The Response of Understory Species Composition, Diversity, and Seedling Regeneration to Repeated Burning in Southern Appalachian Oak-hickory Forests
RESEARCH ARTICLE ABSTRACT: Understory plant composition and diversity levels in oak-hickory (Quercus-Carya) forests have historically been maintained by periodic low-intensity ground fires, but fire suppression has altered the structure and function of these communities. We examined burned and unburned oak"hickory stands to determine the influence of repeated burning on understory communities. We compared understory • herbaceous, shrub, and tree species diversity and composition among four bum categories: unburned stands, and stands that had burned once, twice, and three times over a 20-year period (late 1960s to The Response of late 1980s). We hypothesized that stands that have received repeated bums will have greater understory diversity and reduced importance of shade-tolerant mesophytic species. We found that burned stands had Understory Species greater species richness than unburned stands, regardless of burn frequency. Species composition was not drastically different among the four bum categories; however, individual species were indicative of Composition, particular bum categories. More forest herbs were associated with the single bum category, while more disturbance-dependent species (Desmodium spp. and Solidago spp.) were associated with the repeated Diversity, bum categories. Burned stands contained greater densities of white oak (Quercus alba L.) and hickory species seedlings. Our results suggest that restoring and maintaining the historic fire return interval and Seedling (10-15 years) will promote herbaceous species diversity and favor the regeneration of oak and hickory species. However, it has been 15-22 years since the stands we sampled last burned, and the similarity RegenerationIQ among bum categories suggests that additional burning is needed -to prevent these stands from reverting Repeated Burning to a suppressed condition. in Southern Ii1dex terms: Cmya, central hardwoods, fire, herbaceous, Quercus ...... Appalachi
Volume 29 (3),2009 Natural Areas Journal 255 stands (Wendel and Smith 1986; McGee METHODS L.), black oak (Quercus velutina Lam.), et al. 1995; Nuzzo et al. 1996; Elliot et al. red oak (Quercus rubra L.), scarlet oak 1999; Kuddes-Fischer and Arthur 2002; (Quercus coccinea Munchh.), red maple, Study site Hutchinson et al. 2005). This research has yellow poplar (Liriodendron tulipifera L.), improved understanding of how woody mockernut hickory (Carya alba L.), and Established in 1934, GSMNP is a mostly species mortality and regeneration respond pignut hickory (Carya glabra Mill.). The forested reserve that encompasses over to fire (Wendel and Smith 1986; Ebinger midstory was primarily composed of red 2000 km2 in eastern Tennessee and western 1988; Kruger and Reich 1997; Arthur et maple, striped maple (Acer pensylvanicum North Carolina. Complex ecological gradi al. 1998; Blankenship and Arthur 2006) L.), flowering dogwood (Comus florida ents combine to create a diverse mosaic of and how understory vegetation, including L.), blackgum (Nyssa sylvatica Marsh.), plant communities comprised of over 1600 herbaceous species, respond to single (El and sourwood (Oxydendrun arboreum native species, including over 200 species liot et al. 1999; Kuddes-Fischer and Arthur L.) saplings. Refer to Holzmueller et al. of trees and shrubs. The Park is interna 2002) and repeated burns (McGee et al. (2008) for a more detailed description of tionally renowned as a center of biological 1995; Nuzzo et al. 1996; Franklin et al. the study site. diversity within North America and was 2003; Hutchinson et al. 2005). Generally, designated as an International Biosphere these studies have found that fire reduces Reserve in 1976. Because of its biotic Field Sampling understory density, produces a short-term diversity, large size, and protected status, increase in herbaceous cover, and reduces GSMNP plays an important role in biologi Areas of the Park that burned during the the importance of mesophytic species. cal conservation within the eastern United late 1960s to 1980s and