Impact of Landscape Management on the Genetic Structure of Red Squirrel Populations

Abstract

Landscape management practices that alter the degree of habitat fragmentation can significantly affect the genetic structure of animal populations. British red squirrels use "stepping stone" patches of habitat to move considerable distances through a fragmented habitat. Over the past few decades, the planting of a large conifer forest has connected groups of forest fragments in the north of England with those in southern Scotland. This "defragmentation" of the landscape has resulted in substantial genetic mixing of Scottish and Cumbrian genes in squirrel populations up to 100 kilometers from the site of the new forest. These results have implications for the conservation management of animal and plant species in fragmented landscapes such as those found in Britain.

Does connectivity exist for remnant boreal caribou (Rangifer tarandus caribou) along the Lake Superior Coastal Range? Options for landscape restoration

“…Persistence of wide-ranging species of conservation concern in patchy habitat strongly depends on habitat quality and the ability of animals to move between habitat patches (Fahrig, 2003) as well as corridors for migration to allow for movement (Hale et al, 2001;Mech & Hallett, 2001). Therefore, the identification of dispersal events between source and isolated populations may aid conservation and habitat restoration efforts in gaining a better understanding of population connectivity and in determining favourable migration routes.…”

Gel and staining recipes and electrophoresis conditions used in this study

“…However, since the area between Börsteler Wald and Gehn was not forested about 200 years ago, the gradients must therefore be secondary. Thus, our study (1) highlights the conservation value of ancient woodland and the consequences of landscape connectivity and defragmentation (sensu Hale et al 2001) on the genetic setting of a ground beetle and (2) yields insights into the evolutionary biology of external male genitalia, gene flow and species delineation.…”

“…In general, habitat fragmentation has led to genetic differentiation and extinction processes at the population level and is discussed as one of the driving forces for the loss of species worldwide (Noss et al 2006;Allendorf and Luikart 2007). Corridors have been discussed as a concept to overcome the problems of habitat fragmentation for some decades (Chetkiewicz et al 2006), but only a few studies have been able to demonstrate positive outcomes in terms of recovering lost distribution areas or range expansion or recolonizations (Hale et al 2001;Davies and Pullin 2007).…”

“…Assmann and Günther 2000;Desender et al 2002;Desender et al 2005;Drees et al 2008). Only very few cases are known that have documented that an increase in connectivity after a period of fragmentation in ecological time has had an effect on the distribution, genetic structure and morphology of stenotopic woodland species (Hale et al 2001;Hale and Lurz 2003;.…”

Patch occupancy by squirrels in fragmented deciduous forest: effects of behavior

“…For example, habitat patch area is negatively related to population density and positively related to home range size of cursorial squirrels (Koprowski 2005;Reunanen and Grubb 2005) and can affect the age structure and sex ratio of small generalist rodents (Wilder and Meikle 2006). Further, reducing habitat isolation increased gene flow among populations of the European red squirrel (Sciurus vulgaris) in Britain (Hale et al 2001).…”