Providing evidence to improve practice

Action: Use prescribed fire: effect on understory plants Forest Conservation

Key messages

  • Eight of 22 studies (including seven replicated, randomized, controlled studies) from the USA, Australia and Canada found that prescribed fire increased the cover, density and biomass of understory plants. Six of the studies found it decreased plant cover. Eight found no effect or mixed effects on cover and density of understory plants.
  • Fourteen of 24 studies (including ten replicated, randomized, controlled studies) from the USA, Australia, France and West Africa found that prescribed fire increased species richness and diversity of understory plants. One study found that it decreased species richness.  Nine found no effect or mixed effects on species richness and diversity of understory plants.

 

Supporting evidence from individual studies

1 

A replicated, controlled study in 1957-1964 in temperate coniferous forest in Minnesota, USA (Buckman 1964) found that annual and biannual spring but not summer prescribed fires increased the number of regenerating hazel Corylus spp. stems. Numbers of stems was higher in annual and biannual spring (annual: 38,445; biannual: 30,109/ha) than annual and biannual summer (annual: 3,845; biannual: 13,840) and unburned plots (8,741/ha).  The density in single burn plots (single spring: 16,349; single summer: 16,956) was similar to all other treatments. Four plots (~2.5 ha) of each of seven treatments were established in 1957-1960: spring and summer fires carried out: annually, biennially or just once (single) and control (unburned). Data were collected four years after the beginning of the treatment in each plot.

 

2 

A replicated, controlled study in 1965-1979 in temperate woodland in Minnesota, USA (White 1983) found that annual prescribed burns increased understory plant species richness. Numbers of species was higher in burned (25/100 m2) than unburned plots (13/100 m2). Data were collected in 1979 in ten plots (100 m2) in a 10 ha control (unburned) area and in 11 similar-size plots in an 11 ha burned area (annual prescribed burns 1965-1978).

 

3 

A controlled study in 1991-1997 in temperate coniferous forest in Louisiana, USA (Haywood et al. 1998) found that prescribed burning increased herbaceous biomass. Annual herbs productivity was higher in burned (780-1220 kg dried matter/ha) than in unburned plots (452-472). Data was collected in four replicates of 0.16 ha prescribed burned (in March 1991, February 1994 and March 1997) and control unburned treatment plots. Herbaceous biomass was sampled in July 1997 in three quadrats (0.02 m2) within each plot.

 

4 

A before-and-after trial in 1994-1995 in temperate mixed forest in North Carolina, USA (Elliott et al. 1999) found that prescribed fire increased herbaceous species diversity, and decreased herbs cover. Cover of the herbaceous layer (all herbaceous species plus woody stems <1.0 cm basal diameter) decreased (before: 36; after: 11%) while diversity of the herb-lair increased (Shannon’s H before: 1.01; after: 2.14). Data were collected before (1994) and after prescribed-burning (1995) in six plots (15 × 15 m) and in additional 20 plots (10 × 10 m) after burning.

 

5 

A replicated, controlled study in 1994-1996 in Mediterranean jarrah Eucalyptus marginata forest in Western Australia (GRANT & Loneragan 1999) found that prescribed fire in restored forest sites increased plant species richness and density, but decreased plant cover. The density of all plants was higher in burned (35/m2) and native forest (32/m2) than unburned plots (6/m2), while their cover was lower in burned (10%) than unburned plots (48%) and native forest (60%). Weed density was higher in burned (6/m2) than unburned plots (3/m2) and native forest (2/m2). The number of native plant species was higher in burned (40/80 m2) than unburned plots (28/80 m2) and the highest in native forest (64/80 m2), while plant diversity was lower in unburned and burned plots (Shannon–Weiner index: 2.3 in both) than native forest (3.2). Data were collected in 1995-1996 in 5-10 burned (prescribed fire in 1994-1995) and five unburned plots (20 × 20 m) in each of three bauxite mine sites rehabilitated in 1981, 1982 and 1983, and in ten similar size plots in native forest sites (control).

