Tillväxteffekter för andra generationens granskog efter tidigare genomförd kalkning
Author
Summary, in English
This study aims to investigate the growth of a spruce forest, where the soil has been treated with lime before planting. The study period reaches from 1992, when the spruces were planted until 2016. In Sweden, the forest industry plays an important role of the country´s development and economic conditions. A study of forest growth is therefore of large interest for many actors within the Swedish forest industry.
At the end of the 1960´s, acidification was getting more and more attention from researchers and the public and during the 1970´s, forest damage as a possible result of acidification were first reported. Acidification within a forest means a lower pH, toxic elements such as aluminum and cadmium are being released and nutrients are being leached due to strong acids. This affects the growth and indirect the productivity of the forest in a negative way.
Liming is often used as a countermeasure to acidification in forests. The contribution of lime increases the pH and provides nutrients to the soil. Other studies within the field have shown that liming affects the growth in a positive way. However, the long time span in this study, 29 years since the lime treatments ended, is rare. To what extent a lime treatment will affect the growth is strongly linked to the connection between liming and decomposition rate. Decomposition of organic matter is shown to be benefitted from higher pH-values, and a higher decomposition rate means more available nitrogen for the plants and thus a possible higher growth rate.
Through statistical analysis of collected field data (diameter and height), the aim is to see whether there is a significant difference in growth (diameter, height, basal area, stem volume) between limed plots and untreated control plots. The results show that the growth of the spruces was significant larger on the limed plots compared to the control plots. The effects of lime treatments are not only based on the amount of lime applied, but also the C/N-ratio (the ration between carbon and nitrogen) and the fertility of the soil. A lower C/N-ratio indicates a higher fertility, which is assumed to be the case in the studied plots. In southern Sweden, where the study is carried out, nitrogen is often the limiting factor for forest growth. An addition of plant available nitrogen through increased decomposition rate is therefore considered as a fertilizer, resulting in an increased growth.
Acidification in forests is still a problem and a lot of research is needed to answer the question whether the decreased acidifying emissions are enough for the ecosystems to recover or not. Liming an area does not only result in positive effects. For example, nitrogen leakage might occur if the soil gets saturated with nitrogen, and thus contribute to the eutrophication in lakes and streams.
A more close investigation of the effects from lime treatments on nutrient availability in the soil is desirable in order to get a better appreciation of the treatment. As an interesting continuation of this study, an investigation of the available lime materials on the market could be done. Limestone is the one mostly used (also for this study), but dolomite lime and ash are two other interesting materials and they all have different properties affecting soils in different ways.
At the end of the 1960´s, acidification was getting more and more attention from researchers and the public and during the 1970´s, forest damage as a possible result of acidification were first reported. Acidification within a forest means a lower pH, toxic elements such as aluminum and cadmium are being released and nutrients are being leached due to strong acids. This affects the growth and indirect the productivity of the forest in a negative way.
Liming is often used as a countermeasure to acidification in forests. The contribution of lime increases the pH and provides nutrients to the soil. Other studies within the field have shown that liming affects the growth in a positive way. However, the long time span in this study, 29 years since the lime treatments ended, is rare. To what extent a lime treatment will affect the growth is strongly linked to the connection between liming and decomposition rate. Decomposition of organic matter is shown to be benefitted from higher pH-values, and a higher decomposition rate means more available nitrogen for the plants and thus a possible higher growth rate.
Through statistical analysis of collected field data (diameter and height), the aim is to see whether there is a significant difference in growth (diameter, height, basal area, stem volume) between limed plots and untreated control plots. The results show that the growth of the spruces was significant larger on the limed plots compared to the control plots. The effects of lime treatments are not only based on the amount of lime applied, but also the C/N-ratio (the ration between carbon and nitrogen) and the fertility of the soil. A lower C/N-ratio indicates a higher fertility, which is assumed to be the case in the studied plots. In southern Sweden, where the study is carried out, nitrogen is often the limiting factor for forest growth. An addition of plant available nitrogen through increased decomposition rate is therefore considered as a fertilizer, resulting in an increased growth.
Acidification in forests is still a problem and a lot of research is needed to answer the question whether the decreased acidifying emissions are enough for the ecosystems to recover or not. Liming an area does not only result in positive effects. For example, nitrogen leakage might occur if the soil gets saturated with nitrogen, and thus contribute to the eutrophication in lakes and streams.
A more close investigation of the effects from lime treatments on nutrient availability in the soil is desirable in order to get a better appreciation of the treatment. As an interesting continuation of this study, an investigation of the available lime materials on the market could be done. Limestone is the one mostly used (also for this study), but dolomite lime and ash are two other interesting materials and they all have different properties affecting soils in different ways.
Department/s
Publishing year
2016
Language
Swedish
Publication/Series
Examensarbeten INES
Full text
Document type
Student publication for Bachelor's degree
Topic
- Earth and Environmental Sciences
Keywords
- granskog
- tillväxt
- kalkning
- långtidseffekter
- Physical Geography and Ecosystem Science
Report number
381
Supervisor
- Cecilia Akselsson
- Ulf Sikström