contained oak However, these studies examined the ef States. Biological communities of GSMNP hickory forest types (White et al. 2003) fects of small, often experimental, burns often serve as benchmarks for other state were identified prior to plot establishment « 40 ha) conducted at a limited number and federal conservation lands. using a map of vegetation communities of sites (maximum of four) distributed (Madden et al. 2004), historic disturbance across a limited spatial range. While there Within GSMNP, oak-hickory forest com maps, and fire history records. We sampled is great value in studies that focus on prises approximately 31 % (64,600 ha) of seventy-nine 0.04 ha (20-m x 20-m) plots repeated measurements from spatially total forest cover (Madden et al. 2004). within 20 burned and unburned areas during discrete burns, more information is needed Prior to Park establishment in 1934, these June-August of 200 1-2004 (Holzmueller et about how understory vegetation responds oak-hickory forests burned periodically, al. 2008). Fifty-five plots were randomly to repeated burns of varying size distrib with an average fire return interval of established in 14 stands that had burned up uted across large and variable geographic 10-15 years (Harmon 1982). As observed to three times over a 20-year period (late areas. Restoring fire to fire-suppressed throughout eastern North America, how 1960s to the late 1980s). In addition, 24 ecosystems can have unpredicted effects ever, fires within GSMNP have been heav reference plots were randomly established (Varner et al. 2005), and understanding the ily suppressed since Park establishment in six nearby unburned stands that had potential variability at a landscape scale is (Harmon 1982). similar slopes, aspects, topography, and critical to restoration success. vegetation associations to the burn plots. Study site elevation ranged from 287 to 975 Sampled areas were divided into four burn The objective of this study was to examine m, and plots were located on moderately categories: (1) unburned (six stands, 24 herbaceous, shrub, and tree seedling spe steep to steep slopes (45% ± 1.8%; mean plots); (2) single burn (seven stands, 30 cies composition in unburned and burned ± 1 SE) with aspects ranging clockwise plots); (3) double burn (four stands, 16 areas to determine how understory veg from SE (135°) to NW (315°). Predominant plots); and (4) triple burn (three stands, etation in oak-hickory forests responds to soil series included Cataska-Sylco com nine plots). Four 3.l6-m x 3.l6-m nested repeated burning~ We collected vegetation plex (Typic Dystrudepts), Ditney-Unicoi subplots 00 m2) were placed within the data from a chronosequence of burned sites complex (Typic Dystrudepts and Lithic corners of each 20-m x 20-m plot. All ranging in size from 10 to 120 ha and in fire Dystrudepts), Junaluska-Tsali complex understory « 1.4 m tall) herbaceous, shrub/ frequency from 1 to 3 burns in a 20-year (Typic Hapludults), and Soco-Stecoah vine (hereafter shrub), and tree vegetation period. Sampled burns were distributed complex (Typic Dystrudepts). These soils within these subplots was identified. Cover across Great Smoky Mountains National are well-drained and are typical of ridges and stem density of each understory shrub Park (GSMNP). We hypothesized that and sideslopes in the Southern Appalachian and tree species and cover of each herba stands that have received repeated burns Mountain region (USDA-NRCS 2008). ceous species was estimated within each 10 will have greater understory diversity m2 subplot. Cover was estimated visually and reduced importance of shade-tolerant All study sites were located in secondary using a modified Daubenmire scale (1 = mesophytic species. We also hypothesized forests that were logged prior to Park estab Few; 2 Few-l %; 3 1-2%; 4 2-5%; that repeated burning will increase the = = = lishment (Pyle 1988). Overstory composi 5 = 5-10%; 6 = 10-25%; 7 = 25-50%; 8 density of advanced regeneration of oak tion was dominated by chestnut oal< (Quer 50-75%; 9 75-95%; 10 95-100%) and hickory species. = = = cus prinus L.), white oak (Quercus alba (Daubenmire 1959; Peet et al. 1998).
