Droughts decrease and floods increase carbon sequestration rates of Quercus robur in hardwood floodplain forests

Trees, Forests and People

Kai Jensen¹  Kristin Ludewig²  Jens Oldeland³  Heather Alyson Shupe³ 

[1]Corresponding author.

[2]Institute for Globally Distributed Open Research and Education (IGDORE), Hamburg, Germany

[3]Institute of Plant Sciences and Microbiology, Applied Plant Ecology, Universität Hamburg, Ohnhorststraße 18, Hamburg 22609, Germany

关键词: Carbon sequestration;    Drought;    Flood;    Quercus robur;    Dendrochronology;    Floodplain forest;   

DOI  :  

来源: DOAJ

【 摘 要 】

Trees can contribute to the reduction of atmospheric CO2 concentrations, but they do so at varying rates. The carbon sequestration rate (CSR) of trees is influenced by many factors including tree age, forest density, site conditions, and extreme events such as droughts and floods. This research reconstructs past carbon stocks of Pedunculate oak (Quercus robur) trees in floodplains with different hydrological conditions (low and high active floodplain, the seepage water zone of the former floodplain, and the tributary floodplain). We used increment tree cores and allometric equations and compared the annual changes in stocks as a way of assessing CSR. Furthermore, we used time series data on floods and droughts to analyze possible effects of extreme events on CSR. The aims of this study are to (a) compare the CSR of dominant Q. robur in young plantations to dominant trees in old forest stands, (b) compare the CSR of old Q. robur trees under different hydrological conditions, and (c) analyze how drought and flood events influence the CSR of Q. robur in different hydrological conditions. From 2009 to 2018, old Q. robur trees on the low active floodplain had an average CSR of 18.4 ± 1.1 (SE) Kg tree−1 year−1, while young trees had an average CSR of 8.7 ± 0.6 (SE) Kg tree−1 year−1. From 1976 to 2018, the overall CSR of Q. robur was highest on the high active floodplain (18.6 ± 1.7 (SE) Kg tree−1 year−1) and lowest on the seepage water zone of the former floodplain (13.1 ± 1.1 (SE) Kg tree−1 year−1). CSR was higher during flood years in all hydrological conditions, but was significantly reduced by drought only on active floodplains with a comparatively high elevation. Floodplains are well-suited areas for reforestation as natural climate solutions because the dominant trees in these areas have a high CSR even under severe conditions which are predicted to become more common with climate change in the future.

【 授权许可】

Unknown