Program > Field trips

O3HP & The Organic Biodiversity House of Lubéron National Regional Parc

(Thierry Gauquelin)

Two visits are planned during this day: the visit of the Oak Observatory at the 'Observatoire de Haute Provence' (O3HP) and the visit of the Organic Biodiversity House of the Luberon Natural Regional Park in Manosque.

O3HP (Oak Observatory at the OHP) consists of an experimental field site, situated at the research center of the Observatory of the Upper-Provence (OHP, UMS CNRS Pythéas) at Saint Michel l'Observatoire, close to Forqualquier and devoted to the understanding of the functioning of Mediterranean forests in the light of their future evolution. It includes the Downy Oak forest, one of three major species of importance in the region of the French Mediterranean, that covers more then 250.000 ha in the Provence-Alpes-Cote-d'Azur (PACA) Region.
The O3HP is built up of several elements installed in a 80-year old forest dominated by Downy Oak (Quercus pubescens) mixed with some Montpellier Maple (Acer monspessulanum) :

1. A cross shaped scaffolding for canopy access
2. A rain exclusion device covering about half of the core plot (300 m²): The roof can be opened and closed by retractable covers, intercepted rain is collected in an underground water reservoir. The device allows to apply a precipitation scenario, for the end of the 21st century, predicting a reduction in annual rainfall of about 30% to 40%.. The exclusion and the adjacent control plot can therefore be studied in terms of their biodiversity and ecosystem functioning in order to understand the impact of climate change for this type of Mediterranean ecosystem.
3. An environmental sensing network (atmospheric and soil temperature and humidity in the vertical profile, photosynthetically active and global radiation, precipitation, sap-flow, stem growth, etc.

The O3HP has high scientific potential, commonly used in a pluridisciplinary way by several local laboratories, and is open for new scientific collaborations. Atmospheric physicians are associated with astrophysicians, ecophysiologists and ecologists, with strong interactions between the OHP and the laboratories engaged in ecological or environmental sciences such as the IMBE, CEREGE, CEA Cadarache.


In Manosque the Organic Biodiversity house (Thomassine Domain) offers an original and educational stroll through the extraordinary diversity of crops, including an orchard of over 400 varieties of fruit trees.
A permanent exhibition on the domestication of fruit and eight terraced gardens at the foot of a beautiful Provencal house will help you to understand the millennial work of fruit breeding.

Mountain forests and open habitats of the "Mont Ventoux"

(Brigitte Talon, Bruno Fady)

Mount Ventoux, as well as large areas of the French Southern Alps, were the scene of large scale reforestation at the end of the 19^th century and during the first  half of the 20^th century: soil erosion was successfully controlled and forests  devastated by overexploitation and overgrazing were successfully restored. This  restoration is moving into a second, dynamic phase as, for several decades now,  Beech (Fagus silvatica) and Silver fir (Abies alba), which had remained within residual stands, are recolonizing the planted pine (Pinus nigra, P. sylvestris,  P. uncinata) stands. The new, mostly heterogeneous and mixed stands which result  from this “maturation process” form a complex landscape mosaic that opens  interesting prospects for the sustainability of forest trees and their  associated biodiversity.

However, climate change constitutes a new, very real  threat, of wich consequences are already obvious on Mount Ventoux. The challenge  for foresters is to anticipate as much as possible these changes and to adjust forest  management to this evolution. Mount Ventoux is not only a MAB reserve and a  Natura 2000 site, it is also a unique and original natural scientific  laboratory. The current – and a the short term inavoidable – forest decline in  some areas requires a new approach to ecological restoration which will benefit  from current research at INRA Avignon within the framework of international  networks. During this full day excursion, you will discover the various landscapes and  vegetation types of the "Giant of Provence", from its diverse forests at  mid-elevation to its exceptional, endemic-rich, Alpine flora under its summit,  1,910 m above sea-level.

Hiking shoes recommended.

The Calanques National Park: Nature conservation and plant ecology

 (Arne Saatkamp, Daniel Pavon, Gabriel Nève)

This field trip will take you into the Calanques National Park, where we will hike from the coast to the peaks of the Massif de Marseilleveyre for discovering its terrestrial flora and fauna. The Calanques NP is an important field site for several research projects conducted by the IMBE on nature conservation, population dynamics, ecology and evolution of rare plants, the effect of pollution and community assemblies..

Hiking boots required.

Islands of Marseille, field trip at "Le Frioul"

(Frédéric Médail and Philippe Ponel)

This field trip will be devoted to the discovery of a small Mediterranean archipelago close to Marseilles, the Frioul Islands that includes two main islands, Ratonneau (95 ha) and Pomègues (89 ha). These rocky limestone islands are interesting from an ecological and conservation point of view, since they have undergone severe environmental changes explained by the disturbance induced by seabird (yellow-legged gull) activities. We will discuss about the specific ecological patterns and process characterizing these small islands, and more generally those of the Mediterranean islands.

Hiking boots required.

Ecology and restoration of a Mediterranean steppe vegetation (La Crau)

(Thierry Dutoit)

The Nature Reserve of “Coussouls de Crau”  (7400 ha) is one of the last xeric steppes of Europe. This species rich vegetation hosts many steppic birds and some endemic arthropods. Almost 80% of the original area disappeared due to human activities (dump, military airport, cropping…). For fifteen years, experiments have been conducted by the Mediterranean Institute of Biodiversity and Ecology to assess restoration techniques. For example, turf containing the living dominant perennial species (Brachypodium retusum) was transferred on a filled quarry to assess its effect on plant community assembly. To mitigate future damages, an experiment was also carried out on an underground pipeline where soil was transferred to accelerate the establishment of steppe vegetation. An abandoned 350 ha orchard was rehabilitated in a steppic like habitat: nurse species seeding, topsoil removal and translocation and hay transfer were assessed with the long term objective to restore the steppe vegetation in term of species richness, structure and composition. The field trip will firstly focus on the original steppe ecosystem and on the experimental plots.

Hiking boots recommended.