Adaptation of Willows in River Lowlands to Flooding under Arctic Amplification: Evidence from Nitrogen Content and Stabl
- PDF / 1,328,936 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 38 Downloads / 113 Views
WETLANDS AND CLIMATE CHANGE
Adaptation of Willows in River Lowlands to Flooding under Arctic Amplification: Evidence from Nitrogen Content and Stable Isotope Dynamics Rong Fan 1,2,3 & Kei Tanekura 1 & Tomoki Morozumi 1 & Ryo Shingubara 1 & Shunsuke Tei 4 & Aleksandr Nogovitcyn 1 & Egor Starostin 5 & Trofim C. Maximov 6 & Atsuko Sugimoto 4,7 Received: 7 February 2020 / Accepted: 6 August 2020 # Society of Wetland Scientists 2020
Abstract With the global warming, the frequent and severe river floods in Arctic regions have affected the distribution of willows in river lowlands. To investigate the effect of floods, especially waterlogging, on nitrogen conditions for willows, we measured their foliar nitrogen content and isotopic composition (δ15N), under various hydrological conditions in Northeastern Siberia, which was classified into four conditions according to the previous study: dry, wet, waterlogging [WL], long-period waterlogging [LWL] respects to willows’ physiological response. The δ15N values of willow leaves, which correlate to those of the soil, were significantly lower under dry (−3.6 ± 1.3‰) and wet (−3.5 ± 1.7‰) than WL (0.3 ± 2.6‰) and LWL (2.7 ± 2.4‰), indicates acceleration of soil nitrogen dynamics for waterlogging. There is no higher foliar nitrogen contents found under LWL (2.3 ± 0.3%) than WL (2.4 ± 0.4%). This might be caused by little decreased nitrogen uptake related to the low activity of carbon fixation in willows under LWL. Interestingly, LWL occurred over a wide area following extreme flooding in 2017; yet, willows survived, whereas potential competing species (larch) died. We further predict that the distribution of willows in Arctic riparian areas will expand, particularly after extreme floods under Arctic amplification. Keywords Stable nitrogen isotope . Siberia . Flooding . Waterlogging . Willows . Nitrogen cycles
Introduction Arctic amplification, that trends and variability in surface air temperature tend to be larger in the Arctic region than for the Northern Hemisphere or globe as a whole (Serreze and Barry 2011), is the phenomenon by which polar areas are one of the
most responsive regions to global warming (Giorgi 2006; IPCC 2014). This phenomenon contributes to the increase of annual discharge of water in the Arctic, for example, 19 large rivers locate in the entire Arctic have been observed to show consistent increase in annual discharge (+9.8%) from 1977 to 2007 (Overeem and Syvitski 2010), with floods prevailing in
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s13157-020-01353-x) contains supplementary material, which is available to authorized users. * Rong Fan [email protected] * Atsuko Sugimoto [email protected] 1
Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan
2
Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi’an, Shaanxi, China
3
College of Urban and Environmental Sciences, Northwest University, Xi’an, Shaan
Data Loading...
