Study Number: 

1004

Project Title:

Growth-mortality relationships for southern Appalachian trees.

Investigator(s):

James Clark  E-Mail | Tel. 919.660.7402 | Biographical Sketch | The Clark Lab
Peter Wyckoff  Contact Information
Affiliated Institution(s): Duke University  (Clark)
Guilford College, University of Minnesota 2007  (Wyckoff)
Address: Duke University  
Department of Biology
Durham, North Carolina  27708  USA

Guilford College
5800 West Friendly Avenue
Greensboro, North Carolina 27410 USA
Study Type: Terrestrial
Project Type: Coweeta Core Research
Study Period:

06/1995 - 7/1995
Status/Notes:

Type 1
Funding Sources:

National Science Foundation, Grants BSR944146, DEB8453498, DEB-9632854 (Text Version), DEB9701088 to Coweeta LTER.
Abstract: Ecologists and foresters have long noted a link between tree growth rate and mortality, and recent work suggests that interspecific differences in low growth tolerance is a key force shaping forest structure. Little information is available, however, on the growth-mortality relationship for most species. We present three methods for estimating growth-mortality functions from readily obtainable field data. All use annual mortality rates and the recent growth rates of living and dead individuals. Annual mortality rates are estimated using both survival analysis and a Bayesian approach. Growth rates are obtained from increment cores. Growth-mortality functions are fitted using two parametric approaches and a non-parametric approach.

The three methods are compared using bootstrapped confidence intervals and likelihood ratio tests. For two example species, Acer rubrum and Cornus florida, growth-mortality functions indicate a substantial difference in the two species abilities to withstand slow growth. Both survival analysis and Bayesian estimates of mortality rates lead to similar growth-mortality functions, with the Bayesian approach providing a means to overcome the absence of long-term census data. In fitting growth-mortality functions, the non-parametric approach reveals that inflexibility in parametric methods can lead to errors in estimating mortality risk at low growth. We thus suggest that non-parametric fits be used as a tool for assessing parametric models.


Resources for students about terms used in this study:
Acer rubrum - Source: USDA Plants Database
Predicting tree mortality from diameter growth - Canadian Journal of Forest Research
Who was Thomas Bayes? - Source: Bayesian.org
Bayesian Analysis - Source: International Society for Bayesian Analysis
Location(s), Described: Watershed 18, near plot 218
 Watershed 27, near plots 427 and 527

See Project Summary Sheet 1048 and Terrestrial Gradient Sites: Characteristics (photographs) for detailed information about plot locations and physical descriptions, respectively.
Location(s), Download GPS: ArcView Shape Files (shp.):  UTM, NAD83, Zone 17  |  Lat/Lon
  
Location(s), Online Maps: USGS Topographic Maps of research sites for this project
(Printable for fieldwork)
Methods/Experimental Design: Living and recently dead trees from a variety of trees were cored. Ring widths were measured with a Windendro Measuring System.
Sampling Frequency: Once, non-recurring
Data Columns:

Species - First two letters of Genus and Species name.
Diameter - Diameter of breast height of sample tree.
Status - status; (0 = recently dead, 1 = living trees).
Site - site; (1 = area near gradient plot 218, 2 = area near plot 427, 3 = area near plot 527).
Last10 - average radial growth for the 10 most recent growth years.
Last5 - average radial growth for the 5 most recent growth years; millimeters (mm).
Last4 - average radial growth for the 4 most recent growth years; millimeters (mm).
Last3 - average radial growth for the 3 most recent growth years; millimeters (mm).
Last2 - average radial growth for the 2 most recent growth years; millimeters (mm).
Last1 - average radial growth for the 1 most recent growth years; millimeters (mm).

Missing Data Codes: . (Period)
Publications:

Wyckoff, Peter H.; Clark, James S. 2005. Tree growth prediction using size and exposed crown area. Canadian Journal of Forest Research. 35: 13-20.

Wyckoff, Peter H.; Clark, James S. 2002. The relationship between growth and mortality for seven co-occurring tree species in the southern Appalachian Mountains. Journal of Ecology. 90: 604-615.

Wyckoff, Peter H.; Clark, James S. 2000. Predicting tree mortality from diameter growth: a comparison of maximum likelihood and Bayesian approaches. Canadian Journal of Forest Research. 30: 156-67.

Clark, J.S.; Beckage, B.; Camill, P.; Cleveland, B.; Hille Ris Lambers, J.; Lichter, J.; McLachlan, J.; Mohan, J.; Wyckoff, P. 1999. Interpreting Recruitment Limitation In Forests. American Journal of Botany. 86(1): 1-16.

Wyckoff, Peter Howard. 1999. Growth and mortality of trees in the southern Appalachian Mountains. Ph.D. Dissertation. Duke University.
Data Restrictions: Users must adhere to the Coweeta LTER Data Policy.
Metadata: EML Format (XML Schema) | Information about EML
Data Downloads: Microsoft® Excel (.xls)
 Text Comma Delimited (.csv)
 DBase (.dbf)