Deterioration of Norway spruce vitality despite a sharp decline in acid deposition: a long-term integrated perspective

• Published in: Global change biology Vol. 18; no. 2; pp. 711 - 725
• Main Authors: Jonard, Mathieu, Legout, Arnaud, Nicolas, Manuel, Dambrine, Etienne, Nys, Claude, Ulrich, Erwin, van der Perre, Raphaele, Ponette, Quentin
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.02.2012; Wiley-Blackwell; Wiley
• Subjects: Acid deposition; Acidification; Aluminum; Animal and plant ecology; Animal, plant and microbial ecology; atmospheric deposition; Biogeochemistry; Biological and medical sciences; crown condition; Drought; Ecological studies; Evergreen trees; foliar nutrition; Forests; Fundamental and applied biological sciences. Psychology; General aspects; Leaching; Life Sciences; Nitrogen; Norway spruce; Nutrient cycles; nutrient cycling; Picea abies; Pine trees; Pollutant deposition; Sedimentation & deposition; Soil acidification; Soil chemistry; Soil solution; soil solution chemistry; Sulfur; Synecology; Terrestrial ecosystems; tree vitality; Trees; trend analysis; Acidification; Atmospheric deposition; Vitality; Acid precipitation; tree vitality; Gymnospermae; Tree crown; Tree; Soil solution; Nutrition; Norway spruce; Biogeochemical cycle; Long term; nutrient cycling; crown condition; Soils; soil solution chemistry; Deterioration; Trend analysis; soil acidification; Nutrient; Coniferales; Spermatophyta; Picea abies; foliar nutrition; FOLIAR NUTRIENT STATUS; FRENCH PRIMARY ARDENNES; FOREST ECOSYSTEMS; EUROPEAN BEECH STANDS; SOIL CHEMISTRY; atmospheric deposition; AIR-POLLUTION; BELGIAN ARDENNES; PICEA-ABIES; trend analysis; LEAF-AREA INDEX
• DOI: 10.1111/j.1365-2486.2011.02550.x
• ISSN: 1354-1013

Since the late 1970s, several long‐term ecological studies were conducted to better understand the biogeochemical functioning of Norway spruce stands in the Ardennes as these nutrient‐poor ecosystems were subject to high levels of acid deposition and exhibited symptoms of tree health decline. Between 1978 and 2009, acid deposition declined sharply, especially sulfur and to a lesser extent nitrogen deposition. The aim of this study was (i) to determine if the Norway spruce stands recovered after the reduction of acid deposition and (ii) to explain why such a recovery occurred or not. Therefore, we collected data from different projects carried out in the Ardennes to characterize the long‐term temporal trends in soil solution chemistry, foliar nutrition, and crown condition. In parallel, a model describing the nutrient cycling in forests (NuCM) was calibrated and used to check the consistency of the observed temporal trends and to explain them. The soil solution concentration of most of the elements decreased between 1978 and 2002, which was ascribed to a decrease in atmospheric deposition. For potassium, a decline in the exchangeable pool was also showed based on the simulation carried out with NuCM. As nitrogen (N) deposition remained at an elevated level, Norway spruce stands were progressively saturated in N and mineral nutrition became more and more unbalanced. Except the foliar N and Al concentration that remained constant and increased respectively, the foliar concentration of all other nutrients decreased between 1993 and 2009, which can be explained by the decrease in ion concentration in solution. These nutritional disorders weakened trees and were probably exacerbated during the 2003 summer drought, after which symptoms of vitality loss progressively appeared. In these N‐saturated ecosystems, the N cycle was disrupted by this health decline, which increased NO3− leaching reinforcing soil acidification and risk of aluminum (Al) toxicity.