Throughfall nutrients in a degraded indigenous Fagus orientalis forest and a Picea abies plantation in the of North of Iran

Abstract

<p><em>Aim of study: </em>The objective of this study was to compare<em> </em>the quantity and quality of <em>TF</em> (throughfall) in an indigenous, but degraded, stand of <em>Fagus orientalis </em>and <em>Picea abies</em> plantation.</p><p><em>Area of study</em>: Forests of Kelar-Dasht region located in Mazandaran province, northern Iran.</p><p><em>Material and Methods:</em><em> </em><em>TF</em> measured by twenty collectors that were distributed randomly underneath each stand<em>. </em>For 21 storms sampled in 2012 (August-December) and 2013 (April-June), we analyzed pH, EC, Ca²⁺, Mg²⁺, K⁺, NO₃^-, and P of  gross rainfall (<em>GR</em>) and <em>TF</em>.</p><p><em>Main results:</em> Cumulative interception (<em>I</em>) for <em>F. orientalis</em> and <em>P. abies</em> were 114.2 mm and 194.8 mm of the total <em>GR</em>, respectively. The amount of K⁺ (13.4 mg L^-1) and Ca²⁺(0.9 mg L^-1) were higher (for both elements, <em>p </em>= 0.001) in the <em>TF</em> of <em>P. abies</em> compared to those of<em> F. orientalis</em> (6.8 and 0.5, mg L^-1, respectively) and <em>GR</em> (3.2 and 0.37 mg L^-1, respectively). Conversely, mean P concentration was doubled (<em>p</em> = 0.022) in the <em>TF</em> of <em>F. orientalis</em> (11.1 mg L^-1) compared to <em>GR</em> (5.8 mg L^-1).</p><p><em>Research highlights: </em><em>P. abies</em> plantations may provide a solution for reforestation of degraded <em>F. orientalis </em>forests of northern Iran, yet how <em>P. abies</em> plantations differentially affect the quality and quantity of rainfall reaching subcanopy soils (<em>TF</em>) compared to <em>F. orientalis</em> is unknown. Understanding the connection between hydrological processes and nutrient cycling in forest ecosystems is crucial for choosing the appropriate species to rehabilitate the degraded indigenous forests with nonindigenous species.<em> </em><em> </em><em></em></p><strong>Keywords:</strong> concentration; hydrological process; interception; reforestation.