Topsoil translocation for Brazilian savanna restoration: propagation of herbs, shrubs, and trees

Abstract

Topsoil translocation has been used for vegetation restoration throughout the world, but it has been poorly tested within savannas. This study describes Brazilian savanna (cerrado) regeneration for the first 3 years following topsoil translocation. The topsoil was stripped from 2.5 ha of savanna and spread on 1 ha of an abandoned laterite quarry in the Federal District, Brazil. We assessed vegetation structure and species composition in 18 circular plots (3.14/m 2 ) after 5 and 15 months and in 30 circular plots after 37 months. In the last floristic survey, the coverage of herbs was estimated using the step-point method.To verify the source of regeneration, a total of 181 shrubs and trees were excavated over the first 2 surveys. After 3 years, 24, 40, and 21 species of herbs, shrubs, and trees, respectively, had been recorded by the surveys. Of the 33 families found, Fabaceae, Poaceae, and Asteraceae were the most representative. At 5 and 15 months, 91 and 83% of the individuals (shrubs and trees combined) were derived from resprouting, respectively. Shrub and tree stem density reached 3.2/m 2 at 5 months, but declined to 0.5/m 2 at 37 months. By the final survey, native and exotic grasses completely covered the ground. Topsoil translocation was effective for the propagation of native herbs, shrubs, and trees, despite the need to control invasive grasses. The large number of shrub and tree resprouts from roots suggests that the bud bank is an important component of the topsoil for savanna restoration. Implications for Practice• Topsoil translocation effectively established native savanna species of herbs, shrubs, and trees on an abandoned laterite quarry. The topsoil can be used for restoration rather than being discarded after removal from nearby construction and mining sites. • Root fragments should be taken into account in topsoil translocation of savannas and other sprouter-dominated communities, as their resprouts were responsible for most regenerating trees and shrubs.

Abandoned pastures cannot spontaneously recover the attributes of old‐growth savannas

“…However, if the goals include the recovery and maintenance of part of the ecosystem structure, diversity and/or services previously provided by old‐growth savanna, active restoration is required, and the cost will depend on the level of intervention (McBride et al., ). For example, if the goal is to ensure that rivers and underground waters are recharged (water‐related ecosystem services), interventions may only involve tree removal to avoid thickening the secondary savannas (Honda & Durigan, ), but if the aim is to recover the highly diverse old‐growth savanna ground layer in addition to maintaining the savanna structure (sparse trees scattered over a continuous grass stratum), interventions may include controlling exotic grasses and reintroducing native grasses and shrubs (Ferreira et al., ). In the former case (tree removal), interventions may be executed at low cost, but in the latter (exotic grass control and the reintroduction of native species), excessive financial resources would be required (Breed et al., ).…”

“…In the last 10 years, practically all countries in the world have made ambitious global commitments involving the restoration of degraded ecosystems (Aronson & Alexander, ; Suding et al., ), including Neotropical savannas (Strassburg et al., ), which are biodiversity hotspots (Myers, Mittermeier, Mittermeier, Da Fonseca, & Kent, ). Therefore, restoration scientists and practitioners have developed and tested several methods to actively restore these ecosystems (Ferreira, Walter, & Vieira, ; Pereira, Laura, & Souza, ; Pilon, Buisson, & Durigan, ; Silva, Oliveira, Rocha, & Vieira, ; Silva & Vieira, ). However, active savanna restoration is challenging due to the high cost of controlling exotic grasses (Breed, Lowe, & Mortimer, ) and the unavailability of commercial propagules (vegetative material or seeds) of native plants, especially grasses, forbs and shrubs, to replace exotics (Pilon et al., ).…”

Transposição do banco de sementes para restauração ecológica da floresta estacional no Rio Grande do Sul

“…A utilização do banco de sementes como estratégia de restauração ecológica é citada por diversos autores (Hall et al, 2010;Miranda Neto et al, 2010;Tozer et al, 2012;Ferreira et al, 2015;Fowler et al, 2015), que observaram o recobrimento das áreas, aumento de espécies e inclusão de diferentes formas de vida. Contudo, destaca-se a carência de informações científicas quanto a utilização da transposição do banco de sementes devido às especificidades ecológicas dos ecossistemas na região sul do Brasil, influenciados fortemente pelo clima subtropical, e a necessidade de validar metodologias de restauração para essa região, que sejam ecologicamente eficientes e, ao mesmo tempo, com menores custos (Rovedder et al, 2014).…”

Effect of Topsoil Stockpiling on the Viability of Seed Bank in Field Phytophysiognomies Campos De Altitude

“…The use of topsoil (RIVERA et al, 2012;GOLOS;DIXON, 2014) is a widespread technique in revegetation activities after bauxite mining (Barros, 2013). The seed bank, contained in the stockpiled topsoil, has favorable implications for vegetation succession and restoration (FERREIRA et al, 2015;SHANGA et al, 2016). Nevertheless, the composition, richness, and density of species present in the soil seed bank are influenced by the storage environment (SNYMAN, 2013;SANTOS et al, 2016), which may be a limiting factor for recovery activities in areas of recognized fragility in the floristic composition.…”

“…(BARROS et al, 2012). Thus, innovative surveys in altitude fields become important tools for the development of strategies of seed bank management (BORGY et al, 2015), since these are highly variable or unpredictable environments, with few studies (BARROS et al, 2013;FERREIRA et al, 2015).…”