Element analysis of tree rings in pedunculate oak heartwood: an indicator of historical trends in the soil chemistry, related to atmospheric deposition

Abstract

Summary — When investigating historical alterations of the soil chemistry, it could be interesting to determine the mineral content of the successive annual tree rings. The study reported here aimed at verifying this assumption. Oak heartwood was selected in order to minimize the disturbance due to element translocations in the wood. This study was carried out in a forest included in a floristic and edaphic survey performed earlier throughout northeast France. Xylem cores were extracted from the boles of five over 60-year-old pedunculate oaks in each of 68 plots. The analysis showed on average an increase in nitrogen and aluminum, a decrease in phosphorus, potassium and magnesium, and no change for calcium, in the rings corresponding to the last 30 years of the heartwood . These results are consistent with those of the floristic and edaphic survey, which had shown an increase in nitrogen and a trend towards acidification in most of the soils between 1970 and 1990, mainly due to atmospheric deposition (Thimonier et al, 1992

Radial variations in wood mineral element concentrations: a comparison of beech and pedunculate oak from the Belgian Ardennes

“…No element could be ascribed to the third category. In line with two previous studies [11,18], our results show that pedunculate oak sapwood is markedly richer than heartwood in N, P, K, Mg, Mn. Abrupt increases in mineral element concentrations at the heartwood/sapwood boundary are usually interpreted as resulting from nutrient resorption from senescing sapwood rings [2,6,14,16,18,23,25,27,31].…”

“…By contrast, Ca, Mg and Mn often have higher concentrations in the heartwood [27]. The particular pattern of element resorption found in Quercus robur in this study and by de Visser [11] and Lévy et al [18] is strikingly similar to that reported for other species of Quercus from Northern America (Q. rubra, Q. alba, Q. coccinea: [17,19,31,33]), China (Q. mongolica: [6]) and Japan (Q. mongolica, Q. serrata: [25]). Thus, it would appear that a high resorption of Ca, Mg, Mn, K, at the heartwood/sapwood boundary is a characteristic feature of most (if not all) species of Quercus.…”

“…Specifically, oak is a ring-porous species possessing typical heartwood [3,28], while beech is a diffuse-porous to semi-ring porous species lacking typical heartwood [28,30]. In a recent study, Lévy et al [18] have ascribed patterns of elemental concentrations variation in the last thirty years of the heartwood of oak from NE France to soil acidification. By contrast, beech is not usually regarded as suitable for dendrochemical biomonitoring because of radial translocations of elements [14]; accordingly, the dendrochemistry of beech has been surprisingly little investigated, considering its importance in European forests (but see [15,22]).…”

“…It has been proposed that variations in the mineral element composition of tree rings might reflect corresponding changes in the soil solution chemistry in the course of a tree's lifetime. Thus, a growing amount of evidence suggests that soil acidification due to atmospheric pollution ("acid rain") leads to decreasing concentrations of calcium and magnesium and increasing concentration of aluminium in the wood [4,8,18,20,22]. However, non-uniform radial concentration profiles in the wood may also result from endogenous mechanisms not related to environmental change [6,9,12,23,29,31,34] and, accordingly, monitoring metal pollution using tree rings composition can be extremely difficult [14].…”

Composition, distribution and supposed origin of mineral inclusions in sessile oak wood — consequences for microdensitometrical analysis

“…its absolute distance or age counted from the cambium, and the abundance of mineral inclusions differ considerably between trees, notably between trees I and II. Radial variations of the elementary mineral content found in oak wood have been attributed to differences in soil chemistry [18] and to soil acidification by atmospheric pollution [12]. Differences in soil nutrient factors appeared to play a major role in explaining the autecology of Q. petraea in northern France [1].…”