 

6 

A replicated, randomized, controlled study in 1995-1998 in temperate mixed forest in Florida, USA (Provencher et al. 2001) found that prescribed fire increased plant species richness in fire-suppressed areas. Species richness was higher in burned (47-50/400 m2) than unburned plots (44/400 m2). Data were collected in 1998 in 32 subplots (400 m2) in each of one unburned control and three burned 81 ha plots (burned in 1995) replicated in six blocks. All plots had been fire-suppressed for several decades before treatments.

 

7 

A site comparison study in 2000 in a Mediterranean jarrah Eucalyptus marginata forest in Western Australia (Burrows, Ward & Cranfield 2002) found that prescribed burning increased the abundance of native plants at large and small scales and their species richness only at small scale. The number of native plant species at the small scale was higher in burnt than in unburned plots (burned: 12-13; unburned: 10/m2), while the number of species at the larger scale was similar between treatments (burned: 57; unburned: 51/30 m2). Native plant abundance at the small scale (burned: 38-39; unburned: 29/m2) and large scale (burned: 1,138-1,172; unburned: 876/30 m2) was higher in burned than unburned plots. Data was collected in 2000 using five lines of 30 quadrats (1 × 1 m) placed in burned sites (prescribed burn in 1996) and ten lines of 30 similar size quadrats placed in control sites (unburned since 1986). All lines were located in an 11,000 ha study area.

 

8 

A replicated, controlled study in 1995-1998 in temperate mixed forest in Kentucky, USA (Kuddes-Fischer & Arthur 2002) found no effect of prescribed fire on understory plant species richness. The number of species was similar in burned (32/25 m2) and unburned plots (26/25 m2). Data were collected in 1998 in 6-8 replicates of burned (prescribed burned in 1995) and control (unburned) plots (25 m2) at each of three sites.

 

9 

A replicated, controlled study in 1999-2000 in boreal forest in Alberta, Canada (Frey et al. 2003) found that prescribed burning increased the cover of fireweed Epilobium angustifolium but not the cover of cranberry Viburnum edule, herbs or populus spp. The cover of fireweed was higher in burned plots (burned: 18%; unburned: 4%), while the cover of cranberry (burned: 2%; unburned: 2%), herbs (burned: 6%; unburned: 7%) and populus spp. (burned: 4%; unburned: 6%), as well as the density of populus spp. root-suckers (burned: 25,400; unburned: 35,500/ha) were similar between treatments. Four burned (in May 1999) and four unburned 2 x 2 m plots were established within each of six 10 ha forest units. Cover of herbaceous plants was visually estimated in late July 1999. Cover of fireweed, cranberry and Populus spp., as well as the root sucker density of Populus spp. was evaluated in August 2000.

 

10 

A replicated, before-and-after study in 1993-2001 in sand pine scrub in Florida, USA (Greenberg 2003) found no effect of prescribed fire on plant species richness. The total number of plant species, as well as numbers of herbaceous and woody species was similar before and after the fire (10, 3 and 7 species/50 m transect respectively). Plants were monitored along six 50 m transects randomly established inside a 12 ha study site, before (1993) and after (2001) prescribed burning (in May 1993).

 

11 

A replicated, randomized, controlled study in 1998–2000 in temperate coniferous forest in South Dakota, USA (Wienk, Sieg & McPherson 2004) found that prescribed fire increased plant species richness. Species richness was higher in burned (8/0.25 m2) than unburned plots (3/0.25 m2). Data were collected in July 2000 in 30 plots (0.25 m2) in each of three replicates of control (unburned) and burned (in May 1999) treatments (45 × 45 m).

 

12 

A replicated, controlled study in 2001-2003 in temperate mixed forest in Georgia and Tennessee, USA (Elliott & Vose 2005) found that prescribed burning increased the cover of understory plants but did not affect plant species richness. The cover of herbaceous plants and tree seedlings <50 cm tall was higher in burned sites (burned: 26%; unburned: 24%) while numbers of species was similar between treatments (burned: 34.2 unburned: 34.0). Data were collected in 2002 in five 10 × 20 m plots in each of four burned (prescribed burn in March 2001) and two control unburned sites (total of 30 plots).

