Bat responses to silviculture treatments: Activity over 13 years of regeneration

Abstract

Using silviculture treatments as a tool to create habitat for wildlife is a common practice in wildlife conservation and natural resource management. Although diverse forest age structures and composition benefit many wildlife species, relatively little is known about bat response to young forest habitat. Understanding how the activity of bats changes as young forests age, and the influence of landscape level, stand level, and biologically relevant variables on bat activity, can improve effectiveness of forest management actions designed to benefit bat populations. We measured activity of bats in young forests regenerating from harvests implemented 2007–2018. We selected 26 sites, each of which consisted of a regenerating stand and paired control stand in adjacent interior forest, and used acoustic monitors to record bat activity from 5 May – 9 September 2019 and 2020, with a break from 1 July – 14 July so that monitoring fell into pre- or post-volant timeframes. We used an information theoretic approach to assess support for landscape level, stand level, and biologically relevant variables on bat activity in regenerating stands. Through our research we found (i) bats were more active in young forest stands than natural canopy gaps in interior forests, (ii) bat activity was highest in the first few years post treatment and decreased as young forests continued to age, and (iii) bat activity was highly dependent on biological factors, not landscape or stand level factors. Collectively, these findings suggest that forest management for young forest habitat may benefit forest-associated bats, at least in predominantly forested landscapes where young forest habitat is under-represented.