Use prescribed burning in combination with herbicide application

Supporting evidence from individual studies

1. A replicated, randomized, controlled study in 1997–1998 of pine sandhills in Florida, USA (Litt et al. 2001) found that burning in combination with herbicide had mixed effects depending on species and year. In one of two burn years, capture rates of six-lined racerunners Cnemidophorus sexlineatus and eastern fence lizards Sceloporus undulatus were lower in plots with burning and herbicide (six-lined racerunners: 0.016 captures/trap days; eastern fence lizards: 0.003) than in burn-only plots (racerunners: 0.037; fence lizards: 0.007), but higher than in unburned plots with no herbicide (racerunners: 0.015; fence lizards: 0.002). In the other year, captures were similar all three treatments (racerunners: 0.011–0.017; fence lizards: 0.001–0.006). In one of two years southeastern crowned snake Tantilla coronata captures were lower in burning with herbicide and burning only plots (0.004–0.005) compared to plots with no burning or herbicide (0.014), but in the other year captures were similar (0.011–0.020). Green anoles Anolis carolinensis were not caught in burning and herbicide plots and were caught a similar amount in burn only and no burning or herbicide plots (0.003). Little brown skink Scincella lateralis captures were similar across all treatments (0.001–0.005).  Treatments (burning with herbicide or burn only) were randomly assigned to 81 ha plots within four replicate blocks. Burn-only treatments were carried out in spring 1995. Herbicide treatments were carried out in 1995 and were then burned in March–April 1997. Data were also collected from four frequently-burned reference sites. Monitoring was undertaken using drift-fencing and pitfall traps in April–August 1997–1998.

   Study and other actions tested

   Referenced paper

   Litt A.R., Provencher L., Tanner G.W. & Franz R. (2001) Herpetofaunal responses to restoration treatments of longleaf pine sandhills in Florida. Restoration Ecology, 9, 462-474.

2. A replicated, randomized, controlled, before-and-after study in 1995–2010 in fire-suppressed longleaf pine Pinus palustris forest in Florida, USA (Steen, Smith, Conner et al. 2013, same experimental set-up as Steen, Smith, Morris et al. 2013) found reptile community composition responded differently to herbicide treatment followed by burning or to burning alone when compared to unburned areas. All results reported as statistical model outputs, see original paper for details. Reptile communities in sites treated with herbicide then burned remained similar to unburned sites and different to areas of pristine habitat (1–2 years post treatment). Reptile communities in sites that were only burned were different to both unburned sites and areas of pristine habitat. After 10–12 years of all sites receiving regular burning, all reptile communities became similar to areas of pristine habitat. See original paper for details of individual species responses to management. Reptiles were monitored in four sites (81 ha each) each managed by: prescribed burning (April–June 1995, 4 sites), using herbicides (May 1995, 4 sites) with burning (1997), or unburned and no herbicide until after 1999 when all sites were burned at 2–3-year intervals. Reptiles were also monitored a further four sites in an area of pristine habitat with a history of regular fires. Reptiles were surveyed using drift fences with pitfall traps (16 traps/site) in April–August 1997–1998 and May–September 2009–2010.

   Study and other actions tested

   Referenced paper

   Steen D.A., Smith L.L., Conner L.M., Litt A.R., Provencher L., Hiers J.K., Pokswinski S. & Guyer C. (2013) Reptile assemblage response to restoration of fire-suppressed longleaf pine sandhills. Ecological Applications, 23, 148-158.