 

13 

A site comparison study in 1998-2001 in temperate coniferous forest in Arizona, USA (Huisinga et al. 2005) found that prescribed burning increased plant species richness and cover. Total species richness of plants (burned: 40; unburned: 24 species/0.1 ha) and total plant cover (burned: 50%; unburned: 11%) were higher in burned plots. Herbaceous species richness (burned: 33; unburned: 19) as well as exotic species richness (burned: 2; unburned: 0) and cover (burned: 1%; unburned: 0%) were higher in burned plots. In contrast, there was no difference between treatments for woody species richness (burned: 6; unburned: 6) or plant species diversity (Shannon’s index burned: 1.9; unburned: 1.4). Data were collected in 2001 in 30 plots (0.1 ha) within each of two areas (270 ha): burned (severely burned in 1993) and unburned.

 

14 

A replicated, controlled study in 1994-1999 in temperate oak forest in Ohio, USA (Hutchinson et al. 2005) found that prescribed burning increased plant species richness on a small scale, but not on a larger-scale. Species richness of all plants within 2 m2 plots was higher in burned plots (burned: 18; unburned: 16/2 m2). Species richness of annual forbs (burned: >1; unburned: <1/2 m2), summer-flowering forbs (burned: 4; unburned: 32/ m2), grasses (burned: >1; unburned: <1/2 m2) and woody seed-banking species (burned: >1; unburned: <1/2 m2) was higher in burned plots. Species richness of shade-tolerant tree seedlings (burned: <2; unburned: >2/2 m2) and oak–hickory tree seedlings (burned: 1; unburned: >1/2 m2) was higher in unburned plots. Species richness of spring-flowering forbs (4-5/2 m2), sedges (1/2 m2) and shrubs (2/2 m2) was similar between treatments. Species richness within larger 1,250 m2 plots was similar between treatments (burned: 67; unburned: 63/1,250 m2). Two burned (annually 1996-1999 and twice in 1996 and 1999) and one unburned treatment units (25 ha) were replicated at four sites. Data were collected in 1999 using 16 quadrats (2 m2) in each of nine plots (1,250 m2) within each treatment unit.

 

15 

A replicated, randomized, controlled study in 2001-2004 in temperate coniferous forest in Montana, USA (Metlen & Fiedler 2006) found that prescribed fire increased the number of understory exotic species and forbs at the large plot scale and decreased the number of native species at smaller scale. Plot-scale species richness was higher in burned plots for exotic plants (unburned: 4; burned: 6/1,000 m2) and forbs (unburned: 34; burned: 38/1,000 m2). On a smaller scale species richness for native species was lower in burned plots (unburned: 11; burned: 10/m2). For all plants together, plot-scale and a smaller scale were similar between treatments for species richness (plot-scale: 57 -60/1,000 m2; small-scale: 11/m2) and cover (both scales: 26-28%). Three replicates of burned and unburned control treatments (9 ha) were established in 2001. Species composition was determined in 2004 in 12 quadrats (1 m2) in each of ten plots (1,000 m2) within each treatment (total of 1,440 quadrats).

 

16 

A replicated, randomized, controlled study in 2000-2004 in temperate coniferous forest in Oregon, USA (Youngblood, Metlen & Coe 2007) found no effect of prescribed fire on understory species richness and diversity. Number of species/400 lm2 plot (burned: 29; control: 30) and Shannon-wiener's diversity index (burned: 0.11; control: 0.12) were similar between treatments. Data were collected in 2004 in 10-30 plots (400 m2) in each of four burned (prescribed burnt in 2000) and four control (unburned) experimental units.

