scholarly journals Modeling early height growth in trials of genetically improved Norway spruce and Scots pine in southern Sweden

Silva Fennica ◽  
2017 ◽  
Vol 51 (3) ◽  
Author(s):  
Samuel Egbäck ◽  
Urban Nilsson ◽  
Kenneth Nyström ◽  
Karl-Anders Högberg ◽  
Nils Fahlvik
2019 ◽  
Vol 19 (5) ◽  
pp. 1429-1440 ◽  
Author(s):  
Matts Lindbladh ◽  
Lisa Petersson ◽  
Per-Ola Hedwall ◽  
Renats Trubins ◽  
Emma Holmström ◽  
...  

2002 ◽  
Vol 161 (1-3) ◽  
pp. 133-145 ◽  
Author(s):  
Urban Nilsson ◽  
Pelle Gemmel ◽  
Ulf Johansson ◽  
Matts Karlsson ◽  
Torkel Welander

Silva Fennica ◽  
2018 ◽  
Vol 52 (5) ◽  
Author(s):  
Jaakko Repola ◽  
Hannu Hökkä ◽  
Hannu Salminen

The aim of this study was to develop individual-tree diameter and height growth models for Scots pine, Norway spruce, and pubescent birch growing in drained peatlands in Finland. Trees growing in peatland sites have growth patterns that deviate from that of trees growing in mineral soil sites. Five-year growth was explained by tree diameter, different tree and stand level competition measures, management operations and site characteristics. The drainage status of the site was influencing growth directly or in interaction with other variables. Site quality had a direct impact but was also commonly related to current site drainage status (need for ditch maintenance). Recent thinning increased growth of all species and former PK fertilization increased growth of pine and birch. Temperature sum was a significant predictor in all models and altitude for spruce and birch. The data were a subsample of the 7th National Forest Inventory (NFI) sample plots representing northern and southern Finland and followed by repeated measurements for 15–20 yrs. Growth levels predicted by the models were calibrated using NFI11 data to remove bias originating from the sample of the modelling data. The mixed linear models technique was used in model estimation. The models will be incorporated into the MOTTI stand simulator to replace the current peatlands growth models.


1990 ◽  
Vol 20 (6) ◽  
pp. 757-763 ◽  
Author(s):  
B. G. Bentzer ◽  
G. S. Foster ◽  
A. R. Hellberg

Four mixtures of Norway spruce (Piceaabies (L.) Karst.), each containing 56 clones, were analysed for height at age 7 years at six locations in southern Sweden. The number of clones in each mixture was subsequently reduced in a stepwise manner from 56 to 40, 30, 20, 10, and finally, 5 clones. The reduction process was conducted in three ways: (i) random deletion, (ii) deletion based on height growth, and (iii) deletion based on clone stability. No difference among the means of clone mixtures could be found for 20–56 clones for any elimination procedure tested, and no mixture × location interaction existed despite the number of clones in the mixture or the elimination process used. Location effects were consistently significant, independent of the number of clones in each mixture. Also, replication effects were significant in all cases but one. Random elimination of clones resulted in weak differences between mixture means when 10 and 5 clones were included. Deletion of clones based on lack of stability or inferior height growth only slightly changed the variation pattern compared with when all 56 clones were present in each mixture. Relative height growth performance of clone mixtures with as few as 5 clones appeared to be stable within the region of Sweden that was represented by the trials.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 943
Author(s):  
Katri Nissinen ◽  
Virpi Virjamo ◽  
Antti Kilpeläinen ◽  
Veli-Pekka Ikonen ◽  
Laura Pikkarainen ◽  
...  

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.


2021 ◽  
Vol 490 ◽  
pp. 119102
Author(s):  
Jarosław Socha ◽  
Svein Solberg ◽  
Luiza Tymińska-Czabańska ◽  
Piotr Tompalski ◽  
Patrick Vallet

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