Reduction of timber value from damaged spruce stands after their dieback

The paper presents a method for the derivation of total timber production and of increments in value units, particularly in net financial yield for spruce stands damaged by crown defoliation after their dieback. The value production was derived by means of value growth models of undamaged stands and models for the adjustment of volume and qualitative production of damaged and died stands. Changes in timber quality after tree drying and changes in the production of damaged stands compared with undamaged ones are illustrated in tables and graphs. The changes are expressed by means of the indexes of total mean increment and total current increment. They depend mainly on the degree of stand damage expressed by crown defoliation, age and yield class of stand, the age of stand when the damage started and duration of damage. The value of damaged stands after their dieback is lover minimally by 50% than before their dieback. It is caused mainly by deteriorated quality of timber from dead trees in stand.

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Modeling of Dead Wood Potential Based on Tree Stand Data

Forests ◽

10.3390/f11090913 ◽

2020 ◽

Vol 11 (9) ◽

pp. 913

Author(s):

Ninni Mikkonen ◽

Niko Leikola ◽

Panu Halme ◽

Einari Heinaro ◽

Ari Lahtinen ◽

...

Keyword(s):

Boreal Forests ◽

Large Scale ◽

Dead Wood ◽

Growth Models ◽

Surrogate Marker ◽

Forest Growth ◽

Managed Forests ◽

Dead Trees ◽

History Of

Here we present a framework for identifying areas with high dead wood potential (DWP) for conservation planning needs. The amount and quality of dead wood and dying trees are some of the most important factors for biodiversity in forests. As they are easy to recognize on site, it is widely used as a surrogate marker for ecological quality of forests. However, wall-to-wall information on dead wood is rarely available on a large scale as field data collection is expensive and local dead wood conditions change rapidly. Our method is based on the forest growth models in the Motti forest simulator, taking into account 168 combinations of tree species, site types, and vegetation zones as well as recommendations on forest management. Simulated estimates of stand-level dead wood volume and mean diameter at breast height were converted into DWP functions. The accuracy of the method was validated on two sites in southern and northeastern Finland, both consisting of managed and conserved boreal forests. Altogether, 203 field plots were measured for living and dead trees. Data on living trees were inserted into corresponding DWP functions and the resulting DWPs were compared to the measured dead wood volumes. Our results show that DWP modeling is an operable tool, yet the accuracy differs between areas. The DWP performs best in near-pristine southern forests known for their exceptionally good quality areas. In northeastern areas with a history of softer management, the differences between near-pristine and managed forests is not as clear. While accurate wall-to-wall dead wood inventory is not available, we recommend using DWP method together with other spatial datasets when assessing biodiversity values of forests.

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A Novel Approach to Evaluate the Effect of Neighboring Trees and the Orientation of Tree Social Area on Stem Radial Increment of Norway Spruce Trees

Forests ◽

10.3390/f12020163 ◽

2021 ◽

Vol 12 (2) ◽

pp. 163

Author(s):

Jan Světlík ◽

Jan Krejza ◽

Pavel Bednář

Keyword(s):

Norway Spruce ◽

Tree Growth ◽

Growth Models ◽

Explanatory Power ◽

Radial Increment ◽

Important Indicator ◽

The Czech Republic ◽

Novel Approach ◽

Spruce Stands ◽

Social Area

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.

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Reliability Growth Models for Defect Prediction

Encyclopedia of Information Science and Technology, Second Edition ◽

10.4018/978-1-60566-026-4.ch520 ◽

2011 ◽

pp. 3263-3267

Author(s):

Norman Schneidewind

Keyword(s):

Risk Factors ◽

Life Cycle ◽

Growth Models ◽

Numerical Results ◽

Defect Prediction ◽

Reliability Growth ◽

Software Measurement ◽

Requirements Change ◽

Code Metrics

In order to continue to make progress in software measurement as it pertains to reliability, there must be a shift in emphasis from design and code metrics to metrics that characterize the risk of making requirements changes. By doing so, the quality of delivered software can be improved because defects related to problems in requirements specifi- cations will be identified early in the life cycle. An approach is described for identifying requirements change risk factors as predictors of reliability problems. This approach can be generalized to other applications with numerical results that would vary according to application.

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Galling phenomena in metal forming

Friction ◽

10.1007/s40544-020-0430-z ◽

2020 ◽

Author(s):

Kuniaki Dohda ◽

Masahito Yamamoto ◽

Chengliang Hu ◽

Laurent Dubar ◽

Kornel F. Ehmann

Keyword(s):

Metal Forming ◽

Prediction Models ◽

Growth Models ◽

Future Research ◽

Research Directions ◽

Bulk Metal ◽

Engineered Surfaces ◽

Future Research Directions ◽

Effects Of Temperature

AbstractGalling phenomena in metal forming not only affect the quality of the engineered surfaces but also the success or failure of the manufacturing operation itself. This paper reviews the different galling conditions in sheet and bulk metal forming processes along with their evolution and the effects of temperature on galling. A group of anti-galling methods employed to prevent galling defects are also presented in detail. The techniques for quantitatively measuring galling are introduced, and the related prediction models, including friction, wear, and galling growth models, are presented to better understand the underlying phenomena. Galling phenomena in other processes similar to those occurring in metal forming are also examined to suggest different ways of further studying galling in metal forming. Finally, future research directions for the study of galling in metal forming are suggested.

