Wood volume yield and stand structure in Norway spruce understorey depending on birch shelterwood density

1999 ◽  
Vol 122 (3) ◽  
pp. 221-229 ◽  
Author(s):  
Göran Bergqvist
Keyword(s):  
Norway Spruce ◽  
Stand Structure ◽  
Wood Volume ◽  
Volume Yield

scholarly journals Stand density biases the estimation of the site index especially on dry sites

2020 ◽  
Author(s):  
Astor Toraño Caicoya ◽  
Hans Pretzsch
Keyword(s):  
Norway Spruce ◽  
Stand Structure ◽  
Local Density ◽  
Generalized Additive Models ◽  
Stand Density ◽  
Moisture Stress ◽  
Site Index ◽  
Additive Models ◽  
Climate Conditions ◽  
Density Control

The Site Index (SI) has been widely used in forest management and silviculture. It relies on the assumption that the height of dominant trees in a stand is independent from the local density. However, research on climate change suggests that under certain moisture stress conditions, this may not hold. Here, based on 29 plots from 5 long-term research experiments, we have tested the effect of local stand density on the SI of Norway spruce (Picea abies (L.) H. Karst). With generalized additive models (GAMM), we analyzed the effect of stand structure and climate predictors on SI. The two evaluated models revealed that local stand density and age had a significant effect on SI (p≤0.001 ), showing a clear negative trend especially significant on sites with poor and dry soils, which may reduce the site index by a maximum of approximately 4 m for an increase in density between 400 and 600 trees/ha. We stress that the physiological characteristics of Norway spruce, flat-rooting system and xeromorphism, especially when growing in pure stands, may explain these effects. Thus, density control and growth in mixtures may help to reduce the water stress and losses in height growth under future climate conditions.

scholarly journals Estimation of crown and canopy cover from airborne lidar data

2010 ◽  
Vol 52 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Mait Lang
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Stand Structure ◽  
Canopy Cover ◽  
Airborne Lidar ◽  
Silver Birch ◽  
Lidar Data ◽  
Crown Cover ◽  
Pine Trees ◽  
Airborne Lidar Data

Metsa katvuse ja liituse hindamine lennukilt laserskanneriga Tests were carried out in mature Scots pine, Norway spruce and Silver birch stands at Järvselja, Estonia, to estimate canopy cover (K) and crown cover (L) from airborne lidar data. Independent estimates Kc and Lc for K and L were calculated from the Cajanus tube readings made on the ground at 1.3 m height. Lidar data based cover estimates depended on the inclusion of different order returns significantly. In all the stands first order return based estimate K1 was biased positively (3-10%) at the reference height of 1.3 m compared to ground measurements. All lidar based estimates decreased with increasing the reference height. Single return (Ky) and all return (Kk) based canopy cover estimates depended more on the sand structure compared to K1. The ratio of all return count to the first return count D behaved like crown cover estimate in all stands. However, in spruce stand D understimated Lc significantly. In the Scots pine stand K1(1.3) = 0.7431 was most similar canopy cover estimate relative to the ground estimate Kc = 0,7362 whereas Ky(1.3) and Kk(1.3) gave significant underestimates (>15%) of K. Caused by the simple structure of Scots pine stand - only one layer pine trees, the Cajanus tube based canopy cover (Kc), crown cover (Lc) and lidar data based canopy density D(1.3) values were rather similar. In the Norway spruce stand and in the Silver birch stand second layer and regeneration trees were present. In the Silver birch stand Kk(1.3) and Ky(1.3) estimated Kc rather well. In the Norway spruce stand Ky(1.3) and K1(1.3) were the best estimators of Kc whereas Kk(1.3) underestimated canopy cover. Lidar data were found to be usable for canopy cover and crown cover assessment but the selection of the estimator is not trivial and depends on the stand structure.

