scholarly journals Structure and accumulation of litterfall under Norway spruce stands in connection with thinnings

2012 ◽  
Vol 50 (No. 3) ◽  
pp. 101-108 ◽  
Author(s):  
J. Novák ◽  
M. Slodičák

The effect of thinning on the structure and accumulation of litterfall and holorganic horizons (L, F, H) in young Norway spruce stands was investigated. The research was conducted on a Norway spruce thinning experiment Polom (established in 1980) in the Orlické hory Mts. (north-eastern part of the Czech Republic). In 1992, the monitoring of litterfall started on an unthinned control stand (plot 1) and on a comparative stand with very heavy thinning from below (plot 3). During the period of observation (age of the stand 27–37 years), the total weight of litterfall ranged between 1,800 and 4,800 kg/ha. The amount of litterfall was partly influenced by climatic factors (precipitation and temperature), growth processes (basal area increment) and thinning regimes in individual years. The results of the investigations showed that dry biomass accumulated under a 36 years old Norway spruce stand ranged from 9,200 to 11,300 kg/ha in horizon L, from 37,000 to 38,200 kg/ha in horizon F and from 138,300 to 146,400 kg/ha in horizon H. The quality (content of basic nutrients) of litterfall and material from holorganic horizons are discussed.

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 163
Author(s):  
Jan Světlík ◽  
Jan Krejza ◽  
Pavel Bednář

Tree growth depends on many factors such as microsite conditions, vitality, and variations in climate and genetics. It is generally accepted that higher growth indicates both an economic benefit and better vitality of any tree. Here we use a modified approach of evaluating tree social area to study mutual tree competition based on the orientation and shape of trees social area. The investigation was performed in nine Norway spruce stands in the Czech Republic. The objective of this study performed from 2008 to 2012 was to quantify relative tree radial increments with respect to the lowest and highest competition found in specific sectors of tree social area (AS). Specific groups of trees (tree classes) were evaluated according to their classes (dominant, co-dominant and sub-dominant) and their composition status in ninety-degree sectors of AS using established classifying rules. The results showed that a spatially-available area (AA) is an inappropriate parameter for predicting tree growth, whereas AS provided robust explanatory power to predict relative radial growth. Tree size was observed as an important indicator of relative radial increments. A significantly positive correlation was found for a radial increment of sub-dominant trees with the lowest competition from western directions; whereas a negative correlation was observed when the lowest competition was observed from eastern directions. For dominant trees, there was an evident growth reaction only when more than 50% of the AS was oriented towards one of the cardinal points. Individual differences in the orientation of tree AS may be important parameters with regard to competition and its spatial variability within an area surrounding a particular tree and deserve more detailed attention in tree growth models and practice.


2017 ◽  
Vol 63 (No. 8) ◽  
pp. 344-354
Author(s):  
Novotný Radek ◽  
Lomský Bohumír ◽  
Šrámek Vít

For 17 Norway spruce stands located in the Krkonoše Mts. in the Czech Republic a long-term assessment of defoliation, height increment, foliage concentration of nutrients (N, P, Ca, K, Mg) and stress elements (S, F) was carried out. The results show a decrease of defoliation and a slight increase of height increment, which occur in accordance with the decreasing concentration of sulphur in spruce needles. However, neither sulphur concentration nor height increment trends are significant, suggesting that both the main pollution abatement and the growth resumption took place already in the 1990’s. During the late 1990’s the average spruce defoliation was greater than 35%, while since 2007 it has fluctuated between 18 and 25%, which corresponds with the figures for the forest stands located in the other regions of the Czech Republic. The evaluation of single nutrient concentrations detected occasional deficiencies of P and Mg at individual plots. The good N nutrition (&gt; 15 mg N·g<sup>–1</sup>) in combination with a significantly decreasing trend of P, K and Ca concentrations in Norway spruce needles may potentially constitute a problem in regard to both the future health and the stability of forest stands in the studied region.


