An elevational shift in butterfly species richness and composition accompanying recent climate change

Abstract

The geographic ranges of many species have shifted polewards and uphill in elevation associated with climate warming, leading to increases in species richness at high latitudes and elevations. However, few studies have addressed community-level responses to climate change across the entire elevational gradients of mountain ranges, or at warm lower latitudes where ecological diversity is expected to decline. Here, we show uphill shifts in butterfly species richness and composition in the Sierra de Guadarrama (central Spain) between 1967-1973 and 2004-2005. Butterfly communities with comparable species compositions shifted uphill by 293 m (AE SE 26), consistent with an upward shift of approximately 225 m in mean annual isotherms. Species richness had a humped relationship with elevation, but declined between surveys, particularly at low elevations. Changes to species richness and composition primarily reflect the loss from lower elevations of species whose regional distributions are restricted to the mountains. The few colonizations by specialist low-elevation species failed to compensate for the loss of high-elevation species, because there are few low-elevation species in the region and the habitat requirements of some of these prevent them from colonizing the mountain range. As a result, we estimated a net decline in species richness in approximately 90% of the region, and increasing community domination by widespread species. The results suggest that climate warming, combined with habitat loss and other drivers of biological change, could lead to significant losses in ecological diversity in mountains and other regions where species encounter their lower latitudinal-range margins.

Are Swiss birds tracking climate change?

“…This pattern can well be modelled by a bell-shaped distribution. Previous studies have employed generalized linear models (GLMs) with a quadratic term in order to model the elevational distribution of species (Wilson et al, 2007;Lenoir et al, 2008). This parametric method forces however the response to fit the predefined quadratic shape.…”

Parnassius apollo nevadensis: identification of recent population structure and source–sink dynamics

“…For example, P apollo gadorensis, the southernmost Spanish subspecies, is now considered extinct (Barea-Azc-n et al 2008) and P. apollo filabricus has suffered a severe contraction in its distribution in Sierra de Baza-Filabres (Barea-Azc-n et al 2008;Mart'nez et al 2016 in prep). The loss of suitable habitat has been reported in many other butterfly populations because of climatic change (Wilson et al 2005;Wilson et al 2007;GutiŽrrez-Ill ‡n et al 2012). Warmer temperatures will move the distribution of butterflies to higher altitudes, which will result in smaller and more isolated areas of distribution, and in a different availability of host plants (Wilson et al 2005;Ashton et al 2009).…”

“…This process may be slow, as it affects the larval and adult phases differently, as they feed on different plants and have different requirements (Olivares et al 2011;Radchuk et al 2013). Possible factors that have been found to be the cause of the habitat becoming less suitable for the butterflies are the rise in temperatures and habitat loss through human alterations (Wilson et al 2005;Wilson et al 2007;Forister et al 2010;Oliver et al 2015) The minor presence of private alleles and the asymmetric gene flow indicate that this population is almost isolated against the input of migrants, but not for the output of emigrants, which indicates the existence of filters to migration. The South population boundary towards the northeast (where it meets the North population) could be defined by the distance and presence of natural barriers (Fig.…”

“…Butterflies are known for being very sensitive to changes in their environment, and their populations have already been shown to be vulnerable to climatic change (Parmesan et al 1999;Roy and Sparks 2000;Wilson et al 2005;Wilson et al 2007;Forister et al 2010;Wilson and Maclean 2011;Radchuk et al 2013;Descombes et al 2015;Oliver et al 2015). The effect of climate change seems to be even stronger in montane taxa, which could face extreme increases in temperature (NoguŽs-Bravo et al 2007;Wilson et al 2007).…”

“…The effect of climate change seems to be even stronger in montane taxa, which could face extreme increases in temperature (NoguŽs-Bravo et al 2007;Wilson et al 2007). …”