The relationship between shelterwood cuts and crown thinnings and the abundance and distribution of birds in a southern New England forest

Changes in breeding bird abundance and species composition over a 20 year chronosequence following shelterwood harvests in oak-hardwood forests

“…We used the point count method to survey bird populations (Goodale et al, 2009;Webb et al, 1977). Following King and DeGraaf (2000), we established point counts for measuring bird abundance, richness and diversity within a fixed radius of 50 m. To avoid edge effects, all points were at least 100 m away from the stand edge.…”

“…Timber harvesting and forest management techniques can combat this decline by increasing and diversifying habitats available to birds (Augenfeld et al, 2008;Cahall et al, 2013;Goodale et al, 2009;Keller et al, 2003;King and DeGraaf, 2000;Perry and Thill, 2013). In particular, shelterwood regeneration harvests in temperate-oak forests can increase bird populations by offering more diverse horizontal and vertical habitat compared to mature second-growth forests (Goodale et al, 2009;King and DeGraaf, 2000;Smith et al, 1997).…”

“…Bird surveys done within one to two years of a shelterwood timber harvest suggest timber harvesting can increase bird diversity and abundance by increasing the structural diversity of vegetation (Baker and Lacki, 1997;Faccio, 2003;Goodale et al, 2009;King and DeGraaf, 2000). Though short-term studies are extremely valuable, they generally only offer a fleeting glimpse of bird populations within a single successional stage following a harvest.…”

“…Past studies have shown that recent timber harvests can create habitat with more diverse vertical and horizontal vegetation structures than second-growth forests (Goodale et al, 2009;King and DeGraaf, 2000;Smith et al, 1997). Assuming agreement with the habitat heterogeneity-animal diversity hypothesis, we expected that bird abundance, richness and diversity would dramatically change over a short period of time, as the stand progresses from early-successional to mature habitats.…”

Combined long-term effects of variable tree regeneration and timber management on forest songbirds and timber production

“…These studies mainly focus on understory vegetation, and although many bird species are dependent on structural features in under-and mid-story strata for nesting and foraging, others are more dependent on overstory characteristics (e.g., Annand and Thompson, 1997;Collins, 1983;De Graaf et al, 1985, 1998Germaine et al, 1997;Goodale et al, 2009). To understand how these overstory specialists are likely to respond to management activities, we also need to evaluate the long-term dynamics of managed forests, as immediate changes in canopy characteristics due to tree removal are followed by expansion of the canopies of trees that remain, and gradual recruitment of understory trees into the canopy.…”