Ground Beetle (Coleoptera: Carabidae) Response to Harvest Residue Retention: Implications for Sustainable Forest Bioenergy Production

Abstract

Research Highlights: Our study adds to the scant literature on the effects of forest bioenergy on ground beetles (Coleoptera: Carabidae) and contributes new insights into the responses of ground beetle species and functional groups to operational harvest residue retention. We discovered that count of Harpalus pensylvanicus (DeGeer)—a habitat generalist—increased owing to clear-cut harvests but decreased due to harvest residue reductions; these observations uniquely allowed us to separate effects of additive forest disturbances to demonstrate that, contrarily to predictions, a generalist species considered to be adapted to disturbance may be negatively affected by altered habitat elements associated with disturbances from renewable energy development. Background and Objectives: Despite the potential environmental benefits of forest bioenergy, woody biomass harvests raise forest sustainability concerns for some stakeholders. Ground beetles are well established ecological indicators of forest ecosystem health and their life history characteristics are connected to habitat elements that are altered by forest harvesting. Thus, we evaluated the effects of harvest residue retention following woody biomass harvest for forest bioenergy on ground beetles in an operational field experiment. Materials and Methods: We sampled ground beetles using pitfall traps in harvest residue removal treatments representing variable woody biomass retention prescriptions, ranging from no retention to complete retention of all merchantable woody biomass. We replicated treatments in eight clear-cut stands in intensively managed loblolly pine (Pinus taeda L.) forests in North Carolina and Georgia. Results: Harvest residue retention had no effect on ground beetle richness and diversity. However, counts of H. pensylvanicus, Anisodactylus spp., and “burrower” and “fast runner” functional groups, among others, were greater in treatments with no woody biomass harvest than those with no harvest residue retention; all of these ground beetles may confer ecosystem services in forests. We suggest that H. pensylvanicus is a useful indicator species for burrowing and granivorous ground beetle response to harvest residue reductions in recently harvested stands. Lastly, we propose that retaining 15% retention of total harvest residues or more, depending on regional and operational variables, may support beneficial ground beetle populations.

Ground-Dwelling Invertebrate Abundance Positively Related to Volume of Logging Residues in the Southern Appalachians, USA

“…Our research supports the previously documented importance of logging debris for a variety of saproxylic and non-saproxylic invertebrate taxa, but it differs from prior research for ground beetles (Carabidae) and red imported fire ants. We documented a negative relationship between ground beetles and CWD cover and no relationship between ground beetles and site-level woody debris volume, which contrasts with results of other studies [23,39,77]. Such a discrepancy may be due to the high amount of scattered downed wood in multiple sites in our study, allowing ground beetles to move freely due to increased connectivity of cover.…”

Long‐term drought triggers severe declines in carabid beetles in a temperate forest

“…Droughts, although being a main driver, are probably not the only cause for declines in our study area. Suspected drivers such as pesticides (Nocera et al 2012, Barendregt et al 2022), land‐use change/habitat loss (Habel and Schmitt 2018, Sánchez‐Bayo and Wyckhuys 2019) or intense management (Grodsky et al 2018, 2020, Staab et al 2023) were not present in the study areas. Nevertheless, we found concerning background declines of −2.1 and −3.1% annually for carabid abundance and biomass, respectively.…”

Enhancing precision in quantification and spatial distribution of logging residues in plantation stands

“…In the pursuit of sustainable forest management, various practices are employed to address the presence of logging residues, with each practice carrying its own set of implications. Among these there are the effects and impacts on biodiversity from removal or retention of residues: e.g., on insects (Grodsky et al 2019), on small mammals (Fritts et al 2017), and on vegetation (Law and Kolb 2007), also from burning practices (e.g. Creech et al 2012).…”