P. Ferreras, Landscape structure and asymmetrical inter-patch connectivity in a metapopulation of the endangered Iberian lynx, BIOL CONSER, 100(1), 2001, pp. 125-136
Among the factors threatening the Iberian lynx, (Lynx pardinus) (the most e
ndangered species of all the Felidae), loss and fragmentation of its habita
ts are probably the most important. Connectivity between the remaining popu
lations in the predominantly fragmented landscapes is a key factor in the d
ynamics and persistence of metapopulations. Based on the data collected dur
ing a long-term study on the ecology of this species in a small and fragmen
ted population in SW Spain, I analyse the factors affecting connectivity be
tween the two main sources and the rest of local populations. Connectivity
was estimated as the proportion of dispersers from a source that reached a
given subpopulation. Among the explanatory variables considered, only dista
nce (both straight and effective distance, which takes into account habitat
quality between local populations) and location of the source were clearly
related to connectivity. Some other variables describing landscape feature
s separating sources and target subpopulations (proportion of unsuitable ha
bitats, patch cohesion, size of targets, overall size of subpopulations clo
ser than the target) were not related to connectivity. Differences in the l
andscape surrounding sources help to explain the different connectivity fro
m the two sources. An asymmetrical connectivity between the two sources and
populations surrounding them (north and south) is likely explained by the
configuration of habitats encountered by dispersers, which force those from
one source to behave as crossers of unsuitable habitats. These results hav
e consequences for the conservation of Iberian lynx populations and for eco
logically similar species. Distance, the factor most affecting connectivity
, is difficult to manage, although at least size and configuration of usabl
e patches can be modified. Connectivity could also be improved through reco
very of habitats with cover, suitable for dispersing. Reduction of mortalit
y risks would also enhance connectivity indirectly, by allowing longer time
s and larger areas covered during dispersal. In the case of the study popul
ation, it is urgent to promote connectivity with other Iberian lynx populat
ions due to genetic consequences of small population size and effective iso
lation. (C) 2001 Elsevier Science Ltd. All rights reserved.