Connectivity providers for semi-aquatic vertebrates: the case of the endangered otter in Italy |
| |
Authors: | Maria Laura Carranza Evelina D’Alessandro Santiago Saura Anna Loy |
| |
Institution: | (1) Environmetrics Laboratory, Department STAT, University of Molise, Contrada Fonte Lappone, 86170 Pesche, IS, Italy;(2) ETSI Montes, Polytechnic University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain |
| |
Abstract: | Modeling habitat connectivity for conservation of semi-aquatic vertebrates is a particularly challenging task, due to the
fine-scale and linear distribution of riverine habitats and to the capacity of species to move both on freshwater and terrestrial
realms. We showed how the integrated analytical framework provided by the habitat availability (reachability) metrics and
their fractions can be used to effectively evaluate the distinctive roles and contributions of both habitat patches (aquatic
and riparian) and linkage areas (permeable land matrix) to the connectivity and functioning of a complex system composed of
multiple river catchments. Analysis focused on the Eurasian otter (Lutra lutra L.), one of the most endangered mammals in Italy. We developed a network connectivity model based on suitable otter habitats
and multiple least-cost paths between catchments. A graph analytical approach was used to identify critical nodes and links
for the potential expansion and long-term viability of the species in the region. Our results showed that few basins concentrate
most of the importance for sustaining the overall habitat connectivity, due to the extension of suitable habitats they contain,
their strong connections with other basins, and their importance as stepping stones that uphold ecological fluxes between
otherwise weakly connected habitats. The potential contribution of each basin to enhance the dispersal and expansion of otters
in the area strongly depended on the key functional paths (sequences of links and nodes) among the catchments. We identified
vacant basins that could be colonized by otters in the near future, and connecting areas in the intermediate matrix that might
be preferentially used to conduct and promote dispersal movements and gene flow in the area. The novel approach here adopted
could be easily extended to other semiaquatic species and catchment systems, offering a management strategy to preserve the
hydrographic network as an integrated system, as well as a joint evaluation of the role of both the river courses and the
matrix in between in a single landscape model. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|