256 Natural Areas Journal Volume 29 (3), 2009 Data analysis richness was similar among the four burn seedling species richness, evenness, and categories (P = 0.40); however, evenness Shannon's diversity index (Figure 1; P> Understory herbaceous, shrub, and tree and Shannon's diversity index was great 0.18). When herbaceous, shrub, and tree species values from the four subplots est in the single and triple burn categories seedling species were combined, species were averaged for each main plot. Total and lowest in the double burn category richness was greater in burned stands (28 sluub and tree seedling species density, (Figure 1). There was a significant differ taxa) compared to unburned stands (22 density of selected tree seedling spe ence in shrub species richness, evenness, taxa; P = 0.03). Combined evenness and cies, and herbaceous, shrub, and tree and Shannon's diversity index between Shannon's diversity index, however, did seedling cover were analyzed using burn categories (Figure 1; P < 0.05), but not differ among the four burn categories ANOVA (mixed model procedure; SAS there was no significant difference in tree (Figure 1; P = 0.50). 2004). Species richness, evenness, and Shannon's diversity index were calcu lated for herbaceous, shrub, and tree seedling species with PC-ORD (McCune A. 35 a a a and Mefford 1999) and also analyzed II) 30 II) with ANOVA (mixed model procedure; OJ c: 25 SAS 2004). The mixed model ANOVA ..c: u 20 was comprised of two factors; factor ';: one (frequency of fire, hereafter refened II) 15 OJ to as "burn category") was fixed, and '0 factor two (burn area, nested within OJ 10 Q. . burn category factor) was random. V) 5 The sample size for the mixed model ANOVA was 20 (number of burned and o unburned areas). When ANOVA revealed Total Herbaceous Tree seedling Shrub a significant difference between the four 1.0 burn categories (unburned, single burn, B. double burn, and triple burn), we used the probability of difference (PDIFF) op 0.8 II) tion for post-hoc pairwise comparisons II) OJ 0.6 (SAS 2004). Indicator species analysis c: was used to describe the relationship c: OJ 0.4 of species to categorical variables by combining species abundance in a ai specific category plus the faithfulness 0.2 of OCCUlTence of that species in that specific category (Dufrene and Legen 0.0 dre 1997; Peterson and McCune 2001). Total Herbaceous Tree seedling Shrub The analysis produces a value (IndVal) c. of abundance for each species in each 3.0 ~ "C group and a test statistic produced from .E 2.5 Monte Carlo tests (1000 iterations) to ~ a ab determine if occurrence in the maximum 'iii... 2.0 (indicator) group is greater than would ~ 1.5 be expected from chance. :.c UI -c 1.0 o RESULTS E 0.5 ro .c VI 0.0 Species diversity Total Herbaceous Tree seedling Shrub Of the 138 taxa sampled and used in the species diversity analysis, siXty-eight (49%) FIGURE 1. Measures (mean ± 1 SE) of (A) species richness, (B) evenness, and (C) Shannon's diversity of those taxa were herbaceous, twenty-six index (McCune and Mefford 1999) among the four burn categories for four groups: all species (total), (19%) were slu'ubs, and forty-four (32%) herbaceous species, tree seedling species, and shrub species. Different letters following means for each were tree seedlings. Herbaceous species species group indicate a significant difference among the four burn categories (P < 0.05).
Volume 29 (3), 2009 Natural Areas Journal 257 Indicator species analysis TABLE 1. Indicator values (percent of perfect indication) for understory vegetation (herbaceous, shrub/vines, and tree seedling species) and associated burn category. P-value represents the proportion The indicator species analysis revealed of randomized trials with an indicator value equal to or exceeding the observed indicator value. differences in herbaceous-layer taxa com position among the four burn categories (Table 1). Overall, there were 22 taxa Species Indicator Indicator p_ Species identified as indicator species (P < 0.05). type group value value Eight herbaceous taxa were identified as Galax urceolata Herbaceous Unburned 30.2 0.05 indicator species, and a majority of those taxa identified occurred in the single burn Dioscorea category (Table 1). Beetleweed (Galax ur quaternata Herbaceous Single burn 32.2 