Maria Silvia Pinna

Relationships between coastal sand dune properties and plant community distribution: The case of Is Arenas (Sardinia)

Abstract Coastal dune environments are selective ecosystems characterized by a close interaction between abiotic and biotic factors in a dynamic balance. The present study focused on the psammophilous geosigmetum, the most affected by the interactions between physical processes and biological and anthropic processes. The main purpose was to study the relationships between the abiotic properties of the dune and the presence of the various plant communities, combining morpho-sedimentological, geopedological, and geobotanical data. The study was carried out on the well-preserved dune system of Is Arenas (CW Sardinia) which is one of the most important in the Mediterranean area. The analyses revealed differences at the morphodynamic, sedimentological, and geopedological levels. The micro-topography of the dunes affects the values of the main abiotic variables, and determines the presence of various microhabitats of great heterogeneity. This work shows that thedata on the geomorphological dynamics and the chemical–physical processes, correlated with the geobotanical analyses, might make it possible to identify the ecosystemic processes, and thereby plan adequate management and conservation strategies for this coastal dune system.

Conserving plant diversity in Europe: outcomes, criticisms and perspectives of the Habitats Directive application in Italy

Habitat Directive is the core strategy of nature conservation in Europe aiming at halting biodiversity loss. In this study the results of the third Italian assessment regarding the conservation status (CS) of plants listed in the Habitat Directive (Flora of community interest—FCI) was presented. Data was collected from several sources related to plant distribution, population data, habitats and pressures. Following the official European procedure, all parameters were evaluated and combined to give the CS of each taxon in each biogeographical region of presence. A comparison between the recent Italian IUCN and Reporting assessments was performed in order to evaluate the consistency between these two assessments. The official EU checklist comprises 113 Italian plant taxa, 107 of which were examined in this study. Our results showed a critical situation with only 34% of favourable CS, while 50% were unfavourable (40% inadequate plus 10% bad) and 16% unknown, in particular in the Mediterranean bioregion, where the unfavourable assessments reach the 65%. The results of the Report were consistent with those of the IUCN assessment, in which 41.9% of plants were threatened with extinction. This report highlighted some benefits and criticisms at national level, but it may have a wider significance. Although a general advance of knowledge, a great effort is needed to reach the Habitats Directive goals. Despite the limited resources, monitoring activities needs to be improved in order to close information gaps for several plants. A positive outcome was the development of a specific national project funded by the Italian Ministry of Environment, with the ambitious target to set future monitoring activities for FCI and optimize monitoring efforts.

Inter- and intraspecific morphometric variability in Juniperus L. seeds (Cupressaceae)

In this study, a statistical classifier for Mediterranean taxa of Juniperus, based on 98 seed morphometric parameters, was tested at interspecific, specific and intraspecific levels. Ripe cones of 10 taxa were collected in different regions of the Mediterranean Basin to compare and discuss their taxonomic treatments according to two different sources. High percentages of correct identification were reached for both taxonomic treatments at the specific and intraspecific level and from the comparison among taxa of the J. oxycedrus, J. communis and J. phoenicea complexes. Moreover, ripe cones of J. macrocarpa were collected from four Sardinian populations, in two seasons, and from plant and soil, in order to analyse inter-population, seasonal and source variability in seed morphology. This statistical classifier discriminated J. macrocarpa seeds collected in spring more accurately than those collected in autumn, but it failed to distinguish between the seeds collected from plants and soil, or between those collected from different populations of the same geographic region.

The Aichi Biodiversity Target 12 at regional level: an achievable goal?

