Implications for alpine species conservation
Our finding of a drastic population decline since the last glaciation
retreat, coupled with field observations of extremely limited habitat
and small population sizes, suggests that this species complex may be
vulnerable to localized extinction. For many Nebria species in
North America, lower elevational distributions have shifted upward in
the past 40 years (Kavanaugh 2015). If population range shifts are
associated with warmer temperatures in the Holocene, it is very likely
that populations will continue to shrink with ongoing global warming.
This could be exacerbated by the loss of Sierra Nevada glaciers and a
reduction in winter snowpack (Basagic & Fountain, 2011; Belmecheri,
Babst, Wahl, Stahle, & Trouet, 2016). Although N. ingens complex
is not an economically significant animal, it is difficult to predict
the consequence of a general predator disappearing from a comparatively
depauperate alpine ecosystem.