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Benjamin Bergerot Pierline Tournant Jean-Pierre Moussus Virginie-M. Stevens Romain Julliard Michel Baguette Jean-Christophe Foltête 《Population Ecology》2013,55(1):193-203
Landscape connectivity is a key process for the functioning and persistence of spatially-structured populations in fragmented landscapes. Butterflies are particularly sensitive to landscape change and are excellent model organisms to study landscape connectivity. Here, we infer functional connectivity from the assessment of the selection of different landscape elements in a highly fragmented landscape in the Île-de-France region (France). Firstly we measured the butterfly preferences of the Large White butterfly (Pieris brassicae) in different landscape elements using individual release experiments. Secondly, we used an inter-patch movement model based on butterfly choices to build the selection map of the landscape elements to moving butterflies. From this map, functional connectivity network of P. brassicae was modelled using landscape graph-based approach. In our study area, we identified nine components/groups of connected habitat patches, eight of them located in urbanized areas, whereas the last one covered the more rural areas. Eventually, we provided elements to validate the predictions of our model with independent experiments of mass release-recapture of butterflies. Our study shows (1) the efficiency of our inter-patch movement model based on species preferences in predicting complex ecological processes such as dispersal and (2) how inter-patch movement model results coupled to landscape graph can assess landscape functional connectivity at large spatial scales. 相似文献
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Pierline Tournant Liana Joseph Koichi Goka Franck Courchamp 《Biodiversity and Conservation》2012,21(6):1425-1440
For some wildlife commodities, rare species are especially sought after. The tendency for rare commodities to be of higher
value can fuel their exploitation and as numbers dwindle, the demand can increase. Consequently, this can precipitate these
rare species into an overexploitation vortex where they become increasingly rare, valued and exploited until eventual extinction.
We focus here on the hobby of collecting stag beetles, to ascertain if the market value of these items is driven by rarity
and if, consequently, these species are vulnerable to this overexploitation vortex. Stag beetle collections fuel a large and
lucrative market in Japan, involving more than 700 species from all over the world, with over 15 million specimens imported
a year. Some particularly valued species fetch more than US$5,000 a piece. We assessed the importance of species rarity as
an acquisition criterion in this market using two methods: an Internet online questionnaire responded to by 509 participants
and through examining the quantities imported in Japan and prices paid by collectors. We discovered that species rarity is
one of the main choice criteria for acquisition by collectors: rare stag beetles are valued more than the common species and,
consequently, stag beetles are vulnerable to the anthropogenic Allee effect in this market. Because of the sheer size of the
market and the pervasive nature of this rarity paradox, the attraction to rarity equates to a potential extinction threat
for many rare stag beetles species. 相似文献
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