Forests ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 435 ◽  
Author(s):  
Laura Ķēniņa ◽  
Didzis Elferts ◽  
Endijs Bāders ◽  
Āris Jansons

Old unmanaged forests are commonly assumed to be carbon neutral; however, there is still a lack of reference studies available to increase the recognition of carbon stock changes in these forests. Studies of old forest carbon storage from hemiboreal regions are very rare compared to temperate and boreal forests in Europe; therefore, the aim of this study was to quantify the carbon stock in hemiboreal over-mature (167–213 years) Norway spruce (Picea abies (L.) Karst.) stands. To explore the total ecosystem carbon pool, the carbon stock of tree biomass, deadwood, and soil in unmanaged (for at least the last 40 years) spruce stands was calculated and compared between different forest site types on dry, wet, and drained mineral soils. Total carbon stock of hemiboreal over-mature spruce stands ranged from 164.8 Mg C ha−1 to 386.7 Mg C ha−1, and 238.5 Mg C ha−1 on average, with no significant differences (p > 0.05) between the forest site types. The carbon stock of tree biomass was significantly affected by the basal area of the upper tree layer (p < 0.0001) and the interaction between the forest site type and proportion of spruce in the stand composition (p = 0.002). Tree biomass was the dominant carbon pool, followed by soil and deadwood in over-mature spruce stands.


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.


Biologia ◽  
2009 ◽  
Vol 64 (5) ◽  
Author(s):  
Magdaléna Roháčová ◽  
Pavel Drozd

AbstractDuring the vegetation periods of 2001–2003 Heteroptera associated with the invasive alien tall goldenrods Solidago canadensis and S. gigantea were studied in seven model habitats in the north-eastern part of the Czech Republic. Heteropterans associated with adjacent growths were also studied in 2002–2003. A set of 3,042 specimens of 127 samples was analyzed with the aim of estimating average species richness, abundance and trophic structure of the heteropteran assemblages of the studied plant stand. On alien Solidago, 68 heteropteran species were recorded and 71 species were collected in the stands adjacent to the tall goldenrods with 48 shared species. Despite the nearly indentical species richness and similar abundances in Solidago and adjacent stands, there are differences in the trophic structure. The majority of the shared species and species found on Solidago canadensis only are polyphagous contrary to the majority of stenophagous species found on Solidago free stands only. Only a small proportion of heteropteran species that were recorded on alien Solidago stands are specialized to Asteraceae and their abundance was mostly low. Only the lygaeid Nysius senecionis, an Asteraceae specialist, occured in masses on S. canadensis in sunny and warm habitats. Similarly, predatory Orius minutus and O. niger reached high abundance values in Solidago stands compared to adjacent stands.


Beskydy ◽  
2012 ◽  
Vol 5 (2) ◽  
pp. 173-180 ◽  
Author(s):  
R. Pokorný ◽  
S. Stojnič

This contribution presents LAI data of 17 Norway spruce stands of different age (from 15 to 102 years) and health status (defoliation ranging from 0 to 40 %) located in the Těšínské Beskydy Mts. (NE of the Czech Republic). Defoliation degree was estimated by ocular observation and LAI was estimated indirectly on the base of gap fraction method using LAI-2000 PCA (Li-Cor, USA). It was found that LAI decreased with stand age (approximately from 12.6 to 8.5) whereas defoliation increased. Therefore, strong relationship between defoliation and LAI as well as gap fractions was found. LAI appears valuable parameter for health status of stand evaluation due to linear relationship (r2 = 0.87) between LAI and defoliation. As LAI can be estimated more objectively by a canopy analyzer then the degree of canopy defoliation by ocular observation, there is a perspective for a wide use LAI in forest practice. The LAI values can be used for the evaluation of health status of Norway spruce stands.


1986 ◽  
Vol 3 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Eric J. Jokela ◽  
Russell D. Briggs ◽  
Edwin H. White

Abstract Total and merchantable stem volume prediction equations (English and metric) were developed using data from 228 trees sampled in 38 unthinned Norway spruce stands varying in age from 45 to 55 years on the Allegheny Plateau in central New York. The equations were used to estimate stand volumes for the 38 sample plantations. The results demonstrate the potential of Norway spruce as a fiber source, having growth rates equal to or exceeding those of native northern conifer species. Average total height of dominant and codominant stems, basal area, quadratic mean diameters, and total and merchantable standing volume for the sample stands ranged from 58-93 ft, 150-239 ft2/ac, 6.5-10.6 in, 5431-8833 ft3/ac, and 4431-8218 ft3;/ac, respectively. The most productive stands were generally found on well-drained to moderately well-drained soils, although Norway spruce grew well over a broad range of soil drainage conditions. North. J. Appl. For. 3:7-10, Mar. 1986.


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