The Aichi Biodiversity Target 12 aims to prevent the extinction risk of known threatened species and to improve their conservation status by 2020. We present the integrated strategy implemented in the last 10 years for the keystone plant species of Sardinia (Italy, W. Mediterranean Basin), which includes the following activities: conservation status assessment (following the IUCN protocol), ex situ conservation, in situ monitoring and active protection measures. To date, an average of 51.8% of keystone plant species have been subjected to the latter first three activities while, due to the higher costs, only few active conservation measures have been carried out. Considering the activities realised since 2004, we have also predicted the conservation effectiveness towards 2020 and have elaborated an index to evaluate it. Halfway through the strategic plan, we argue that more efforts are needed to guarantee the effective conservation of all threatened plants in Sardinia.

Threatened Sardinian vascular flora: A synthesis of 10 years of monitoring activities

The in situ conservation activities carried out in the last 10 years on endemic and threatened Sardinian vascular flora were analysed. Monitored species were selected following the policy species (listed in the Habitat Directive) and following the regional responsibility criterion. A monitoring scheme, with three levels of intensity, was applied and economic costs of the monitoring activities were analysed. In the 10-year long field work, 49 taxa corresponding to 50% of policy species and to 22.5% of the Sardinian endemics were monitored. The Sulcitano-Iglesiente sector showed the highest number of monitored taxa (20), whereas the Gennargenteo sector showed the highest number of populations monitored (32). A variation of the relative importance of the three levels of monitoring has been detected and most of the protocols showed a high level of intensity and complexity (90%). Plant-monitoring programmes have been considerably intensified over time with an increase in the total costs; the most important cost was the staff. The economic resources increased significantly over time, both in personnel and travelling costs. Consequently, in order to ensure sufficient support to in situ conservation activities in Sardinia, increased public funding will be necessary.

Using extinctions in species distribution models to evaluate and predict threats: a contribution to plant conservation planning on the island of Sardinia

Recent extinction rates suggest that humans are now causing the sixth mass extinction, and the Mediterranean islands are at the forefront of many of the environmental issues involved. This study provides an alternative approach for investigating documented local plant extinctions that occurred in Sardinia (western Mediterranean) during the last half century. A total of 190 local extinctions of 62 plant species were used to investigate the independent effects of eight ecological and anthropogenic variables and to model the areas of potential extinctions where plant conservation efforts could be focused. If all analysed plant species were considered together, ecological factors explained local extinctions more than anthropogenic factors. The independent effects of each factor considerably varied among species of different lifeforms and altitude ranges. Accordingly, distribution models of local extinctions outscored areas that are potentially rich in plant species with conservation interest, but which are particularly affected by humans. This paper suggests a reproducible, operational framework for analysing which extinction factors may play important roles in similar contexts and where they might be relevant.

Initial constraints in seedling dynamics of Juniperus macrocarpa Sm.

The micro-forests dominated by Juniperus macrocarpa inhabiting coastal dunes in the Mediterranean Basin are European priority habitats. Their conservation is hindered by both anthropic and natural causes, although the regeneration problems for J.macrocarpa are still poorly understood. In this study, several factors influencing emergence and mortality of J. macrocarpa seedlings were investigated. For this purpose, permanent plots were placed in coastal dunes of Sardinia (Italy) and periodically monitored to record seedling parameters (emergence, survival and growth), as well as several biotic and abiotic variables (solar radiation, tree cover, herbaceous plus scrub cover, number of female cones on the soil and number of herbivory traces). Linear mixed models were fitted to test the effects of several types of explanatory variables on seedling dynamics. A total of 536 seedlings were marked, most of which emerged in winter. The microhabitat was the most important factor in models explaining emergence, with the number of emerged seedlings decreasing with solar radiation. Survival was very low, reaching the highest mortality percentage in the first summer. Herbivory and location in open interspaces had significant negative effects on seedling survival. In conclusion, the recruitment of J. macrocarpa is highly limited in the initial life cycle phases, with microhabitat and herbivory constraints influencing seedling dynamics. The identification of critical stages in the recruitment process of J. macrocarpa, together with factors influencing them, suggests some implication for management as well the hypotheses for future studies about conservation and recovery of the J. macrocarpa habitat.