Hệ thống quản lý khoa học - Towards global applicability? Erosion source discrimination across catchments using compound-speciﬁc δ13 C isotopes

Tên bài báo:	Towards global applicability? Erosion source discrimination across catchments using compound-speciﬁc δ13 C isotopes (Lượt xem: 547)
Tên tạp chí:	Agriculture, Ecosystems and Environment
Tạp chí thuộc:	Tạp chí KH quốc tế ISI
Chỉ số IF/H:	4.099
Năm xuất bản:	2018
Nước xuất bản:	Hà Lan
Tác giả thuộc Học viện:	PGS.TS. Nguyễn Thanh Lâm
Các tác giả bài báo:	Christian Brandt, Gerd Derconb, Georg Cadisch, Làm T. Nguyễn, Paulina Schuller, Claudio Bravo Linares, Alejandra Castillo Santana, Valentin Golosove, Moncef Benmansour, Nourredine Amenzoug, Zhang Xinbaoh, Frank Rasche
Tóm tắt bài báo:	Accurate identiﬁcation of soil erosion hot spots across catchments of diﬀerent sizes and agro-ecologies through the use of conventional tracing techniques has proven challenging. Since this problem hinders implementation of precise soil conservation measures by land managers and decision-making bodies, novel evidence-based techniques are needed. To meet this need, the International Atomic Energy Agency (IAEA, Vienna, Austria) initiated the Coordinated Research Project entitled “Integrated Isotopic Approaches for an Area-wide Precision Conservation to Control the Impacts of Agricultural Practices on Land Degradation and Soil Erosion – D1.20.11” in 2008. This project emphasized the application of isotopic approaches to identify hot spots of land degradation in agricultural catchments to develop eﬀective soil conservation measures. As one key outcome of this project, we present here an aligned protocol to explore the potential of compound-speciﬁc stable isotope (CSSI) analysis of individual fatty acids (FA) combined with Bayesian statistics to discriminate sediment sources across six catchments of diﬀerent sizes and agro-ecologies. The global applicability of the CSSI approach was ﬁrst tested on the basis of major land use categories (i.e., forest, cultivated and non-cultivated land) as potential sediment sources in the studied catchments. These land use categories were then further resolved into speciﬁc land use types (e.g., cassava and maize ﬁelds, orchards) to assess the potential resolution threshold of the CSSI technique. In a ﬁnal step, the inﬂuence of miscellaneous sources (e.g., roads, channel banks) that had the potential to distort proportional contributions to sediment deposition was assessed. The introduced aligned protocol of the CSSI technique was applied to discriminate individual erosion sources based on land use types of tested catchments. Merging catchment-speciﬁc land use types with broader land use categories made it possible to determine intercatchment comparisons of isotopic signatures due to signiﬁcant diﬀerences in δ13C values of fatty acids when cultivated land was present. Notably, no correlations were found between diﬀerent catchment sizes, agro-ecologies, number and type of land use types, or soil organic carbon concentrations and the number of signiﬁcant δ13C fatty acid values of the various land use types. Thus, we propose that the presented CSSI technique has the potential to identify soil erosion hot spots in contrasting catchments of diﬀerent sizes and agro-ecologies.
Link:	https://doi.org/10.1016/j.agee.2018.01.010