Characteristics of Coastal Dune Topography and Vegetation in Environments Recently Modified Using Beach Fill and Vegetation Plantings, Veneto, Italy

Abstract

Human actions can contribute to degradation of coastal environments or they can increase the likelihood that these environments will be restored. Beach nourishment provides a basis for restoration, but ways must be found to add habitat improvement to projects designed for shore protection. This study examines how beach nourishment projects can help reinstate dune landscapes in locations where beaches and dunes had been replaced by static shore protection structures. Dune topography and vegetation on three nourished sites on the northern Adriatic Coast of Italy are compared to a reference site to evaluate changes after beach fill was emplaced. Results reveal how nourishment projects used for shore protection can restore the space available for dunes to form, increase the likelihood of sediment transfers inland and increase the diversity of topography and vegetation. Beach raking prevents formation and growth of hummocky, incipient backshore dunes that would otherwise evolve into a naturally functioning foredune. Sand-trapping fences can speed the process of foredune development but can be counterproductive if they interfere with transport to beach grass (Ammophila littoralis) planted landward of them. Shore protection structures can provide stability and more time for dune evolution on eroding shores, resulting in greater species richness and longer retention of ecological niches. These structures need not be required if re-nourishment occurs frequently enough to provide a beach wide enough to protect against storm wave uprush.

Mediterranean coastal dune systems: Which abiotic factors have the most influence on plant communities?

“…As seen in other studies (Fenu et al, 2013;Ciccarelli, 2014), coastal dunes are dramatically complex ecosystems subjected to a plethora of environmental factors. In any case, the most important evidence from variance partitioning is that the main factors explaining the variability in vegetation zonation were related to local soil properties, confirming that soil characteristics primarily limit vegetation patterns at a local scale in Mediterranean coastal dune ecosystems (Nordstrom et al, 2009;Fenu et al, 2012Fenu et al, , 2013Angiolini et al, 2013).…”

“…In particular, the CCA analysis highlighted how the distance to the coastline, the mean grain-size, the organic matter concentration and the shoreline trend constitute the most important parameters able to significantly affect the plant composition of the Tuscany coast. The distance to the coastline is confirmed as a major correlate of the composition of sand dune communities in Mediterranean and Ocean coasts (Guara-Raquena, 1989;Stallins and Parker, 2003;Forey et al, 2008;Levin et al, 2008;Kim and Yu, 2009;Nordstrom et al, 2009;Angiolini et al, 2013). In our work, the distance to the coastline of the FD plots was lower in those transects located in a portion of the coast subjected to erosion, indicating in some cases a particularly short backshore (see transects D and E in Table 2).…”

Patterns of plant community assembly in invaded and non‐invaded communities along a natural environmental gradient

“…; Nordstrom et al. ). Elymus and Ammophila can facilitate other species by consolidating the substrate and providing shelter from wind abrasion.…”

“…But facilitation has already been highlighted in near-shore plant communities (Bruno 2000;Franks & Peterson 2003), and in our specific case, patterns of habitat heterogeneity are likely to be influenced directly by the benefactor species in the vegetation. In fact, the dominant species of these two communities, Elymus farctus (a clonal rhizomatous grass) and Ammophila arenaria (a tall bunch grass), are both important dune-builders and sand-stabilizers (Forey et al 2009;Nordstrom et al 2009). Elymus and Ammophila can facilitate other species by consolidating the substrate and providing shelter from wind abrasion.…”

The response of plant community diversity to alien invasion: evidence from a sand dune time series

“…Few of these still survive and the coastline suffers from increasing erosion, reduction in sand supply, alteration of geomorphic processes and heavy human use (Nordstrom et al 2009). From the 1950s onward, large stretches of coastal dunes have been fragmented by housing and resort development and by road construction.…”