Temporal variability of size–growth relationships in a Norway spruce forest: the influences of stand structure, logging, and climate

2012 ◽  
Vol 42 (3) ◽  
pp. 550-560 ◽  
Author(s):  
Daniele Castagneri ◽  
Paola Nola ◽  
Paolo Cherubini ◽  
Renzo Motta
Keyword(s):  
Interannual Variability ◽  
Norway Spruce ◽  
Stand Structure ◽  
Individual Growth ◽  
Large Trees ◽  
Size Growth ◽  
Growth Partitioning ◽  
Long Term Trends ◽  
Ring Analysis

In a forest stand, competition plays a central role, affecting individual growth. The size–growth relationship (SGR) indicates whether large trees grow proportionally more than (asymmetric SGR), equal to (symmetric), or less than (inversely asymmetric) smaller trees. SGR is thus an indicator of the growth partitioning and competition intensity within a stand. Using tree-ring analysis, we investigated long-term trends and interannual variability of SGR in several Norway spruce (Picea abies (L.) Karst.) stands in the Paneveggio Forest (eastern Italian Alps) over a 100-year period. The study plots were characterized by different stand structures (one multilayered and two monolayered) and disturbance histories (different dates of logging). Logging conducted until the 1940s induced an inversely asymmetric SGR in all the plots. During the successive five decades, in the monolayered plots, it shifted to direct asymmetric (plot 1) and to symmetric (plot 2). In the multilayered plot (plot 3), SGR remained inversely asymmetric. A direct effect of climate on SGR interannual variability was not found. However, fast-growing trees had a stronger climatic signal than slow-growing trees, indicating that growth rate affects tree response to climate. Moreover, we observed that sensitivity to climate was reduced in the monolayered plots over the study period, possibly as a consequence of increased competition.

scholarly journals Investigations of mature Scots pine stands in wind-throw areas in Norway spruce forests in Western Rhodopes

2020 ◽  
Vol 47 (1) ◽  
pp. 1-9
Author(s):  
Milan Barna ◽  
Angel Ferezliev ◽  
Hristo Tsakov ◽  
Ivan Mihál
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Tree Species ◽  
Natural Regeneration ◽  
Stand Structure ◽  
Climatic Conditions ◽  
Pine Forests ◽  
Lignicolous Fungi ◽  
Tree Species Composition ◽  
Forest Stand Structure

AbstractWe investigated the current health condition (defoliation), state of natural regeneration, and mycoflora and phytopathogen-caused attacks in Scots pine forests (Pinus sylvestris L.) planted in the 1960s in areas affected by wind disturbances in the West Rhodope Mountains in Bulgaria. Some damage types (resin outflow and anthropogenic damage) were present to a low extent in the research plots (S – Selishte and PK – Pobit Kamak). Some were missing completely (damage by deer and other animals, the presence of lignicolous fungi and abiotic damage). The most important results of this study were the following: i) the occurrence of the bark beetle pest Tomicus minor Hartig (Coleoptera, Scolytinae) was recorded on average in 4.6 (S) and 2.3 (PK) of fallen shoots under the tree crown within 1 m diameter around the stem; ii) significant damage to tree crowns due to the loss of assimilation organs in Scots pine trees (28% – S and 39% – PK, respectively) was several times higher than that recorded in Norway spruce (Picea abies L.) (10%); iii) tree species composition resulting from natural regeneration showed 95–100% proportion of Norway spruce despite the predominance of Scots pine in the maternal stand. These observations might provide evidence of unsuitable environmental conditions in the studied localities for pine forests on the southern range of the natural P. sylvestris occurrence. Forest management in similar ecological and climatic conditions should aim at significant diversification of the forest stand structure by utilizing tree species suitable for the given ecosystems.

scholarly journals A Permanent Research Platform for Ecological Studies in Intact Temperate Mountainous Forests from Slătioara UNESCO Site and Its Surroundings, Romania

