© 1999 Heron Publishing—Victoria, Canada
Role of roots in winter water relations of Engelmann spruce saplings
Richard L. Boyce (1) and Scott A. Lucero (1)
1. Department of Biological Sciences, University of Denver, Denver, CO 80208, USA / Received March 17, 1998
Summary
Roots play a role in maintaining foliar water balance in subalpine conifer saplings during winter. We used deuterium-labeled
water to demonstrate that roots of Engelmann spruce (Picea engelmannii Parry) take up water during the late-winter–early spring period. Based on a root severing experiment, we conclude that small,
snow-covered saplings were largely dependent on root water uptake to meet winter transpiration needs, whereas larger saplings
relied more on water stored in stem sapwood. Both water uptake and water stored in roots appeared to be critical for the survival
of saplings exposed above the snowpack during the late-winter–early spring period, when sap reserves were insufficient to
meet increasing
transpirational demands.
Keywords:
water balance, conifers, Colorado, Rocky Mountains, roots, Picea engelmannii, root excision, sapwood, snow cover, water uptake, winter damage.
