Assessment of the use of spontaneous cover crops for erosion mitigation in vineyards

Soil is a finite and non-renewable natural resource that provides a variety of ecosystem or environmental services. Not only is it the natural basis for the production of food and raw materials on which the world's society depends, but it is also host to a quarter of our planet's biodiversity. However, soil degradation is one of the greatest threats of the 21st century. According to literature studies, soil degradation processes have already affected 33% of the earth's surface, leading to a significant reduction in soil quality and functionality. Among the soil degradation processes, water and wind erosion are among the most important. The European Environment Agency estimates that 115 million hectares are exposed to water erosion processes (12% of the European land area) and 45 million hectares to wind erosion. It is estimated that between 8 and 12 million hectares of fertile soil are lost annually in Europe, resulting in an economic loss of approximately EUR 1.25 billion.

Within the framework of the MONTCLIMA project, a study of soil erosion is being carried out in a vineyard in Rioja Alavesa with a high risk of erosion due to its topography, but which in turn represents the general situation of vineyards in Rioja Alavesa, since most of them are located in areas with steep slopes. It is essential to find measures to reduce soil erosion in vineyards since, as a result of climate change, this risk is expected to worsen due to changes in the distribution of rainfall.

Map of slopes in the vineyards of Rioja Alavesa.

 

The trial that began in 2019 with the MONTCLIMA project is being carried out on a plot of Graciano grapes located in the municipality of Elvillar (Álava), with slopes of 10-20%, managed in organic farming and belonging to the Maisulan winery. It consists of three treatments:

  1. Usual tillage carried out in the area (4-5 passes of machinery: rotavator, cultivator, harrow, etc.).
  2. Spontaneous cover crop in the centre of the lanes (approximately 1.5 m wide).
  3. Minimal tillage by the farmer (1-3 shallow tillage/field, in alternating tramlines).

Image of the Gerlach boxes installed on the plot.

 

Sampling of erosion is carried out in the erosion traps installed in the field (Gerlach Boxes), both of the soil and of the amount of water and solutes collected by runoff. In order to study the effect of the three treatments, each of the vines that makes up the elementary plots (13 vines per repetition) are harvested separately and grape samples are taken to analyse their quality.

Harvest and microvinifications of the experimental vineyards.

 

Territorial resilience to risks in mountain areas in the Valentin valley - Cerema & ONF-RTM

Implementation of a participatory and co-constructed approach to territorial resilience to natural hazards in the Valentin valley, commune of Eaux-Bonnes, to better integrate the challenges of adaptation to the consequences of climate change.

The valley of Valentin on the commune of Eaux-Bonnes (64) presents many stakes concentrated on a restricted linear:

- The biggest ski resort of the Pyrénées - Atlantiques (Gourette)

- Three or four campings close to the river or at risk of flooding,

- The Rd 918 access to the resort in winter and to the Aubisque pass in summer

- The hydroelectric production.

- Thermal baths at Les Eaux Bonnes

This valley is subject to many risks and environmental constraints that leave limited opportunities for sustainable development.

 Flooding 2018 Gourette station and RD918 road embankment collapse

The knowledge of these risks in the current context is globally well identified and has been the subject of additional inventories by ONF-RTM in the framework of Montclima: 680 events recorded since 1800, including 604 avalanches, 11 block falls, 33 landslides / mudflows and 32 torrential events.

In addition to the updated inventory of these 4 hazards, Cerema has calculated the potential envelope of the runoff hazard on the basis of a 5 m DTM of the IGN with the Exzeco method.

An analysis of the stakes impacted (BD TOPO 2019) in the study area by these envelopes of torrential floods (ONF-RTM) and potential envelope of runoff hazard (Cerema - Exzeco) shows the stakes impacted or contained in these envelopes:

37 single-storey buildings out of 157 (23.5%), 104 multi-storey buildings (housing and activities) out of 332 (31.3%), 43 engineering structures out of 80 (53.7%), 5,303 kms of main and secondary roads out of 80,330 kms (6.6%) and finally 69 jobs and activities (BD Sirene 2021) out of 261 (26.4%)

 

The challenge and interest of the risk resilience approach undertaken in this territory is :

- While updating locally the past knowledge on hazards, to integrate as well as possible the uncertainties and trends calculated on the scale of the Pyrenean massif (scientists) on the effects of climate change in terms of intensity or frequency by considering these trends as acquired within the framework of this territorial approach, which postpones in part the reflections / debates and energies on "how to adapt and become more resilient".