0.03 ceo lata Poir.), however, was identified as an Houstonia indicator species in the unburned category species Herbaceous Single burn 16.7 0.04 (IndVaI30.2, P =0.05). Tick-trefoil species Lysimachia (Desmodium Desv. spp.) were indicative of quadrifolia Herbaceous Single burn 20.0 0.02 the double burn category (lndVal 57.2, P < Maianthemum 0.01), while goldenrod species (Solidago racemosum Herbaceous Single burn 50.1 <0.01 L. spp.) were indicative of the triple burn category (IndVal 35.7, P = 0.02). Polygonatum biflorum Herbaceous Single burn 20.7 0.04 Seven shrub taxa were identified as in Desmodium spp. Herbaceous Double burn 57.2 <0.01 dicator species (Table 1). All but one of Solidago spp. Herbaceous Triple burn 35.7 0.02 these taxa, poison ivy (Toxicodendron radicans L.), were indicator species in the triple burn category. Plots in the triple Toxicodendron burn category had the highest level of radicans Vine Double burn 29.2 0.04 disturbance and taxa identified as indica Rhus copallinum Shrub Triple burn 33.3 <0.01 tor species, including Virginia creeper Vaccinium (Parthenocissus quinquefolia L.), winged arboreum Shrub Triple burn 20.5 0.02 sumac (Rhus copallinum L.), farkleberry Vaccinium (Vaccinium arboretum Marsh.), highbush corymbosum Shrub Triple burn 30.0 blueberry (Vaccinium corymbosum L.), 0.03 lowbush blueberry (Vaccinium pallidum Vaccinium Alton), and grape species (Vitis L. spp.) pallidum Shrub Triple burn 35.0 0.05 have been documented as responding well Parthenocissus to disturbances, particularly fire (USDA quinquefolia Shrub Triple burn 63.4 <0.01 Forest Service 2008). Vitis spp. Vine Triple burn 43.9 0.04
Striped maple and eastern hemlock, shade tolerant species commonly found Acer Tree in undisturbed areas, were indicative of pensylvanicum seedling Unburned 31.9 0.04 the unburned category (Table 1; P <0.04). Tsuga canadensis Tree Species more tolerant of disturbance were seedling Unburned 37.6 0.03 indicative of burned stands, including red Acerrubrum Tree maple in the single burn category, white oak seedling Single burn 41.0 0.03 and red oak in the double burn category, Quercus rubra Tree and mockernut hickory and black locust (Robinia pseudoacacia L.) in the triple seedling Double burn 35.7 0.03 burn category (Table 1). Caryaalba Tree seedling Triple burn 32.9 0.02 Shrub and tree seedling density Robinia Tree pseudoacacia seedling Triple burn 28.8 0.05 Because of high plot variability, mean shrub and tree seedling density did not 0.15). In addition, no significant difference mean shrub and tree seedling densities were differ among burn categories (Table 2; P > was found among the burn categories when combined and analyzed together (Table
258 Natural Areas Journal Volume 29 (3), 2009 TABLE 2. Mean C± 1 SE) shrub and tree seedling density and mean herbaceous, shrub, aud tree seedling cover among the fonr burn categories.
Unburned Single burn Double burn Triple burn P-value Density (seedlings-l ha-l) Shrub 18200 (5200) 24200 (5100) 11000 (6900) 37000 (9000) 0.15 Tree seedlings 27200 (4600)* 37500 (6100)* 30000 (8200)* 22000 (10000) 0.53 Total density 45400 (9000) 61700 (8300) 41000 (11100) 59000 (14300) 0.34 Cover (%) Herbaceous 5.8 (1.7) 6.4 (1.6) 12.8 (2.2) 3.7 (2.8) 0.19 Shrub 9.9 (4.2) 16.0 (3.8) 5.1 (5.2) 16.9 (6.3) 0.22 Tree seedlings 6.6(3.1) 11.0 (2.8) 6.1 (3.8) 6.1 (4.7) 0.89 Total cover 22.3 (6.0) 33.4 (5.5) 24.0 (7.5) 26.7 (9.2) 0.63
lIndicates a significant difference (P < 0.05) between tree and sluub density
2; P = 0.34). When mean tree seedling values ranged from 22.3% coverage (un attributed these changes to resprouting of density was compared to mean shrub burned) to 33.4% coverage (single burn). the dominant species and lack of ruderal density within each burn category, mean Significant difference among burn catego species persistence as the interval since the tree seedling density was greater than mean ries, however, was not observed (Table 2; last burn increased. In our study, a majority shrub density for the unburned, single, P = 0.63). of the species inventoried have the ability to and double burn categories (Table 2; P < resprout, and the amount of time since the 0.02); however, no difference was found last burn may have been long enough for DISCUSSION between mean tree seedling and mean understory species