3. A replicated, randomized, controlled, before-and-after study in 1995–2010 in fire-suppressed longleaf pine Pinus palustris forests in Florida, USA (Steen, Smith, Morris et al. 2013, same experimental set-up as Steen, Smith, Conner et al. 2013) found that areas where herbicide was applied prior to regular burning had similar numbers of six-lined racerunners Aspidoscelis sexlineatus compared to unburned areas and fewer than areas of pristine habitat, whereas burn only sites had similar numbers to areas of pristine habitat. Six-lined racerunner abundances were lower in sites treated with herbicide followed by burning (adults: 14 individuals/site; juveniles:  4) and unburned and no herbicide sites (13, 2) compared to burn-only sites (23, 10) or more pristine areas with a history of fires (38, 10). After a further 10–12 years of prescribed burns on all sites, six-lined racerunner abundances were similar in sites managed initially by burning (adult: 40 individuals/site; juvenile: 7), herbicide followed by burning (33, 6) unburned and no herbicide (30, 6) and pristine sites with a history of fires (37, 10). Reptiles were monitored in six sites each (81 ha each) managed by: prescribed burning (April–June 1995, 6 sites), herbicides (May 1995, 6 sites) followed by burning (1997), or unburned with no herbicide until after 1999 when all sites were burned at 2–3-year intervals. Reptiles were also monitored at a further six sites in a more pristine area with a history of fires. Reptiles were surveyed using drift fences with pitfall traps (16 traps/site) in April–August 1997–1998 and May– September 2009–2010. 

   Study and other actions tested

   Referenced paper

   Steen D.A., Smith L.L., Morris G., Mike Conner L., Litt A.R., Pokswinski S. & Guyer C. (2013) Response of six-lined racerunner (Aspidoscelis sexlineata) to habitat restoration in fire-suppressed longleaf pine (Pinus palustris) sandhills. Restoration Ecology, 21, 457-463.

4. A replicated, randomized, controlled, before-and-after study in 1999–2007 in six pine plantations in Mississippi, USA (Iglay et al. 2014) found that prescribed burning in combination with herbicide application did not increase reptile and amphibian richness, diversity or most species abundances compared to burning or herbicide application alone or no management, though eastern fence lizard Sceloporus undulatus abundance was higher in the year after management for all treatment types. In six of seven years after burning and/or herbicide applications, species richness, diversity measures and most species abundances were similar in burn with herbicide, burn only, herbicide only and unmanaged plots (data reported as model outputs, see paper for details). Eastern fence lizard abundance was higher in managed plots (burn with herbicide applied, burn only and herbicide only: 0.02 lizards/plot) in the first year after management compared to unmanaged plots (0.002 lizards/plot). Four 10 ha plots were set up in six intensively-managed, 18–22-year-old commercial pine stands (59–120 ha). Plots were either burned in the dormant season (December–February) in 2000, 2003 and 2006 and treated with herbicide (‘Imazapyr’) in September 1999; burned only; treated with herbicide only; or unmanaged. Reptiles were monitored using drift fences with pitfall and funnel traps in May–June 1999–2007 (one year before management and seven years after management began).

   Study and other actions tested

   Referenced paper

   Iglay R.B., Leopold B.D. & Miller D.A. (2014) Summer herpetofaunal response to prescribed fire and herbicide in intensively managed, mid-rotation pine stands in Mississippi. Wildlife Society Bulletin, 38, 33-42.

5. A replicated, randomized, controlled study in 2014–2015 in six rock and grassland areas in Australian Capital Territory, Australia (McDougall et al. 2016) found that after rocky outcrops were treated with prescribed burns in combination with herbicide application, some were recolonised by Australian pink-tailed worm-lizards Aprasia parapulchella within one year. Results were not statistically tested. Four worm-lizards were observed on plots treated with burning and herbicide, two on burn only plots, and zero were observed on unrestored plots. A further four worm-lizards were observed in nearby high-quality habitat (4 worm-lizards and 3 shed skins observed). In April–May 2014, plots (4 x 4 m) in six replicate sites (150 m apart) were each randomly assigned either burning and herbicide application (burned using a blow torch; one plot/site), burning only (one plot/site) or unburned (two plots/site, one adjacent to managed plots and the second in nearby high-quality lizard habitat). In February 2015, rocks were surveyed for lizards. All sightings or shed skins were recorded.

   Study and other actions tested

   Referenced paper

   McDougall A., Milner R.N.C., Driscoll D.A. & Smith A.L. (2016) Restoration rocks: integrating abiotic and biotic habitat restoration to conserve threatened species and reduce fire fuel load. Biodiversity and Conservation, 25, 1529-1542.