Island biogeography theory explains the genetic diversity of a fragmented rock ptarmigan (Lagopus muta) population

Abstract

The island biogeography theory is one of the major theories in ecology, and its applicability to natural systems is well documented. The core model of the theory, the equilibrium model of island biogeography, predicts that species diversity on an island is positively related to the size of the island, but negatively related by the island's distance to the mainland. In recent years, ecologists have begun to apply this model when investigating genetic diversity, arguing that genetic and species diversity might be influenced by similar ecological processes. However, most studies have focused on oceanic islands, but knowledge on how the theory applies to islands located on the mainland (e.g., mountain islands, forest islands) is scarce. In this study, we examined how the size and degree of isolation of mountain islands would affect the genetic diversity of an alpine bird, the rock ptarmigan ( Lagopus muta ). Within our study area, we defined the largest contiguous mountain area as the mainland, while smaller mountains surrounding the mainland were defined as islands. We found that the observed heterozygosity ( H o ) was significantly higher, and the inbreeding coefficient ( F is ) significantly lower, on the mainland compared to islands. There was a positive significant relationship between the unbiased expected heterozygosity ( H n.b. ) and island size (log km 2 ), but a negative significant relationship between H o and the cost distance to the mainland. Our results are consistent with the equilibrium model of island biogeography and show that the model is well suited for investigating genetic diversity among islands, but also on islands located on the mainland.

Scale-dependent effects of habitat fragmentation on the genetic diversity of Actinidia chinensis populations in China

“…Populations in island-like habitats are usually thought to have low genetic diversity 9 , 10 , which is explained by the species–area relationship from island biogeography theory 11 . Population size is positively related to island area, so small islands are likely influenced by genetic drift, which usually leads to low genetic diversity 12 , 13 . Habitat fragmentation can decrease gene flow among populations because low connectivity between habitats limits seed dispersal and insect pollination 14 – 16 .…”

Drivers of black grouse trends in the French Alps: The prevailing contribution of climate

“…On a given site, years with warm temperatures and early snowmelt and vegetation growth were associated with higher black grouse population growth rates. Numerous studies on grouse have demonstrated that vegetation and snowmelt phenology influence population growth rates (Clark & Johnson 1992; Liebezeit et al., 2014; Novoa et al., 2016; Pulliainen & Tunkkari, 1991). Warm temperatures probably favour an early start to snowmelt and the vegetative growth season (Visser et al., 2009).…”

Species‐specific responses to landscape features shaped genomic structure within Alaska galliformes

“…Previous assessments of genetic structure within ptarmigan and grouse uncovered regional (rock ptarmigan, Caizergues et al, 2003;ruffed grouse, Jensen et al, 2019) and fine-scale (rock ptarmigan, Bech et al, 2009;Costanzi & Steifetten, 2019;willow ptarmigan, Piertney et al, 1998willow ptarmigan, Piertney et al, , 2000Wenzel et al, 2015) differences. Partitions in genetic variation are concordant with subspecific designations in rock ptarmigan (Holder et al, 2004;Pruett et al, 2010), spruce grouse (Barry & Tallmon, 2010), sharp-tailed grouse (Spaulding et al, 2006) and white-tailed ptarmigan (Langin et al, 2018).…”