Nursery stock type, nitrogen fertilization and shoot pruning effects on the growth of juvenile hybrid poplar in Saskatchewan

Abstract

. 2009. Nursery stock type, nitrogen fertilization and shoot pruning effects on the growth of juvenile hybrid poplar in Saskatchewan. Can. J. Plant Sci. 89: 289Á301. Increased demand for wood from the forest-products and bio-energy industries in Canada has generated interest in large-scale hybrid poplar production for the prairie-boreal transition region. Because of the harsh climate and short growing season, this region of Canada poses significant challenges for establishment and production of hybrid poplar plantations and currently little silviculture information specific to this region is available. Trials were established at two sites with different prior land use histories: a former alfalfa field and a mixed-grass pasture. Cutting (Ct), rooted cutting (RCt) and rooted plug (RPg) nursery stock of hybrid poplar [P. deltoides)(P. laurifolia)P. nigra) var. Walker] were established with two fertilization rates (0 and 100 kg N ha(1 ) and pruned and unpruned treatments. Despite the alfalfa site having higher amounts of available N than the pasture site and tree growth being superior at the alfalfa site, foliar N concentrations indicated an N deficiency at the alfalfa site in 2003. The difference in growth between sites was attributed to a higher degree of weed competition at the pasture site. Survival of saplings was affected by the nursery stocks. The presence of roots on the initial stock was key to early survival with approximately 92% of rooted stocks surviving over winter the first year of planting, and only 41% of unrooted cuttings surviving the same period. The short growing seasons (115 to 127 frost-free days) provided enough time for RCt to recover from pruning and produce stem volumes larger than unpruned trees. . Effets de la nature du mate´riel de pe´pinie`re, de l'amendement azote´et de l'e´lagage des pousses sur la croissance des jeunes peupliers hybrides en Saskatchewan. Can. J. Plant Sci. 89: 289Á301. La demande accrue de bois par les industries des produits forestiers et de la bioe´nergie au Canada fait qu'on s'inte´resse a`la production a`grande e´chelle de peupliers hybrides dans la zone de transition entre les plaines et la foreˆt bore´ale. À cause du climat rigoureux et de la courte saison ve´ge´tative, l'e´tablissement et la culture du peuplier hybride dans cette re´gion du Canada s'ave`rent cependant plus complique´s, d'autant qu'on connaıˆt mal les conditions sylvicoles locales. Les auteurs ont proce´de´a`des essais a`deux endroits de vocation ante´rieure diffe´rente, en l'occurrence un ancien champ de luzerne et un paˆturage de gramine´es mixtes. Ils y ont plante´des boutures, des boutures enracine´es et des mottes enracine´es de peuplier hybride [P. deltoides x (P. laurifolia ) P. nigra) var. Walker] venant d'une pe´pinie`re a`deux taux de fertilisation (0 et 100 kg de N par hectare), en e´laguant certains plants et pas d'autres. Malgre´une plus forte quantite´de N disponible et une meilleure croissance des arbres, la concentration de N dans les feuilles a re´ve´le´une carence en N dans l...

Juvenile growth of hybrid poplars on acidic boreal soil determined by environmental effects of soil preparation, vegetation control, and fertilization

“…The well-developed root system on mounds could also explain the strong height response of the trees to an added nutrient supply. Early root development in mounds has indeed been shown to be a great asset for the subsequent success in height growth (Block et al, 2006(Block et al, , 2009. In addition, the surface of mounds, with mineral soil exposed, was generally almost devoid of competing vegetation for a few years after the treatment (Bilodeau-Gauthier et al, personal observations).…”

“…To date, hybrid poplar plantations in northern latitudes, for example in Sweden (Christersson, 2008(Christersson, , 2010 or in the prairie-boreal forest transition region of central Canada (Block et al, 2009;Amichev et al, 2010), are all located on agricultural lands; only a few have been tested on recently logged or otherwise formerly forested sites of eastern Canada (Coll et al, 2007;Bona et al, 2008;Guillemette and DesRochers, 2008;Sigouin, 2008). Hybrid poplar plantations established at these sites, as opposed to agricultural lands, pose further challenges in terms of soil fertility and tree nutrition since forest soils do not have long histories of anthropogenic use and fertilizer amendments the way agricultural soils do (Vande Walle et al, 2007) and as such are often less fertile, at least in the boreal zone.…”

Vergleich unterschiedlicher Anbaumethoden von Energieholzplantagen

“…Die Ausfallhäufigkeit ist aber nicht allein durch den Deckungsgrad zu erklären, der in der vorliegenden Arbeit bei 60-120 % lag. Der Anwuchs wurde deutlich von der Artzusammensetzung der Begleitvegetation bestimmt, ebenso wie der Zuwachs von der Intensität und der Artenzusammensetzung der Konkurrenzvegetation beeinflusst wird (Block et al, 2009). Die Anwuchsraten der Pappelstecklinge korrelierten signifikant negativ mit dem Auftreten von Lolium perenne, dem Deutschen Weidelgras.…”