 

17 

A replicated, randomized, controlled study in 2001-2004 in temperate coniferous forest in Montana, USA (Dodson, Metlen & Fiedler 2007) found that prescribed burns increased species richness of uncommon but not of common plant species. The number of uncommon species was higher in burned plots (burned: 14; unburned: 11) while the number of common species was similar between treatments (burned: 30; unburned: 32). Data were collected in 2004 in ten burned (prescribed burn in 2002) and ten control (unburned) treatment plots (1,000 m2) in each of three blocks.

 

18 

A replicated, randomized, controlled study in 2001-2004 in temperate coniferous forest in California, USA (Knapp et al. 2007) found no effect of prescribed fire on cover and species richness of understory vegetation. Total plant cover increased by 0.6% in unburned compared with 0.8% in early- and 2.0% in late-burned plots. Numbers of species/1 m2 increased by 0.12 in unburned compared with a 0.34 increase in early and a 0.03 decrease in late burned plots. Numbers of species/0.1 ha decreased by 0.7 in unburned compared with increases of 6.0 in early- and 6.6 in late-burned plots. Data were collected in 2004 in ten plots (0.1 ha) that were established in each of three unburned, three early-burned (June 2002) and three late-burned (September-October 2001) randomly assigned treatment units (15-20 ha).

 

19 

A replicated, randomized, controlled study in 2000-2004 in temperate broadleaf forest in Ohio, USA (Schelling & McCarthy 2007) found no effect of burning on soil seed-bank species richness or diversity. The total number of species (burned: 43; unburned: 38/1000 cm3 soil) as well as diversity (Shannon's index burned: 3.23; unburned: 3.11) were similar between treatments. Ten plots (20 × 50 m) were established within each burned (prescribed burned in spring 2001) and control (unburned) treatments (20 ha) at each of two sites. Species richness and diversity were determined by monitoring emerging seeds in ten soil samples (1,000 cm3) extracted from each plot in summer 2004.

 

20 

A replicated, randomized, controlled study in 2000-2003 in temperate mixed forest in California, USA (Wayman & North 2007) found no effect of prescribed burning on understory plant species richness and cover. Numbers of species (burned: 3; unburned: 4/10 m2) and cover (burned: 9%; unburned: 8%) were similar between treatments. Data were collected in 2003 in 9-49 plots (10 m2) in each of three control (unburned) and three burned (prescribed fire in 2001) treatments units (4 ha).

 

21 

A replicated, controlled before-and-after study in 2000-2004 in Piedmont forest in South Carolina, USA (Philips & Waldrop 2008) found that prescribed burning decreased the density of tree saplings, but increased the density of seedlings and other plants species richness and cover. The density of tree saplings >1.4 m tall and <10 cm diameter at breast height decreased in burned plots (-175/ha) whereas it increased in unburned plots (243/ha). Increases in tree seedlings <1.4 m tall (burned: 17,850; unburned: 8,550/ha), the cover of vines (burned: 3.2%; unburned: -2.7%), herbaceous species (burned: 2.6%; unburned: -0.2%) and grasses (burned: 3.3%; unburned: -0.5%) and the number of plant species (burned: 41; unburned: 32/0.1 ha) were greater in burned plots. Declines in the cover of shrubs were similar between treatments (burned: -0.03%; unburned: -0.41%). Ten plots (0.1 ha) were established in each of three control (unburned) and three burned (in 2001-2002) treatment units. Data were collected three years after treatment.

 

22 

A replicated, randomized, controlled study in 1994-2003 in savanna woodland in West Africa (Savadogo et al. 2008) found no effect of annual prescribed fire on herbaceous species richness or diversity. Numbers of species (unburned: 13-16; burned: 14-16/0.25 ha) and diversity (Shannon's index unburned: 2.4-2.8; burned: 2.7-2.9) was similar between treatments. Data were collected in 2003 in two control (unburned) and two burned treatment plots (0.25 ha) replicated in eight blocks, at each of two sites (18 ha). Annual prescribed fires were carried out at the end of the rainy season in 1994-2003.