composition to return shrub density in the triple burn category to pre-burn conditions. The results of our study show that past (Table 2; P = 0.59). burning has had a subtle, but clearly Although differences in overall species discernable, effect on understory vegeta The difference in seedling density of a composition were slight, burn frequency tion composition. Although it has been select group of species (oak and hickory did appear to have a pronounced effect on 15-22 years since the stands we sampled species) among the four burn categories the frequency and abundance of multiple last burned, we observed greater species was also tested (Figure 2). White oak taxa. For example, beetleweed, a shade richness in the burned stands. In addition, density was greater in the double burn tolerant herbaceous species that thrives according to indicator species analysis, a category compared to the single and in undisturbed oak-hickory forests, was greater number of taxa were indicative of unburned burn categories (Figure 2; P < indicative of unburned stands. The single past burning. However, the long interval 0.04); however, other oak speCies densities burn-category had the greatest number of since the stands last burned has likely al did not differ among the burn categories indicator species, including a mix of taxa lowed homogenization among burn catego (Figure 2; P > 0.62). Mockernut hickory that are typically associated with distur ries. The slight differences in understory density was greatest in the double and triple bance [wild yam (Dioscorea quaternata community composition despite differ burn categories compared to the single IF. Gmel.), bluet species (Houstonia L. ences in burn frequency are potentially and unburned categories (P < 0.02), while spp.), and whorled yellow loosestrife explained by several factors. Hutchinson pignut hickory was greater in the single (Lysimachia quadrifolia L.)] and with et al. (2005) attributed lack of community burn category compared to the unburned shaded forest conditions [false Solomon's differences in understory vegetation in category (Figure 2; P < 0.05). seal (Maianthemum racemosum L.) and burned and unburned stands to dormant Solomon's seal (Polygonatum bifiorum season burns (before the emergence of Walter)] (White et al. 2003). Taxa from Species cover most perennial species) and low fire in two genera that are often associated with tensity in a mixed-oak forest in southern disturbance and high light conditions, There was no significant difference found Ohio. In an oak-hardwood stand in New Desmodium and Solidago, were associated among the burn categories in herbaceous, York, McGee et al. (1995) reported minor with double and triple burns, respectively sluub, or tree seedling cover (Table 2; P composition differences in understory (Reid 1964; Goldberg and Werner 1983), > 0.19). When shrub, tree seedling, and vegetation 8-12 years following 0, 1, or 2 and prescribed burning may be used to herbaceous cover values were combined, springtime prescribed fires. The authors
Volume 29 (3), 2009 Natural Areas Journal 259 increase the abundance and persistence the overstory and midstory of multiple use of prescribed fire to increase oak and of these herbaceous taxa (Huang et al. burn stands and a greater frequency and hickory regeneration because, typically, 2007). Most shrub species were indica abundance of mesophytic, shade tolerant single prescribed burns will not reduce tive of stands with a high burn frequency species in unburned stands. Holzmueller competition enough for oak and hickory (triple burn plots). While repeated burning et al. (2008) reported decreased overstory regeneration to succeed (Arthur et al. 1998; has been shown to reduce the density of stem density in burned stands, which po Holzmueller et al. 2008). While white oak shrubs and saplings (Blake and Schuette tentially increased light availability on the and hickory species continue to have higher 2000), prolific sprouting occurs if regular forest floor. This suggests that past burn seedling densities in the burned stands we burning ceases (Matlack et al. 1993; McGee ing favored the successful reproduction sampled, these seedlings are unlikely to et al. 1995; Blankenship and Arthur 2006). of oak and hickory species by increasing advance above the