Residual Long-Term Effects of Forest Fertilization on Tree Growth and Nitrogen Turnover in Boreal Forest

Abstract

Abstract:The growth enhancing effects of forest fertilizer is considered to level off within 10 years of the application, and be restricted to one forest stand rotation. However, fertilizer induced changes in plant community composition has been shown to occur in the following stand rotation. To clarify whether effects of forest fertilization have residual long-term effects, extending into the next rotation, we compared tree growth, needle N concentrations and the availability of mobile soil N in young (10 years) Pinus sylvestris L. and Picea abies (L.) H. Karst. stands. The sites were fertilized with 150 kg·N·ha −1 once or twice during the previous stand rotation, or unfertilized. Two fertilization events increased tree height by 24% compared to the controls. Needle N concentrations of the trees on previously fertilized sites were 15% higher than those of the controls. Soil N mineralization rates and the amounts of mobile soil NH4-N and NO3-N were higher on sites that were fertilized twice than on control sites. Our study demonstrates that operational forest fertilization can cause residual long-term effects on stand N dynamics, with subsequent effects on tree growth that may be more long-lasting than previously believed, i.e., extending beyond one stand rotation.

Nutrient optimization of tree growth alters structure and function of boreal soil food webs

“…In Scandinavian forestry, fertilizers are commonly applied as a single dose or as repeated applications of solid N fertilizer (ca. 150 kg N ha −1 ) (Bergh et al, 2005;From et al, 2015). However, solid N fertilization can also have detrimental effects on boreal forest ecosystems, such as compositional shifts in understory vegetation, nutrient imbalances, nutrient toxicity effects, nutrient leaching, as well as shifts in soil community structure and functioning (Binkley and Högberg, 2016;Gundale et al, 2011;Lucas et al, 2011;Strengbom and Nordin, 2008;Treseder, 2008).…”

Yabani Kiraz Dikim Sahasında Kontrollü Salınımlı Gübrenin Etkileri: Beşinci Yıl Sonuçları

“…Fertilization (300 kg ha -1 N) significantly increased annual diameter and height of Abies magnifica in the first ten years yet no difference was found later in a 30 year study (Zhang et al, 2005). Fertilization effects on tree growth generally may not be large and fade away in the long term except that it is integrated with other site preparation practices (Headwall et al, 2014, From et al, 2015.…”

Nitrogen and Boron Dosage Effects on Arginine Accumulation in Scots Pine Needles

“…In addition, N-induced foliar biomass gain in Pinus sylvestris and Picea abies mainly happened in the second and third growing seasons after fertilization [14]. The most pronounced effect of N fertilization on pine growth was observed in the first five to ten years after the treatment, but the effect lasted even longer on a minor scale [18,19].…”

“…Many experiments have been carried out on the effect of nitrogen and boron fertilizers on the growth of conifers because N and B are elements that plant growth in forest ecosystems-in many ecosystems of Fennoscandia [1][2][3][4][5][6][7][14][15][16]18,19,39,44,52,53]. Doses of N and B application were tested in a wide range to increase the growth rate of coniferous trees.…”

“…Excessive competition between trees for nutrients, light, and water is prevented by precommercial cuts (thinning) with retention of a sufficient number of trees to secure high productivity of the site [8], while the supply of nutrients to trees is optimized by fertilization [9][10][11]. Alongside many other factors, the effect of fertilization on tree species depends on the content of nutrients in soil and on fertilizer form and dosage [6,8,[12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”