Scots pine and Norway spruce stands responses to annual N, P and Mg fertilization

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.…”

“…Mutikainen et al (2000) reviewed the carbon-nutrient balance hypothesis, which explains the variation of herbivore-induced resistance in terms of different soil fertility and light regimes. Defoliation can affect the carbonnutrient balance of plants by removing more nutrients than carbon, as observed both at the ecosystem level (Finér 1992, Nilsen & Abrahamsen 2003, Hytönen et al 2014 and under a controlled environment (Huttunen et al 2007, 2013, Kula et al 2012, Varnagiryte-Kabašinskiene et al 2015. Moreover, it has been suggested that fertilization is required for more intensive mineralization rates of organic nitrogen in soil under climate warming or increased N depositions (Mäkipää et al 1999, Galloway et al 2004, Verburg 2005.…”

Aboveground biomass and nutrients in an 18-years-old stand of blue spruce (Picea pungens Engelm.) as a substitute tree species

“…indicated decreasing availability not only of P but also of Mg, which in combination with soil acidification may be limiting factors for the forest nutrition in the future (Lomský et al 2012). On poor sites under former acidification stress the improved nutrient supply may act as a stimulus promoting growth and influencing the vitality and survival of especially young trees (Nilsen, Abrahamsen 2003;Podrázský et al 2003;Kupka 2005;Óskarsson et al 2006). Liming increasing the Ca and Mg supply can partly improve the accessibility of P (Formánek, Vránová 2002).…”

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

“…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).…”

“…This suggests that old pine stands might also be able to respond to fertilization. On the other hand, ample supplies of nitrogen may at least theoretically lead to deficiencies of other nutrient elements (Nilsen, Abrahamsen 2003;Högberg et al 2006). The objective of our study was to investigate stem growth in old Scots pine stands treated with repeated fertilizations with nitrogen in various forms, doses and intervals.…”