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Are there habitats that contribute best to plant species diversity in coastal dunes?
No full textThe following paper describes patterns of diversity across major habitat types in a relatively well
preserved coastal dune system in central Italy. The research addresses the following questions: (a) whether different
habitats defined on the base of a land cover map support similar levels of biodiversity in terms of vascular flora
richness and number of rare and endangered species, and (b) how each habitat contributes to the total species
diversity of the coastal environment. A random stratified sampling approach based on a detailed land cover map was
applied to construct rarefaction curves for each habitat type and to estimate total species richness. In addition, the
number of exclusive, rare and endangered species was calculated for each habitat type. Results highlight the
importance of the coastal dune zonation (embryo-dune, main dune, transition and stabilized dune) in species
conservation because they harbour progressively higher species richness. However, differences among these habitats
were not significant, so no particular species rich "hotspots" could be evidenced. On the contrary, rarefaction curves
show that the upper beach (strand) habitat sustains significantly smaller number of species, but surprisingly, it shows
the highest rarity values and highest proportion of endangered species. Therefore, for the establishment of successful
biodiversity conservation programs in these coastal environments, it is imperative not only to conserve biologically
rich hotspots but also to include species poor habitats containing endangered or unique elements. Thus, the complete
coastal vegetation mosaic including all coastal habitats is important to adequately characterize the plant species
diversity of coastal dune ecosystems
Combining land cover mapping of coastal dunes with vegetation analysis
No full textQuestion: Coastal dune systems are characterized by a natural mosaic that promotes species diversity. This heterogeneity often represents a severe problem for traditional mapping or ground survey techniques. The work presented here proposes to apply a very detailed CORINE land cover map as baseline information for plant community sampling and analysis in a coastal dune landscape. Location: Molise coast, Central Italy. Method: We analysed through an error matrix the coherence between land cover classes and vegetation types identified through a field survey. The CORINE land cover map (scale 1 :5000) of the Molise coast was used with the CORINE legend expanded to a fourth level of detail for natural and semi-natural areas. Vegetation data were collected following a random stratified sampling design using the CORINE land cover classes as strata. An error matrix was used to compare, on a category-by-category basis, the relationship between vegetation types (obtained by cluster analyses of sampling plots) and land cover classes of the same area. Results: The coincidence between both classification approaches is quite good. Only one land cover class shows a very weak agreement with its corresponding vegetation type; this result was interpreted as being related to human disturbance. Conclusions: Since it is based on a standard land cover classification, the proposal has a potential for application to most European coastal systems. This method could represent a first step in the environmental planning of coastal systems
Applicazione della cartografia della copertura del suolo nell’analisi del paesaggio vegetazionale delle dune costiere
No full text
Community types and alien species distribution in Italian coastal dunes
No full textThe present study concentrates on recent dunes (Holocene) of the Molise region (Central Italy). We
focus on different plant communities along the coastal zonation with the aim of quantifying their
degree of invasibility by alien plants. Vegetation data were collected following a random stratified
sampling design, using a CORINE land cover map (scale 1:5,000) with the land cover classes as strata.
In order to identify the major community types present in the study area, 125 sampling plots were
classified through cluster analysis and ordinated with PCoA. The percentage of the flora comprised
by alien species and the mean alien species richness for each community type was calculated using a
one-way ANOVA to test for significant differences. Five community types were identified along a gradient
of increasing distance from the sea. Despite the higher proportion of aliens, the beach and
embryo dune communities showed mainly archaeophytes, or at least species introduced many centuries
ago, which have clearly adapted to the particularly stressful conditions. On the other hand,
mobile dunes showed lower proportion of aliens but included neophytes. In the Mediterranean macchia
the lowest proportion of aliens was observed. Our results suggest that in coastal dune communities
both human disturbance and environmental stress affect alien invasions. The interaction of
these two factors probably plays an important role in the distribution of alien species
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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