Katarzyna Kaźmierczak

Allocation of oaks to Kraft classes based on linear and nonlinear kernel discriminant variables

Summary A method of discriminant variable determination was used to visualize the division of oak trees into Kraft classes. Usual discriminant variables and several types of kernel discriminant variables were studied. For this purpose the traits of oak (Quercus L.) trees, measured on standing trees, were used. These traits included height of tree, breast height diameter and crown projection area. The use of the Gaussian kernel and modified Gaussian kernel enabled the clearest division into Kraft classes. In particular, the latter method proved to be the most effective.

Tree crown size as a measure of tree biosocial position in 135-year-old oak (Quercus L.) stand

Abstract The paper presents an attempt to apply measurable traits of a tree – crown projection area, crown length, diameter at breast height and tree height for classification of 135-year-old oak (Quercus L.) trees into Kraft classes. Statistical multivariate analysis was applied to reach the aim. Empirical material was collected on sample plot area of 0.75 ha, located in 135-year-old oak stand. Analysis of dimensional traits of oaks from 135-year-old stand allows quite certain classification of trees into three groups: pre-dominant, dominant and co-dominant and dominated ones. This seems to be quite promising, providing a tool for the approximation of the biosocial position of tree with no need for assessment in forest. Applied analyses do not allow distinguishing trees belonging to II and III Kraft classes. Unless the eye-estimation-based classification is completed, principal component analysis (PCA) method provided simple, provisional solution for grouping trees from 135-year-old stand into three over-mentioned groups. Discriminant analysis gives more precise results compared with PCA. In the analysed stand, the most important traits for the evaluation of biosocial position were diameter at breast height, crown projection area and height.

Height increments of Scots pine (Pinus sylvestis L.). The effect of weather conditions

This study suggests a method of valuation for wood coming from dead trees which was applied for pricing of such wood found in Polish forests. This study shows that in Polish forest there are approx. 52 million m3 biocenotic wood coming from dead or dying trees with an estimated value of 1.5 billion PLN/10 years.In 2007 and 2008 studies aimed to determine the effect of indoxacarb, substance classified as oxadiazines (Steward 30 WG) and beta-cyfluthrine, belonging to synthetic pyrethroids (Bulldock 025 EC), on the oxygen consumption rate by adult Anoplotrupes stercorosus were performed. Experiments were carried out under various ambient temperature conditions (14, 19, 24 i 29°C) using two ways of intoxication – contact intoxication, or by an ingestion of the biocide. In insects of control group an ambient temperature affected the oxygen consumption only to a small extent. Conversely – applying insecticides markedly potentiated the oxygen consumption, whereas it was also increasing together with an increase of the temperature. The way of the intoxication affected the oxygen consumption only to quite a small extent. However, its greatest changes were noted in animals treated by contact intoxication.The rising demand for energy and the need to acquire ever more energy quantities from renewable sources call for seeking energy sources in forestry. The analysis presents a simulation of wood quantities needed to meet the obligation to produce electricity from woody biomass. Three sources of energy were specified, which can be delivered to power plants: medium dimensional round firewood, small dimensional firewood and logging residues. The calculated quantity of wood required by the industrial energy sector will reach 15 million cu. meters. Forestry will be able to directly supply about 5.8 mill. cu. meters of wood for energy purposes, including 3.1 mill. cu. m of medium dimensional roundwood, 1.4 mill. cu. m of small dimensional wood and 1.35 mill. cu. m of woody material in the form of logging residues. The largest quantities of woody material will come from western and northern parts of the country. Taking into account the fact that considerable quantities of wood suitable for energy purposes are currently utilized for heating by rural communities, not much will be left for the industrial energy sector.The study was conducted on 13 areas in the Wołów Forest District in oak stands with the common oak as the dominant species. The stands in the Wołów Forest District located in the Odra valley, including the oak stands, were flooded in 1997 and 2010. The aim of this study was to analyse the influence of defoliation on radial growth of oaks in the post-flood stands. Recorded results showed an inferior growth in thickness and greater defoliation in the common oak in the post-flood stands. The average defoliation at 40% has a significant influence on radial growth. It seems advisable to include the capacity of radial growth in the assessment of the condition of trees.The effect of weather conditions on height increments of trees was investigated within eight age classes. Weather conditions (temperature and precipitation) were presented using Sielianinow’s hydrothermal index in the quarterly periods and the De Martonne index in the annual periods. Drought index in a given year was found to have a negative effect on height increments of trees in the following year. A significant effect of weather conditions found in a given increment year was observed only in the case of the youngest trees.

The influence of temperature on the height increment of Scots pine (Pinus sylvestis L.)

The annual height increment of Scots pine exerts a direct influence on the determination accuracy of the tree and the stand volume increment. It is considered as a major dendrometric characteristic. However, the growth of trees depends on the meteorological conditions in the year that preceded increments, as well as in the given incremental year. In this study the relationship between annual increments, and temperature was examined. For this purpose correlation coefficients between monthly temperature and mean annual height increments were designated. Next, the forward stepwise regression procedure was used. For this purpose the SAS software package was applied. On the basis of the presented research it was found that the Scots pine increments are greater when summer months, both of the pervious year and of the given vegetation season, are cooler and when March is warmer.

Self-pruning of pedunculate oak (Quercus robur L.) stems and the diameter at breast height of trees in commercially managed stands

Proces oczyszczania się pni dębu szypułkowego (Quercus robur L.) a pierśnica drzew w drzewostanach gospodarczych Self-pruning of pedunculate oak (Quercus robur L.) stems and the diameter at breast height of trees in commercially managed stands The focus of this study was on the knottiness and self-pruning of trees at 10 study sites from which 30 trees were selected for observation. These areas represent two main forest site types (fresh mixed deciduous forest - LMśw and fresh deciduous forest - Lśw) characteristic of the silvicultural regime of oaks in Polands lowland area. Sample trees were selected according to the principles of the Urich method (with the same number of trees in the diameter class) and Krafts biosocial classification. Trees from the dominant stand (class I, II and III according to Krafts classification) were subjected to analysis. Normal distribution of length parameters was found for the majority of analysed zones of sample trees. On this basis correlation values were calculated describing the relationships between the diameter at breast height (dbh) and self-pruned zones on the stem: with knobs visible on external surface of tree stem, with snags remained after the dead branches, with the still unbroken dead and dying branches, live crown (active with regard to transpiration and photosynthesis). The length of the self-pruned tree stems from the fresh deciduous forest was greater in comparison with the trees from the fresh mixed deciduous forest. In turn, the length of the knob and snag zones was greater in trees from the fresh mixed deciduous forest. The variation in these parameters was rather insignificant. No statistically significant differences were detected in mean lengths of the examined zones between the two forest site types. Trees in the oldest age classes (VI and VII) showed a higher mean length of individual stem zones compared with those in younger age classes.