Epsilon Archive for Student Projects

Abstract

Climate change is an ongoing issue in various fields, including forestry. More frequent
and severe droughts have been already noted around the world, also in Europe. Visible reduction
in available water in forests has adverse consequences such as increased tree mortality, higher
vulnerability and smaller growth. Appropriate silviculture treatment can improve forest conditions.
Proper thinning practices can reduce belowground competition for water.
In the current study, water with a detectable isotope (deuterium, 2H) was applied in Scots pine
stands with different intensities of thinning in order to investigate water route and horizontal root
systems structure. Based on the amount of the label in the sapwood cores of trees, water uptake
was examined. In addition the sapwood area of each analysed tree was calculated. Knowing
the exact location of trees, the water route on the plot was mapped.
The results showed a strong correlation between the place of water application and the distance
of a tree. Belowground roots overlap was proven and reached 3,5 trees /m2. In heavily thinned plots
labelled trees uptook the biggest amount of 2H. There was no correlation between the sapwood area
of a tree and the amount of uptaken label. Visual presentation of trees distribution showed
belowground avoidance of competition – root systems are not developed uniformly around tree
stem.
Although there are some limitations of this study such as the short time between thinning
and experiment establishment, the results obtained gave a valuable insight into the root system
and connected with other research, including examination of root development after thinning
in a few years, can be helpful and useful in adjusting thinning practice in face of lack of water
in the forest.