Details

Autor(en) / Beteiligte

• Campbell, Steven P.
• Witham, Jack W.
• Hunter Jr, Malcolm L.

Titel

Long-term changes in spatial distribution of birds responding to a group-selection timber harvest

Ist Teil von

• Wildlife Society bulletin, 2012-06, Vol.36 (2), p.313-327

Ort / Verlag

Hoboken, USA: John Wiley & Sons, Inc

Erscheinungsjahr

2012

Beschreibungen/Notizen

• We investigated the spatial response of 20 bird species to a group-selection timber harvest within a 40-ha forest stand over a 20-year period (5 yr preharvest and 15 yr postharvest). To characterize the spatial response of each species, we examined trends in 3 metrics: proportion of harvest-created canopy-gap area that occurred within the area used by a species in each year, average distance to the nearest gap of all observations of a species in a year, and distribution of distances between observations and gaps for each species in each year. Eight species (eastern wood-pewee [Contopus virens], winter wren [Troglodytes troglodytes], hermit thrush [Catharus guttatus], Nashville warbler [Vermivora ruficapilla], black-and-white warbler [Mniotilta varia], pine warbler [Dendroica pinus], common yellowthroat [Geothlypis trichas], and whitethroated sparrow [Zonotrichia albicollis]) responded positively to the timber harvest (i.e., the proportion of gaps in their area of use increased, the distance from gaps decreased, and their use of gaps and edges [0–25 m from gaps] increased). In contrast, veeries (Catharus fuscescens), black-throated green warblers (Dendroica virens), and ovenbirds (Seiurus aurocapillus) avoided gaps and edges. Changes in spatial distributions were generally short-lived; by 15 years postharvest the use of the harvested areas by nearly all species had approached preharvest levels. The spatial response of birds to group-selection timber harvesting indicates that there are unlikely to be serious long-term effects of the harvest on forest bird populations. However, there may be more subtle, short-term effects, such as crowding of mature-forest bird species into surrounding forest, which merit further study.