Similar Patterns of Change in Stemwood Calcium Concentration in Red Spruce and Siberian Fir

• Published in: Journal of biogeography 1995-03, Vol.22 (2/3), p.467-473
• Main Authors: Shortle, W. C., Smith, K. T., Minocha, R., Alexeyev, V. A.
• Format: Article
• Language: English
• Subjects: Anions; Calcium; Cations; Chemical bases; Coniferous forests; Datasets; Ecosystem Physiology; Forest service; Forest soils; Picea abies; Picea rubens; Pollutant emissions; Wood chemistry
• ISSN: 0305-0270; 1365-2699
• DOI: 10.2307/2845943

Changes in stemwood clacium concentration ([Ca]) for the last 120 years occurred in a common pattern for two sample collections of red spruce (n=33 and 20) from the northeastern United States and for one sample collection of Siberian fir (n = 20) from southcentral Siberia, Russia. The [Ca] was measured for wood formed during the periods 1871-90, 1891-1910, 1911-30, 1931-50, 1951-70 and 1971-90. For each core, the relative increase or decrease in [Ca] for adjacent periods of wood formation was recorded. The relative frequency of positive change in [Ca] for each period of wood formation was calculated for the three sample collections. Previous research indicated that under equilibrium conditions, [Ca] in stemwood tended to decrease in more recently formed wood, due to declining numbers of Ca binding sites. Consequently, we expected a low frequency of positive changes in [Ca] in successively formed wood. Consistent with expectation, the relative frequency of positive change from the preceding period to the periods 1891-1910, 1911-30, 1931-50, and 1971-90 were low. Contrary to expectation, the frequency of positive increases in [Ca] more than doubled in 1951-70 compared to 1931-50. The frequency of positive increases in the 1951-70 period relative to the preceding period was 48%, significantly greater than all other periods (P ≤≤ 0.01). The frequencies of positive increases for all other periods were not significantly different from each other (overall mean = 21%, SD = 7). This anomaly in the frequency of positive change in [Ca] in wood formed in 1951-70 relative to wood formed in 1931-50 indicated a perturbation in the ion exchange chemistry of stemwood in two widely separated parts of the northern coniferous forest. This anomaly coudl be due to external or internal factors. Changes in sap chemistry that affected stemwood chemistry could have been due to changes in the rooting zone. Such changes in rooting zone chemistry could result from the atmospheric deposition of ionic pollutants. Other external factors that could cause the observed anomaly include unusual climatic periods or enrironmental disturbances such as logging or fire. Internal factors that might produce an anomalously high frequency of positive change of [Ca] include heartwood formation, stemwood infection and a hypersensitive response of the tree against infection.