Model data to investigate wood frog abundance in 17-year post harvest variable retention mixed wood forests

Variable retention forest harvesting aims to reduce negative effect of
harvesting on forest biodiversity, but its effectiveness is not well
understood for many taxa. To better understand the effects of
variable retention forest management and environmental features on
amphibians, we used pitfall traps to capture wood frogs (Lithobates
sylvaticus) across 4 levels of retention harvest (clearcut [0%], 20%, 50%,
and unharvested control [100%]), and 2 forest types (deciduous and
coniferous), in 17-year post-harvest forests in northwest Alberta. We
mapped breeding sites and used a terrain moisture index (Depth-to-Water)
derived from airborne LiDAR to examine relationships between relative
abundance, breeding site proximity and soil moisture. Retention level
alone had no effect on relative abundance, but in late summer (July and
August) there was a significant interaction between retention level and
forest type: capture rates decreased with amount of retention for
deciduous forests, but increased with amount of retention in conifer
forests. During late summer, capture rates were higher in conifer forests
than in deciduous forests, with soil moisture (lower Depth-to-Water)
positively related to capture rates. Though timber retention may be
beneficial to wood frogs in the short-term, any impacts of forest
harvesting on wood frog abundance was undetectable in stands 17 years
post-harvest.