Record ID No. |
1823 |
Author(s) |
Cleavitt N.L., Fahey T.J., Groffman P. M., Hardy J.P., Henry K.S., Driscoll C.T , 2008 |
Affiliation |
Cornell University, Department of Natural Resources, Fernow Hall, Ithaca,NY 14853 USA |
Title |
Effects of soil freezing on fine roots in a northern hardwood forest |
Source. Vol.(no):Page |
Canadian Journal of Forest Research.38(1):82-91p. |
Categories |
Mycorrhiza General |
Subjects |
Biochemistry |
Sub-subjects |
Miscellaneous |
Organism |
n.a. |
Country |
United States |
Abstracts |
We reduced early winter snowpack in four experimental plots at the Hubbard Brook
Experimental Forest in New Hamphire for 2 years to examine the mechanisms of root injury
associated with soil freezing. Three lines of evidence suggested that direct cellular damage,
rather than physical damage associated with frost heaving, was the principal mechanism of root
injury: (i) decreases in root vitality were not greater on sites with more frost heaving, (ii) in
situ freezing damage was confined to first- and second-order roots in the organic horizons rather
than entire root systems, and (iii) tensile strength of fine roots was not significantly
compromised by experimental stretching to simulate ice lens formation. Although significant
differences in the intensity of soil freezing (depth, rate, and minimum temperature) were
observed across the plots, no clear effects of soil freezing intensity on root injury were
observed. Snow manipulation had no effect on mycorrhizal colonization of sugar maple (Acer
saccharum Marsh.) roots. A significant increase in root growth was observed in the second summer
after treatments, coincident with a significant pulse of soil nitrate leaching. Through their
effects on fine roots, soil freezing events could play an important role in forest ecosystem
dynamics in a changing climate. |