- To avoid exclusively technical and/or expert approaches and to engage in a reflection with the actors of the territory through a co-constructed diagnosis, fed by their field visions and reflections or knowledge of other territories.

- To engage a systemic approach, which establishes links between issues and actors, loops, networks and chains of impacts at several levels.

- To question the long term (30 - 50 years) and to move towards an operational action plan that will guide the adaptation of the territory towards more resilience.

Resilience Compass - Framework for Thinking

 

Agropastoralism Poster - trends

Application of adaptive forest management in the Montnegre-Corridor Natural Park (Spain) to reduce the forest's vulnerability to fire risk

One of the key actions of the SUDOE MONTCLIMA project is the design and implementation (testing and development) of common Action Plans for prevention and management of natural hazards, which will be validated and/or improved through pilot trials.

One of these pilot trials, led by CREAF, is being carried out in a Mediterranean oak forest in the Montnegre-Corridor Natural Park (Barcelona, Catalonia, Spain) with the aim of reducing the vulnerability of the forest to the fire risk. The pilot trial consists of applying adaptive forest management in a Strategic Management Point (PEG) for the control of large forest fires. The PEGs are locations in the territory where the modification of the fuel and / or the preparation of infrastructures allow the extinguishing service to carry out safe attack manoeuvres that reduce the progress of a large forest fire. In this sense, they represent spaces that, due to their spatially strategic location, have a key role as protective effect on a relevant surface of the Natural Park.

The pilot trial has been carried out at the Can Bordoi estate, in the municipality of Llinars del Vallès (Barcelona), which covers an area of 214 ha. Within this estate, the trial is performed in the extreme southwest, since in the case of a large forest fire that comes from the west and which would be the most likely in the area, it could lower the intensity of the fire, facilitating the tasks of extinguishing firefighters and preventing the entire massif from burning. Moreover, the applied management helps to strengthen the forest mass to the risk of drought affectation.

Location of the Can Bordoi estate, in the municipality of Llinars de Vallès, North of Barcelona.

The pilot trial has consisted of the application of adaptive forest management (selective felling, where the largest holm oaks are left, and scrubland clearing) on a 5.4-hectare plot and of creating open woodlands (elimination of stone pines affected by Tomicus and pasture recovery) on a 4.7 ha plot to create an open area that helps improve the fire resistance of the massif. In addition, a control plot of 1.9 ha has been left where no action will be taken and which will serve to compare with the managed area. The action has been carried out between February and June 2020 by the Montnegre-Corredor Forest Owners Association.

Delimitation of the action plots within the Can Bordoi estate.

The characterisation of the actuation and the annual monitoring is based in the installation of eight permanent inventory plots (10 m circular plots), five in the managed area and three in the control area. In these plots, a pre-action inventory was performed between January and February 2020 to characterize the forest stand before the management. Later on, a post-action inventory was implemented in June 2020 to estimate the weight of the intervention (volume and basimetric area extracted, changes in fuel continuity ...). Finally, a monitoring network was installed in July 2020 to monitor and measure the forest and environmental variables during two years (2020-2021). This campaign consists of recording the evolution over time of a series of indicators that allow to know if the Holm oak forest is less vulnerable to the risk of fire thanks to the applied adaptive forest management. To do this, these indicators are monitored in the area where management has been applied and in the control plot, and compared. The monitoring indicators are the following: changes in forest structure, fuel continuity, fuel moisture, forest health, soil moisture, temperature and relative humidity.

 

Initial state of the oak forest of Can Bordoi.

 

Final state of the oak forest of Can Bordoi after the application of adaptive forest management