seedling layer in the Seedlings of individual tree species were light availability and reducing competition absence of additional burning. also indicative of burn categories. Shade from fire-intolerant species. In a study tolerant species such as eastern hemlock of understory response to disturbance, CONCLUSION and striped maple were indicator species Dolan and Parker (2004) reported greater of the unburned category, while fire toler photosynthetically active radiation levels Although it has been 15-22 years since the ant species such as white oak, red oak, reaching the forest floor on burned plots stands we sampled last burned, the results and mockernut hickory were indicative compared to unburned plots in a mesic oak of our study suggest that repeated burning of multiple burn categories. In addition, hickory forest in Indiana. Increased light may have long-lasting effects on understory black locust, a shade intolerant species availability would favor shade intolerant community composition and density of oak commonly found on frequently disturbed species, such as oak and hickory species. and hickory seedlings. Maintaining the sites, was indicative of the triple burn However, merely increasing light availabil historic fire regime interval (10-15 years) category. ity to the forest floor does not correspond of oak-hickory forests is necessary to stop to an increase in oak and hickory species the shift of these forests towards more The density of white oak and hickory spe regeneration. For example, silvicultural mixed-me sophy tic, shade-tolerant compo cies seedlings was greater in burned stands, treatments can increase light availability, sition. In addition, repeated burning may even though 15-22 years had passed since but research indicates that in order for increase understory species richness and the stands we sampled had last burned. oak and hickory advanced regeneration to promote herbaceous species, such as naked In a companion study that sampled the succeed, competition must also be reduced tree tick-foil, as well as the abundance of same stands, Holzmueller et al. (2008) with fire (Franklin et al. 2003; Albrecht desirable woody species, such as white reported greater frequency and abundance and McCarthy 2006). Furthermore, mul oak and hickory species. Furthermore, the of multiple oak and hickory species in tiple studies have recommended frequent
5000 o Unburned • Single burn 4000 ..t o Double burn Ires ..c III Triple burn I/) 3000 tl.O .-C "ts 2000 CIJ CIJ Vl 1000
0 Quercus alba Quercus prinus Quercus rubra Quercus velutina Carya alba Carya glabra Species
FIGURE 2. Mean (± 1 SE) seedling density of select oak and hickory species among the four burn categories. Different letters following means for each species indicate a significant difference among the four burn categories (P < 0.05).
260 Natural Areas Journal Volume 29 (3),2009 results indicate that repeated burning can of oak forests. BioScience 42:346-353. Forest Service, Southern Research Station, be used to restore and maintain the oak Albrecht, M.A., and B.C. McCarthy. 2006. Ef Asheville, N.C. hickory forest type in areas such as national fects of prescribed fire and thinning on tree Dufrene, M., and P. Legendre. 1997 Species parks, where intensive silviculture may not recruitment patterns in central hardwood assemblages and indicator species: the be an option for managers. forests. Forest Ecology and Management need for a flexible asymmetrical approach. 226: 88-103. Ecological Monographs 67:345-366. Aldrich, P.R., G.R. Parker, J.S. Ward, and C.H. Ebinger, J.E. 1988. Woody understory after a ACKNOWLEDGMENTS Michler. 2003. Spatial dispersion of trees in spring burn at the Rocky Branch Nature an old-growth temperate hardwood forest Preserve, Clark County, Illinois. Transac We thank the National Park Service South over 60 years of succession. Forest Ecology tions of the Illinois Academy of Science east Region Natural Resources Preserva and Management 180:475-491. 81:25-30. tion Program, Great Smoky Mountains Arthur, M.A, RD. Paratley, and B.A Blanken Elliott, K.J., RL. Hendrick, AE. Major, J.M. Association, and the University of Florida ship. 1998. Single and repeated fires affect Vose,and W.T. Swank. 