United States Department of Analyses of Great Smoky Agdcuttore Forest Service Mountain Red Spruce Sout-n Forest Tree Ring Data New Orleans, Louisiana i -%. Both mortality rate and radial growth of high elevation (>900 m) red spruce-Fraser fir forests of the southern Appalachians have experienced change since approximately 1960. Scientific interest In a study of these forests have increased because atmospheric pollution is a possible cause of the change. Scientists with statis tical and biological expertise independently analyzed a tree ring data set collected by the Tennessee Valley Authority and the National Park Service. The objective of the analysis was to develop new or improved techniques for extracting information from such data; tree rings represent a natural data storage system that is one of the few sources of long- term information for these forests. Although no definite statements are made about the role of atmospheric deposition in observed forest decline, the results should contribute to the success of future research. The four techniques employed in the study involved: (1) a dendrochronological approach employing spline detrending and multiple regression to study the effects of climate on ring width, (2) an application of fractals to study the dependence of variance on mean ring width over time, (3) an approach that combined Box-Jenkins methods and spatial analysis, and (4) a method of studying time dependence of ring width on climate using the Kalman filter. May 1988 Analyses of Great Smoky Mountain Red Spruce Tree Ring Data Paul C. Van Deusen EdLzor Contents INTRODUCTION ....................................................... 1 Southern Appalachian Red Spr~ce--FraserFir Forests--Elizabeth Groton and Christopher Eagar .................................... 2 A Tree Ring Analysis of Red Spruce in the Southern Appalachian Mountains--Edward R. Conk ........................................ 6 Utilizing Time Series Models and Spatial Analysis of Forecast Residuals for Tree Ring Analysis of Red Spruce--2. Keith Ord and Janice A. Derr .................................................. 21 A Fractal Approach to Analysis of Tree Ring increments--P.A. J. Taylor .......................................................... 40 Red Spruce Tree Ring Analysis Using a Kalman Filter--Paul C. Van Beusen ...................................................... 57 The Institute for Quzntitative Studies at the evidence of anomalous behwior In the red spruce USOA Forest Serv.i_ce,Southern Forest Experiment forests of the Great Smoky Mountains and suggests Station, has been engaged in a study of that this is partly due to warmer s stiatistlhcal methods used in researching temperatures in recent years. He also staces Atmospheric Deposition Influences on Forests that the situation in southern red spruce is not AD. The siludy was funded by the ifd'ationai sfml"riar Lo that Pri rzurthern red sprcjce. Vegetation Survey, which is under the Nacio _ 1 Drs. Old and Derr performed a spatial analysis Acid Precipitation Assessment Program (NABAP). on the data. They concluded that there was a The study began with a distributed seminar; for tendency for ring wldths to diminish In recent EO weeks articles about ADIF were sent to a years and that there is a strong spatial number of participants who returned eoments each dependence in forecast residuals that cannot be week, A final report was produced (Kiester and explained by geographic or biotic factors alone, others 1985) consisting sf critiques of past ADIF They did not consider climate, which they mention studies, suggestions for additional reading, and could explain some of the remaining spatial philosophy about the type and quality of research dependence. The analysis performed here is novel needed in the ADIF area. for the field of dendrochronology and may lead to The study indicated that tree ring analyses useful results in the future. held promise for the study of ADIF, but further To study the dependence of variance on the mean development of appropriate statistical methods of the data, Dr. Taylor investigated the use of would be useful. Therefore the idea of "fractals," a term coined to denote fractional "replicated-statisticiansrrwas employed. Because dependence. He conc~uded that the change in there are several. ways to approach a tree ring fractional dimension over time may be due to analysis, it was probable that allowing a number successional, climatic, or anthropogenic of individuals to work independently would yield influences. This technique has not been applied some Lnteresting new dendrochronobogieal previously to tree ring data and nay show promise techniques. Red spruce (Pieea rubens Sarg.) was after further development. chosen for this study because claims were Dr. Van