 

23 

A replicated, randomized, controlled study in 2000-2007 in temperate broadleaf forest in North Carolina and Ohio, USA (Waldrop et al. 2008) found that prescribed burning had mixed effects on the cover of different plant groups at two different sites. At the 'cool temperate climate' site the number of hardwood tree saplings (>1.4 m tall) (burned: 430/ha, unburned: 370/ha), cover of herbs (burned: 20%, unburned: 13%) and shrubs and tree seedlings (< 1.4 m tall) (burned: 50%, unburned: 25%) were higher in burned plots. At the same site, the cover of shrubs (>1.4 m tall) was lower in burned plots (burned: 2%, unburned: 8%). At the 'warm continental climate' site, the number of tree saplings (burned: 900/ha, unburned: 1,800/ha) and cover of shrubs (>1.4 m tall) (burned: 9%, unburned: 28%) were higher in unburned plots, while the cover of tree seedlings (burned: 8%, unburned: 6%) was higher in burned plots. At the 'cool temperate climate' site, cover of herbaceous species (burned: 4%, unburned: 5%) and shrub seedlings (burned: 8%, control: 11%) was similar between treatments. Three pairs of burned (in 2002-2003) and control (unburned) treatment units (10-26 ha) were established at each of a 'cool temperate climate' and 'warm continental climate' site. Data were collected 3-4 years post-treatments in ten plots (0.1 ha) in each treatment unit.

 

24 

A replicated, randomized, controlled study in 1997-2006 in temperate coniferous forest in Oregon, USA (Bates & Svejcar 2004) found that winter burning of cut western juniper Juniperus occidentalis trees increased annual herbaceous plant cover. Cover of all herbaceous plants and cover of perennial grasses was higher in 1st-year burn (30% and 22% respectively) and 2nd-year burn plots (28% and 18%) than in unburned plots (18% and 8%). Cover of annual herbaceous species and of Sandberg’s bluegrass Poa secunda was higher in 1st-year burn (5% and 2% respectively) than in unburned plots (1% and 0%) and intermediate in 2nd-year burn plots (4% and 1%). Cover of cheatgrass Bromus tectorum was higher in unburned (10%) than in 1st-year and 2nd-year burn plots (2% in both), while cover of perennial forbs was similar (<1%) in all treatments. Three treatments (0.5 ha) were randomly assigned to each of five blocks in which all juniper trees were cut down in 1997. Treatments were: unburned, 1st-year and 2nd-year burned (cut trees burned the first and second winter after cutting respectively). In 2006 herbaceous cover was measured in four 0.2 m2 quadrats under each of ten cut trees in each treatment.

 

25 

A replicated, controlled study in 1998-2006 in temperate forest in Louisiana, USA (Haywood 2009) found that prescribed fire decreased understory vegetation cover. The total cover of understory vegetation was lower in burned treatments than in unburned plots (burned: 58-62%; unburned 68%).  Data were collected in 2006 in three plots (0.07 ha) of each of March, May and July burns (prescribed burn in 1999, 2001, 2003, and 2005), and control (untreated since 1998) treatments. Each of the 12 plots was planted with 196 longleaf pine seedlings in 1993-1994.

 

26 

A replicated, before-and-after study in 2005-2009 in Mediterranean type shrubland in Western Australia (Herath et al. 2009) found that prescribed fire increased plant species richness in natural sites, but decreased species richness in restored mine-sites. Plant species richness increased in natural areas after fire (pre-fire: 99; post-fire: 116) and decreased after fire in restored areas (pre-fire: 118; post-fire: 80). The percentage of species that persisted after fire was lower in restored (50%) than in natural areas (91%). Prescribed fire was applied in 2005-2007 to a 40 × 40 m plot at each of three restored mine-sites (8-24 years before the experiment) and five natural sites. Data were collected before (2005) and two years after fire.

