Skip to Main Content
Thinning effects on foliar elements in eastern hemlock: implications for managing the spread of the hemlock woolly adelgidAuthor(s): Kathryn B. Piatek; Mary Ann Fajvan; Richard M. Turcotte
Source: Canadian Journal of Forest Research. 47(1): 81-88.
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
Download Publication (1.0 MB)
DescriptionStand thinning is being tested as a means to limit the impacts of the invasive hemlock woolly adelgid (HWA; Adelges tsugae Annand) on eastern hemlock (Tsuga canadensis (L.) Carriere). The efficacy of this strategy may be reduced if thinning increases hemlock foliar nutrients because HWA densities are correlated with foliar concentrations of N, P, K, Ca, and Mn. We determined foliar N, P, K, Ca, and Mn concentrations in 1-year-old and all other (older) needles prior to and for 4 years after thinning in northwestern Pennsylvania stands of eastern hemlock without HWA. Average foliar concentrations in 1-year-old needles were 1.30–1.80 g N·100 g−1, 1300–1700 mg P·kg−1, 4200–6300 mg K·kg−1, 2500–5200 mg Ca·kg−1, and 2393 μg Mn·g−1. N, P, and K decreased, Ca increased, and Mn first increased and then stabilized. Thinning by itself did not affect the tested foliar nutrients. The interaction between treatment and year was significant and evident in temporal trajectories of foliar N and K. However, the differences between thinned and unthinned plots within years averaged only 0.03 g N·100 g−1 and 340 mg K·kg−1. We concluded that even though thinning changed the temporal trajectories of foliar N and K, the nutritional shifts were minimal, brief, and unlikely to affect the efficacy of thinning in limiting the impacts of HWA.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationPiatek, Kathryn B.; Fajvan, Mary Ann; Turcotte, Richard M. 2017. Thinning effects on foliar elements in eastern hemlock: implications for managing the spread of the hemlock woolly adelgid. Canadian Journal of Forest Research. 47(1): 81-88.
Keywordseastern hemlock, foliar elements, foliar nutrients, thinning, hemlock woolly adelgid
- Shade and hemlock woolly adelgid infestation increase eastern hemlock foliar nutrient concentration
- Impacts of hemlock decline and ecological considerations for hemlock stand restoration following hemlock woolly adelgid outbreaks
- Hemlock infestation and mortality: impacts on nutrient pools and cycling in Appalachian forests
XML: View XML