Foliar and wood chemistry of sugar maple along a gradient of soil acidity and stand health

Abstract

The decline of sugar maple (Acer saccharum Marsh.) in forest of north-eastern North America is an important environmental issue. In this study, relationships between, soil, wood and foliar chemistry were assessed for 17 stands distributed within a large area of the Quebec sugar maple forest and that were growing on soils with a strong gradient of acidity and base saturation. There were many significant relationships between variables describing the acid-base status of the top-B soil (Ca and Mg concentrations, exchangeable acidity and base saturation) and Ca and Mn concentrations and Ca/Mn and Mg/Mn in tree tissues. Manganese was the element that showed the strongest inverse non-linear relationships with top-B soil base saturation with variance explanation of 71 and 65%, for wood and foliage, respectively. The 17 sites were divided in two groups according to their level of decline. The declining stands had significantly higher wood Mn and Mg concentrations and lower Ca/Mn ratios and significantly higher foliar Mn and lower Ca and Al concentrations. It was impossible to determine if these differences were a cause or a symptom of sugar maple health. However, the increase in Mn concentrations in tree tissues with increasing soil acidity, as well as the higher Mn concentrations in declining as compared to healthy stands suggest that Mn, as well as low Ca availability, could be an important contributing factor in the sugar maple decline.

Assessment of sugar maple tree growth in relation to the partitioning of elements in xylem along a soil acidity gradient

“…The observed decreasing trend in total concentrations of base cations in sapwood at higher soil acidity is in good agreement with those of previous studies that have linked total concentrations of base cations in wood with soil chemistry (Bondietti et al, 1989DeWalle et al, 1991DeWalle et al, , 1999Penninckx et al, 2001;Fisher et al, 2002;Houle et al, 2002Houle et al, , 2007Watmough, 2002). Earlier studies had related decreasing radial trends of (total) base cation concentrations in tree-rings of recent decades (1960+) to the increased atmospheric acidic deposition on forest soils, although they had not directly measured soil acidity (Bondietti et al, 1989.…”

“…The negative correlation found between tree growth and the total xylem concentrations of Cd and Mn is consistent with most other studies concerning these metals (McQuattie and Schier, 2000;Reichman, 2002;Benavides et al, 2005;Kogelmann and Sharpe, 2006;Houle et al, 2007). The acid-soluble fraction of Cd and Mn was also significantly and negatively correlated to tree growth and consequently did not yield more information than the residual fraction.…”

“…Moreover, the correlations with soil acidity were stronger for the water-and acid-soluble fractions of Cd and Mn than for their residual fraction. If Mn solubility in soils has been often assumed (Guyette et al, 1992;Kogelmann and Sharpe, 2006) to depend mostly on soil pH, results indicate that Mn uptake by tree roots is governed by physicochemical mechanisms that depend not only on pH, but also on the soil acid-base status, notably base saturation (Houle et al, 2007).…”

Mimosa pigra dieback in the Northern Territory, Australia: Investigation into possible causes

“…Soil acidity (pH) restricts the availability of essential macro-nutrients, leading to root mortality and eventually dieback (Houle et al 2007;Watmough 2010). Studies such as those of (Burke & Raynal 1998;Duchesne et al 2002) have indicated that soil acidification restricts the availability of plant macronutrients, leading to root mortality, nutrient deficiency and eventually tree dieback.…”

“…Drought conditions have caused increased soil salinity, thereby potentially contributing to massive die-off of the salt marshes in southern United States (Silliman, 2005). In addition, soil acidity (pH) restricts the availability of essential macro-nutrients, leading to root mortality and eventually dieback in sugar maple, Acer saccharum (Houle et al 2007;Watmough 2010). In blackberry (Rubus anglocandicans) decline in Western Australia, flooding events is considered as a predisposing factor and this stress condition makes blackberries susceptible to root pathogen infection (Aghighi et al 2014).…”