Silviculture of Scots pine and thinning strategies
This is a research project with main focus on increasing the understanding of interactions between tree growth and response to competition release. The aim of this PhD-project is to create knowledge for improved thinning guidelines that are adapted to a more precise forest management based on individual tree information from remote sensing, rather than guidelines on a stand level. The aim is also to create knowledge how thinning can be done to better meet consequences of climate changes and extreme weather events
Four objectives are formulated for this 5-year long project:
- Growth effect of thinning on trees of different size classes in Scots pine
- The importance of spatial distribution after thinning when comparing growth of individual trees.
- Timing of thinning response of different above-ground parts of individual trees.
- An understanding of mechanisms behind thinning response is crucial for the construction of future thinning guidelines.
Most thinning experiments in Sweden, and internationally, are empirical studies where effects of various thinning strategies on volume production and economy are investigated. However, with a changing climate, empirical knowledge will be more difficult to put into practical operations because future environment may be different from the environment at the time of the study.
Water- and nutrient availability are both affected by the thinning operation, and by climate change. Today, we have very little mechanistic knowledge about thinning-response. Most growth-function have an underlying assumption of competition for light, but many experiments indicate that competition for water and nutrients below ground are equally or more important. The response of individual trees after thinning is of fundamental importance for the construction of future thinning guidelines on pixel- or individual tree scale. Therefore, a more basic understanding of thinning-response is needed in order to construct thinning-guidelines that will be near optimal in future climate.
In this project, we will contribute to the mechanistic understanding of thinning-response which in turn may be necessary in future adaptation of forest management to climate change. This will be done through a new thinning experiment in Scots pine will be established in the Siljansfors experimental forest. In addition to growth parameter such as height and diameter, several ecophysiological parameters will be registered. The aim is to record change in availability of light, water and nutrients as a response to thinning, and explain individual tree thinning responses with these parameters.
Amanda Segowich is a newly recruited Ph. D. student with a background from the University of Sao Paolo, Brazil. The research group is mainly situated in Alnarp at Southern Forest Research Centre but the main study area are situated at Siljansfors experimental station. In addition, the experiments included in this project are distributed all over Sweden.
Emma Holmström +4640415114
Ola Langvall +46 472263180