Tag Archives: height increment

xxx A. Jansons, J. Dzenis, R. Matisons, V. Samariks and B. Jansone
Intra-annual height growth dynamics of Scots and lodgepole pines and its relationship with meteorological parameters in central Latvia
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Intra-annual height growth dynamics of Scots and lodgepole pines and its relationship with meteorological parameters in central Latvia

A. Jansons¹*, J. Dzenis², R. Matisons¹, V. Samariks¹ and B. Jansone¹³

¹Latvian State Forest Institute ‘Silava’, Rigas 111, LV 2169 Salaspils, Latvia
²Nature Conservation Agency, Baznīcas 7, LV 2150 Sigulda, Latvia
³Latvia University of Life Sciences and Technologies, Forestry Faculty, Liela 2, LV-3001 Jelgava, Latvia
*Correspondence: aris.jansons@silava.lv

Abstract:

The Scots pine (Pinus sylvestris L.) is the second-most widely used tree species in forestry in Latvia and is the only species used for afforestation on nutrient poor soils that cover considerable forest land in Latvia. Several studies have shown that, in such conditions, the lodgepole pine (Pinus contorta var. latifolia) may be more productive in terms of biomass and yield. It is important to consider climate change studies to assess the potential for a larger-scale use of the lodgepole pine in forestry. The aim was to assess the intra-annual height growth patterns of both species, the differences between them, and the influence of meteorological parameters on their height growth. Their height growth was monitored on a weekly basis in two sampling sites in central Latvia, and the height increment curves were described by Gompertz’s model. The height growth dynamics of individual trees and species differed notably, indicating the potential for the selection of the best-adapted genotypes. Our results indicate that the early onset of the active growth phase might be the most important factor determining the total height increment for both species. Temperature-related meteorological parameters were the only ones with a statistically significant influence on pines height growth and only when at least one of the variables were standardised prior to the analysis. A temperature increase had a slightly stronger positive effect on the growth of the lodgepole pine, indicating that it might be suitable for more intensive use in forestry under the climate change scenarios for Latvia.

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109–122 D. Lazdiņa, S. Šēnhofa, M. Zeps, K. Makovskis, I. Bebre and Ā. Jansons
The early growth and fall frost damage of poplar clones in Latvia
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The early growth and fall frost damage of poplar clones in Latvia

D. Lazdiņa*, S. Šēnhofa, M. Zeps, K. Makovskis, I. Bebre and Ā. Jansons

Latvian State Forest Research Institute ʻSilava’, Rigas 111, LV 2169 Salaspils, Latvia
*Correspondence: dagnija.lazdina@silava.lv

Abstract:

The early growth and frost damage of Populus spp. was studied in two sites. The height of 23 five-year-old poplar clones was measured in the central part of Latvia; and the early-fall frost damage of 19 one-year-old and two-year-old poplar clones were assessed in the eastern part of Latvia. The relation between the height growth and frost damage of 16 clones, which were common for both sites, was assessed. The phenologically dormant stage was denoted for three clones, among which two are collected across Latvia (the origin un-known; introduced in 1960s). All the other clones had trees with damaged leaves and two clones had stem damage. The height of the clones ranged from 273.3 ± 60.2 to 711.0 ± 32.0 cm. The 3 most productive clones (LV3, LV1 and LV4) significantly (P < 0.01) exceeded others, by 34 and 65% for height and biomass, respectively. The mean height of these clones was 649.0 ± 21.5 cm and stem biomass varied from 33.7 ± 4.2 to 55.0 ± 6.4 tfresh=ha-1 (planting density 6,500 trees=ha-1). The clone had significant (P < 0.01) effect on the phenological stage, leaf and stem frost damage, as well as on the height and stem biomass. No relation (P > 0.05) between the frost damage of leaves and both tree height and stem biomass was found. The results suggest that fast-growing frost-tolerant clones might be selected.

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354-360 U. Neimane,, M. Zadina, L. Sisenis, B. Dzerina and A. Pobiarzens
Influence of lammas shoots on productivity of Norway spruce in Latvia
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Influence of lammas shoots on productivity of Norway spruce in Latvia

U. Neimane¹,*, M. Zadina¹, L. Sisenis², B. Dzerina¹ and A. Pobiarzens³

¹Latvian State Forest Institute ‘Silava’, Rigas 111, LV2169 Salaspils, Latvia
²Latvia University of Agriculture, Forest Faculty, Akademijas 11, LV3001 Jelgava ,Latvia
³Forest Competence Centre, Dzerbenes 27, LV1006 Riga, Latvia *Correspondence: una.neimane@silava.lv

Abstract:

The Norway spruce is widely spread in Eastern Europe and it is managed mainly for the production of sawlogs, though its logging residues are now increasingly used for the production of wood chips for bioenergy. The growth of the Norway spruce is and will be affected by climatic changes; one of the possible effects might be an increase in the frequency of trees with lammas shoots. Therefore, the aim of this study was to assess the influence of lammas shoots on the length of height increment of young Norway spruce in Latvia. Tree height and height increment was repeatedly measured and the presence of lammas shoots, bud flushing grades and frost injuries were assessed in two young (8–13 years) open-pollinated progeny tests in the central part of Latvia (56°46´N, 24°48´E). The mean portion of trees with lammas shoots in one experiment was 6% at the end of 8th growing season. In another experiment, it was 8.7%, 26.9% and 8.1% at the end of 10th, 11th and 13th growing seasons, respectively; 32.3% of trees had lammas shoots at least in one of three seasons. Faster growing and earlier flushing trees had a significantly higher frequency of lammas shoots. Lammas shoots increased the length of annual height increment by 10 to 14 cm, resulting in a 14–20% taller tree height at the age of 13 years. The reduction of height increment as a result of frost damages for very early flushing trees was less pronounced for trees with lammas shoots than without them.

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