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Ecosystem services and land-use under global change in the Haute Provence
Report of the Excursion day
1. Plateau de Valensole
1.1 Introduction
The Plateau de Valensole is on of the most photographed areas in Europe. The
colourful combination of yellow wheat fields, blue lavender fields, almond trees
and oaks and the geometric aspect of the landscape represent a contrast to the
mountainous region to the east. The Plateau de Valensole is situated in the
NW part of the Parc Naturel Regional du Verdon. It is embedded between the river
Asse and the Durance river valley. It is not a single morphological feature
in the area since the Plateau de Piumichel can be considered as a northern twin.
The morphology of the region is characterised by the transition from a mountainous
region with high peaks and deep valleys to a flat and open landscape that forms
a very special relief for SE France. The complex morphology of the region is
strongly linked to geology, an important driver of erosion: e.g. soft siltstones
(“marnes jaunes”) occurring at the slopes of the Asse valley are
very unstable and bear difficulties for tree settlement. On the other hand the
Plateau de Valensole is built up of thick, erosion resistant conglomerates that
were deposited in two big ancient river systems during the Tertiary.
1.2 History an current land use on the Plateau de Valensole
The main crops today on the Plateau are lavender (5-10 years) and wheat (4-6
years). Agriculture is organised in rotating crops. The theoretical case is
turning after 5 to 6 years, but the rotation is very profit-dependent. Before
the 80´s lavender agriculture was mainly dependent on the perfume industry
in Grasse. Then lavender was used by the washing powder industry but prices
went down as demand stopped. In the 90´s lavender production came up again
(new distilling technology) and now the conditions are quite stable.
One of the main questions was to answer: Where did the lavender come from and
what was the natural vegetation? The natural vegetation on the Plateau was oak.
From the 13th century to the Middle Age the main crop was wheat. It was not
for local consumption but was a speculative production depending on the demands
in the city of Marseille according to prices and benefits. The lavender came
down from the mountains. There are two species of lavender: (i) the “lavende
fine” which is the natural form in an altitude of 700 to 1000m and (ii)
the “lavende officinale” in an altitude of 400 to 700m. In 1945/50
the demand increased (industry interests) and it became too expensive to crop
lavender up in the mountains. Today 50% of the national production of lavender
comes from the Plateau de Valensole.
1.3 Land-use change
Driving in the direction of Valensole we focused our view on the changing agricultural
buildings. Traditional housing was replaced due to the development of modern
systems (technology, machinery). The traditional farming system on the Plateau
de Valensole was based on dry cultures. A modern example of changing land-use
came from the 1960´s. A rich landowner expanded his farmland by cutting
of remaining woodland and set up an irrigation system. Today only three farmers
use irrigation. This method allows fruit tree plantation resulting in a possible
future landscape change. At the next stop (dry valley) the abandonment of old
stone buildings and farms from the 18th century was obvious. In some cases new
ones replaced them (e.g. sheep farm on one side of the way). Between 1850 and
1980 the population decreased rapidly and nearly the whole area was emptied.
The movement of people away and the remaining agriculture was a demographic
problem for the region. Today population is growing again, even if agriculture
is still declining. Local policy makers emphasise on keeping and increasing
population. This new dynamic is a result of the improved infrastructure: Two
years ago the TGV high-speed connection Aix-Avignon-Paris (3h) was established
and Aix is only 45 minutes by car. Nevertheless a lot of villages and houses
are ruined. Most of the new or rebuilt houses are leisure or secondary homes.
Attempts to increase local tourism are mainly focused on the Gorge de Verdon.
For the Plateau de Valensole the only point for tourism is the open landscape
and the colourful scenery in early summer. No infrastructure for tourism exists,
e.g. like accommodation and therefore there is no local profit. Thus, why maintain
landscape and agriculture? The planed project “Route de Lavende”
could be a first step.
2. Les Salles sur Verdon: Maison des Lacs “Memoire des Les Salles
sur Verdon”
2.1 Formation of the Verdon Canyon
In the Cretaceous (~140-65 Ma) and Early Tertiary (~65-40 Ma) massive limestone
beds were deposited in the Tethys realm. Erosion of the limestone started in
the Late Tertiary (< 25 Ma) after the formation of the Alps. Vertical cracks
disrupting the limestone enable water infiltration and sub-surface carstic erosion.
