Home About Browse Search
Svenska


Asbeck, Thomas, 2015. Silvicultural practices for wild pear. Second cycle, A2E. Alnarp: SLU, Southern Swedish Forest Research Centre

[img]
Preview
PDF
4MB

Abstract

The research objective is to construct a model for crown radius (CR) based on DBH and significant quantifiers for wild pear (Pyrus pyraster), using regression analyses, to develop guidelines for silvicultural practices for wild pear. To establish the model empirical data of a wild pear population in Western Germany was collected. Site measurements include prevailing vegetation, soil characteristics, location and neighbouring trees. Tree measurements include DBH, height, crown radius and quality characteristics: living branches, forking, bending and spiral grain. 52 trees have been measured of which 41 have been used for modelling purposes. Selection criteria for the model are residual plots and coefficient of determination (R²). In order to find a linear relationship, (semi-) logarithmic transformations of the dependent and independent variables have taken place. A backward variable elimination from a full model was used to find significant predictors. The logarithmic model is selected best as residual plots show a homoscedastic distribution and follow a normal distribution around the zero-line. The R² of 0.6101 gives an indication of a significant relationship. The final relation can be formulated as:CR=e^(0.61388∗ln(DBH)−0.75029), where CR in m and DBH in cm. No other independent variables than DBH have been significant. From the derived model, tree spacing and number of stems per ha can be calculated at any DBH. Based on collected data and the model silvicultural guidelines for a pure and two mixed wild pear stands including planting density and layout, pruning, thinning and regeneration cutting are established.

Main title:Silvicultural practices for wild pear
Authors:Asbeck, Thomas
Supervisor:Skovsgaard, Jens Peter and Wilhelm, Georg Josef
Examiner:Gemmel, Per
Series:Examensarbete / SLU, Institutionen för sydsvensk skogsvetenskap
Volume/Sequential designation:242
Year of Publication:2015
Level and depth descriptor:Second cycle, A2E
Student's programme affiliation:SM001 Euroforester - Master's Programme 120 HEC
Department:(S) > Southern Swedish Forest Research Centre
Keywords:wild pear, Pyrus pyraster, crown radius, silviculture guidelines
URN:NBN:urn:nbn:se:slu:epsilon-s-6120
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-s-6120
Subjects:Forestry production
Language:English
Deposited On:12 Dec 2016 15:09
Metadata Last Modified:12 Dec 2016 15:09

Repository Staff Only: item control page

Downloads

Downloads per year (since September 2012)

View more statistics

Downloads
Hits