A longitudinal height–diameter model for Norway spruce in Finland

2004 ◽  
Vol 34 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Lauri Mehtätalo
Keyword(s):  
Norway Spruce ◽  
Mixed Model ◽  
Basal Area ◽  
Tree Height ◽  
Growth Patterns ◽  
Diameter Distribution ◽  
Stand Age ◽  
Canopy Layer ◽  
Mixed Model Approach ◽  
D Model

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.

scholarly journals Advance Regeneration of Norway Spruce and Scots Pine in Hemiboreal Forests in Latvia

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 215
Author(s):  
Solveiga Luguza ◽  
Guntars Snepsts ◽  
Janis Donis ◽  
Iveta Desaine ◽  
Endijs Baders ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Management Practices ◽  
Basal Area ◽  
National Forest Inventory ◽  
Stand Age ◽  
Natural Disturbances ◽  
Canopy Layer ◽  
Advance Regeneration ◽  
Continuous Cover Forestry

Continuous cover forestry (CCF) aims to emulate small natural disturbances and take advantage of natural regeneration. To implement these management practices successfully, knowledge of advance regeneration under the canopy in different conditions is crucial. Therefore, the aim of this study was to assess the influence of stand inventory parameters of canopy layer (age, basal area, height, and density) on the probability and density of advance regeneration of the Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) in hemiboreal forests in Latvia. The data were obtained from the National Forest Inventory, from a total of 879 plots. In the study, only Norway spruce or Scots pine dominated stands were used and the sampled stand age ranged from 21 to 218 years. The probability of advance regeneration differed between stands dominated by Scots pine versus Norway spruce. The probability and density of the advance regeneration of Norway spruce were positively linked to increased stand age, whereas the probability of the advance regeneration of Scots pine was negatively linked to the basal area of the stand. In stands dominated by Norway spruce and Scots pine on mesic soils, the advance regeneration of Norway spruce has a high density, whereas the advance regeneration of Scots pine is sporadic and scarce.

scholarly journals Deriving Tree Size Distributions of Tropical Forests from Lidar

2021 ◽  
Vol 13 (1) ◽  
pp. 131
Author(s):  
Franziska Taubert ◽  
Rico Fischer ◽  
Nikolai Knapp ◽  
Andreas Huth
Keyword(s):  
Size Distribution ◽  
Spatial Scales ◽  
Basal Area ◽  
Tree Height ◽  
Tree Size ◽  
Diameter Distribution ◽  
Forest Inventories ◽  
Allometric Relations ◽  
Lidar Measurements ◽  
Derived Data

Remote sensing is an important tool to monitor forests to rapidly detect changes due to global change and other threats. Here, we present a novel methodology to infer the tree size distribution from light detection and ranging (lidar) measurements. Our approach is based on a theoretical leaf–tree matrix derived from allometric relations of trees. Using the leaf–tree matrix, we compute the tree size distribution that fit to the observed leaf area density profile via lidar. To validate our approach, we analyzed the stem diameter distribution of a tropical forest in Panama and compared lidar-derived data with data from forest inventories at different spatial scales (0.04 ha to 50 ha). Our estimates had a high accuracy at scales above 1 ha (1 ha: root mean square error (RMSE) 67.6 trees ha−1/normalized RMSE 18.8%/R² 0.76; 50 ha: 22.8 trees ha−1/6.2%/0.89). Estimates for smaller scales (1-ha to 0.04-ha) were reliably for forests with low height, dense canopy or low tree height heterogeneity. Estimates for the basal area were accurate at the 1-ha scale (RMSE 4.7 tree ha−1, bias 0.8 m² ha−1) but less accurate at smaller scales. Our methodology, further tested at additional sites, provides a useful approach to determine the tree size distribution of forests by integrating information on tree allometries.

scholarly journals Effects of heavy thinnings on the increment and selection of trees for tending in Norway spruce monoculture in natural hazard conditions

2017 ◽  
pp. 31-54
Author(s):  
Martin Bobinac ◽  
Sinisa Andrasev ◽  
Andrijana Bauer-Zivkovic ◽  
Nikola Susic
Keyword(s):  
Norway Spruce ◽  
Growth Stage ◽  
Natural Hazard ◽  
Basal Area ◽  
Growth Potential ◽  
Stand Age ◽  
Diameter Increment ◽  
Volume Increment ◽  
Selection Of ◽  
Area And Volume

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.

scholarly journals Breeding value of Norway spruce (Picea abies [L.] Karst.)

