Action: Replant vegetation
- Three studies (including two replicated studies) in Australia, Canada and Spain found that amphibian abundance or community composition was similar to natural sites following tree planting, or became more similar with time since grassland reseeding. One before-and-after study in Australia found that numbers of frog species increased following restoration that included planting shrubs and trees.
- One replicated, site comparison study in Canada found that following logging, amphibian abundance was lower or similar in forests that were planted and had herbicide treatment compared to those left to regenerate naturally, depending on species and forest age.
- Four studies (including one replicated study) in Australia, Spain and the USA found that amphibians colonized replanted forest, reseeded grassland and seeded and transplanted upland habitat. Three of the studies investigated restoration following mining. One site comparison study in the USA found that wetlands within reseeded grasslands were used more frequently than those within farmland, but less than those in natural grasslands.
Vegetation can be replanted to replace habitat that has been lost.
Studies that investigated the effect of replanting as one of a combination of interventions during the restoration of wetlands are discussed in ‘Restore wetland’.
Supporting evidence from individual studies
A site comparison study in 1978–1984 of restored sites within bauxite mined areas in Western Australia (Nichols & Bamford 1985) found that six frog species were recorded in replanted sites compared to eight in the surrounding unmined forest. Community composition comparisons indicated high degrees of similarity between some rehabilitated sites and high quality forests. Species use of revegetated sites depended largely on suitable microhabitats being present. Restoration included just planting native eucalypt species or adding topsoil soil, planting with 50% eucalypts and a native understory and fertilizing the area. Amphibians were monitored monthly in a wide range of restored areas and in surrounding unmined forest. More detailed studies were conducted between December 1980 and February 1981 in three rehabilitated areas and four unmined forests. Surveys involved pitfall trapping, live-traps and hand-collecting.
A replicated, before-and-after, site comparison study in 1988–1994 of spoil benches of a lignite mine in northwest Spain (Galán 1997) found that reseeded benches were colonized by nine amphibian species. Species richness increased steadily with time since seeding. Species composition was most similar to that in control plots in the oldest restored plots (10-years-old). Common midwife toad Alytes obstetricans and Perez's Frog Rana perezi were the first species to colonize, in the second year. Spoil benches (60 ha) were created, planted with a slurry of pasture mix seeds and mulch and were fertilized in 1984–1994. Subsequent management was minimal. Monitoring was undertaken annually on a single 2 ha plot over the six years following seeding and in 1994 on 10 randomly selected 2 ha plots seeded 0–10 years previously. Three randomly selected undisturbed control plots close to the mine were also monitored in 1994. Surveys involved a total of 30 hours of visual searches in February–November.
A before-and-after study in 1999–2003 of retired agricultural land in California, USA (Uptain et al. 2005) found that upland habitat restored by seeding and transplanting native plant species was colonized by western toads Bufo boreas. The species was recorded annually from 2000 and was the only amphibian observed. In 1999, native plants were introduced to 20 plots (4 ha) in randomized blocks by either seeding or transplanting, with or without surface contouring. Visual encounter surveys (circular plots and transects) and artificial coverboard surveys (4/plot) were undertaken four times annually.
A replicated, site comparison study in 2001–2002 of boreal forest stands in Ontario, Canada (Thompson et al. 2008) found that amphibian abundance was not higher following planting and herbicide treatment after logging compared to stands left to regenerate naturally. Wood frogs Rana sylvatica were significantly less abundant in 20–30-year-old stands that had been managed by planting and herbicide treatment with or without scarification (0.06 captures/trap night) compared to those that had been left to regenerate naturally (0.09). However, capture rates in 32–50 year old managed stands (0.07) did not differ significantly from naturally regenerated (0.12) and unharvested stands (0.06). For American toads Bufo americanus, there was no significant difference in capture rates between treatments or ages of stands (managed: 0.02–0.04; natural regeneration: 0.02–0.03; unharvested: 0.03). Nineteen stands that had received each treatment and five unharvested stands were selected. Drift-fencing with pitfall traps were used for monitoring in August–September 2001–2002.
