Speaker
Description
Forests cover nearly a third of Earth’s land and provide key ecosystem services. With climate change, forests face intensified drought episodes and shifting precipitation regimes. While important advances have been made to improve our understanding of tree responses to drier conditions, effects on belowground processes remain elusive, despite their importance for shaping forest functioning.
We explored how drier conditions affect key morphological and biochemical root traits linked to carbon and nitrogen dynamics in mature European beech forests distributed along a precipitation gradient in Germany. Fine roots were extracted from soil cores collected beneath mature beech trees and separated into absorptive roots (root order < 3) and transportive roots (root order > 3). Root samples were scanned and analyzed with RhizoVision Explorer to determine morphological characteristics such as root length and diameter. Samples were then dried to constant weight to assess the root biomass. Carbon and nitrogen concentrations, together with stable isotope ratios (δ¹³C and δ¹⁵N), were analyzed using an elemental analyzer coupled to an isotope ratio mass spectrometer. These measurements were integrated with climatic, soil, and vegetation data provided through the ICP Forests and ICOS monitoring networks.
Clear differences were observed between absorptive and transportive roots in terms of biomass, morphology, and tissue chemistry across the precipitation gradient. Along the precipitation gradient, absorptive roots showed stronger increases in biomass density (g/m2), root length density (m/m2), and root tip and branch frequency (n/cm1) than transportive roots. In contrast, root tissue density (g/cm3) declined more markedly for absorptive roots. Both root types also exhibited increasing δ¹³C and decreasing δ¹⁵N values along the precipitation gradient.
Overall, the findings indicate that absorptive fine roots are more responsive to changes in water availability than transportive roots. These results improve understanding of belowground tree responses to a drier environment and contribute to predicting forest resilience.
| Status Group | Master Student |
|---|---|
| FOR TALKS: Poster Presentation Option | Yes, I’m willing to present as a poster. |