2012 ◽  
Vol 50 (No. 1) ◽  
pp. 17-23
Author(s):  
Rożkowski KR
Keyword(s):  
Survival Rate ◽  
Norway Spruce ◽  
Growth Traits ◽  
Block Design ◽  
Basal Area ◽  
Tree Height ◽  
Breeding Value ◽  
Cross Sectional ◽  
Qualitative Traits ◽  
Crown Density

This is the first report on measurements and observations of an experimental plot of 35-year-old Norway spruce, established in 1970 by the Institute of Dendrology at K&oacute;rnik, where progenies of 22 plustrees from the Kłodzko Forest District were planted. The experiment was established in an incomplete block design of 20 families with 3 replications. Survival rate and growth traits determining productivity (plant height or basal area &ndash; stem cross-sectional area at breast height per 1&nbsp;ha) were assessed in several years, and qualitative traits (trunk straightness; degree of natural pruning; thickness, length and angle of branches; crown density; presence of galls caused by the aphids Adelges laricis Vall. and Sacchiphantes viridis Ratz.) were evaluated once in 2001. Analysis of variance revealed significant differences between the half-sib families in survival rate and productivity but no significant differences in qualitative traits. Statistically significant positive correlations were found between trunk straightness at the age of<br />&nbsp;36 years and height of 2-year-old seedlings in the nursery, and between the degree of natural pruning at the age of 36 years and both tree height at the age of 9 years and basal area at the age of 13 years.

Meta-analysis of understory white spruce response to release from overstory aspen

2004 ◽  
Vol 80 (6) ◽  
pp. 694-704 ◽  
Author(s):  
Rongzhou Man ◽  
Ken J Greenway
Keyword(s):  
Growth Response ◽  
Mixed Model ◽  
Polynomial Regression ◽  
Meta Analysis ◽  
Basal Area ◽  
Tree Height ◽  
White Spruce ◽  
Response Ratio ◽  
Mixed Effect ◽  
Individual Tree

Meta-analysis was used to summarize the research results on the growth response of understory white spruce to release from overstory aspen from different studies available from published and unpublished sources. The data were screened for the suitability for meta-analysis. Treatment effect sizes were calculated using response ratio from mean cumulative increments of released and control trees since release in height, diameter, and volume and modeled using a polynomial mixed effect regression procedure. Predictor variables include linear, quadratic, and cubic components of three independent variables — initial tree height, number of years after release, and residual basal area at release — and their linear interactions. Models with a reasonable predictive power were developed for height, diameter, and volume response, but no significant model was identified for survival. The models developed in this study can be applied to predict the growth response of understory white spruce to release, based on the growth of unreleased control trees, initial tree height, residual basal area at release, and time since release. The individual tree prediction can be easily scaled up to stand level if residual tree density and distribution is known. Key words: meta-analysis, boreal mixedwood, mixed model, polynomial regression, response ratio, growth, survival

Modelling survival probability of individual trees in Norway spruce stands under different thinning regimes

2005 ◽  
Vol 35 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Kjell Karlsson ◽  
Lennart Norell
Keyword(s):  
Norway Spruce ◽  
Goodness Of Fit ◽  
Basal Area ◽  
Site Index ◽  
Stand Age ◽  
Goodness Of Fit Test ◽  
Individual Tree ◽  
Thinning Intensity ◽  
Diameter At Breast Height ◽  
Breast Height

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.

A new method for evaluating forest thinning: growth dominance in managed Pinus resinosa stands

2010 ◽  
Vol 40 (5) ◽  
pp. 843-849 ◽  
Author(s):  
John B. Bradford ◽  
Anthony W. D’Amato ◽  
Brian J. Palik ◽  
Shawn Fraver
Keyword(s):  
Tree Growth ◽  
Basal Area ◽  
Pinus Resinosa ◽  
Growth Patterns ◽  
Red Pine ◽  
New Method ◽  
Stand Age ◽  
Individual Tree ◽  
Individual Tree Growth

Growth dominance is a relatively new, simple, quantitative metric of within-stand individual tree growth patterns, and is defined as positive when larger trees in the stand display proportionally greater growth than smaller trees, and negative when smaller trees display proportionally greater growth than larger trees. We examined long-term silvicultural experiments in red pine ( Pinus resinosa Ait.) to characterize how stand age, thinning treatments (thinned from above, below, or both), and stocking levels (residual basal area) influence stand-level growth dominance through time. In stands thinned from below or from both above and below, growth dominance was not significantly different from zero at any age or stocking level. Growth dominance in stands thinned from above trended from negative at low stocking levels to positive at high stocking levels and was positive in young stands. Growth dominance in unthinned stands was positive and increased with age. These results suggest that growth dominance provides a useful tool for assessing the efficacy of thinning treatments designed to reduce competition between trees and promote high levels of productivity across a population, particularly among crop trees.

