Root architecture and root/shoot-ratios of Norway spruce as affected by thinning intensity and soil type in Denmark

Author(s):  
C. N. Nielson ◽  
I. Dencker
Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Roberts Matisons ◽  
Oskars Krišāns ◽  
Āris Jansons ◽  
Toms Kondratovičs ◽  
Didzis Elferts ◽  
...  

In Northern Europe, an increase in heterogeneity of summer precipitation regime will subject forests to water deficit and drought. This is particularly topical for Norway spruce (Picea abies Karst.), which is a drought sensitive, yet economically important species. Nevertheless, local populations still might be highly plastic and tolerant, supporting their commercial application. Accordingly, the tolerance of Norway spruce seedlings from an Eastern Baltic provenance (western part of Latvia) to artificial drought according to soil type was assessed in a shelter experiment. To simulate drought, seedlings were subjected to reduced amounts (0%, 25%, 50%, 75%, and 100%) of naturally occurring precipitation (irrigation intensity). Three soil types (oligotrophic mineral, mesotrophic mineral, and peat) were tested. Seedling height, chlorophyll a concentration, and fluorescence parameters were measured. Both growth and photochemical reactions were affected by the irrigation intensity, the effect of which experienced an interacted with soil type, implying complex controls of drought sensitivity. Seedlings were more sensitive to irrigation intensity on mesotrophic mineral soil, as suggested by growth and photosynthetic activity. However, the responses were nonlinear, as the highest performance (growth and fluorescence parameters) of seedlings occurred in response to intermediate drought. On peat soil, which had the highest water-bearing capacity, an inverse response to irrigation intensity was observed. In general, fluorescence parameters were more sensitive and showed more immediate reaction to soil water deficit than concentration of chlorophyll on mesotrophic mineral and peat soils, while the latter was a better indicator of seedling performance on oligotrophic soil. This indicated considerable plastic acclimation and hence tolerance of seedlings from the local Norway spruce population to drought, though drought sensitivity is age-dependent.


2005 ◽  
Vol 278 (1-2) ◽  
pp. 119-134 ◽  
Author(s):  
Lionel Dupuy ◽  
Thierry Fourcaud ◽  
Alexia Stokes

2005 ◽  
Vol 35 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Kjell Karlsson ◽  
Lennart Norell

The probability that an individual tree will remain in even-aged Norway spruce (Picea abies (L.) Karst.) stands subjected to different thinning programmes was modelled, using data from a thinning experiment established in 25 localities in southern Sweden. A logistic regression approach was used to predict the probability and the Hosmer–Lemeshow goodness-of-fit test to evaluate the fit. Diameter at breast height (DBH), quadratic mean DBH, thinning intensity, thinning quotient, basal area, number of stems per hectare, stand age, number of thinnings, and site index were used as explanatory variables. Separate analyses for stands thinned from below, stands thinned from above, and unthinned stands were performed. The modelled probability graphs for trees not being removed, plotted against their diameter at breast height, had clear S-shapes for both unthinned stands and stands thinned from below. The graph for stands thinned from above was bell-shaped.


2005 ◽  
Vol 35 (7) ◽  
pp. 1767-1778 ◽  
Author(s):  
Tuula Jaakkola ◽  
Harri Mäkinen ◽  
Pekka Saranpää

The effect of thinning intensity on growth and wood density in Norway spruce (Picea abies (L.) Karst.) was investigated in two long-term thinning experiments in southeastern Finland. The stands were approaching maturity, and their development had already been studied for 30 years. The intensities of thinning were low, normal, and high (i.e., the stand basal area after the thinning was, on average, 40, 27, and 24 m2·ha–1, respectively, in Heinola, and 30, 28, and 17 m2·ha–1 in Punkaharju, respectively). Compared with the low thinning intensity, the normal and high thinning intensities increased the basal-area increment of individual trees by 52% and 68%, respectively. Normal and high thinning intensities resulted in a relatively small reduction (1%–4%) of mean ring density compared with low thinning intensity. The random variation in wood density between and within trees was large. About 27% of the total variation in wood density was related to variation between rings. Our results indicate that the prevailing thinning intensities in Norway spruce stands in Fennoscandia cause no marked changes in wood density. At least, the possible reduction in wood density is low compared with the increase in individual tree growth.


Author(s):  
Lisma Safitri ◽  
Sri Suryanti ◽  
Valensi Kautsar ◽  
Agung Kurniawan ◽  
Fajar Santiabudi
Keyword(s):  
Oil Palm ◽  

Holzforschung ◽  
2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Tuula Jyske ◽  
Seija Kaakinen ◽  
Urban Nilsson ◽  
Pekka Saranpää ◽  
Elina Vapaavuori

AbstractThe effects of thinning intensity on wood structure and chemistry of Norway spruce [Picea abies(L.) Karst.] have been studied in a long-term thinning experiment established in the 1960s in south-western Sweden. The experiment comprised datasets of unthinned control trees and trees of four thinning treatments, in which thinning operations of different intensities were carried out. These thinning operations were applied either once, three, or five times over the course of the stand rotation. Thinning intensities varied from 0% to 60% based on the stand basal area (BA) before thinning: (A) 5×20% (i.e., 20% of the BA removed five times); (B) 3×40% (i.e., 40% of the BA removed three times); (C) 1×60% (i.e., 60% of the BA removed once); and (D) 5×40% (i.e., 40% of the BA removed five times). Altogether 60 trees that were 67 years old were sampled 38 years after the treatment onset. Radial growth rate, wood density, tracheid properties, and the chemical composition of wood were studied in detail. All four thinning treatments increased growth rate and decreased wood density; however, treatment D showed the greatest change. Single, heavy thinning in treatment C resulted in unfavourable intra-stem variation in ring width and wood density. No significant differences in tracheid properties and wood chemistry were found between the treatments. We conclude that only a remarkable increase in growth rate would induce detrimental changes in tracheid properties and wood chemistry in the context of thinning.


2006 ◽  
Vol 36 (10) ◽  
pp. 2684-2695 ◽  
Author(s):  
Mathieu Jonard ◽  
Laurent Misson ◽  
Quentin Ponette

The long-term impact (30 years) of three contrasting thinning programs (unthinned, moderately thinned, and heavily thinned) on selected forest-floor properties and on the foliar nutrient status of Norway spruce (Picea abies (L.) Karst.) stands (46, 50, and 67 years old) was evaluated at three sites on acid soils in the Belgian Ardennes. Sampling involved needles (current-year, 1-year-old, and recently fallen) and soil organic layers (OL, OF, OH, OA). For all samples, dry mass and element concentrations (C, N, P, Ca, Mg, K, Na, Mn, Al, Fe) were determined. Linear mixed models were used to analyze these data and showed that forest-floor mass was negatively affected by thinning (p = 0.0003) and that the N concentration in the forest floor increased with thinning intensity (p = 0.0008), while its Mn concentration decreased (p < 0.0001). The N, P, and K concentrations in the current-year needles were decreased by thinning (p < 0.05), while the Ca, Mg, and Na concentrations were not affected. We hypothesize that thinning negatively affected N, P, and K nutrition by removing the nutrients contained in the thinned trees and by decreasing the forest-floor thickness, thus reducing its nutrient contents and its ability to support root growth.


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