3^rd Annual Congress on Soil, Plant and Water Sciences November 11-12, 2019 Rafael Hoteles forum Alcala, Madrid, Spain

Biography:

Dr. Asit Mazumder, Professor of Biology at the University of Victoria, is considered a world leader for his pioneering research on aquatic ecosystems in terms of water quality, nutrient dynamics, foodweb structure, contaminant transport and public health risks. His research showed how land-use and climate variability affect chemical and microbial quality of water, and developed several new technologies to track sources of chemical and microbial contaminant. He had been awarded the Chandler-Misener Award by the International Association for Great Lakes Research, and the Miller Institute Professorship for Basic Science at the University of California Berkeley 2011, and Ruth Patrick Award by American Society of Limnology and Oceanography (ASLO) in 2013 for his contributions to solving water quality problems with sound aquatic sciences concepts and a 1000 talent award from the Government of China. He has published over 140 international peer reviewed journal publications.

Abstract:

Nitrogen is a critical nutrient linked to degradation of freshwater and marine ecosystems. The nitrogen inputs to terrestrial ecosystems and subsequent loadings to aquatic ecosystems have been doubled and changed the nitrogen cycle as population and human activities increased over the past century (Filoso et al., 2006; Howarth and Marino, 2006; Smil, 1999; Vitousek et al., 1997; Larsson et al., 1985). One of the consequences of human alternation of the nitrogen cycle is the eutrophication of marine and freshwater ecosystems (Rabalais, 2002; McIsaac et al., 2001).

We tested if climate variability can change nitrogen loading from terrestrial to aquatic ecosystems. We used stream nitrogen concentrations from 2,125 sites and climate data from 301 stations from 30 eco-regions across British Columbia, Canada, to test our objective and to compare it with anthropogenic loading of nitrogen in the same regions. We show that elevated air temperature and associated precipitation resulted in increase in nitrogen loading from terrestrial to aquatic ecosystems. Furthermore, inorganic nitrogen (IN) loading increased more rapidly than organic nitrogen (ON) with increasing air temperature. Each oC increment annual air temperature caused a 24% increase in nitrogen loading to aquatic ecosystems and a 22% increase in ratio of IN: ON concentrations in stream water. We also show that the coastal mountains ecosystems seem to be more vulnerable to temperature induced nitrogen loss than the interior ecosystems. We suggest that climate warming and elevated loading of nitrogen from terrestrial to aquatic ecosystems will have major implications for the quality of water in freshwater and coastal marine ecosystems.

Biography:

Emily Lloret is associate professor at the LGCgE (Laboratoire de Génie Civil et géo-Environnement, Univ. Lille, France). She is an expert analyst of soils, biogeochemical cycles of nutrients and transfers in environment. After a PhD on the impact of natural disturbances (meteorological events) on dissolved nutrient (dissolved organic carbon) transfers in tropical environment, she specialized in the study of the impact of natural and anthropic disturbances on soil and biogeochemical cycles of nutrients in mining context. She is particularly implicated in the organization of her laboratory, especially as a member of the laboratory council (since 2016) and of the Earth sciences research/teaching committee of the University of Lille. She is involved in several research projects with industrial (ADEME, GESIPOL 2015, Mis’Char project), national and international partners (INTERREG France and Belgium, RISSC project). She is co-porter of an interlab project (IRePSE program, with F. Bourdelle and A. Hofmann) and of several synchrotron-based programs (analysis campaigns).

Abstract:

The North of the France was the scene of an active past coal mining activity, whose wastes form about 300 spoil tips. Although these materials are considered as sterile, spoil tips are colonized by pioneer species, which contribute to the weathering of parent geological material and the formation of a neo-soil. Due to their composition and weathering processes, spoil tips – and neo-soils on its - can be at the origin of elemental transfers in the environment (pollutants as trace elements, sulfur, organic compounds?). These transfers must be strongly understood and quantified to manage spoil tips and minimize their impacts.

To qualify the spoil tip/environment interactions, we have characterized the parent geological material and alteration processes, we have studied the neo-soil and its role in elemental transfers, and we have determined transfers, through field measurements and laboratory leaching tests.

We selected one spoil tip made of black schists (quartz, clays, pyrites, oxides, coal residues), partially covered by a forest at the origin of a neo-soil, and surrounded by ponds.

The spoil tip shows an unexpected neo-soil including three distinct horizons, corresponding to different degrees of parent material weathering (variation of mineralogy and oxidation state) and of organic matter incorporation.

The mineralogical characterization (XRD, SEM, TEM) shows a S-rich alteration front at the schist surface, coupled to mineralogical transformations, and the formation of jarosite and Fe-oxides.

Ponds at the bottom of this spoil tip present various chemical and biological characteristics. Especially, the heavy metal concentrations measured in pond water are very variable from one pond to another. These analyses coupled to lixiviation test from each neo-soil horizon allow to quantify elemental transfers from black schist spoil tip (Figure 1) and inform about the extent of the area of spoil tip influence.