Spatio-temporal diversity of spontaneous extremophile flora in a context of climate change and biological invasions

The objective of WP1 is to characterize in the studied areas the spatio-temporal diversities of pastoral vegetation to identify the most valuable and undesirable halophytes, in a context of climate change and biological invasions. The main specific objectives of WP1 are to 1) Characterize pastoral vegetation diversities in the study sites.2) Describe bio-ecological features and pastoral values of halophytes 3) Model potential impacts of climatic changes on the most valuable and undesirable halophytes 4) Estimate pastoral vegetation biomass and predict its evolution in a context of climate change

The WP1 is subdivided in two tasks;

1.1: Analyse spatio-temporal vegetation diversity to identify valuable and undesirable halophytes and to model the dynamic of the most valuable and undesirable taxa in a context of climate change (ISA, MAKU, AUA)

1.1.1. Conduct a desktop study to collect contextual information on each study area from existing surveys, literature, databases and spatial information. The first step is a literature review to collect adequate information on the studied sites and address their flora data bases and habitats characteristics. The second step is the evaluation of the previous flora and vegetation surveys and data basis.

1.1.2. Undertake reconnaissance surveys of the studied area to describe their context, validate the information obtained from the desktop study, delineate the broad vegetation units, and select the sites for the detailed flora surveys. A primary reconnaissance survey during the most suitable seasons will be conducted to validate the information collected throughout the desktop study, and delineate the vegetation units present. A supplementary reconnaissance survey may be carried out for additional information.

1.1.3. Undertake detailed surveys to gather comprehensive information on targeted halophyte flora (valuable pastoral flora and weedy flora: unpalatable, very low palatable, toxic to sheep, and potential invasive alien plants). Three sites will be selected, based on the flora being targeted and its habitat preference. Digital maps and reconnaissance surveys will be useful to locate these sites. In each site, a vegetation survey protocol will include multiple quadrats located at representative points throughout a transect within each vegetation unite. A minimum of three quadrats will be sampled in each transect. The number of quadrats is proportional to the area (hectares) of each vegetation unit. Species accumulation curves (nested quadrats) will determine the optimal size of sampling unites. The collected information will include location, GPS coordinates and datum, habitat characteristics (soil, land occupation, description of disturbances, and assessment of vegetation condition), vegetation composition and taxa frequency and abundance. The data will be recorded from quadrats or by using point or line intercept methods. Opportunistic collections and targeted inspections may be required to prove the proper design of flora surveys. Multivariate analysis will be performed to analyse flora diversity. All field data will be stored on a secure hard-disk within 1-2 weeks of each sampling event.

1.1.4. Conduct a questionnaire and field surveys to evaluate halophytes palatability and toxicity to sheep. The Sheep grazing itineraries in each studied site will be defined and a traverse within each itinerary will be delineated to monitor valuable and undesirable taxa. Further, a questionnaire survey will be conducted with local shepherds and sheep owners.

1.1.5 Use MaxEnt model to predict current and future distributions of the most valuable and undesirable pastoral halophytes taxa to elaborate a conceptual framework guide for sustainable management of pastoral valuable and undesirable taxa. The MaxEnt model will be used to predict current and future distributions of the most valuable and undesirable pastoral taxa, based on two representative concentration pathways (RCP2.6 and RCP8.5) for the year 2050s and 2070s.

T1.2. Estimation of biomass and prediction of its evolution (ISA, AUA, MAKU)

Task Leader : Faiza Khbour Data sets from Sentinel-2 mission from the Copernicus Program of the European Space Agency (ESA) will be analyzed to estimate the pastoral vegetation biomass. In regular time intervals, multispectral raster data will be uploaded, trimmed on the relevant investigation area, calibrated and referenced. Thematic classification outputs for quantitative forecasts and biomass estimation for verified vegetation (Herbaceous, shrubs) will be executed using radiometric indexes (e.g., NDVI, NDWI, LAI). The information will be implemented in a GIS database to be analyzed with the geospatial GIS tools. Open-source multispectral images from Landsat TM and OLI instruments on board Landsat 5 and 8 satellites, respectively, and SENTINEL will be used for detecting and mapping changes. A GIS will be used to generate spatial references of the collected data. It will integrate the remote sensing classifications, biomass mapping and produced thematic maps. Pre- and Postclassification approaches will be used for change detection. Different GPS way points will be taken in the study area using a classification schema.