Interactive effects of atmospheric CO{sub 2} enrichment and soil N on growth and ectomycorrhizal colonization of ponderosa pine seedlings
- Univ. of Nevada, Reno, NV (United States)
Interactive effects of elevated atmospheric CO{sub 2} and soil N fertility on above- and below-ground development of juvenile ponderosa pine were examined. Seedlings were grown from seed in atmospheres containing 700 {mu}l 1{sup {minus}1}, 525 {mu}l 1{sup {minus}1}, or ambient CO{sub 2}. Medium and high soil N treatments had total N increased by 100 {mu}g g{sup {minus}1} and 200 {mu}g g{sup {minus}1}, respectively, while unamended mix,(total N concentration of approximately 300 {mu}g g{sup {minus}1}), served as the low N treatment. After 4 months, CO{sub 2} enrichment increased shoot volume and dry weight of seedlings grown in high soil N, but this result was not evident in the other N treatments and did not persist to the second harvest. Root weight, however, increased, and shoot/root ratio decreased as the CO{sub 2} concentration increased within all three N treatments at the first harvest. At the second harvest, root weights within the high and intermediate N treatments were lowest in seedlings grown in ambient CO{sub 2} and shoot/root ratios decreased as CO{sub 2} increased in these two N treatments as well. Although the ectomycorrhizal infection percentage of seedlings grown in 700 {mu}l 1{sup {minus}1} CO{sub 2} was highest among the seedlings grown in high N after 4 months, mycorrhizal colonization was variable overall at the first and second harvests. After 1 yr, the 525 {mu}l 1{sup {minus}1} CO{sub 2} concentration stimulated above- and belowground growth more than the high CO{sub 2} atmosphere in both high and medium soil N. These seedlings also have relatively extensive ectomycorrhizal formation, but colonization was again variable. Results presented here suggest the response of juvenile ponderosa pine to CO{sub 2} enrichment is ephemeral, with the effects on roots more pronounced and persistent overall than those on shoots, and that the response is dependent on N availability. 19 refs., 2 tabs.
- OSTI ID:
- 482536
- Journal Information:
- Forest Science, Vol. 41, Issue 3; Other Information: PBD: Aug 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nitrogen limitation and growth response to CO{sub 2} in ponderosa pine
Elevated carbon dioxide effects on nitrogen dynamics in grasses, with emphasis on rhizosphere processes