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¹⁵N network

Champenoux, 54280, France; sites en France, en Europe (Allemagne, Italie, Denmark), en Brazil, en Afrique (Congo) et en Sibérie

https://www6.nancy.inrae.fr/bef

The objective of the ¹⁵N network is to monitor changes in nitrogen levels in the plant litter-soil continuum over several decades to identify the mechanisms controlling nitrogen turnover in forest ecosystems.

Currently, the network consists of 20 experimental sites. When a plot is set up, litter that has been highly enriched in 15N is deposited on the ground over several m2. This deposit is considered to be a substitute for natural litter fall, both in terms of quantity and chemical and biochemical quality. The treated plots are then compared with control plots. Since the early 2000s, soil samples (organic and mineral) and plant samples (roots, mycorrhizae, leaves, litter, wood) have been analysed. All the samples are stored under appropriate conditionsand a database has been created.

Data collected from all the sites is centralized and available for use in collaborative projects.

A research engineer and an assistant engineer manage the network, the analyses and the database. Sampling is carried out by the research engineer, technicians and students. The research unit also provides scientific knowledge in biogeochemistry in forest ecosystems, mainly on C, N and cation cycles. International students and researchers are regularly welcomed.

The average time research projects spend using the devices is one week. The work consists in collecting soil and plants samples, and pre-treating and analysing the samples. The team interacts as much as possible with the user(s) to discuss all aspects of their project. This allows for individual treatment of each request and ensured adapted support. The team mainly provides scientific, technical and logistical support. It is possible to use ANAEE-France's mobile platform (MPOETE) as an additional support for field campaigns, experiments and data acquisition.

The duration of acces is set at one week. During that time, we offer access to all the sites in the ¹⁵N network, laboratory space for sample preparation and processing and training by highly qualified technicians. The package also includes access to maintenance data at each site. The cost of access per week, excluding the applicant’s travel expenses, is XXXX euros for private institutions and 1,100 euros for public institutions.

The devices vary according to the location and whether or not a site also belongs to another network (such as ICOS and RENECOFOR). In most cases, soil moisture and soil temperature data are recorded, though the database contains a multitude of other information (soil, vegetation) for each site in the ¹⁵N network.