Current issue: 58(5)
The article discusses entomological analyses and their applications. Recent improvements in the methodology are presented and examples of application in the field of pines drying up standing are discussed. Further improvements to the method are proposed. The results of the studies so far indicate that there is need for further studies on duration of the generation of pine weevils (Pissodes sp.)
The PDF contains a summary in Finnish.
There has been earlier publications on calculating the standard error of the strips. However, they have been calculated with very small amount of data. In the article the confidence of standard error will be examined throughout. The article is a response to the article written by A. Langsaeter on the theme.
The article tries to develop the method for defining the requirements of fertilizers for soil. The chemical soil analysis is also seen as the requirement for exact site classification based on height over age. The study is based on 1500 soil samples, one half of them from forest soils, the other half from arable land soils.
The productivity of different forest types and the results of soil analyses are in line with each other. The most important growth factors are discerned. Some shortcomings of the method are discussed. Combining the soil analysis and the plant analyses of the sample plots seems to give the most accurate about the amount of nutrients that are available for the plants.
The data used to control the developed methods are presented in chapter two. The third chapter presents the statistical analysis conducted. The factor analysis shows that tree stand characteristics must be divided into three factors to able the information needed for site indexing to distinguish different site classes. The phases of model development are presented and the results of calculations with control data are shown.
The results indicate that for calculations of nature-normal forests the suitable amount of tree stand characters for creating the site indexing function, is three. These are: number of trees (N), basal area of the stand (G) and mean height (H).
The PDF contains a summary in Finnish.
The article is the first part of a wider project aiming to study the measurement practices of stand’s height-over-age based classifications and to develop new methods for actually measuring the side index.
The first part of the article presents the concepts of site indexing and discusses it with a mathematical model. The second part of the article examines the structure of site indexing system regarding the reliability of the method. Third part presents the factors affecting the method development and the fourth part discusses the possible site index classes and their characteristics.
The PDF contains a summary in Finnish.
With developing possibilities to analyse data automatically there is a need to develop the mathematical and statistical practices for calculations. The article presents the basis about the growth of trees and the existing models of growth, the basics on growth functions, and the construction of a regression model to analysis the growth. The theoretical model development has been tested with three existing data sets.
The analysis of growth should be considered with dynamic models. The model need to take into account various aspects and growth factors. The model should have practical implications.
The PDF contains a summary in German.