Deusen analyzed the data using the previously made that spruce forests were Kalman filter technique, which is commonly used experiencing unexplained growth declines in both in engineering applications, At the time of this the Northeast and the South (Hornbeck and Sxith study, the method had not been used in 1985; Adams and others 1985). Although the study dendrochronology, although scientists in the was intended to develop statlstieal methods and Netherlands (Visser 1986) have recently published not explanations of growth declines, using this a paper on independent applications of the method data allowed for that possibility to tree rings. The Kalman Filter allowed the This study was a joint endea- or by the USDkr Forest Service, the National Park Service (NBS), climatic data to be modeled dpamically so that and the Tennessee Valley Authority (TVA). its effect over time could be studied. He Funding came from the Forest Service and the5 TVA, concluded that these trees have become data from the TVA and NPS, and statistical progressively more sensitive to climate since the analyses were conducted by the Forest Service. late 1950's. This increased sensitivity may Agreements were made with the following coincide with insect-caused thinning in the scientists to perlorm analyses and provide stands. individual reports: All the studies concluded that the growth patterns in these stands have changed in the last (1) Edward R. Cook, Ph.D. 20 years. The causes of these changes are Tree-Ring Laboratory uncertain, but the sensitlivity of the stand to Lamont-Doherty Geological Observatory climate appears to be increasing. To enhance the of Colmbia University reader ' s ability to interpret the various PalLsades, New York 10964 analyses, the individual reports are prefaced by a review by EIizsrbeth Croton and Christopher (2) Keith Ord, Bh.D. and Janice Derr, Ph.D. of the geographical and biological Department of Management Science Eagar background of the Southern Appalachian Spruce Fir Pennsylvania State University Forest. University Park, PA 16802 References cited in this seetron are: Adams, (3) Robin A. J. Taylor, Ph.D H.S.; Stephenson, S.L.; BLasing, T.J.; Duvick, Department of Entomology D.N. 1985. Growth-trend declines of' spruce and 106 Patterson Building fir in mid-Appalachian subalpine forest. Pennsylvania State University En~riro~entaland Experimental Botany. 25(4): University Park, PA IS802 315-325. Hornbeck, J.W. ; Smith, R.B. 1985. Documentation of red spruce growth decline. (4) Paul C. Van Deusen, Ph.D, Canadian Journal of Forest Research, 15: 1199- Institute for Quantitative Studies 1201. Kiester, A.R.; Van Deusen, P.C.; Dell, Southern Forest Experiment Station T.R. 1985. Status of the concepts and 701 Loyola A-~enue nethodlogies used in the study of the effects of New Orleans, 'LA 70113 atmospheric deposition on forests. Internal report for the National Vegetation Survey of Dr. Cook is considered to be one of the Leaders NAPAP. Visser, ti. 1986. Analysis of tree ring in the field of dendrochronology, and his data using the Kalman Filter techniques. IAWA analysis therefore includes the most currently Bulletin n.s., Vol. 7(4) 289-297. Published at accepted techniques. He concluded that there is the Rijksherbarium, Netherlands. Soutlxern Appalachian Red Spruce--Fraser Fir Forests Elizabeth Groton and Christopher Eagar Host spruce-fir forests of the southern The southern Appalachian red spruce- Fraser fir+ Appalachians have been recently disturbed by the forests are found in southwestern Virginia, extensive mortality of Fraser fir caused by an western North Carolina, and eastern Tennessee introduced insect, the balsam woolly adelgid (fig. I), Total area of these southern . This pest, a native of Europe, Appalachian spruce-fir forests is estimated at i t that feeds on the bark of true 26,577 hectares, with 19,755 hectares occurring firs (Abies spp.). Fraser fir is quickly killed within the Great Smoky MountaFns National Park by the balsam woolly adelgid. Mortality occurs (GSMNP), Extensive logging and other between 3 and 9 years front the time of initial disturbances early in the 20th century have depending on the size and vigor of reduced the extent of the southern Appalachian an and Speers 1965). Tree death is spruce-f ir forests. Today this forest trpe caused by the diffusion of compounds secreted by occurs on high-elevation peaks (above 1,370 m) in the adelgid into the xylem during feeding, which islandlike patches. causes formation of premature heartwood. Species ' composition in the southern Translocation of water and minerals to the crown Appalachian forests changes with the elevational are greatly reduced, causing water stress and gradient. At lower elevations (1,370-1,580m) in eventual death of the tree (Puritch