Identifier

etd-11102011-115906

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

Disturbance-dependent birds throughout the United States have recently experienced significant declines due to fire suppression and conversion of wilderness to human-dominated landscapes. In Louisiana, young loblolly pine plantations are an important source of early- successional habitat for these specialist birds. However, changes in management practices may affect forest stand suitability for bird communities that rely on them. Here I examined how changes in two site preparations, tree row spacing [14 ft (4.3 m) vs. 20 ft (6.1 m)] and arrangement of post-harvest woody debris (piled vs. scattered), impacted breeding, disturbance- dependent birds. During four summers in 2006-2010, observers conducted point counts and extended searches to determine species richness, abundance, and breeding activity for birds using 0-5 year old plantations at four locations across Louisiana. Vegetation measurements were also recorded and reduced to three composite variables: structure, evergreen cover, and groundcover, to determine how they might influence birds. Although bird communities increased by all measures as stands matured, I found no evidence that they were impacted by any of the experimental site preparations. Similarly, no vegetation measures differed among treatments, although they were highly influential to birds. It appears that bird communities responded positively to increases in vegetation structure, evergreen cover, and groundcover over time as plants became established and breeding resources increased, regardless of either row spacing or woody debris placement. Therefore, it does not appear that row spacing or debris distribution in this study is an important consideration relative to disturbance-dependent bird communities. Due to the importance of vegetation structure and cover to these birds, however, timber managers should employ other methods that maximize non-competitive vegetation, such as thick herbaceous groundcover, to improve habitat quality for disturbance-dependent birds.

Date

2011

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Stouffer, Philip C

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