (aCO2) grown trees was highly correlated with height of 22-year-old field-grown trees of the same or similar crosses. Bud flush was earliest in BS and declined linearly with increasing proportion of RS with no significant CO2 effect. Percent stem (stem + branches) mass increased under elevated CO2 (eCO2), a quarter of which was due to ontogeny. Conversely, percent needle mass had a significant negative relationship with increasing tree size, and there was a CO2 × tree size interaction. Shoot-to-root ratio was greatest for BS, whereas RS had among the lowest. Hybrid index (HI) 50 had the greatest root mass allocation, lowest shoot-to-root ratio, and among the greatest total mass under eCO2. Growth efficiency increased with tree size and eCO2 but decreased with HI. Percent total biomass stimulation under eCO2 was lowest for BS at 6.5%, greatest for HI 50 at 20.3%, and RS had 17.5%. [ABSTRACT FROM AUTHOR]

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Highlights: [•] Wet site have greater stem wood N and bark N (%) than the dry site, but equal soil N. [•] Slow trees have greater wood density than fast trees on the wet site, but are equal on the dry site. [•] Drought-tolerant and wet-site trees have greater partitioning to stem than belowground. [•] They also have greater growth efficiency through greater photosynthesis (Pn ) and partitioning. [•] Greater Pn and re-allocation likely underlie greater stem growth from tree improvement. [Copyright &y& Elsevier]

Genetic maps provide an important genomic resource of basic and applied significance. Spruce (Picea) has a very large genome size (between 0.85 × 1010 and 2.4 × 1010 bp; 8.5-24.0 pg/1C, a mean of 17.7 pg/1C ). We have constructed a near-saturated genetic linkage map for an interspecific backcross (BC1) hybrid of black spruce (BS; Picea mariana (Mill.) B.S.P.) and red spruce (RS; Picea rubens Sarg.), using selectively amplified microsatellite polymorphic loci (SAMPL) markers. A total of 2284 SAMPL markers were resolved using 31 SAMPL-MseI selective nucleotide primer combinations. Of these, 1216 SAMPL markers showing Mendelian segregation were mapped, whereas 1068 (46.8%) SAMPL fragments showed segregation distortion at α = 0.05. Maternal, paternal, and consensus maps consistently coalesced into 12 linkage groups, corresponding to the haploid chromosome number (1n = 1x = 12) of 12 in the genus Picea. The maternal BS map consisted of 814 markers distributed over 12 linkage groups, covering 1670 cM, with a mean map distance of 2.1 cM between adjacent markers. The paternal BS × RS map consisted of 773 markers distributed over 12 linkage groups, covering 1563 cM, with a mean map distance of 2.0 cM between adjacent markers. The consensus interspecific hybrid BC1 map consisted of 1216 markers distributed over 12 linkage groups, covering 1865 cM (98% genome coverage), with a mean map distance of 1.5 cM between adjacent markers. The genetic map reported here provides an important genomic resource in Picea, Pinaceae, and conifers. Les cartes génétiques constituent des ressources importantes pour des travaux fondamentaux et appliqués. L'épinette (Picea) possède un très grand génome (0,85 × 1010 - 2,4 × 1010 pb; 8,5 - 24,0 pg/1C, 17,7 pg/1C en moyenne). Les auteurs ont produit une carte génétique presque saturée pour un rétrocroisement (BC1) interspécifique entre l'épinette noire (BS ; Picea mariana (Mill.) B.S.P.) et l'épinette rouge (RS ; Picea rubens Sarg.), en employant des marqueurs SAMPL (« selectively amplified microsatellite polymorphic loci »). Au total, 2284 marqueurs SAMPL ont été examinés à l'aide de 31 combinaisons d'amorces sélectives SAMPL-MseI. De ce nombre, 1216 marqueurs SAMPL présentant une ségrégation mendélienne ont été cartographiés, tandis 1068 (48,6 %) des fragments SAMPL affichaient une distorsion de la ségrégation au seuil de α = 0,05. Les cartes maternelle, paternelle et consensus étaient toutes constituées de 12 groupes de liaison, soit le nombre haploïde de chromosomes (1n = 1x = 12) chez le genre Picea. La carte maternelle BS comptait 814 marqueurs formant 12 groupes, de liaison s'étendant sur 1670 cM, pour une distance moyenne de 2,1 cM entre les marqueurs. La carte paternelle BS × RS totalisait 773 marqueurs sur 12 groupes, de liaison s'étendant sur 1563 cM, soit une moyenne d'un marqueur à tous les 2,0 cM. La carte consensus pour le rétrocroisement BC1 interspécifique comptait 1216 marqueurs sur 12 groupes, de liaison couvrant 1865 cM (98 % de couverture génomique), pour une distance moyenne de 1,5 cM entre les marqueurs. La carte génétique décrite dans ce travail représente une ressource génomique importante chez le genre Picea, les pinacées ainsi que les conifères. [ABSTRACT FROM AUTHOR]

Soft-tissue sarcomas, which result in approximately 10,700 diagnoses and 3,800 deaths per year in the United States, show remarkable histologic diversity, with more than 50 recognized subtypes. However, knowledge of their genomic alterations is limited. We describe an integrative analysis of DNA sequence, copy number and mRNA expression in 207 samples encompassing seven major subtypes. Frequently mutated genes included TP53 (17% of pleomorphic liposarcomas), NF1 (10.5% of myxofibrosarcomas and 8% of pleomorphic liposarcomas) and PIK3CA (18% of myxoid/round-cell liposarcomas, or MRCs). PIK3CA mutations in MRCs were associated with Akt activation and poor clinical outcomes. In myxofibrosarcomas and pleomorphic liposarcomas, we found both point mutations and genomic deletions affecting the tumor suppressor NF1. Finally, we found that short hairpin RNA (shRNA)-based knockdown of several genes amplified in dedifferentiated liposarcoma, including CDK4 and YEATS4, decreased cell proliferation. Our study yields a detailed map of molecular alterations across diverse sarcoma subtypes and suggests potential subtype-specific targets for therapy. [ABSTRACT FROM AUTHOR]