A before-and-after study in 1997–2004 of a golf course with degraded woodland and grassland in Sydney, Australia (Burgin & Wotherspoon 2009) found that restoration that included planting increased frog species over two years. Frogs increased from seven to 10 species in the first year and then remained stable for the following six years. A total of 18 species of frogs were predicted in the area and so 56% were present following restoration. The golf course was developed in 1993 and restoration undertaken in 1997–2001. Endemic shrubs and trees were planted, non-native weeds were removed and coarse woody debris was reintroduced onto the woodland floor. The mowing regime was changed to develop grasslands and a narrow band of herb vegetation retained around ponds as a buffer zone. Pond perimeters were walked to record frog calls in 1996–2004.
A before-and-after study in 2009 of a coal spoil prairie in Indiana, USA (Lannoo et al. 2009) found that four species of salamanders and nine species of frogs and toads colonized habitat restored by planting, over 27 years. Two species recorded were species of conservation concern. Each of the four study wetlands had different species compositions. As a comparison, another restoration site (in a former prairie area) had one species of salamander and eight species of frogs and toads. Abundances varied from 6–2739 captures/species. Once extraction was completed in 1982, the area was graded to the approximate original contours, topsoil was added (15–38 cm) and the area was re-vegetated. Planting was initially of non-native tall fescue Festuca arundinacea, but since 1999 was replaced with native prairie grasses and forbs. Drift-fences with pitfall traps were installed (920 m) around four seasonal or semi-permanent wetlands and were sampled daily in March–August 2009. Visual encounters were also recorded.
A site comparison study in 2005–2006 of four restored wetlands in restored grasslands in the Prairie Pothole Region, USA (Balas, Euliss Jr. & Mushet 2012) found that wetlands within restored grasslands were used more frequently by amphibians than those within farmland, but not as much as those within native prairie grasslands. This was true for two frog, one toad and one salamander species. Four wetlands from each category were selected: farmed (drained with ditches), conservation grasslands (wetland hydrology restored, area reseeded with perennial grassland ≤ 10 years previously) and native prairie grasslands (natural). Call surveys, aquatic funnel traps and visual encounter surveys were undertaken biweekly in May–June 2005–2006.
- Nichols O.G. & Bamford M.J. (1985) Reptile and frog utilisation of rehabilitated bauxite minesites and dieback-affected sites in Western Australia's Jarrah Eucalyptus marginata forest. Biological Conservation, 34, 227-249
- Galán P. (1997) Colonization of spoil benches of an opencast lignite mine in northwest Spain by amphibians and reptiles. Biological Conservation, 79, 187–195
- Uptain C.E., Garcia K.R., Ritter N.P., Basso G., Newman D.P. & Hurlbert S.H. (2005) Results of a habitat restoration study on retired agricultural lands in the San Joaquin Valley, California. Pages 107-175 in: Land Retirement Demonstration Project five year report. US Department of the Interior, Interagency Land Retirement Team, Fresno, California.
- Thompson I.D., Baker J.A., Jastrebski C., Dacosta J., Fryxell J. & Corbett D. (2008) Effects of post-harvest silviculture on use of boreal forest stands by amphibians and marten in Ontario. Forestry Chronicle, 84, 741-747
- Burgin S. & Wotherspoon D. (2009) The potential for golf courses to support restoration of biodiversity for biobanking offsets. Urban Ecosystems, 12, 145-155
- Lannoo M.J., Kinney V.C., Heemeyer J.L., Engbrecht N.J., Gallant A.L. & Klaver R.W. (2009) Mine spoil prairies expand critical habitat for endangered and threatened amphibian and reptile species. Diversity, 1, 118-132
- Balas C.J., Euliss N.H. & Mushet D.M. (2012) Influence of conservation programs on amphibians using seasonal wetlands in the Prairie Pothole region. Wetlands, 32, 333-345