Trees

, Volume 12, Issue 4, pp 215–223

Branch growth of riparian cottonwoods: a hydrologically sensitive dendrochronological tool

  • Jennifer Willms
  • S. B. Rood
  • Walter Willms
  • Melvin Tyree
ORIGINAL ARTICLE

DOI: 10.1007/s004680050143

Cite this article as:
Willms, J., Rood, S., Willms, W. et al. Trees (1998) 12: 215. doi:10.1007/s004680050143

Abstract

 The conservation of riparian (river valley flood plain) forests relies on the provision of instream flows that are sufficient to sustain tree growth. In the present study, annual branch growth increments were investigated as an indicator of environmental favorability for riparian cottonwoods. Trees of three species, Populus angustifolia, P. balsamifera, and P. deltoides, and their natural interspecific hybrids, were studied at five sites along the Oldman and South Saskatchewan rivers in Alberta, Canada. Annual branch growth increments for the interval from 1983 to 1992 were positively correlated with stream flows (r2 = 0.79 at Lethbridge) and slightly negatively correlated with weather variables that contribute to water demand: evaporation, temperature, wind, and/or sunshine. The combination of January to May stream flow (water supply) and June evaporation (water demand) almost entirely accounted for the branch growth variation across years (r2 = 0.91 at Lethbridge). Tree ring increments were also investigated but were less closely correlated than branch increments across trees or with stream flow. Branch growth increments thus provide an accurate but short duration (1 or 2 decades) record of environmental favorability for growth. The close correlation between branch growth and stream flow indicates that water is the principal limitation to growth of these riparian cottonwoods and that these trees obtained their water from a source linked to the stream, the riparian water table. Analyses of branch increments should provide a management tool for (i) determining instream flow needs for riparian cottonwoods and (ii) analyzing impacts of stream flow alterations due to river damming or water diversion.

Key words Branch growthCottonwoodsInstream flow needsPopulusRiparian ecosystems

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Jennifer Willms
    • 1
  • S. B. Rood
    • 1
  • Walter Willms
    • 2
  • Melvin Tyree
    • 3
  1. 1.Department of Biological Sciences, University of Lethbridge, Alberta, Canada T1K 3M4 Tel.: +01 403 329 2327; Fax: +01 403 329 2082; e-mail: ROOD@ULeth.CACA
  2. 2.Agriculture and Agri-Foods Canada, Lethbridge Research Center, Alberta, Canada T1J 4B1CA
  3. 3.Aiken Forestry Sciences Laboratory, U.S.D.A. Forest Service, P.O. Box 968, Burlington, VT 05402, USAUS