Carlo Ferrari

Evaluating landscape quality with vegetation naturalness maps: an index and some inferences

ABSTRACT Question: Can landscape quality be evaluated and compared with a single numerical value using vegetation maps? Location: Northern Apennines (Italy), ca. 44° N, 10–11° E. Methods: Seven phytosociological vegetation maps (1 : 25 000), which correspond to mans different impact on mountain landscapes, were considered. Syntaxa were classified into five degrees of naturalness: urbanized, agricultural, semi-natural, sub-natural, and natural. Vegetation maps showing naturalness were derived in a vectorial GIS. The degrees of naturalness were ordered according to increasing naturalness. If ci is the cumulative relative value of every mapped area of the degrees of naturalness, the sum of these cumulative values A = Σ ci is is a measure of vegetation artificiality. Its maximum value is Amax = n – 1. The Index of Vegetation Naturalness IVN = 1 - A / Amax, ranging from 0 to 1. Our IVN is an extension of the ILC by Pizzolotto & Brandmayr (1996) due to the ordinal character of the vegetation classification into degrees of naturalness. The maps of vegetation naturalness were also analysed by two known metrics for the evaluation of landscape quality: TECI (Total Edge Contrast Index) and MSI (Mean Shape Index). Results: The case studies show that IVN is linearly correlated with decreasing area of urbanized and agricultural vegetation types as well as with increasing area of the highest degree of naturalness. Conclusions: IVN can be joined with the TECI for the evaluation of naturalness of landscapes. TECI can supply additional information about the importance of landscape ecotones. Our case studies suggest that an urbanized landscape should correspond to IVN values lower than 0.20. A natural landscape will have IVN values higher than 0.80. Nomenclature: Oberdorfer (1994) for plant communities, except for mixed oak woods (Ubaldi 1993).

Genetic variability of relict Rhododendron ferrugineum L. populations in the Northern Apennines with some inferences for a conservation strategy

Abstract In this study, the genetic diversity of three Rhododendron ferrugineum L Apennine populations (AP1, AP2, and AP3) was analyzed and compared to three populations of the Maritime Alps and six populations of Central-Eastern Alps. Genetic variations across microsatellite markers revealed that the Apennine populations show some clonal individuals and the lowest genetic diversity values (AP1 and AP3 A[18] values are 2.46 and 2.31, respectively), as well as heterozygosity deficiency with respect to the Alpine populations. Genetic relationships among populations (Neis genetic distance) showed that populations from the Central-Eastern Alps and from the Maritime Alps clustered in two separate groups. Unweighted pair group method with arithmetic averages as well as PCA analysis showed a clear separation of the three Apennine populations according to the high FST values detected (AP1–AP2 = 0.427; AP1–AP3 = 0.446; AP2–AP3 = 0.325). Mantel test revealed a significant correlation between genetic and geographical distance matrices (r = 0.314, P = 0.001, 999 permutations). Concerning the relationship between Apennines and alpine population, PCA analysis showed a clear genetic similarity among Maritime Alps populations and individuals of AP1 population. Considering the geographical and ecological peripheral condition of these populations and the high impact of the climatic changes on their habitat, we suggest the combination of in situ and ex situ conservation strategies to preserve the genetic diversity of this species in the Northern Apennines.

Genetic diversity of the rare and endangered meadow violet (Viola pumila Chaix) at the southern margin of its range

Viola pumila Chaix is a rare violet with a Eurasian-continental distribution. It has undergone a severe population decline during the last decades, and is endangered in Europe. Its southernmost extrazonal occurrence is in northern Italy, with only four populations. Inter-simple sequence repeat markers were used to detect genetic diversity level and distribution in the Italian stand and to compare it to a small sample from Germany. Estimates of genetic diversity revealed retention of genetic variation and weak genetic structure in the Italian populations of V. pumila. Comparable levels of genetic variation were detected in the German population. Principal component and cluster analyses on the whole data-set grouped individuals regardless of their geographical distribution, pointing out that genetic diversity in the V. pumila populations surveyed is homogeneously distributed. Analysis of molecular variance showed that most of the genetic variation is within populations rather than among them. Our results indicate that habitat fragmentation has not induced genetic depauperation and differentiation in the Italian stand of V. pumila; moreover, they provide evidence of past extensive outcrossing and a common evolutionary history of the examined populations. The high diversity detected in this study suggests effective measures for conservation strategies of this rare species.

