Growth of Populus tremula on CO2-enriched soil at a natural mofette site

Abstract

Abstract:The main objective of the study was to evaluate inter-annual ring-width variation and cumulative growth of aspen (Populus tremula L.) trees growing on the spots of different soil CO 2 concentration at natural mofette site. We hypothesized that growth rate of trees is affected by CO 2 concentration within their rooting zone. The study site was situated in the flood plain of Plesná stream near Hartoušov (Western Bohemia). Trees growing in a pure aspen stand were selected according to the CO 2 -gas regime within their rooting zone. Five high [CO 2 ] trees (10-25% CO 2 in the soil) and five low [CO 2 ] trees (up to 3% CO 2 in the soil) were sampled. Stem growth analysis of each trunk was carried out to study growth pattern in detail. High and low [CO 2 ] trees significantly differed in a growth rate. At the age of 25 years, the basal area of high [CO 2 ] trees exceeded low [CO 2 ] trees by 39 %. The positive effect of CO 2 on annual increment was pronounced particularly in the years with optimal growing conditions. Results suggest that trees can be fertilized not only by elevated atmospheric CO 2 but also when fed with CO 2 via the roots.

Evidence for magmatic carbon bias in 14C dating of the Taupo and other major eruptions

“…The δ 13 C values (−22 to −20 ‰) of the second wiggle match tree 11 were significantly higher than those of New Zealand forest trees (Fig. 2 ) and lacked the lower range of values in the earliest decades of growth expected for a subcanopy sapling, supporting the view that the tree incorporated magmatic CO 2 degassed from local groundwater and taken up through the roots 34 , 35 , as well as from the subcanopy air 5 , 30 – 32 , 36 , 37 .…”

Mofette Vegetation as an Indicator for Geogenic CO2 Emission: A Case Study on the Banks of the Laacher See Volcano, Vulkaneifel, Germany

“…It moves upward through fissures and cracks within the rocks [1][2][3]. Along its path, it reacts with wet and dry soil phases, finally exerting its influence on organisms living either within the subterranean soil or directly on the soil surface [4][5][6][7][8][9][10]. Depending on the local geological and hydrogeological conditions, the upward migration of CO 2 gas may appear at the surface either as dry CO 2 emanation (mofette) or as CO 2 -rich mineral water.…”