Establishment in tree shelters I: shelters reduce growth, water use, and hardiness, but not drought avoidance
Document Type
Article
Journal/Book Title/Conference
HortScience
Volume
32
Issue
7
Publisher
American Society for Horticultural Science
Publication Date
12-1-1997
First Page
1281
Last Page
1283
Abstract
We investigated water use and potential drought avoidance of Norway maple (Acer platanoides L.) and green ash (Fraxinus pennsylvanica Marsh) seedlings grown in protective plastic shelters. Gravimetric tree water use and reference evapotranspiration for fescue turf (ETo) were monitored for 1 to 3 days during the growing season. Water use of trees was 8% to 14% of ETo in shelters vs. 29% to 40% for trees not in shelters. Trunk diameter was affected more than whole-tree water relations by lack of irrigation, suggesting that the nonirrigated trees were subjected to only mild water stress. Shelters did not improve drought avoidance, as water potentials were generally more negative and trunk diameter increment was lower for nonirrigated trees in shelters. Maples in shelters were affected more adversely by lack of water than were ash. Higher temperatures in shelters also may have reduced trunk growth. Air temperatures were 13 °C warmer than ambient in nonirrigated shelters, but only 5 °C warmer in irrigated shelters. Tree shelters can reduce transpiration rates by over half, but benefits from reduced water loss may be offset by negative effects of higher air temperatures. Shelters reduced cold hardiness of both species, but maple was affected more than ash.
Recommended Citation
Kjelgren, R., and L. Rupp. 1997. Establishment in tree shelters I: shelters reduce growth, water use, and hardiness, but not drought avoidance. HortScience 32:1281-1283.