Changes in Fire Regimes and the Successional Status of Table Mountain Pine in the Southern Appalachians

Henri D. Grissino-Mayer

Michael R. Armbrister

Laboratory of Tree-Ring Science

Department of Geography

University of Tennessee

Knoxville, Tennessee 37996

• Table Mountain pine endemic to Appalachians• Fire-dependent species: cone serotiny, site prep• Considerable human alterations to native communities• Primary among these is 20th century fire exclusion = new fire regime• Effects on this species are a major concern for management agencies

• Information needed on site-specific fire history• Retrospective study provides needed reference conditions

Problem Statement

• Evaluate current age structure of select TMP stands

• Identify and characterize historical fire regimes in these stands

• Combine this information to assess its current successional status

Objectives

Field Methods

1. Age structure analysis

Cored minimum 75 trees at 5 sites, 2 cores per tree

Aged seedlings and saplings via bud scars, branch nodes

2. Fire-scar analysis

Located suitable fire-scarred logs and snags

Collected small wedges from selected living trees

All sections collected via hand saws

Laboratory Methods

1. Age structure analysis

Mounted, sanded, dated all tree rings on all cores

Developed histograms that depicted the age structure of all 5 stands

2. Fire-scar analysis

Sanded, dated all tree rings on all sections

Dated all embedded fire scars to year of formation *

Developed graphs depicting fire occurrence over time

0

20

40

60

80

100

120

140

160

180

0 - 9

10 -

19

20 -

29

30 -

39

40 -

49

50 -

59

60 -

69

70 -

79

80 -

89

90 -

99

100 -

109

110 -

119

120 -

129

130 -

139

140 -

149

150 -

159

160 -

169

170 -

179

180 -

189

190 -

199

Age Classes

Fre

quen

cy

Stagnation!

Undated samples were very useful!

0

1

2

3

4

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Interval

Fre

quency

Mean Fire Interval 8 yrsMedian Fire Interval 6Weibull Modal Interval (MOI) 5Weibull Median Interval (MEI) 7

Lower Exceedance Interval (LEI) 3Upper Exceedance Interval (UEI) 13Maximum Hazard Interval (MHI) 81

Preliminary statistics on fire history in TMP stands of the Great Smoky Mountains National Park

Major Conclusions

1. Living TMP crossdate very well = great potential.

2. Older dead and downed more difficult.

3. Age structure shows peaks in 60-69 and 70-79 classes.

4. Little to no regeneration is occurring in these stands.

5. Fire history information can be obtained even on undated samples.

6. Fires occurred ca. every 6-7 years in pre-park era.

7. Maximum Hazard Interval indicates conditions in these park stands are strongly conducive to burning.

Acknowledgements

Thank you JFSP!

GSMNP, NPS, Mike Jenkins

TVA, Charles Smart

Committee members: Ken Orvis, Sally Horn

Laboratory of Tree-Ring Science

Department of Geography, University of Tennessee

Field and lab help from:

Daniel Lewis, David Mann, Jake Cseke, Beth Atchley, Damian Kolbay, Bill Dennis, Brian Reed