The relative effects of habitat loss and fragmentation on population genetic variation in the red‐cockaded woodpecker (Picoides borealis)

Abstract

The relative influence of habitat loss, fragmentation and matrix heterogeneity on the viability of populations is a critical area of conservation research that remains unresolved. Using simulation modelling, we provide an analysis of the influence both patch size and patch isolation have on abundance, effective population size (N(e)) and F(ST). An individual-based, spatially explicit population model based on 15 years of field work on the red-cockaded woodpecker (Picoides borealis) was applied to different landscape configurations. The variation in landscape patterns was summarized using spatial statistics based on O-ring statistics. By regressing demographic and genetics attributes that emerged across the landscape treatments against proportion of total habitat and O-ring statistics, we show that O-ring statistics provide an explicit link between population processes, habitat area, and critical thresholds of fragmentation that affect those processes. Spatial distances among land cover classes that affect biological processes translated into critical scales at which the measures of landscape structure correlated best with genetic indices. Therefore our study infers pattern from process, which contrasts with past studies of landscape genetics. We found that population genetic structure was more strongly affected by fragmentation than population size, which suggests that examining only population size may limit recognition of fragmentation effects that erode genetic variation. If effective population size is used to set recovery goals for endangered species, then habitat fragmentation effects may be sufficiently strong to prevent evaluation of recovery based on the ratio of census:effective population size alone.

Using a genetic network to parameterize a landscape resistance surface for fishers, Martes pennanti

“…These techniques have become widespread in ecology and are now beginning to be applied to landscape genetics (e.g. Bruggeman et al. 2010; Goldberg & Waits 2010; Murphy et al.…”

Estimating size and trend of the North Interlake woodland caribou population using fecal‐DNA and capture–recapture models

“…It also generates ancillary data for population genetic structure analysis (Ball et al 2010) and landscape genetic analysis (Galpern et al 2011) that can detect early signs of fragmentation, decline, or other information pertaining to biological and ecological processes (Bruggeman et al 2010). The robust design model, using annual primary periods, normalizes survival and trend rates to annual rates and estimates them efficiently.…”

Moderate grazing promotes genetic diversity of Stipa species in the Inner Mongolian steppe

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