27 

A controlled study in 2004-2006 in temperate mixed forest in North Carolina and Georgia, USA (Elliott & Vose 2010) found that prescribed fire increased the cover of herbaceous plants only in one out of three sites. The cover of herbaceous plants was higher in burned than unburned plots at one site (burned: 132; unburned: 88%) and similar between treatments at the second (burned: 55; unburned: 37%) and the third sites (burned: 2; unburned: 1%). Data were collected in 2006 in 10-12 plots (10 × 20 m) in a burned area (in 2004) and in 4-6 plots in an adjacent unburned area (control) in each site.

 

28 

A replicated, controlled study in 2004-2008 in temperate broadleaf forest in Pennsylvania, USA (Huebner et al. 2010) found that prescribed fire decreased fruit production but not the cover of some herbaceous species. Four years after treatment, the total number of fruit/plot for three herbaceous species: painted trillium Trillium undulatum, sessile bellwort Uvularia sessilifolia, and Indian cucumber root Medeola virginiana was lower in burned plots (burned: 0-380; unburned: 0-430), while their relative cover (0-3%) was similar between treatments. Cover of bramble Rubus spp. (1-25%) and hay-scented fern Dennstaedtia punctilobula (0-70%) and the number of tree saplings (0.0-1.8/m2) were similar between treatments. Data was collected in 2008 in three blocks of 12 burned (prescribed fire on May 2004) and 12 unburned plots (50 × 80 m).

 

29 

A replicated, randomized, controlled study in 2002-2005 in temperate coniferous forest in Alabama, USA (Outcalt & Brockway 2009) found that prescribed fire decreased the density of understory shrubs and trees and increased the cover of grasses. The density of small hardwoods (<3 cm diameter at breast height) (burned: ~300; unburned: >1,500 trees/ha) and cover of tall shrubs (>1.4 m) (burned: 10%; unburned: 33%) were higher in unburned plots. The cover of grasses was higher in burned plots (burned: 20%; unburned: 7%) and the cover of short shrubs (<1.4 m) (45-57%) and forbs (3-10%) was similar between treatments. Control (unburned) and burned (prescribed burned in 2002 and 2004) treatment units were replicated in three blocks. Data were collected in 2005 in ten 20 × 50 m subplots within each treatment unit.

 

30 

A replicated, controlled study in 2000-2006 in temperate broadleaf forest in West Virginia, USA (Royo et al. 2010) found that prescribed fire increased understory vegetation cover and diversity. Cover (burned: 28%; unburned: 7%), species richness (burned: 2.9; unburned: 1.5 species/m2) and diversity (Shannon's index burned: 1.31; unburned: 1.06) were higher in burned plots. Eight burned (in 2001) and eight control (unburned) treatment plots (20 × 20 m) were established in each of four sites. Data were collected in 2006 in five quadrats (1 m2) in each plot.

 

31 

A replicated, randomized, controlled study in 1976-2008 in temperate coniferous forest in Arizona, USA (Scudieri et al. 2010) found that frequent prescribed burning increased the cover of grasses and specifically wheatgrasses, but not of forbs and of total herbaceous plants. At one site, cover of grasses was higher with 1-year interval burns than in unburned plots (1-year: 8%; 2-, 4-, 6-, 8- and 10-years: 5-8%; unburned: 5%) and cover of wheatgrasses was higher with 1-, 2- and 4-year intervals than in unburned plots (1-, 2- and 4-years: 4-5%; 6-, 8- and 10-years: 2-3%; unburned: <1%). At that same site, cover did not differ between treatments for forbs (all burn intervals: 3-6%; unburned: 2%) or total herbaceous vegetation (all burn intervals: 9-12%; unburned: 5%). At a second site the cover of grasses (all burn intervals 3-7%; unburned: 3%), wheatgrasses (all burn intervals: <1%; unburned: 0%), forbs (all burn intervals: 1-3%; unburned: 2%) and total herbaceous cover (all burn intervals: 4-10%; unburned: 5%) were similar between treatments. Data were collected in 2007-2008 in three plots of each of 1-, 2-, 4-, 6-, 8- and 10-year intervals between prescribed fires and control (unburned >75 years) treatment plots (100 × 100 m) established in 1976-1977 in each of two sites.

