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In-Depth Information
The problem is that we have considerable, if patchy, evidence that niches can
rapidly evolve (reviewed in Thompson 1998), change within the fundamental niche
(Dormann et al. 2010) or at least that variability within a species is large enough to
allow it to shift its niche when confronted with novel environments (e.g. Ackerly
et al. 2006; Broennimann et al. 2007; Hajkova et al. 2008; Holt 2003; Holt and
Gaines 1992). There is, as yet, no synthesis of niche evolution nor, to my knowledge,
any mechanistic approach to incorporate geno- and phenotypic plasticity into SDMs
or spatial population models. There is, on the other hand, more than anecdotal
evidence that microevolutionary processes are at play and matter ecologically
(Hampe and Petit 2005; Phillips et al. 2006a). Hence, this field still awaits being
embraced by species distribution models.
13.4 Concluding Remarks
This chapter tries to strike a balance between guidance for novices to species
distribution modelling - by providing a recipe for the most crucial elements of
SDMs - and an embedding of SDMs into the currently most relevant statistical
challenges. Analysing a species' distribution can be a very useful starting point for
further investigations or process-based modelling attempts. The correlative nature
of modelling in general, and species distribution modelling specifically, should
always be remembered. Tempting as it may be to incorporate a lot of ecological
knowledge into mechanistic or statistical models, only little of this information will
actually be relevant
at the focal scale
. The main intellectual challenges that remain
are to not over-interpret one's findings and to seek independent corroboration.
Acknowledgments Over the years, many colleagues helped develop the above recipe. I am
particularly grateful to Boris Schr
orn Reineking and Jane Elith, as well as the many
participants of statistical workshops on this topic. I am also grateful to Fred Jopp, Hauke Reuter
and Dietmar Kraft for improving a previous version. Funding by the Helmholtz Association is
acknowledged (VH-NG-247).
oder, Bj
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