Big underground cave systems were established and cracks widened till the ceiling
collapsed. Further downstream transport enlarged the canyon. Rotating boulders
formed open caves. In pre-historic times these caves were places of first human
settlement in the region.
2.2 History of Les Salles sur Verdon
Les Salles sur Verdon was a rich farming village in the Haute Provence by centuries
with an economy based on agriculture (lavender, truffle, olives, juniper) and
sheep farming. Until the 1970’s an ecological equilibrium was preserved.
In the first half of the decade the dramatic increase of population at the Côte
d’Azur let rise the demand of water. A water resource analysis was initiated
in the surrounding regions. As a result the French government decided that the
Verdon region offers the best infrastructure to build a dam and flood the valley
for freshwater storage. The human dimension and impact was played down and confrontations
were ignored. The old village of Les Salles was abandoned and today only half
of the ancient inhabitants live in the rebuilt village, partly supported by
the Electricity Company. From the second half of the decade until now the lake
has become a tourist site. These days the village has to cope with the positive
(taxes, campsite) and negative (seasonality, concentration of people in a short
time) ecological impacts of tourism development.
2.3 Maison des Lacs
Because of the negative ecological impact on the human-environmental system
the Maison des Lac was founded as a sustainable development project. It’s
main objectives focus on different issues
(i) Economic: employment, out-season activity, diversification, infrastructure
development
(ii) Social: quality employment, year-round activity and affordable houses
(iii) Environmental: education, conservation of cultural and natural heritage
(iv) Democratic: citizen involvement.
3. Grand Canyon du Verdon
3.1 Parc Naturel Regional du Verdon
The Grand Canyon du Verdon is also part of the Parc Naturel Regional du Verdon
that covers an area of 180 km2 and offers space to 21.000 inhabitants. The impressive
diversity of the landscape is mostly based on geology leading to different modes
of occupation. In the NW of the Parc the Plateau de Valensole is situated which
is the main agriculture area in the Parc. Half the amount of farms is situated
in this open landscape and as mentioned before the main crops are lavender,
wheat and truffles. The NE is characterised by the foothills of the southern
French Alps. Extensive sheep farming has great importance in terms of land-use
and therefore consequences for landscape conservation. In comparison the landscape
in the SE is small-scaled and heterogeneous and climate is much drier. The farms
are smaller and even half of them disappeared. The farms left concentrated their
production on winery, lavender, sheep farming and vegetable growing. Further
military land covers a huge part of the SE area.
The main missions of the Parc are to preserve the natural and cultural heritage,
to develop the social, cultural, and economic sectors, to educate and inform
and play a major role in involving new natural management strategies. The main
purpose of the Parc is to be a platform for dialogue bringing different stakeholders
together. Tourism in the region depends on annual seasonality and is concentrated
on the gorge, the lake and the two scenic roads. The aim of the Parc is to enlarge
the season and extend tourism outside the canyon, so that the positive impacts
of tourism should not only be concentrated on the canyon. Concerning the gorge
the project “the great site” is planed. Different parties were tried
to be involved to discuss the future tourism management of the canyon area:
e.g. one of the issues is to control parking spaces and the flux of cars on
both scenic roads.
3.2 Comments on the scenery
The canyon is characterised by a very diverse landscape. Some of the cliffs
are up to 700m. The S-facing slopes are not as steep as the N-facing slopes
observing open patches for agriculture. For the scenic beauty of the canyon
these patches are very important. The N-facing slopes are very steep and are
forestry dominated. Agriculture totally disappeared. Risen land prices follow
stronger land abandonment. This causes problems for the economic and social
activity of the region, because agriculture is still the main activity. Therefore
the Parc started a project involving interviews with farmers and elected officials.
The knowledge about the current way of using their land should help to assess
activities in the future. People awareness concerning land abandonment rises
and a planed stakeholder dialogue should increase people’s sensibility
to conserve this impressive landscape.
Dorothee Hippler
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