Carbon pools in a montane old-growth Norway spruce ecosystem in Bohemian Forest: Effects of stand age and elevation

2015 ◽  
Vol 346 ◽  
pp. 106-113 ◽  
Author(s):  
Meelis Seedre ◽  
Jiří Kopáček ◽  
Pavel Janda ◽  
Radek Bače ◽  
Miroslav Svoboda
Silva Fennica ◽  
2021 ◽  
Vol 55 (2) ◽  
Author(s):  
Jouni Siipilehto ◽  
Harri Mäkinen ◽  
Kjell Andreassen ◽  
Mikko Peltoniemi

Ageing and competition reduce trees’ ability to capture resources, which predisposes them to death. In this study, the effect of senescence on the survival probability of Norway spruce ( (L.) Karst.) was analysed by fitting alternative survival probability models. Different model formulations were compared in the dataset, which comprised managed and unmanaged plots in long-term forest experiments in Finland and Norway, as well as old-growth stands in Finland. Stand total age ranged from 19 to 290 years. Two models were formulated without an age variable, such that the negative coefficient for the squared stem diameter described a decreasing survival probability for the largest trees. One of the models included stand age as a separate independent variable, and three models included an interaction term between stem diameter and stand age. According to the model including stand age and its interaction with stem diameter, the survival probability curves could intersect each other in stands with a similar structure but a different mean age. Models that did not include stand age underestimated the survival rate of the largest trees in the managed stands and overestimated their survival rate in the old-growth stands. Models that included stand age produced more plausible predictions, especially for the largest trees. The results supported the hypothesis that the stand age and senescence of trees decreases the survival probability of trees, and that the ageing effect improves survival probability models for Norway spruce.Picea abies


2017 ◽  
pp. 31-54
Author(s):  
Martin Bobinac ◽  
Sinisa Andrasev ◽  
Andrijana Bauer-Zivkovic ◽  
Nikola Susic

The paper studies the effects of two heavy selection thinnings on the increment of Norway spruce trees exposed to ice and snow breaks in eastern Serbia. In a thinning that was carried out at 32 years of age, 556 candidates per hectare were selected for tending, and at the age of 40, of the initial candidates, 311 trees per hectare (55.9%) were selected as future trees. In all trees at 41-50 age period, diameter increment was higher by 31%, basal area increment by 64% and volume increment by 67% compared to 32-40 age period. The collective of indifferent trees is significantly falling behind compared to future trees in terms of increment values in both observed periods. However, the value of diameter, basal area and volume increments, of the collective of "comparable" indifferent trees are lower in comparison to the values of increments of future trees by 10-15% in the 32-40 age period, and by 15-21% in the 41-50 age period and there are no significant differences. The results show that heavy selective thinnings, initially directed at a larger number of candidates for tending at stand age that does not differ much from the period of carrying out first "commercial" thinnings, improve the growth potential of future and indifferent trees, where it is rational to do the tree replacement for the final crop in "susceptible" growth stage to snow and ice breaks.


Geoderma ◽  
2014 ◽  
Vol 213 ◽  
pp. 287-295 ◽  
Author(s):  
Bernard Galka ◽  
Beata Labaz ◽  
Adam Bogacz ◽  
Oskar Bojko ◽  
Cezary Kabala

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 495 ◽  
Author(s):  
Lars Drössler ◽  
Eric Agestam ◽  
Kamil Bielak ◽  
Małgorzata Dudzinska ◽  
Julia Koricheva ◽  
...  

Pine-spruce forests are one of the commonest mixed forest types in Europe and both tree species are very important for wood supply. This study summarized nine European studies with Scots pine and Norway spruce where a mixed-species stand and both monocultures were located in an experimental set-up. Overyielding (where growth of a mixed stand was greater than the average of both monocultures) was relatively common and often ranged between 0% and 30%, but could also be negative at individual study sites. Each individual site demonstrated consistent patterns of the mixing effect over different measurement periods. Transgressive overyielding (where the mixed-species stand was more productive than either of the monocultures) was found at three study sites, while a monoculture was more productive on the other sites. Large variation between study sites indicated that the existing experiments do not fully represent the extensive region where this mixed pine-spruce forest can occur. Pooled increment data displayed a negative influence of latitude and stand age on the mixing effect of those tree species in forests younger than 70 years.


2015 ◽  
Vol 35 (6) ◽  
Author(s):  
于洋 YU Yang ◽  
贾志清 JIA Zhiqing ◽  
朱雅娟 ZHU Yajuan ◽  
刘艳书 LIU Yanshu ◽  
刘海涛 LIU Haitao ◽  
...  
Keyword(s):  

2004 ◽  
Vol 34 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Lauri Mehtätalo

A height–diameter (H–D) model for Norway spruce (Picea abies (L.) Karst.) was estimated from longitudinal data. The Korf growth curve was used as the H–D curve. Firstly, H–D curves for each stand at each measurement time were fitted, and the trends in the parameters of the H–D curve were modeled. Secondly, the trends were included in the H–D model to estimate the whole model at once. To take the hierarchy of the data into account, a mixed-model approach was used. This makes it possible to calibrate the model for a new stand at a given point in time using sample tree height(s). The heights may be from different points in time and need not be from the point in time being predicted. The trends in the parameters of the H–D curve were not estimated as a function of stand age but as a function of the median diameter of basal area weighted diameter distribution (dGm). This approach was chosen because the stand ages may differ substantially among stands with similar current growth patterns. This is true especially with shade-tolerant tree species, which can regenerate and survive for several years beneath the dominant canopy layer and start rapid growth later. The growth patterns in stands with a given dGm, on the other hand, seem not to vary much. This finding indicates that the growth pattern of a stand does not depend on stand age but on mean tree size in the stand.


2001 ◽  
Vol 31 (2) ◽  
pp. 292-301 ◽  
Author(s):  
B Berg ◽  
V Meentemeyer

Litter fall data was available for 64 sites in Europe, most of them in Fennoscandia. Included were 48 sites with pine (Pinus spp.), mainly Scots pine (Pinus sylvestris L.), and 16 sites with spruce (Picea spp.), mainly Norway spruce (Picea abies (L.) Karst.). Regressions were calculated for needle and total litter fall against a set of climatic parameters, and the best simple relationships were obtained with annual actual evapotranspiration (AET) and other parameters including temperature, whereas for example, precipitation gave lower r values. For needle litter fall and AET using all data, the R2adj value was 0.635 (n = 64), and for needle litter for pine and spruce separately, the R2adj were 0.576 (n = 48) and 0.775 (n = 16), respectively. AET plus stand age gave highly significant relationships for both coniferous genera combined (R2adj = 0.683), and for pine and spruce separately the corresponding values were 0.655 and 0.843, respectively. Using all available data we found highly significant relationships between needle litter fall and total litter fall. For Fennoscandia, litter fall for Scots pine and Norway spruce were compared. AET versus needle litter fall gave highly significant relationships for Scots pine (R2adj = 0.448, n = 34) and for Norway spruce (R2adj = 0.678, n = 13); the relationships were significantly different from each other.


2004 ◽  
Vol 188 (1-3) ◽  
pp. 211-224 ◽  
Author(s):  
A Lehtonen ◽  
R Mäkipää ◽  
J Heikkinen ◽  
R Sievänen ◽  
J Liski

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