Tree Size and Drought Affect Ponderosa Pine Physiological Response to Thinning and Burning Treatments
Abstract:Thinning and burning treatments based on presettlement (prior to Euro-American settlement) stand conditions have been proposed for improving the vigor and growth of Pinus ponderosa. No study has examined effects of different levels of such thinning treatments on tree water, carbon, and nitrogen relations, or compared effects between postsettlement (trees established after Euro-American settlement) and presettlement (established before Euro-American settlement) trees. We investigated responses of presettlement and postsettlement trees to three levels of thinning and burning (unthinned/unburned control, light thinning/burning, heavy thinning/burning) over 2 yr that differed in precipitation in northern Arizona. Both thinning treatments consistently increased predawn water potential of both tree sizes compared with the control. Effects of thinning on leaf gas exchange varied between tree sizes and measurement times. Thinning increased net photosynthetic rate and stomatal conductance only when soil water availability was lowest, and increases were greater for postsettlement than presettlement trees. In contrast, thinning had no effect on foliar nitrogen concentration.
Our results suggest greater positive effects of restoration thinning on tree water and carbon relations for postsettlement versus presettlement trees, and under drought versus nondrought conditions. Photosynthetic response to thinning in old trees may be constrained by physiological factors associated with large size such as low soil-to-leaf hydraulic conductance. FOR. SCI. 50(1):81–91.
Keywords: Arizona; Pinus ponderosa; Water relations; carbon isotope; environmental management; forest; forest management; forest resources; forestry; forestry research; forestry science; natural resource management; natural resources; nitrogen; photosynthesis; stomatal conductance
Document Type: Regular Article
Affiliations: 1: School of Forestry The University of Montana 32 Campus Drive #0576 Missoula MT 59812-0576 Phone: 406-243-4487;, Fax: 406-243-4845, Email: email@example.com 2: School of Forestry Northern Arizona University P.O. Box 15018 Flagstaff AZ 86011-5018 Phone: 928-523-7491, Email: Tom.Kolb@nau.edu 3: Forest Science Department Oregon State University Corvallis OR 97331 kwallin_, Email: firstname.lastname@example.org
Publication date: 2004-02-01
- Forest Science is a peer-reviewed journal publishing fundamental and applied research that explores all aspects of natural and social sciences as they apply to the function and management of the forested ecosystems of the world. Topics include silviculture, forest management, biometrics, economics, entomology & pathology, fire & fuels management, forest ecology, genetics & tree improvement, geospatial technologies, harvesting & utilization, landscape ecology, operations research, forest policy, physiology, recreation, social sciences, soils & hydrology, and wildlife management.
Forest Science is published bimonthly in February, April, June, August, October, and December.
2015 Impact Factor: 1.702
Ranking: 16 of 66 in forestry
Average time from submission to first decision: 62.5 days*
June 1, 2016 to Feb. 28, 2017
Also published by SAF:
Journal of Forestry
Other SAF Publications
- Submit a Paper
- Membership Information
- Author Guidelines
- Ingenta Connect is not responsible for the content or availability of external websites