scholarly journals Importance of the first thinning in young mixed Norway spruce and European beech stands

2017 ◽  
Vol 63 (No. 6) ◽  
pp. 254-262 ◽  
Author(s):  
Novák Jiří ◽  
Dušek David ◽  
Slodičák Marian ◽  
Kacálek Dušan
Keyword(s):  
Norway Spruce ◽  
Basal Area ◽  
European Beech ◽  
Static Stability ◽  
Diameter Distribution ◽  
Mixed Stands ◽  
Lower Altitude ◽  
Commercial Thinning ◽  
Dead Trees ◽  
Study Sites

Experimental results from the first thinning in mixed stands are not broadly experienced by forestry practice. To extend the experience with the thinning of a mixed stand, we studied thinned and unthinned mixtures of Norway spruce with European beech on two study sites in the Czech Republic, which represented different conditions: Všeteč (age of 19–35 years) – originally beech dominated site at 440 m a.s.l. and Deštné (age of 17–33 years) – originally spruce with beech site at 990 m a.s.l. Spruce and beech were mixed individually or in small groups. As the for number of trees, mixtures were 35–54% beech and 46–65% spruce at a lower altitude and 7–30% beech and 70–93% spruce at a higher altitude. In the period 1997–2013, we observed annually: mortality, diameter at breast height of all trees and height of trees (minimum 30 individuals) that represented diameter distribution. Results showed that the growth and development of young mixed spruce/beech stands were positively influenced by the first pre-commercial thinning on both locations. The most pronounced effect of thinning consisted in a decreased amount of basal area of dead trees. On control plots, salvage cut accounted for 34 and 46%, while on thinned plots it reached only 7–8% (thinned from above) and 18% (thinned from below) of basal area periodic increment during the 16-year study period. In contrast, diameter distribution was still relatively wide (i.e. an important amount of thin trees was left) at the end of observations on all plots of both study sites. Thinned stands also showed the better static stability (expressed as an h/d ratio) of dominant spruces compared to unthinned stands on both locations. Additionally, thinning supported the spruce share at a lower altitude and the  beech share at a higher altitude.

scholarly journals Common garden comparisons confirm inherited differences in sensitivity to climate change between forest tree species

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6213 ◽  
Author(s):  
Cuauhtémoc Sáenz-Romero ◽  
Antoine Kremer ◽  
László Nagy ◽  
Éva Újvári-Jármay ◽  
Alexis Ducousso ◽  
...  
Keyword(s):  
Climate Change ◽  
Tree Species ◽  
Mixed Model ◽  
Tree Height ◽  
Climatic Conditions ◽  
Published Data ◽  
Response Curves ◽  
Climate Conditions ◽  
Mixed Model Approach ◽  
Provenance Test

The natural distribution, habitat, growth and evolutionary history of tree species are strongly dependent on ecological and genetic processes in ecosystems subject to fluctuating climatic conditions, but there have been few experimental comparisons of sensitivity between species. We compared the responses of two broadleaved tree species (Fagus sylvatica and Quercus petraea) and two conifer tree species (Pinus sylvestris and Picea abies) to climatic transfers by fitting models containing the same climatic variables. We used published data from European provenance test networks to model the responses of individual populations nested within species. A mixed model approach was applied to develop a response function for tree height over climatic transfer distance, taking into account the climatic conditions at both the seed source and the test location. The two broadleaved species had flat climatic response curves, indicating high levels of plasticity in populations, facilitating adaptation to a broader range of environments, and conferring a high potential for resilience in the face of climatic change. By contrast, the two conifer species had response curves with more pronounced slopes, indicating a lower resilience to climate change. This finding may reflect stronger genetic clines in P. sylvestris and P. abies, which constrain their climate responses to narrower climatic ranges. The response functions had maxima that deviated from the expected maximum productivity in the climate of provenance towards cooler/moister climate conditions, which we interpreted as an adaptation lag. Unilateral, linear regression analyses following transfer to warmer and drier sites confirmed a decline in productivity, predictive of the likely impact of ongoing climate change on forest populations. The responses to mimicked climate change evaluated here are of considerable interest for forestry and ecology, supporting projections of expected performance based on “real-time” field data.

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