Remove tree canopy to reduce pond or waterway shading

Overall effectiveness category Awaiting assessment
Number of studies: 1
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Background information and definitions

The edges of ponds and waterways provide open, sunny habitats favoured by many species, including both wetland specialists and more generalist butterflies and moths. However, management of tree growth along waterways may be necessary to prevent the habitat becoming enclosed, leading to increased shading and a loss of important habitat patches.

Study locations

Key messages

One study evaluated the effects on butterflies and moths of removing tree canopy to reduce pond or waterway shading. This study was in the USA.

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (1 STUDY)

Survival (1 study): One replicated, randomized, paired, controlled study in the USA¹ found that removing trees to reduce stream shading reduced the survival of Appalachian brown caterpillars and pupae, but did not affect egg survival.

BEHAVIOUR (0 STUDIES)

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A replicated, randomized, paired, controlled study in 2011–2012 in a pine forest in North Carolina, USA (Aschehoug et al. 2015) found that removing trees to reduce stream shading reduced the survival of Appalachian brown Satyrodes appalachia caterpillars and pupae, but did not affect egg survival. In plots where trees were removed, the survival of Appalachian brown eggs (12–36%) was not significantly different to plots where trees remained (56–74%), but the survival of caterpillars and pupae was lower (trees removed: 7%; trees remained: 20%). In plots where trees were removed and artificial dams were installed, both egg (33–42%) and caterpillar and pupal (14%) survival were similar to plots where trees remained and artificial dams were not installed (egg: 56–74%; caterpillars and pupae: 20%). In May 2011, four 30 × 30 m plots in each of four blocks were randomly assigned to four treatments: manual removal of 90% of trees, installation of temporary dams, tree removal and dam installation, and no manipulation. The 0.5-m high dams spanned the downstream edge of their plot. From 15 May–15 June and 7 July–7 August 2012, a potted sedge Carex mitchelliana plant was placed in the centre of each plot. Each plant had a known number of butterfly eggs, laid by caged wild-caught females prior to placement. The number of eggs on each plant which survived after 48 hours was counted. In addition, in each of three arenas/plot (created from polyethylene food drums), centred on mature sedge, five captive-reared caterpillars (first to third instar) were released and the number of emerging adults was counted.
Study and other actions tested
Referenced paper
Aschehoug E.T., Sivakoff F.S., Cayton H.L., Morris W.F. & Haddad N.M. (2015) Habitat restoration affects immature stages of a wetland butterfly through indirect effects on predation. Ecology, 96, 1761-1767.

Please cite as:

Bladon A.J., Bladon, E. K., Smith R.K. & Sutherland W.J. (2023) Butterfly and Moth Conservation: Global Evidence for the Effects of Interventions for butterflies and moths. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.