Long-term monitoring of an invasion process: the case of an isolated small wetland on a Mediterranean Island, second stage: toward a complete restoration

Abstract

In the present article, the results of the first-stage of monitoring, following restoration works on a small Mediterranean wetland (Lake Stagnone, Capraia Island, Tuscan Archipelago), are reported. The recent spread of Typha and Phragmites in the lake changed diversity and composition of the plant communities. Nine years after their first monitoring (2009), a rarefaction of hydrophytes and small helophytes of conservation interest was detected. In 2010, the restoration started with the aim to remove (or at least reduce) the populations of the large, expansive helophytes. In 2012, the first post-actions monitoring were carried out using the same methods as previously, analysing the plant presence/absence and their cover value recorded in the same 15 plots selected in 2000 and 2009. The rise and fall of the populations of the various flora and vegetation types during this invasion process and the following restoration were statistically analysed. One year following the restoration, some recovery (replacement) had occurred of autochthonous hydrophytes and small helophytes. Many of these species are of conservation interest. Some aquatic plants, present on the site until the more or less recent past, were once more recorded. Given the rapid recovery of populations of many autochthonous species, the results are reasonably encouraging, rendering planned reintroductions unnecessary at the moment. On the other hand, because of the short time elapsed since restoration, the current community structure cannot in any way be considered an "equilibrium" one. Continued and regular monitoring is required to allow the reestablishment of the large expansive helophytes populations.

Analysis of genetic structure of Ranunculus baudotii in a Mediterranean wetland. Implications for selection of seeds and seedlings for conservation

“…been largely reported for other geographical areas (Grillas et al, 1993). However, since the top 10-20 cm of soil was removed during the restoration work (Foggi et al, 2014), we suggest that the reappearance of R. baudotii in the pond was derived from a resilient seed bank of the soil, probably not completely damaged during the restoration or even encouraged by a mixing of the substrate by the earthmoving machinery. This hypothesis finds further support in evidence from the analyses of genetic diversity of SG collected before (Pi1, Pi2, St1 and Fi) and after the restoration (ST2).…”

“…A first evaluation of the vegetation response after the restoration has shown a self-recovery of the former aquatic vegetation (Foggi et al, 2014). The population of R. baudotii (St2) has recolonised the Stagnone pond without any reintroduction and/or reinforcement activity.…”

“…Furthermore, this approach should be applied at all stages of plant regeneration from seeds, measuring the genetic variation of living collections obtained through different laboratory germination conditions and/or propagation methods, and eventually providing an assessment of the likely success of the whole restoration protocol (Alonso et al, 2014). In this study, we refer to a restoration experience undertaken in a natural pond in the Tuscan Archipelago National Park involving habitat management (Foggi et al, 2011(Foggi et al, , 2014 and the constitution of seed bank collections and the cultivation of living plants in the Botanic Gardens of Florence and Pisa (Carta et al, 2012). We focus on these ex-situ samples, by comparing their genetic diversity and structures with those of the natural populations before and after restoration.…”

“…Restoration activities which included removal of these tall, expansive helophytes (see Foggi et al, 2014 for details), could perhaps have negatively affected the soil seed bank.…”

“…baudotii (Godron) Meikle ex C.D.K. Cook (Ranunculaceae; hereinafter R. baudotii) (Foggi et al, 2011(Foggi et al, , 2014.…”