The study of riparian vegetation is based on the observation of natural plant communities spontaneously colonizing newly exposed areas following the erasure of the Vezins and La-Roche-Qui-Boit dams.

The vegetation monitoring system includes two complementary approaches:

i) a vegetation sampling method based on floristic surveys (composition & structure) carried out within a series of quadrats positioned along a transect

ii) a monitoring of the vegetation units (UV) observed within the valley

This sheet specifically concerns the monitoring of vegetation units (UV) observed within the valley, only for data from the Sélune Observatory (2021-2026).

The monitoring system for Vegetation Units is based on the identification of vegetation distributed along the transect at each station in the main stream. It aims to obtain a representative view of diversity and the organization of plant formations and communities.

This monitoring consists of identifying the discontinuities in terms of composition and structure of the various vegetation types that develop within the neo-valley along the transect that descends to the bank, and to report their influence. (distance in metres from the reference point at the edge of the old dam).

These data can be used to establish a pro rata of the different plant formations encountered along the transect. Although this value is thus really valid only at the transect of each station, this information can potentially constitute an approximation of the heterogeneity and distribution of vegetation at the valley scale.

This layer gives, for each riparian vegetation monitoring station and each campaign from 2021 to 2026, the following information:

– Campaign information (id, code, date, campaign),

– Station information (code, name, protocol applied, number of quadrats, code for the associated Sélune reference point and, as a result: location on the watershed, distance to sea, distance to source and water course)

– Information on the transect by campaign (number and length, X, Y, LON coordinates, LAT of reference points "NGF" and end point "rive")

– Information regarding the Vegetation Units (VU) identified by campaign (number, description: code, start position, end position, EUNIS3 characteristics, 4)

– Origin of the data ("Observatoire Sélune," "Hors Observatoire Sélune," "Projet Séripage," or "Projet Restaure")

– “Point” geometry (default) corresponding to the transect reference point

– Line (alternative) geometry of the associated transect for each campaign.

The study of riparian vegetation in exposed areas is based on the observation of natural plant communities colonizing newly exposed mudflats, at different time scales (intra- and interannual variations) and at nested spatial scales. The botanical inventory is carried out according to the Braun-Blanquet method.

The sampling protocol is stratified in order to maximize the recorded diversity. For each study area, a transect perpendicular to the riverbed is established, where strips parallel to the watercourse are marked on the ground according to the exposure rate.

This layer indicates the location of these study areas, the layout of transects and information regarding vegetation units recorded between 2021 and 2026.