Articles by Oskars Krišāns

• Jansons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: aris.jansons@silava.lv
• Zeps, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: martins.zeps@silava.lv
• Rieksts-Riekstiņš, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: Juris.Riekstins@silava.lv
• Matisons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: robism@inbox.lv
• Krišāns, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: oskars.krisans@silava.lv

Lodgepole pine (Pinus contorta var. latifolia Engelm.) has been extensively introduced in Scandinavia on less productive sites. Under a changing climate, it also has a high potential in the eastern Baltic region; still, its performance there has scarcely been reported. This study investigated the performance of 36 Canadian provenances in 14 trials in western Latvia. Tree dimensions showed notable provenance and provenance-by-environment variation, implying that local selection by provenance can be applied for improved yield. Southern provenances showed the best height growth, while southwestern (more oceanic) provenances excelled in diameter growth. Most of the quality traits were affected by provenance or provenance-by-environment interaction, yet the variation was lower than for the growth traits.

• Jansons, Latvian State Forest Research Institute ”Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail: aris.jansons@silava.lv
• Matisons, Latvian State Forest Research Institute ”Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail: robism@inbox.lv
• Baliuckas, Forest Institute, Lithuanian Centre for Agriculture and Forestry, Department of Forest Tree Genetics and Breeding, Liepu St. 1, Girionys, LT-53101 Kaunas distr., Lithuania E-mail: virgilijus.baliuckas@mi.lt
• Purina, Latvian State Forest Research Institute ”Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail: liga.purina@silava.lv
• Krišāns, Latvian State Forest Research Institute ”Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail: oskars.krisans@silava.lv
• Jansons, Latvian State Forest Research Institute ”Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail: janis.jansons.silava@gmail.com
• Baumanis, Latvian State Forest Research Institute ”Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail: imants.baumanis@silava.lv

Initial fertilisation, when the fertilizer is supplied during the plantation, is applied to improve the competitive ability of the seedlings and hence to increase their growth and productivity; however, fertilization could also alter wood properties and timber quality. In this study, the dimensions and tree-ring parameters – width, proportion of latewood, maximum and mean density, mean earlywood and latewood density – of initially fertilized (by 14, 6 and 11 g of N, P and K per seedling, respectively) Norway spruce (Picea abies Karst.) growing in an experimental plantation in Kalsnava, Latvia (temperate climate region) were assessed. The fertilization significantly increased the dimensions of trees in long-term (ca. 17% increase of stemwood volume). The analysis of tree-ring width suggested that the duration of the effect was ca. 15 years. The maximum and latewood density were higher for the fertilized trees only in a few years. The mean and earlywood density of tree-rings were mainly similar for both treatments. Altogether, considering the one-time application of a limited amount of fertilizer, such treatment had notable and lasting effect on Norway spruce.

• Jansons, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: aris.jansons@silava.lv
• Matisons, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: robism@inbox.lv
• Krišāns, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: oskars.krisans@silava.lv
• Džeriņa, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: baiba.dzerina@silava.lv
• Zeps, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: martins.zeps@silava.lv