Handcrafting, suitable tools

The yellow-flowered Oenothera stucchii Soldano is an alien species that has colonized the dune systems to the detriment of the native species. The particular germination niche with high affinity for light, high seed production and rapid growth guarantee greater competitiveness in disturbed contexts and a strong tendency to invasiveness. In the areas of intervention of Life Redune, the habitat of choice of O. stucchii is represented by 2130 *.

The Life Redune project involved annual eradication of O. stucchii for three years and monitoring of the populations of O. stucchii to evaluate the effectiveness of the containment action in reducing their density in the intervention areas.

The monitoring activity envisaged the delimitation of four test areas – two at the Cavallino Treporti Punta Sabbioni site and two at Punta Capalonga – subjected to different containment practices: eradication by hand or by brush cutter. Within each test area, 3 permanent plots of 1m × 1m were geo-referenced, in each of which the number of O. stucchii individuals was recorded in July 2019 (before the implementation of the interventions), in July 2020 (at one year from the first cycle of interventions) and in July 2021 (one year after the second cycle of interventions).

From the monitoring it emerged that the number of individuals of O. stucchii has generally decreased, regardless of the site examined and the type of containment action implemented . In particular, compared to the conditions prior to the start of the interventions, in 2021 there was an average reduction in the number of individuals equal to 28.6% in areas subjected to manual eradication and 58.5% in areas subjected to intervention by brush cutter.

The greater reduction in the number of individuals of O. stucchii following the intervention with a brush cutter can be traced back to the less disturbance caused to the habitat by this type of action compared to manual eradication, which even if carried out correctly, still involves movement of the sand, due both to the extraction of the root system and to the foot traffic by the operator.
O. stucchii tends to form particularly abundant populations precisely in conditions of high anthropic disturbance, especially in the form of trampling. Trampling, in fact, determines a lower resistance of the indigenous communities to invasion, and contributes to the resuspension of the seeds of O. stucchii on the surface of the sand, favoring their germination.