Breeding, Early-Successional Bird Response to Forest Harvests for Bioenergy

Steven M Grodsky; Christopher E Moorman; Sarah R Fritts; Steven B Castleberry; T Bently Wigley

doi:10.1371/journal.pone.0165070

Breeding, Early-Successional Bird Response to Forest Harvests for Bioenergy

PLoS One. 2016 Oct 25;11(10):e0165070. doi: 10.1371/journal.pone.0165070. eCollection 2016.

Authors

Steven M Grodsky¹, Christopher E Moorman¹, Sarah R Fritts², Steven B Castleberry³, T Bently Wigley⁴

Affiliations

¹ North Carolina State University, Department of Forestry and Environmental Resources, Fisheries, Wildlife, and Conservation Biology Program, Box 7646, Raleigh, NC 27695, United States of America.
² Texas Tech University, Department of Natural Resources Management, P.O. Box 42125, Lubbock, Texas, 79409, United States of America.
³ University of Georgia, Warnell School of Forestry and Natural Resources, 180 E. Green St., Athens, GA 30602, United States of America.
⁴ National Council for Air and Stream Improvement, Inc., P.O. Box 340317, Clemson, SC 29634, United States of America.

Abstract

Forest regeneration following timber harvest is a principal source of habitat for early-successional birds and characterized by influxes of early-successional vegetation and residual downed woody material. Early-successional birds may use harvest residues for communication, cover, foraging, and nesting. Yet, increased market viability of woody biomass as bioenergy feedstock may intensify harvest residue removal. Our objectives were to: 1) evaluate effects of varying intensities of woody biomass harvest on the early-successional bird community; and (2) document early-successional bird use of harvest residues in regenerating stands. We spot-mapped birds from 15 April- 15 July, 2012-2014, in six woody biomass removal treatments within regenerating stands in North Carolina (n = 4) and Georgia (n = 4), USA. Treatments included clearcut harvest followed by: (1) traditional woody biomass harvest with no specific retention target; (2) 15% retention with harvest residues dispersed; (3) 15% retention with harvest residues clustered; (4) 30% retention with harvest residues dispersed; (5) 30% retention with harvest residues clustered; and (6) no woody biomass harvest (i.e., reference site). We tested for treatment-level effects on breeding bird species diversity and richness, early-successional focal species territory density (combined and individual species), counts of breeding birds detected near, in, or on branches of harvest piles/windrows, counts of breeding bird behaviors, and vegetation composition and structure. Pooled across three breeding seasons, we delineated 536 and 654 territories and detected 2,489 and 4,204 birds in the North Carolina and Georgia treatments, respectively. Woody biomass harvest had limited or short-lived effects on the early-successional, breeding bird community. The successional trajectory of vegetation structure, rather than availability of harvest residues, primarily drove avian use of regenerating stands. However, many breeding bird species used downed wood in addition to vegetation, indicating that harvest residues initially may provide food and cover resources for early-successional birds in regenerating stands prior to vegetation regrowth.

MeSH terms

Animals
Biomass
Birds / physiology*
Breeding*
Conservation of Natural Resources
Ecosystem
Georgia
North Carolina
Population Dynamics
Wood / growth & development*

Grants and funding

National Council for Air and Stream Improvement, Inc. - http://www.ncasi.org/ - CEM, SBC, SMG; Department of Interior Southeast Climate Science Center - https://www.doi.gov/csc/southeast/ - SMG, CEM; Department of Agriculture National Institute of Food and Agriculture Managed Ecosystems Program - https://nifa.usda.gov/grants - CEM; Biofuels Center of North Carolina - http://www.biofuelscenter.org/ - SMG, SRF, CEM. The author(s) received no specific funding for this work.