Soil bioengineering techniques for Mediterranean coastal dune restoration using autochthonous vegetation species

Abstract

Coastal dunes are extremely fragile and threatened ecotones, which play a key environmental role in terms of functional connection between terrestrial and marine ecosystems. To counteract the hydrogeological vulnerability in coastal risk areas, reliance can be made on soil bioengineering techniques, consisting of planting native species in combination with natural inert materials. These interventions involve the use of typical Mediterranean plant species, which are fundamental for increasing soil surface protection as well as for their ecologic function in coastal dune consolidation. Monitoring studies on plant growth parameters are useful to assess the suitability of the different species to be used in soil bioengineering works. Hence, this study aimed to (i) identify some Mediterranean herbaceous and shrubby plant species to be used in coastal interventions, (ii) evaluate different plant propagation methods and short-term growth parameters, and (iii) provide useful insights into field management strategies before and after transplanting.Juniperus phoenicea L., Juniperus macrocarpa Sm., Pistacia lentiscus L., Tamarix africana Poir. and Tamarix gallica L. were the selected shrubs species while Ammophila arenaria (L.) Link, Sporobolus pungens (Schreb.) Kunth., Agropyron junceum (L.) P. Beauv., Eryngium maritimum L., Calystegia soldanella (L.) R. Br., and Pancratium maritimum L. were the selected herbaceous species. As to shrubs, seeds and cuttings proved the best propagation methods with an efficiency of up to 90%. Agamic propagation methods, on the other hand, were the most efficient (80–90%) for the herbaceous species. After transplantation, all the species showed an adaptation period to the new climatic and edaphic conditions. In particular, Pistacia lentiscus L. was found withered with the presence of some radical shoots.

Morphological performance and seasonal pattern of water relations and gas exchange in Pistacia lentiscus plants subjected to salinity and water deficit

“…These conditions can affect the capacity for grow and survive in plants, even for species that are adapted to these regions. Species that grow in Mediterranean regions, such as Pistacia lentiscus provide important ecosystem services such as ornamental production, soil protection, and carbon capture ( Romano et al., 2022 ). Therefore, it is essential to find ways to protect and improve their capacity to adjust to changing conditions.…”

In-Depth Monitoring of Anthropic Activities in the Puglia Region: What Is the Acceptable Compromise between Economic Activities and Environmental Protection?

“…To solve this problem, a very effective solution is to resort to naturalistic engineering, a technique with which it is possible to intervene to protect and restore degraded dune systems, without altering the local physical, landscape, and cultural aspects. Many experiences [61][62][63] demonstrate that it is possible to obtain good results especially when the restoration work is carried out with the utmost respect for the naturalness of involved ecosystems. These interventions have a cost, certainly much lower than the usual coastal engineering interventions.…”

An Integrated Approach between Multispectral Satellite Images and Geophysical and Morpho-Topographic Surveys for the Detection of Water Stress Associated with Coastal Dune Erosion

“…The vegetation of the embryonic dunes is primarily represented by an agro-prairie ecosystem, composed of vegetation dominated by beach crabgrass (Agropyron junceum), a perennial plant that uses its high stoloniferous capacity to spread and avoid burial. A. junceum exhibits root lengths that range between 10.5 cm and 16.5 cm and heights ranging from 100.7 cm to 102.4 cm [37]. The pioneer plants are followed by massive vegetation colonization; here, sand begins to accumulate due to the cohesion provided by the stems of plants, with small deposits of embryonic dunes reaching elevations that are a few centimeters high.…”