Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (1.1 MB)

Title: Future species composition will affect forest water use after loss of eastern hemlock from southern Appalachian forests

Author: Brantley, Steven; Ford, Chelcy R.; Vose, James M.;

Date: 2013

Source: Ecological Applications 23(4):777-790

Publication Series: Scientific Journal (JRNL)

Description: Infestation of eastern hemlock (Tsuga canadensis (L.) Carr.) with hemlock woolly adelgid (HWA, Adelges tsugae) has caused widespread mortality of this key canopy species throughout much of the southern Appalachian Mountains in the past decade. Because eastern hemlock is heavily concentrated in riparian habitats, maintains a dense canopy, and has an evergreen leaf habit, its loss is expected to have a major impact on forest processes, including transpiration (Et). Our goal was to estimate changes in stand-level Et since HWA infestation, and predict future effects of forest regeneration on forest Et in declining eastern hemlock stands where hemlock represented 50–60% of forest basal area. We used a combination of community surveys, sap flux measurements, and empirical models relating sap flux-scaled leaf-level transpiration (EL) to climate to estimate the change in Et after hemlock mortality and forecast how forest Et will change in the future in response to eastern hemlock loss. From 2004 to 2011, eastern hemlock mortality reduced annual forest Et by 22% and reduced winter Et by 74%. As hemlock mortality increased, growth of deciduous tree species—especially sweet birch (Betula lenta L.), red maple (Acer rubrum L.), yellow poplar (Liriodendron tulipifera L.), and the evergreen understory shrub rosebay rhododendron (Rhododendron maximum L.)— also increased, and these species will probably dominate post-hemlock riparian forests. All of these species have higher daytime EL rates than hemlock, and replacement of hemlock with species that have less conservative transpiration rates will result in rapid recovery of annual stand Et. Further, we predict that annual stand Et will eventually surpass Et levels observed before hemlock was infested with HWA. This long-term increase in forest Et may eventually reduce stream discharge, especially during the growing season. However, the dominance of deciduous species in the canopy will result in a permanent reduction in winter Et and possible increase in winter stream discharge. The effects of hemlock die-off and replacement with deciduous species will have a significant impact on the hydrologic flux of forest transpiration, especially in winter. These results highlight the impact that invasive species can have on landscape-level ecosystem fluxes.

Publication Notes:

  • 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.



Brantley, Steven; Ford, Chelcy R.; Vose, James M. 2013. Future species composition will affect forest water use after loss of eastern hemlock from southern Appalachian forests. Ecological Applications 23(4):777-790.


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.