1999. Vegetation College of Agriculture and Life Sciences survival and regeneration of woody and dynamics after a prescribed fire in the herbaceous species in an oak-pine forest. southern Appalachians. Forest Ecology and for providing funding for this project. We Journal of the Torrey Botanical Society Management 114: 199-213. also thank the faculty at the IFAS-Statistics 125:225-236. , Franklin, S.B., P.A Robertson, and J.S. Fralish. Division for their help in data analyses. Beck, D.E., and R.M. Hooper. 1986. Develop 2003. Prescribed burning effects on upland Huma Alverado, Kim Biedermann, Beth ment of a southern Appalachian hardwood Quercus forest structure and function. Forest any Bins, Jennifer Griggs, Travis Martin, stand after cIearcutting. Southern Journal Ecology and Management 184:315-335. Hanni Muerdter, Playalina Nelson, Art of Applied Forestry 10: 168-172. Goldberg, D.E., and P.A Werner. 1983. The vonLehe, Jeremy Volkening, and Mark Blake, J.G., and B. Schuette. 2000. Restoration effects of size of opening in vegetation Whited assisted with fieldwork. of an oak forest in east-central Missouri: and litter cover on seedling establishment early effects of prescribed fire on woody of goldenrods (Solidago spp.). Oecologia vegetation. Forest Ecology and Management 60:149-155. Eric Holzmueller is an Assistant Professor 139: 1.09-126. Harmon, M.E. 1982. Fire history of the west of Forest Management and Ecology in the Blankenship, B.A, and M.A Arthur. 2006. ernmost portion of Great Smoky Mountains Department ofForestry at Southern illinois Stand structure over 9 years in burned and National Park. Bulletin of the Torrey Botani fire"excIuded oak stands on the Cumberland cal Club 109:74-79. University. His research focuses on the Plateau, Kentucky. Forest Ecology and ecology of central hardwood forests and HolzmuelIer, E.J., S. Jose, and M.A Jenkins. Management 225:134-145. 2008. The relationship between fire history the effects of exotic pests and pathogens Boerner, RE,J., AT. Coates, D.A Yaussy, and and an exotic fungal disease in a deciduous on forest communities. T.A Waldrop. 2008. Assessing ecosystem forest. Oecologia 155:215-403. restoration alternatives in eastern decidu Huang, J., R.E.J. Boerner, and J. Rebbeck. 2007. Shibu Jose is a Professor of Forest Ecol ous forests: the view from belowground. Ecophysiological responses of two herba ogy in the School of Forest Resources and Restoration Ecology doi: 1O.1111/j .1526- ceous species to prescribed burning, alone Conservation at the University ofFlorida. 100X.2007.00312.x. or in combination with overstory thinning. His research efforts focus on production Brose, P., T. Schuler, D. Van Lear, and J. Bersr. American Journal of Botany 94:755-763. ecology and ecophysiology of intensively 2001. Bring fire back: the changing regimes Hutchinson, T.E, RE. Boerner, S. Sutherland, managed pine and hardwood forests, of the Appalachian mixed-oak forests. Jour~ E.K. Sutherland, M. Ortt, and L.R. Iverson. nal of Forestry 99:30-35. restoration ecology of the longleaf pine 2005. Prescribed fire effects on the herba ecosystem, invasive plant ecology and Brose, P.H., and D.H. Van Lear. 1998. Response ceous layer of mixed-oak forests. Canadian of hardwood regeneration to seasonal pre Journal of Forest Research 35:877-890. management, and ecological interactions scribed fires in oak-dominated shelterwood in tree-crop mixed systems and mixed spe Jenkins, M.A, and G.R Parker. 1998. Compo stands. Canadian Journal of Forest Research sition and diversity of woody vegetation in cies forest plantations. 28:331-339. silvicultural openings of southern Indiana Crow, T.R. 1988. Reproductive mode and forests. Forest Ecology and Management Mike Jenkins is 'an Assistant Professor , mechanisms for self-replacement of northern 109:57-74. of Forest Ecology in the Department of red oak (Quercus rubra) - a review. Forest Jenkins, M.A., and P.S. White. 2002. Comus Forestry and Natural Resources at Purdue Science 34:19-40. florida mortality and understory composition University. His researchfocuses on the in Daubenmire, RE 1959. 