 

32 

A replicated, before-and-after study in 2006-2010 in temperate coniferous forest in Washington State, USA (Fonda & Binney 2011) found that prescribed burning decreased the cover of understory vegetation. Understory vegetation cover was lower 3 years post-fire (pre-fire: 107%; post-fire: 40%). Data was collected in 2006 (pre-fire) and in 2010 (post-fire) in five 20 x 20 m plots that were prescribed burned in 2007.

 

33 

A replicated, randomized, controlled study in 2005 in Mediterranean Aleppo pine Pinus halepensis woodland in France (Prévosto et al. 2011) found that prescribed burning increased plant species richness and diversity and decreased shrub cover but did not affect the cover of herbaceous plants. Numbers of species (unburned: 27; burned: 33/plot) and diversity (Shannon's index unburned: 3.2; burned: 3.7) were higher in burned plots, while shrub cover was lower in burned plots (unburned: 40%; burned: 29%). Herbaceous plant cover was similar between treatments (unburned: 24%; burned: 30%). Data were collected in 2009 in eight unburned control and eight burned (prescribed fire in 2005) plots (14 × 14 m). All plots were thinned in 2004 (from 410 to 210 trees/ha).

 

34 

A replicated, controlled study in 1946-2012 in temperate broadleaf forest in North Carolina, USA (Keyser et al. 2012) found that prescribed fire decreased the soil seed-bank species richness but not species diversity or density. Numbers of emerged species was lower after prescribed fire (before: 12.1-12.3; after: 11.0-11.3/m2), while diversity (Shannon's index in m2 1.9-2.1) and total density (419-603 emergents/m2) were similar between treatments. Five plots (5 ha) were burned in 2009-2010. Data were collected using four 0.06 m2 soil seed-bank samples, two before and two after burning, taken from each of six subplots (0.5 ha) within each plot.

 

35 

A replicated, controlled study in 2001-2005 in temperate eucalyptus forest in Queensland, Australia (Lewis et al. 2012) found that prescribed fire increased plant density and species richness. The density of <1 m tall native plants (burned: 13; unburned: 9 individuals/6 m2), ferns (burned: 2-3; unburned: 2) and resprouters (burned: 12-13; unburned: 9) and of 1-3 m tall native plants (burned: 3; unburned: 2) and resprouters (burned: 3; unburned: 2) was higher in burned than unburned plots. The density of other <7.5 m tall plant groups examined was not affected by burning. Data were collected in 2009 in three subplots (6 × 1 m) in each of four burned (prescribed burn with 2 or 4 year intervals since 1971) and two control (no fires since 1969) 0.08 ha plots.

 

36 

A before-and-after study in 2003-2005 in temperate coniferous forest in California, USA (Walker et al. 2012) found that prescribed fire decreased the cover of understory vegetation. The change (after minus before) in understory vegetation cover was more negative in burned (-19%) than unburned plots (-2%). Data were collected in 2003 (before) and 2005 (after) in five plots (0.04 ha) in each of two burned (in June 2004) and two control (unburned) treatment units of approximately 1 ha.

 

37 

A replicated, controlled study in 2004-2011 in temperate coniferous forest in Arizona, USA (Huffman et al. 2013) found no effect of burning on plant cover or on species richness. Total plant cover (3-5%), species richness (33-37 species) and diversity (Simpson's index 0.8-0.9) were similar between treatments. Four burned (prescribed burn in 2006) and four unburned treatment units (1 ha) were replicated in six blocks. Data were collected in 2011 in one 0.04 ha plot in each treatment unit (total of 48 plots).

 

Referenced papers

Please cite as:

Agra, H., Schowanek, S., Carmel, Y., Smith, R.K. & Ne’eman, G. (2017) Forest Conservation. Pages 285-328 in:W.J. Sutherland, L.V. Dicks, N. Ockendon & R.K. Smith (eds) What Works in Conservation 2017. Open Book Publishers, Cambridge, UK.