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Amici V.,University of Siena | Geri F.,University of Siena | Battisti C.,Ufficio Conservazione natura
Journal for Nature Conservation | Year: 2010

Given the pervasive influence of human induced habitat fragmentation in ecological processes, landscape models are a welcome advance. The development of GIS software has allowed a greater use of these models and of analyses of the relationship between species and habitat variables. Habitat suitability models are thus theoretical concepts that can be used for planning in fragmented landscapes and habitat conservation. The most commonly used models are based on single species and on the assignment of suitability values for some environmental variables. Generally the cartographic basis for modeling suitability are thematic maps produced by a Boolean logic. In this paper we propose a model based on a set of focal species and on maps produced by a fuzzy classification method. Focal species, selected by an expert-based approach, provide a practical way of extending the scope of habitat suitability models to the conservation of biodiversity at landscape scale. The utilisation of a classification method that applies a continuity criterion may allow more consideration of the connectivity of an area because it allows a better detection of ecological gradients within a landscape. We applied this methodology to the Tuscany region focusing on terrestrial mammals. Performing a fuzzy classification we produced five land cover maps and through image processing operations we obtained a suitability model which applies a continuity criterion. The resulting suitability fuzzy model seems better for the study of connectivity and fragmentation, especially in areas with high spatial complexity. © 2009 Elsevier GmbH. All rights reserved. Source


Vignoli L.,Third University of Rome | Battisti C.,Ufficio Conservazione natura | Bologna M.A.,Third University of Rome
Rendiconti Lincei | Year: 2010

The point count method (PCM) and time species count (TSC) are thought to be applicable to specific bird assemblages and habitat types and to give different kind of outputs: quantitative (abundances) and qualitative (scores), respectively. In this work, we tested if the faster TSC method can be used instead of the time-consuming PCM. We compared results obtained from the application of both methods to bird assemblages in three different habitat types in mountains of Central Italy with different levels of spatial heterogeneity (oak and beech woods, and open-forest mosaics). The application of both methods to the forest ecosystems revealed the absence of a direct correlation between PCM abundance values and TSC mean scores, highlighting that the latter method did not explain the variation in species abundance. The opposite was true in the mosaic habitats. In the Apennine forest ecosystems, species sampled first in the TSC sampling sessions did not correlate with species abundance values evaluated by means of PCM. The species with the highest PCM values (i.e., the more abundant species) were randomly distributed in all of the TSC 10-min sampling subsessions. Therefore, we rejected the hypothesis that the species sampled first (e.g., in the first 10 min) in TSC are more abundant than those sampled in the next 10 min subsession, and so on. This result differs greatly from that found for non-Mediterranean habitat types that are richer in species number (e.g., tropical forests and savannahs), where scores obtained for single bird species when applying the TSC method correlate well with the species abundance parameters obtained using quantitative methods. In the mountainous complex of the Mediterranean area, the TSC method should only be applied in mosaic habitats, which are richer in species, more spatially heterogeneous, and possess a high γ-diversity at the landscape scale, and thus show a direct correlation between species abundance and TSC scores. © 2010 Springer-Verlag. Source


Battisti C.,Ufficio Conservazione natura | Amori G.,CNR Institute of Ecosystem Study | Capizzi D.,Agenzia Regionale Parchi | De Felicp S.,University of Rome Tor Vergata | And 4 more authors.
Vie et Milieu | Year: 2013

The Red squirrel Sciurus vulgaris Linnaeus, 1758 is currently expanding its range in plains and hills of Central Italy, colonizing or re-colonizing areas where it was never or only irregularly recorded since the 1950s. Here we report some observations regarding this range expansion based on a relatively large data-set covering the period 1850-2011 (471 records: 72 published, 399 unpublished) in a large study area covering the hills and plains of Tyrrhenian Central Italy (Latium). After considering the temporal patterns of a more recent sub-set of presence data (1950-2009: i.e. six decades) we identified three geographic regions: (i) a large northern region with an area where the species occurred historically (at least since 1950: Volsini Mts) and an area where the species occurs more recently (after the 1970s); (ii) a region with two areas, one where the species occurred irregularly between the 1970s and 2000s, and, a second one where it has occurred from the 2000s; (iii) a region where the species was locally extinct in the 1950s-1960s, where significant amounts of land reclamation and forest fragmentation and isolation occurred in the 20 th century. These geographic and temporal patterns mirror (i) some recent changes in temporal and spatial regime of coppice management, (ii) abandonment of traditional farming and cultivation of mountainous areas, leading to an increase of forested area, (iii) implementation of conservation measures in nature reserves and in Special Areas of Conservation (from the second half of 1970s), and (iv) the ageing of planted coniferous forests (mostly from 1950s). These co-occurring factors may explain the range expansion of the species in recent times. Source


Battisti C.,Ufficio Conservazione natura | Amori G.,CNR Institute of Ecosystem Study | Angelici F.M.,Environmental Studies Center Demetra s.r.l. | Luiselli L.,Environmental Studies Center Demetra s.r.l. | Zapparoli M.,University of Tuscia
ORYX | Year: 2011

To trace the local extinction of the Eurasian otter Lutra lutra in Latium, central Italy, and examine the causes of the species- disappearance, we reviewed and classified information from both the scientific and grey literature according to the reliability and geographical accuracy of the records. The temporal and spatial patterns of 160 records from 23 geographical subunits from 1832 to 2006 suggest that the species collapsed between 1960 and 1975; two different extinction patterns were revealed by a set of multivariate analyses. In northern Latium the species collapsed because of several independent local threats. In central and southern Latium the species collapsed because of catastrophic habitat alteration (land reclamation during the 1930s) that negatively affected the source population. After this event the species went extinct in hilly and mountainous areas, where several population sinks occurred. We presume that this latter process drove the remnant otter subpopulations to extinction in central Italy, emphasizing the role of an extinction vortex in causing the collapse of this metapopulation rather than the classical threats recognized for this species. The value of the grey literature for a posteriori historical analysis of local extinction dynamics is highlighted by this research. © 2011 Fauna & Flora International. Source


Battisti C.,Ufficio Conservazione natura | Vignoli L.,Third University of Rome | Bologna M.A.,Third University of Rome
Ekologia Bratislava | Year: 2010

Breeding bird communities were studied in eight habitat types in the Majella massif (central taly) in two years (2007 and 2008) with two sampling methods (general survey and random point counts). At level of the general survey, our data confirm as bird communities are structured in response to vegetation structure and internal heterogeneity induced either by human activities (e.g., landscape patchiness) or natural limiting factors (e.g., linked to altitude). Richer habitat types correspond to mosaics of oak woods in both of years. In this habitat, the high level of habitat heterogeneity could increase the species richness at landscape level (Le., y-diversity). The low values in species richness observed in Pinus mugo formations and in primary pastures may be due to the altitudinal gradient of species richness (inverse correlation between altitudinal mid-point of each habitat type and number of species). Cluster analysis showed a first level of dissimilarity among faunal communities linked to the vegetation structure (forest versus open/shrubby habitat types), and a second one for open/shrubby habitats could be based either on spatial-heterogeneity and altitudinal effect At level of species richness, a large proportion of the species (≥ 80%) has been sampled with random point count method when compared to general survey. Therefore, at species richness level, the method with lower research effort could furnish a reasonable description of the communities. At species composition level, data obtained by random sampling point count method showed different pattern between years for several habitat typology, turning out less exhaustive than general survey method. Therefore, in those habitat types a low research effort could expose the data to stochastic oscillations. Source

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