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1004
Author(s):  
Gabriel Duduman ◽  
Mihai-Leonard Duduman ◽  
Daniel Avăcăriței ◽  
Ionuț Barnoaiea ◽  
Cătălina-Oana Barbu ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Tree Species ◽  
Dead Wood ◽  
Future Research ◽  
Silver Fir ◽  
Wood Volume ◽  
Square Grid ◽  
Main Research ◽  
Research Platform ◽  
Unesco Site

This paper describes a permanent research platform (PRP) designed and implemented in “Codrul secular Slătioara” and its surroundings (2205.85 ha), having also the role of introductory paper for future research articles based on data collected from this platform. “Codrul secular Slătioara” is known as one of the largest temperate mountainous intact forests of Europe and, in 2017, it was included in UNESCO World Heritage List, as part of the “Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe”. Moreover, the PRP overlaps other three scientific reserves, the share of strictly protected forests exceeding 70%. This platform has a multiple role, being developed for research, conservation and educational activities. The PRP was designed for an ecological analysis of the intact forest ecosystems. It contains 193 circular sample plots, each of them of 500 m2, and it is structured on two levels. The first level contains 58 sample plots corresponding to a square grid of 500 × 500 m, stretching over the entire forested area, and the second level contains 135 plots, placed according to a square grid of 100 × 100 m, covering 136 ha within the core area of the UNESCO site. We measured the characteristics of 8296 living trees, 1743 standing dead trees, 1900 dead wood trunks, 3214 saplings, and the abundance–dominance indices of flora species. Thus, we identified 14 tree species, 17 shrub species, and 248 other cormophyte species forming the herbaceous layer. In terms of volume, the main tree species are Norway spruce, silver fir and European beech. The tallest species are Norway spruce (56 m) and silver fir (51 m). The average volume of living trees is 659 m3·ha−1, with a maximum of 1441 m3·ha−1. The mean total dead wood volume is about 158 m3·ha−1, with sample plots where the total dead wood volume exceeds 600 m3·ha−1. After presenting the results of preliminary data processing, the paper describes the main research topics to be further considered, based on the PRP, and the foresights related to the PRP’s monitoring and development.

Effects of stand structure and physiology on forest gas exchange: a simulation study for Norway spruce

Trees ◽  
1997 ◽  
Vol 11 (7) ◽  
pp. 436 ◽  
Author(s):  
E. Falge ◽  
R. J. Ryel ◽  
M. Alsheimer ◽  
J. D. Tenhunen
Keyword(s):  
Gas Exchange ◽  
Norway Spruce ◽  
Simulation Study ◽  
Stand Structure

The accuracy of estimating individual tree variables with airborne laser scanning in a boreal nature reserve

2004 ◽  
Vol 34 (9) ◽  
pp. 1791-1801 ◽  
Author(s):  
M Maltamo ◽  
K Mustonen ◽  
J Hyyppä ◽  
J Pitkänen ◽  
X Yu
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Laser Scanning ◽  
Stand Structure ◽  
Tree Height ◽  
Heterogeneous Structure ◽  
Mixed Stands ◽  
Individual Tree ◽  
Tree Layer ◽  
Pine Trees

This study examines the ability of high-density laser scanning to produce single-tree estimates in mixed stands of heterogeneous structure. Individual trees were detected from a constructed digital canopy height model by locating local maxima of the height values. The reference material comprised accurately measured field data for 10 mapped sample plots containing Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and different birches. To verify the accuracy of height measurements of single trees in more detail, the height of 29 Scots pine trees and their annual shoots of the last few years was carefully measured with a tacheometer and a glass fibre rod. The considered variables were the proportion of detected trees and tree height. As more than 80% of the dominant trees were detected, the results indicated that laser scanning can accurately describe the trees of the dominant tree layer. Because of the dense understorey tree layer in most of the sample plots, about 40% of all trees were detected. On the plot level, the stand structure affected the accuracy of the results considerably. The scanning-based tree height was most accurate for Norway spruce and least accurate for birches. The height of the separately measured 29 Scots pine trees was obtained with an accuracy of ±50 cm or better.

