Adverse Effects From Mulching Spruce Seedlings

Mulching, especially light colored or reflective materials, can be expected to increase maximum air temperatures above the mulch surface and might, therefore, be detrimental to tree seedlings (Geiger 1965, Maguire 1955). Yet several successful tests of various mulching materials to improve seedling survival have been reported from regions with relatively severe summer climate (Hunt 1963, Hermann 1964). For this reason, the adverse heat effects of mulch treatments on spruce seedlings observed in two studies in the moderate summer climate of the Allegheny Uplands of New York emphasize this potential hazard under some conditions. A study of the effects of herbaceous vegetation control on white spruce (Picea glauca (Moench) Voss) seedlings included white fiberglass batts, 22 inches square by 2 inches thick, as one of the treatments. These batts placed around newly planted 3-0 seedlings in April 1964 resulted in nearly as effective soil moisture conservation during the first summer as did complete vegetation removal by herbicides. Maximum temperatures of the soil surface under the mulch averaged up to 5° F. lower than under adjacent untreated vegetation. However, during July many mulched seedlings began to brown and by September, 25 percent had died. Another 25 percent were damaged so severely that they succumbed the following year. In contrast, no first year mortality occurred among untreated seedlings.

Download this file:

Download this file

Details

Author(s): N. A. Richards

Publication: Tree Planters' Notes - Volume 21, Number 1 (1970)

Volume: 21

Number: 1