Long-term cropland abandonment does not lead per se to the recovery of semi-natural herb communities deemed habitats of community interest

Abstract Anogramma leptophylla is one of the rarest fern species in Balkan Peninsula. In Croatia, several localities were noted prior to this study, when its presence was confirmed with a discovery of a small population on the island of Mljet (Southern Adriatic). This was, after almost 80 years, the first reliable finding of this species along Eastern Adriatic. The establishment of A. leptophylla on the western part of the island of Mljet may be attributable to certain favourable environmental conditions, but essentially to higher air and soil humidity. Its unusual bryophyte-like life strategy, with short-living annual sporophytes, facilitates its survival under Mediterranean climate, generally unfavourable for pteridophytes.

Genetic introgression of hybrid Rhododendron x intermedium Tausch is habitat mediated: Evidences from south-eastern Alps (Italy)

Hybridization between Rhododendron ferrugineum L. and R. hirsutum L. in south-eastern Alps was examined in order to (i) evaluate the breeding direction and the extent of backcrossing between hybrids and the parental species, (ii) define which processes facilitate speciation and maintain species identities and (iii) clarify the role of rock geochemistry in hybridization events. Individuals of three hybrid populations were analysed by morphological and molecular markers. The internal transcribed spacer and trnH–psbA distinguished the parental species and F1 hybrids while only the simple sequence repeat markers recognized genotype classes: F, H, F1, F2, BxF (backcross to R. ferrugineum) and BxH (backcross to R. hirsutum). Combining morphological and molecular data, we found that the tested populations had complex genetic structure: the F1 individuals produce F2 hybrids and backcross to parental species. Due to R. hirsutum phenology, most backcrossing events were with this parental species (asymmetric hybridization). Geochemical analyses indicate that alkaline soil conditions linked to calcareous dolomitic rocks promoted the genetic assimilation of R. hirsutum. In addition, R. x intermedium shows a higher edaphic adaptation than R. hirsutum as it can be found on a wide range of calcareous-dolomitic rocks as well as on weakly acidic soils of natural or anthropogenic origin.

Synchorology of the Northern Apennine summit vegetation. An outline

Abstract A numerical chorological analysis of the 28 vegetation types still described in the boreal vegetation belt of the Northern Apennines was performed. Chorotypes were grouped into 7 main types: arctic-alpine, circumboreal, cosmopolitan, endemics, European orophytes, Eurasian, Mediterranean. Phytosociological vegetation types were classified into 9 groups on the basis of their chorological composition. Such groups include vegetation types with high ecological similarities. The reciprocal ordering of chorotypes and vegetation groups show that most chorotypes are distributed into two or more vegetation groups. The chorotypes which locally have the less number of taxa (Mediterranean and endemic elements) are linked to single vegetation types. The synchorological analysis supplies useful information for a preliminary ecological description of communities as well as suggestions for the biological conservation.

Timberline and Alpine Vegetation in the Northern Apennines: Bioclimate Scenery and Vegetation Diversity

From Mt. Orsaro to Mt. Corno alle Scale, the Northern Apennines include some of the highest peaks of the whole chain. The areas above the timberline are chiefly above 1700 m asl, and corresponds to the altitudinal limit of beech forests, which appears as an abrupt timberline. They are rare and scattered on the highest peaks areas above the timberline are can be considered an “archipelago” of alpine islands.