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The association of socioeconomic status with quality of life in cancer patients over a 6-month period using individual growth models

Supportive Care in Cancer ◽

10.1007/s00520-018-4634-y ◽

2019 ◽

Vol 27 (9) ◽

pp. 3347-3355 ◽

Cited By ~ 1

Author(s):

Julia Roick ◽

Helge Danker ◽

Anette Kersting ◽

Arne Dietrich ◽

Andreas Dietz ◽

...

Keyword(s):

Quality Of Life ◽

Socioeconomic Status ◽

Cancer Patients ◽

Growth Models ◽

Individual Growth

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Relation between selected indicators of forest stand diversity and quality of timber production in managed Central European forests

Journal of Forest Science ◽

10.17221/94/2015-jfs ◽

2016 ◽

Vol 62 (No. 3) ◽

pp. 97-106 ◽

Cited By ~ 1

Author(s):

J. Merganič ◽

K. Merganičová ◽

R. Marušák ◽

L. Tipmann ◽

L. Šálek ◽

...

Keyword(s):

Forest Stand ◽

Timber Production ◽

Central European ◽

European Forests

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HEALTH, HUMAN CAPITAL FORMATION AND KNOWLEDGE PRODUCTION: TWO CENTURIES OF INTERNATIONAL EVIDENCE

Macroeconomic Dynamics ◽

10.1017/s1365100514000650 ◽

2016 ◽

Vol 20 (4) ◽

pp. 909-953 ◽

Cited By ~ 12

Author(s):

Jakob B. Madsen

Keyword(s):

Knowledge Production ◽

Growth Models ◽

Population Based ◽

Annual Data ◽

Human Capital Formation ◽

International Evidence ◽

The Past ◽

Working Age ◽

Endogenous Growth Models

Recent medical research shows that health is highly influential on learning and the ability to think laterally; however, past economic studies have failed to empirically examine the influence of health on learning, schooling, and ideas production, the main drivers of growth in endogenous growth models. This paper constructs a measure of health-adjusted educational attainment among the working age population based on their health status during the time they obtained their education. Using annual data for 21 OECD countries over the past two centuries, it is shown that health has been highly influential on the quantity and quality of schooling, innovation, and growth.

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Tree Hollow Requirements of Leadbeater's Possum and Other Possums and Gliders in Timber Production Ash Forests of the Victorian Central Highlands.

Wildlife Research ◽

10.1071/wr9880347 ◽

1988 ◽

Vol 15 (4) ◽

pp. 347 ◽

Cited By ~ 102

Author(s):

AP Smith ◽

D Lindenmayer

Keyword(s):

Forest Management ◽

Regression Models ◽

Timber Production ◽

Total Density ◽

Management Options ◽

Eucalyptus Regnans ◽

Dead Trees ◽

Production Forests ◽

Leadbeater's Possum ◽

Tree Hollow

A model is presented of relationships between the density of Leadbeater's possum (Gymnobelideus leadbeateri) and other tree-hollow dependent possums and gliders and the density of potential nest trees (PNT) in Eucalyptus regnans/E. delegatensis forests, where PNT are defined as all living or dead trees with d.b.h. more than or equal to 0.5 m and ht. more than or equal to 6 m. The total density of all possums and gliders increased linearly with PNT density, in an approx. 1:1 ratio, then plateaued at an av. max. density of 11.3 animals per 3 ha once PNT density exceeded 12 per 3 ha. Regression models predict that G. leadbeateri will be absent from the majority of sites with less than 4.2 PNT per 3 ha and will increase linearly in density to an av. max. of 7.8 animals (or 3.1 colonies) per 3 ha on sites with more than 10 PNT per 3 ha. The absence of G. leadbeateri from sites with fewer than 4.2 PNT per 3 ha was attributed to: competition for hollows from other species; use of more than one PNT by individual colonies; and unsuitability of hollows in up to 2 out of every 3 PNT. Regression models predict that current logging prescriptions in ash forests, which call for retention of a minimum of 15 trees for every 10 ha clear felled, will result in elimination of G. leadbeateri from the majority of clearfelled coupes, and will reduce the total number of hollow-dependent possums and gliders to less than one-eighth of their av. max. density in unlogged forest. A range of forest management options are presented and discussed to ensure the continued availability of PNT for hollow-dependent arboreal mammals in timber production forests.

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