Forest Fertilization Research in Finland: A Literature Review

Response of artificially defoliated Betula pendula seedlings to additional soil nutrient supply

“…This is in agreement with most general assertions, which emphasize optimal nutrition as a limiting factor for vegetation. Several previous studies have confirmed the essential role of N as a key nutrient for growth (Tamm 1991, Ferm et al 1992, Hög-berg et al 2000, Thelin 2000, Nilsen & Abrahamsen 2003, but the addition of other macronutrients could induce a higher incremental response than N alone (Ferm et al 1992, Saarsalmi & Mälkönen 2001, Ozolinčius et al 2007. In this study, height and stem diameter of birch seedlings increased by several times as a response to fertilization.…”

Tree nutrition of Norway spruce as modified by liming and experimental acidification at the Höglwald site, Germany, from 1982 to 2004

“…The expected positive effects of forest liming are the deacidification of soil and seepage water, and the increase in Ca and Mg supply of the soil [2], which may have been decreased by various processes of soil acidification [4]. However, negative effects have also occurred: emission of CO 2 due to the loss of organic matter [22,32], NO − 3 leaching [25], and reduced tree growth [31,36]. Therefore, forest liming is still controversial in Central and Northern Europe [19,24,27,31,32,36,41] and the various foci and interpretations of the findings of the acidification/liming problems have resulted in very diverse policies, especially in the German states [19].…”

“…However, negative effects have also occurred: emission of CO 2 due to the loss of organic matter [22,32], NO − 3 leaching [25], and reduced tree growth [31,36]. Therefore, forest liming is still controversial in Central and Northern Europe [19,24,27,31,32,36,41] and the various foci and interpretations of the findings of the acidification/liming problems have resulted in very diverse policies, especially in the German states [19]. However, there is still little information about the long-term effects of liming on the nutrient concentrations in the leaves, although this criterion is widely used for evaluation of the nutrient status, soil nutrient availability, and as an indicator of forest health [13].…”

Effect of repeated fertilization on stem growth in old stands of Pinus sylvestris in South East Norway

“…This indicates that the real fertilization effects in our experiment were even greater than shown by the data. The significant effects of fertilization with ammonium nitrate on basal area increment, whether the dose per application was 100 or 200 N kg·ha -1 , and the somewhat poorer responses to urea, are supported by numerous experiments in less aged stands of Scots pine in Fennoscandia (Nilsen 2001;Nohrstedt 2001;Saarsalmi, Mälkönen 2001). There is a risk of N volatilization after the application of urea under certain conditions of moisture, temperature and pH at the soil and vegetation surface (Derome 1979).…”

“…(Brantseg et al 1970;Pettersson, Hög-bom 2004). The effects of repeated fertilization in boreal coniferous forests in Fennoscandia have been widely studied in stands prior to full maturity (Nilsen 2001;Nohrstedt 2001;Saarsalmi, Mälkönen 2001;Bergh et al 2014;Saarsalmi et al 2014). These studies include fertilizer application both at intervals (Kukkola, Saramäki 1983;Mälkönen, Kukkola 1991;Jacobson, Pettersson 2001, 2010Pettersson, Högbom 2004;Hyvönen et al 2008) and annually (Tamm 1991;Nilsen, Abrahamsen 2003;Högberg et al 2006).…”