中文版 | English
CSpace  > 水库生态学研究中心
Rising flux of nutrients (C, N, P and Si) in the lower Mekong River
Li, Siyue1,2; Bush, Richard T.1
2015-11-01
摘要Changing human land use is accelerating global element cycling and appreciably altering ecosystems in the riverine-estuarine systems. This is evident by dramatic shifts in the supply of nutrients (C, N, P, Si). However, very little is known about the magnitude and rates of these changes. We examine the Mekong, one of the world largest rivers, to assess on a whole-of-system scale, the spatial, monthly and inter-annual flux of nutrients and stoichiometric ratios using a huge data-set (1985-2011). Seasonal and spatial patterns are apparent and linked to hydrology. The estimated mean flux (x10(9) mol/y) of elements from the Mekong at Pakse are 414.5 for DIC, 4.1 for DIN (3.3 for NO3--N and 0.8 for NH4+-N), 10.2 for TN, 0.32 for DIP, 0.46 for TP and 62.8 for DSi, respectively, which are intermediate relative to other large rivers. However, compared to the river reach at Pakse, the total river fluxes are two-fold greater for C, N, P and DSi. Annual flux increases significantly for DIC, NO3--N, DIN, TN and DSi, and is especially pronounced for all N and P species during the recent decade (1998 onward). Distinct shifts of nutrient stoichiometry, with far-reaching changes for phytoplankton productivity in the Mekong estuary are also evident, as the system shifts from potentially N limited to P limited. These notable changes to the exports and ratios of nutrient variables and anthropogenically-driven nutrient concerns are becoming a defining feature of the Mekong Plume to the South China Sea. (C) 2015 Elsevier B.V. All rights reserved.
关键词Nutrient flux Anthropogenic activities Nutrient limitation Nutrient stoichiometry Global change
DOI10.1016/j.jhydrol.2015.10.005
发表期刊JOURNAL OF HYDROLOGY
ISSN0022-1694
卷号530页码:447-461
通讯作者Li, SY (reprint author), So Cross Univ, Southern Cross GeoSci, POB 157, Lismore, NSW 2480, Australia.
收录类别SCI
WOS记录号WOS:000365050600037
语种英语