Agrocampus Ouest

About: Agrocampus Ouest is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Soil water. The organization has 2160 authors who have published 3219 publications receiving 75606 citations. The organization is also known as: Institut supérieur des sciences agronomiques, agroalimentaires, horticoles et du paysage & Higher Institute for agricultural sciences, food industry, horticulture and landscape management.

Estimation of nitrate removal by riparian wetlands and streams in agricultural catchments: effect of discharge and stream order

Abstract: Summary 1 Assessment of the role of landscape structures such as buffers is a necessary prerequisite for the sustainable management of water resources in an agricultural setting 2 We monitored nitrate concentrations during interstorm periods at the outlet of 16 subcatchments of different orders within a catchment of 378 km2 We characterised stream network, wetlands, agricultural practices and land cover and identified their relationships with nitrate fluxes and concentrations 3 Two main factors controlled annual nitrate fluxes: the agricultural nitrogen surplus and the nature of the system comprising the wetland zone and adjoining watercourses In the latter case, nitrate fluxes were reduced in proportion to the surface area of the riparian wetland and the flowpath distance of fluxes in the stream network At the scale of the order-6 stream, 53% of annual nitrate flux during interstorm periods was removed during transfer via the wetland and the river, corresponding to 211 kg N ha−1 per year 4 The influence of the riparian wetland zone/watercourse system increased during periods of low water level, explaining up to 64% of nitrate concentration variation among locations within the river network, but only 9% during periods of high water level 5 The buffering role was stronger at higher stream orders, and the dependence on stream order was more apparent at low water level, when we observed mean nitrate concentrations in the order-6 stream that were 47% lower than observed in order-2 or order-3 streams

Biological invasion: The influence of the hidden side of the (epi)genome

Abstract: Understanding the mechanisms underlying biological invasions and rapid adaptation to global change remains a fundamental challenge, particularly in small populations lacking in genetic variation. Two understudied mechanisms that could facilitate adaptive evolution and adaptive plasticity are the increased genetic variation due to transposable elements (TEs), and associated or independent modification of gene expression through epigenetic changes. Here, we focus on the potential role of these genetic and non‐genetic mechanisms for facilitating invasion success. Because novel or stressful environments are known to induce both epigenetic changes and TE activity, these mechanisms may play an underappreciated role in generating phenotypic and genetic variation for selection to act on. We review how these mechanisms operate, the evidence for how they respond to novel or stressful environments, and how these mechanisms can contribute to the success of biological invasions by facilitating adaptive evolution and phenotypic plasticity. Because genetic and phenotypic variations due to TEs and epigenetic changes are often well regulated or “hidden” in the native environment, the independent and combined contribution of these mechanisms may only become important when populations colonize novel environments. A focus on the mechanisms that generate and control the expression of this variation in new environments may provide insights into biological invasions that would otherwise not be obvious. Global changes and human activities impact on ecosystems and allow new opportunities for biological invasions. Invasive species succeed by adapting rapidly to new environments. The degree to which rapid responses to environmental change could be mediated by the epigenome—the regulatory system that integrates how environmental and genomic variation jointly shape phenotypic variation—requires greater attention if we want to understand the mechanisms by which populations successfully colonize and adapt to new environments. A free Plain Language Summary can be found within the Supporting Information of this article.