Landscape-scale characteristics of forest tornado damage in mountainous terrain
- 405 Downloads
Landscape patterns created by natural disturbance such as windstorms can affect forest regeneration, carbon cycling, and other ecological processes.
We develop a method for remotely measuring tornado damage severity and describe landscape-scale patterns of tornado damage. We examine the extent and distribution of damage severity and gaps created by tornadoes, and examine how topographic variation can influence tornado damage severity.
Focusing on two April 2011 tornadoes that struck the Chattahoochee National Forest (CNF) in Georgia and the Great Smoky Mountains (GSM) in Tennessee, we used supervised classification of aerial photographs to map damage severity. We report the extent and distribution of damage severity from each track and characterize patterns of damage using FragStats. Using topographic overlays, we test hypotheses regarding how physiographic features such as valleys and ridges affect tornado damage severity.
Tornado damage severity estimates were significantly correlated with ground-truth measurements. The 64-km CNF track damaged 1712 ha (>25 % severity), while the 26-km GSM track damaged 1407 ha. Tornado damage severity was extremely variable and frequency of gap sizes drastically decreased with size, with many small gaps and few very large gaps, consistent with other types of wind damage. Damage severity declined as tornadoes ascended ridges and increased as they descended ridges. This effect was more consistent on shallow slopes relative to steeper slopes.
This study outlines an objective methodology for remotely characterizing tornado damage severity. The results from this study fill an important gap in ecological understanding of the spatial components of the forest tornado disturbance regime.
KeywordsBlowdown Disturbance Landscape pattern Remote sensing Topography Tornado damage
The authors would like to thank Paul Super, Tom Troutman, and the staff of Great Smoky Mountains National Park for their support and cooperation and all who participated in fieldwork including Michael Bailey, Meredith Barrett, Patrick Johnson, Sophia Kim, Uma Nagendra, Nick Richwagen, Luke Snyder, and Andrei Stanescu. We also thank Daniel Markewitz, Richard Lankau, Joseph O’Brien, and three anonymous reviewers for their helpful comments on the manuscript. This study was made possible by grants from the National Park Service’s Climate Change Youth Initiative and the University of Georgia, Department of Plant Biology, and by grants from the National Science Foundation in Ecology (DEB1143511) and Meteorology (AGS1141926).
- Congalton RG, Green K (2009) Assessing the accuracy of remotely sensed data—principles and practices, 2nd edn. CRC Press, Taylor Francis Group, Boca RatonGoogle Scholar
- ESRI (2011) ArcGIS Desktop Release 10. Environmental Systems Research InstituteGoogle Scholar
- Forbes GS (1998) Topographic influences on tornadoes in Pennsylvania. Preprints, 19th conference on severe local storms. Minneapolois, MN, American Meteorological Society, 269–272Google Scholar
- Godfrey CM, Peterson CJ (2014) Estimating enhanced Fujita scale levels based on forest damage severity. Preprints, 24th Conference on severe local storms: the current state of the science and understanding impacts. Atlanta, GA, American Meteorological Society, P832Google Scholar
- Lewellen DC (2012) Effects of topography on tornado dynamics: a simulation study. Preprints, 26th conference on severe local storms. Nashville, TN, USA, American Meterological Society, 4B.1Google Scholar
- Lyza AW, Knupp K (2014) An observational analysis of potential terrain influences on tornado behavior. In: 27th Conference on severe local storms. American Meteorolgoical Society, Madison, WI. 11A.1AGoogle Scholar
- McGarigal K, Cushman SA, Ene E (2012) FRAGSTATS v4: Spatial pattern program for categorical and continuous maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at http://www.umass.edu/landeco/research/fragstats/fragstats.html
- Nagendra UJ, Peterson CJ (2015) Plant-soil feedbacks differ in intact and tornado-damaged areas of the southern Appalachian mountains, USA. Plant Soil 4:1–14Google Scholar
- NOAA (2011) Service Assessment: the historic tornadoes of April 2011. Available at http://www.nws.noaa.gov/om/assessments/pdfs/historic_tornadoes.pdf
- Nowacki G, Kramer M (1998) The effects of wind disturbance on temperate rain forest structure and dynamics of southeast AlaskaGoogle Scholar
- Peterson CJ, Godfrey CM (2014) Side-by-side tree and house damage in the May 2013 Moore, OK EF-5 tornado: lessons for the enhanced Fujita scale. Preprints, 24th Conference on Severe Local Storms, Atlanta, GA, American Meteorological Society, P831Google Scholar
- Pickett STA, White PS (1985) The ecology of natural disturbance and patch dynamics. The ecology of natural disturbance and patch dynamics. Academic Press, Orlando, pp 3–13Google Scholar
- Storm Prediction Center (2012) The online tornado FAQ. In: The National Oceanic and Atmospheric Administration. http://www.spc.noaa.gov/faq/tornado/. Accessed 26 Nov 2012
- U.S. Geological Survey (2015) The National Map: 3D elevation program. http://viewer.nationalmap.gov
- Vaillancourt M-A, De Grandpré L, Gauthier S, Kneeshaw D, Drapeau P, Bergeron Y (2009) How can natural disturbance be a guide for forest ecosystem management? In: Gauthier S, Vaillancourt M-A, Leduc A, De Grandpré L, Kneeshaw D, Morin H, Drapeau P, Bergeron Y (eds) Ecosysteme management in the boreal forest. Presses de l’Université du Québec, Montreal, pp 39–55Google Scholar
- White PS, Jentsch A (2001) The search for generality in studies of disturbance and ecosystem dynamics. Ecosystems 62:399–450Google Scholar