Economics of harvesting boreal uneven-aged mixed-species forests

2015 ◽  
Vol 45 (8) ◽  
pp. 1102-1112 ◽  
Author(s):  
Janne Rämö ◽  
Olli Tahvonen
Keyword(s):  
Steady State ◽  
Interest Rate ◽  
Interest Rates ◽  
Norway Spruce ◽  
Net Present Value ◽  
Single Species ◽  
Mixed Species ◽  
Volume Yield ◽  
Gradient Based ◽  
The Interest Rate

The subject of this study is the economics of harvesting boreal uneven-aged mixed-species forests consisting of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), birch (Betula pendula Roth and B. pubescens Ehrh.), and other broadleaves. The analysis is based on an economic description of uneven-aged forestry, applying a size-structured model. The optimization problem is solved in its general dynamic form using gradient-based interior point methods. When volume yield is maximized, the optimal steady state is a nearly pure Norway spruce stand at all site types, producing slightly higher yields than single-species stands. After including sawlog and pulpwood prices, the net present value of stumpage revenues is maximized using 1%, 3%, and 5% interest rates and a 15-year harvesting interval. At less productive sites, the stands are nearly pure Norway spruce stands, regardless of the interest rate. At more productive sites, increasing the interest rate increases the species diversity, with optimal steady states consisting of both Norway spruce and birch. In some cases, rather small changes in relative prices change the optimal steady state into a birch-dominated stand. Optimal solutions converge to the same steady-state solutions, independent of the initial stand state. If other broadleaves without commercial value are not harvested, they will eventually dominate the stand.

scholarly journals Merchantable wood volume response of P. radiate D. Don post thinned plots on coated and uncoated urea fertilizers

2020 ◽  
Vol 30 (2) ◽  
pp. 36-47
Author(s):  
R. Nirola ◽  
C. Saint ◽  
J. O. Hehir ◽  
J. Liu
Keyword(s):  
South Australia ◽  
Ammonium Phosphate ◽  
Tree Height ◽  
Control Treatment ◽  
Fertilizer Treatment ◽  
Growth Stages ◽  
Wood Volume ◽  
Volume Yield ◽  
Standing Trees ◽  
Volume Response

Our study was focused on whether the optimization of nutrition at various growth stages of Pinus radiate D. Don plantation was an important factor to increase its merchantable wood volume yield in Silviculture. The present study site is located within the ‘Green Triangle’ bordering the Australian states of South Australia and Victoria. A total of 24 sampling sub-plots, averaged to 12 super plots, were established in both the sites, and all the plots, except one set aside as 'controlled plot' in each site, were treated with 5 types of coated and un-coated urea fertilizers. The data on tree-height and diameter at breast height over bark (DBHOB) of all the standing trees were measured and recorded. A five-year sampling data from the 24 sub-plots consisting of two sites, namely Picks (Site 'A') and Hollands Lane (Site 'B') in post thinned condition were analysed. The specific target was to evaluate a productivity response in terms of merchantable volumes based on fertilizer types. The statistical analysis employing ANOVA, t-test, a neural network model, decision tree and box-plot model based on fertilizer treatment determined that Di-Ammonium Phosphate Entec Urea (DAPEU) fertilizer was found to be more effective in increasing productivity. As such, the merchantable wood volume increments measured after four years of application of DAPEU were found to be 48.61 m3 ha-1 at Site 'A' and 41.97 m3 ha-1 at Site 'B', higher than the 46.71 m3 ha-1 at Site 'A' and 39.79 m3 ha-1 at Site 'B' with 'control' treatment. Hence, the application of DAPEAU was found to be effective as compared to the 'control' treatment in silviculture to increase the merchantable wood volume.

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