A NURSERY FOR THE FLORA OF THE DUNES

A NURSERY FOR THE FLORA OF THE DUNES

The LIFE REDUNE project aims to the reconnection and restoration of 92,000 m2 of mobile dunes and redevelopment and / or expansion of 823,000 m2 of transition and fixed dune habitats, variously altered by disturbance factors due to human action. The restoration of the precious coastal habitats can be achieved on the one hand by acting on the containment of the impact due to tourist use and erosion, and on the other by recreating the dune habitats through the planting of native plants that speed up the reconstruction of the green cover.

LIFE REDUNE is “mending” the dune habitats, with 151,000 native plants, germinated and grown in the nursery, divided as follows:

  • habitat of mobile dunes 2110 and 2120 (Ammophila arenaria, Elymus farctus, Echinophora spinosa, Medicago marina, Eryngium maritimum, Euphorbia paralias, Calystegia soldanella, and others): n. 35,000
  • habitat of the edapho-xerophilic series 2130 * (Teucrium polium, Fumana procumbens, Sanguisorba minor, Lomelosia argentea, Centaurea tommasinii, Globularia bisnagarica, Koeleria macrantha, Heliantemum nummularium ssp. Obscurum, and others): n. 45,000
  • habitat 2250 * (Juniperus communis, Crataegus monogyna Berberis vulgaris, Viburnum lantana, Phillyrea angustifolia, and others): n. 55,000
  • habitat 2270 * (Phllyrea angustifolia,, Asparagus acutifolius, Rubia peregrina, Smilax aspera, and others): 15,000
  • Stipa veneta *: 1,000

Native seedlings accelerate the times of reconstruction of the plant mantle where damaged, at the same time subtracting soil to the harmful invasive alien species. According to studies conducted by the Cà Foscari University, for example, the invasive alien species Oenothera stucchii seems to suffer ground highly covered by native species, whereas it proliferates in the points most degraded by trampling and erosion which, stripping the soil of the natural grassy turf, make it subject to invasion of this and other unwanted plants. Stipa veneta is a highly endangered priority species of which less than 300 mature individuals remain in the wild. Some of the thorniest plants in the 2250 * and 2270 * habitats are used for the creation of living interdiction systems, in synergy with walkways, fences and information signs, to promote the use only of the allowed paths to reach the beach.

Upstream of the reconstruction interventions there is therefore a demanding nursery action, conducted by the Plant Biodiversity Center of Veneto Agriculture in Montecchio Precalcino (Vicenza). A regional structure specialized in the multiplication of native plants, the Center in fact operates by transforming the seeds collected in nature into seedlings that can be used in the restoration interventions in the area.

A sequence of actions that begins with the research, in nature, of wild plants populations suitable for supplying seeds in quantities and of quality adequate to guarantee the “production” of the number of seedlings required by the project. This first, fundamental phase involves inspections on the territory and presupposes botanical skills, a trained eye and experience. Once the most suitable wild populations have been identified, usually those with a large number of individuals, the seed is collected, with the utmost attention to organize the harvesting days at the right time. If the seed is not yet ripe, in fact, the collection must be post-poned and an “empty” trip has therefore been made: a waste of time and the useless travel of hundreds of kilometers. If on the contrary, even worse, it arrives too late, the seed has already fallen and is no longer available. The Nature rarely grants replicas and arriving even a single week later can sometimes force to postpone for longtime the production of seedlings.

It should be considered that for many of these species, almost a year and a half can pass from the day the seed is harvested to the achievement of the suitable degree of development of the seedling obtained from it. For this reason, the optimal collection period, far from being constant over the years as it is subject to the direct influence of the climate and its unpredictable variability, is carefully evaluated by the operators and it is often preferred to have some empty trips in advance rather than to much more disastrous late trips. It is interesting to note that, for most of the species in these environments, the seed ripening season is summer. The collection therefore takes place on hot summer mornings: strange fellows with yellow vests, bags, gloves and scissors walk around, under the curious glances of tourists in their swimming suits.

Once the seed has been collected, it is transferred to the nursery where, depending on the needs of the different species, it is subjected to different treatments: The seeds in fact often manifest various forms of “dormancy”, meaning that they do not germinate immediately after they are sown. These are evolutionary adaptations of the plants, which are not deceived by favorable conditions for germination which, in nature, can be ephemeral: water and mild temperatures can in fact be followed by drought, heat or frost.

The seeds germinate therefore when in the nursery are simulated a series satisfactory conditions, which vary between the different species. The sowing is carried out in honeycomb containers: normally these are plastic or polystyrene containers with 32 or 45 holes, filled with a suitable substrate, corresponding to as many “pots” in which the single plant will grow for the time necessary for its development.

Particularly important is the choice of the culture substrate, a mixture of peat and other materials, adapted and “customized” by operators based on the particular needs of these dune plants, “designed” by Nature for the life on the sand. It is one of the most extreme environments of our climates, with living conditions sometimes impossible for most plants, and above all, very different from those obtainable in a nursery. Under those conditions, and not others, our dune plants are however perfectly adapted, and with them must rekon those who claim to cultivate them in an artificial context, and very far from the sea. Once born, the young plants are subjected to a constant threat from potential predators such as fungi, molds, insects, and to keep them healthy, the constant effort, all along the cultivation period in the nursery, is above all to meet their water needs in order to make them strong and resilient to the always possible biotic attacks. The lots of plants are therefore under constant monitoring, aimed at maintaining a delicate water balance avoiding the drying out as well as the excessive hydration of the “loaves of earth” in which the young plants sink their roots.

Once collected, the seeds and the seedlings that derive from them will spend part of the summer, autumn, winter, spring and the entire following summer in the nursery: the latter season, is decisive for the complete development of stems and leaves. Finally, the second autumn arrives, the time when our plants return home: more than a year has passed since expert hands had taken the seeds from the mother plants, and now they are well-developed seedlings, ready to be entrusted to other expert hands, those of the operators in charge of the planting in the restoration interventions foreseen by the LIFE REDUNE project.

These young plants are entrusted with the task of colonizing the eroded and stripped soils, the woods made artificial by the inhospitable and monotonous pine forest. Their genetic background, selected by evolution and adapted to respond to the inclemency of the soil and climatic conditions thanks to the fact that the seed was harvested not far away, is the best guarantee of success for this difficult mission.

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