Forest lepidopteran communities are more resilient to shelterwood harvests compared to more intensive logging regimes

Published source details Summerville K.S. (2013) Forest lepidopteran communities are more resilient to shelterwood harvests compared to more intensive logging regimes. Ecological Applications, 23, 1101-1112.
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This study is summarised as evidence for the following.

	Action	Category
	Harvest groups of trees or use thinning instead of clearcutting Action Link
	Use shelterwood harvesting instead of clearcutting Action Link

Harvest groups of trees or use thinning instead of clearcutting

A replicated, controlled, before-and-after study in 2007–2011 in two hardwood forests in Indiana, USA (Summerville 2013, same study as Summerville 2011) found that after group-selection harvesting, the number of moth species did not recover faster than after clearcutting, and both were slower to recover than after shelterwood harvesting. Three years after group-selection harvesting, the total number of moth species (52 species/stand) was similar to after clearcutting (48 species/stand), and both were lower than before harvesting (group-selection: 100; clearcutting: 98 species/stand) or after shelterwood harvesting (73 species/stand). After group-selection harvesting, the number of specialist species (8 species/stand) was lower than before harvest (19 species/stand), or after shelterwood harvesting (23 species/stand). However, the number of herbaceous-feeding species was higher after group-selection harvesting (10 species/stand) and clearcutting (16 species/stand) than before harvesting (group-selection: 3; clearcutting: 4 species/stand), but remained similar after shelterwood harvesting (after: 6; before: 4 species/stand). In 2008, forest stands (3–5 ha, 350–750 m apart) in two watersheds (500 ha, 10 km apart) were logged. In one watershed, four stands were harvested by group-selection (80% of trees removed) and four stands were unharvested. In a second watershed, three stands were shelterwood harvested (15% of trees removed), two stands were clearcut (100% of trees removed), and three stands were unharvested. All stands had been clearcut around 60 years earlier. From June–August 2007 and 2009–2011, moths were surveyed every 14 nights (five times/year) from 8pm–7am using a black-light trap placed 2 m above the ground in the centre of each forest stand.

(Summarised by: Andrew Bladon)
Use shelterwood harvesting instead of clearcutting

A replicated, controlled, before-and-after study in 2007–2011 in two hardwood forests in Indiana, USA (Summerville 2013, same study as Summerville 2011) found that after shelterwood harvesting, the number of moth species recovered faster than after group-selection harvesting or clearcutting. Three years after shelterwood harvesting, the total number of moth species (73 species/stand) and the number of specialist species (23 species/stand) was similar to before harvesting (total: 96; specialist: 23 species/stand). Numbers of species had not recovered following group-selection harvesting (total: after: 52; before: 100; specialist: after: 8; before: 19 species/stand) or clearcutting (total: after: 48; before: 98 species/stand; data for specialists not presented). However, the number of herbaceous-feeding species was higher after group-selection harvesting (10 species/stand) and clearcutting (16 species/stand) than before harvesting (group-selection: 3; clearcutting: 4 species/stand), but remained similar after shelterwood harvesting (after: 6; before: 4 species/stand). In 2008, forest stands (3–5 ha, 350–750 m apart) in two watersheds (500 ha, 10 km apart) were logged. In one watershed, three stands were shelterwood harvested (15% of trees removed), two stands were clearcut (100% of trees removed), and three stands were unharvested. In a second watershed, four stands were harvested by group-selection (80% of trees removed) and four stands were unharvested. All stands had been clearcut around 60 years earlier. From June–August 2007 and 2009–2011, moths were surveyed every 14 nights (five times/year) from 8pm–7am using a black-light trap placed 2 m above the ground in the centre of each forest stand.

(Summarised by: Andrew Bladon)