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Volume 29 (3),2009 Natural Areas Journal 261 cal recommendations. General Technical McGee, G.G., DJ. Leopold, and R.D. Nyland. western Maryland, U.S.A. Canadian Journal Report SE-48, United States Forest Service, 1995. Understory response to springtime of Forest Research 31:1437-1443. Southeastern Forest Experiment Station, prescribed fire in two New York transition Smith, B.w., P.D. Miles, J.S. Vissage, and S.A. Asheville, N.C. oak forests. Forest Ecology and Manage Pugh. 2004. Forest resources of the United Kruger, E.L., and P.B. Reich. 1997. Responses ment 76:149-168. States, 2002. General Technical Report NC- of hardwood regeneration to fire in mesic Nuzzo, V.A., W. McClain, and T. Strole. 1996. 241, United States Forest Service, North forest openings. 1. Post-fire community dy Fire impacts on groundlayer flora in a sand Central Research Station, St.· Paul, Minn. namics. Canadian Journal of Forest Research forest 1990-1994. American Midland Natu [USDA Forest Service] U.S. Department of 27: 1822-1831. ralist 136:207-221. Agriculture, Forest Service. 2008. Fire Ef Kuddes-Fischer, L.M., and M.A. Arthur. 2002. Ozier, T.B., J.w. Groninger, and C.M. Ruffner. fects Information System, [Online]. United Response of understory vegetation and tree 2006. Community composition and struc States Forest Service, Rocky Mountain regeneration to a single prescribed burn tural changes in a managed Illinois Ozark Research Station, Fire Sciences Laboratory in oak-pine forests. Natural Areas Journal Hills Forest. American Midland Naturalist (Producer). Available online http://www. 22:43-52. 155:253-269. fs.fed.us/database/feis. Accessed 19 March Lorimer, C.G. 1984. Development of the red Peet, R.K., T.R. Wentworth, and P.S. White. 2008. maple understory in northeastern oak forests. 1998. A flexible, multipurpose method [USDA-NRCS] U.S. Department of Agricul Forest Science 30:3-22. for recording vegetation composition and ture, Natural Resources Conservation Ser Lorimer, C.G., J.W. Chapman, and W.D. structure. Castanea 63:262-274. vice. 2008. Soil survey geographic database Lambert. 1994. Tall understory vegetation Peterson, E.B., andB. McCune. 2001. Diversity for Great Smoky Mountains National Park, as a factor in the poor development of oak and succession of epiphytic macrolichen Tennessee and North Carolina. U.S. Depart seedlings beneath mature stands. Journal of communities in low-elevation managed ment of Agriculture, Natural Resources Ecology 82:227-237. conifer forests in western Oregon. Journal Conservation Service, Fort Worth, Tex. Madden, M., R. Welch, T. Jordan, and P. of Vegetation Science 12:511-524. Varner, Ill, J.M., D.R. Gordon, EE. Putz, and Jackson. 2004. Digital vegetation maps for Pyle, C. 1988. The type and extent of anthro J.K. Hiers. 2005. Restoring fire to long Great Smoky Mountains National Park: final pogenic vegetation disturbance in the Great unburned Pinus palustris ecosystems: novel report. Center for Remote Sensing and Map Smoky Mountains before National Park fire effects and consequences for long-un ping Science, Department of Geography, Service acquisition. Castanea 53:183-196. burned ecosystems. Restoratiori Ecology 13:536-544. University of Georgia, Athens. Pyne, S.J. 1982. Fire in America. University of Matlack, G.R., DJ. Gibson, and R.E. Good. Washington Press, Seattle. Wendel, G.w., and H.C. Smith. 1986. Effects of a prescribed fire on a central Appala 1993. Regeneration of the shrub Gaylus Reid, A. 1964. Light intensity and herb growth chian oak-hickory stand. NE-RP-594, U.S. sacia baccata and associated species after in white oak forests. Ecology 45:396-398. low-intensity fire in an Atlantic Coastal Department of Agriculture, Forest Service, Ruffner, C.M., and J.w. Groninger. 2006. Plain forest. American Journal of Botany Northeastern Forest Experiment Station, Making the case for fire in southern Illinois 80:119-126. Broomall, Pa. forests. Journal of Forestry 104:78-83. McCune, B., and M.J. Mefford. 1999. PC White, R.D., K.D. Patterson, A. Weakley, CJ. SAS Institute. 2004. Version 9.1. SAS Institute, ORD. Multivariate analysis of ecological Ulrey, and J. Drake. 2003. Vegetation clas Cary, N.C. data. Version 4.0. MjM Software, Gleneden sification of Great Smoky Mountains Na Beach, Ore. Shumway, D.L., M.D. Abrams, and C.M. Ruff tional Park. Report submitted to BRD-NPS ner. 2001. A 400-year history of fire and oak Vegetation Mapping Program. NatureServe, recruitment in an old-growth oak forest in Durham, N.C.
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