Passive Restoration of Atlantic Forest Following Pinus taeda Harvesting in Southern Brazil

Abstract

The understory of exotic tree plantations can have nonnegligible native species richness. Ecological restoration of these sites may include the harvest of trees, depending on the tradeoff between timber income and harvest impacts on biodiversity. This study aimed to investigate how a site can recover from harvest disturbance, by comparing the regeneration of woody species in the understory of two types of 37-year-old Pinus taeda plantation (P1 and P2, high and low relative density of pine seedlings in the understory, respectively), with stands that were similar to P2 but subjected to harvest and then abandoned for 15 years (R sites). Secondary forests (SF) were used as references. We sampled three different sites for each stand condition; soil chemical properties, estimations of litter mass, and canopy cover were measured. P1 had low species diversity, and P2 and R had 50 and 46% of SF richness, respectively. The R site contained few pine saplings and was floristically similar to P2; this indicated that 15 years was sufficient for the recovery of plant diversity to near pre-harvesting levels. Soil fertility was highest in SF and lowest in P1. Thus old plantations of P. taeda with low relative density of pine juveniles can be cost-effective starting points for restoration. Despite the destructive effects of pine harvest, recovery of native species can occur rapidly. In situations in which clearcutting of pine stands is not planned or possible, modest thinning of P. taeda adults and/or intensive thinning of juveniles could expedite restoration.

Passive Restoration of Mixed Ombrophilous Forest a Decade After Forest Plantation Removal in the South of Brazil

“…According to Giehl et al (2007), zoochory is the main dispersion form for Mixed Ombrophilous Forest; a fact reinforced by the obtained results. The sites under passive restoration have a close relationship with zoochoric species, meaning there is a great dependence of animals on this phytophysiognomy (FERREIRA et al, 2012;FERRACIN et al 2013;SCARIOT et al, 2014;CIELO-FILHO;SOUZA, 2016).…”

“…Passive restoration is the most used method for recovering anthropized environments throughout the world (MELI et al, 2017). In the Mixed Ombrophilous Forest this methodology is able to reincorporate high species richness in areas previously occupied by forest plantations, spontaneously promoting the return of ecological interactions of plant and animal communities in the ecosystem (FERREIRA et al, 2012;FERRACIN et al 2013;SCARIOT et al, 2014).…”

“…The evaluation of fragments in the secondary stage, called ecological reference, in the same landscape matrix, enables conducting comparative studies with the sites to be restored (RUSCHEL et al 2009;SUGANUMA et al, 2013), in addition to making it possible to obtain ecological reference variables, called ecological indicators according to Rodrigues et al (2015). Among the reference variables, we highlight species composition, associated dispersion syndromes, ecological groups, forest structure and species diversity (SCHORN et al 2013;FERRACIN et al 2013;CIELO-FILHO;SOUZA, 2016).…”

Restauração da vegetação de Cerrado após silvicultura de >i<Pinus>/i< spp.

“…Plantações florestais podem ser consideradas redutos de biodiversidade e catalizadores da regeneração natural (ABREU et al, 2011a;JÚNIOR et al, 2015;LOPES et al, 2016;LOUMETO;HUTTEL, 1997;MALYSZ;MENDES, 2012;MODNA;VITAL, 2010;PARROTTA;TURNBULL;JONES, 1997;PIIROINEN;VALTONEN;ROININEN, 2016;VIANI;MELO, 2010). O impacto das plantações florestais sobre a biodiversidade e o sucesso da regeneração em seu sub-bosque podem variar dependendo da densidade de indivíduos plantados, da espécie escolhida, da matriz circundante, e de fatores como a quantidade de serapilheira e as propriedades do solo (ABREU et al, 2011a;ANDRADE et al, 2005;FERRACIN et al, 2013;MODNA; DURIGAN; VITAL, 2010; VIANI; DURIGAN; MELO, 2010). O tempo de rotação e o manejo da área para a produção comercial, como a intensidade de poda, os herbicidas e fertilizantes aplicados, assim como os métodos de colheita e desbaste, também influenciam a capacidade de estabelecimento das espécies nativas no sub-bosque das plantações (BROCKERHOOF et al 2008;CARNUS et al, 2006;MENDES, 2012).…”

“…Resultados promissores de regeneração natural de espécies nativas após o corte das monoculturas em áreas originalmente florestais (FERRACIN et al, 2013;PIIROINEN;VALTONEN;ROININEN, 2016), na região dos pampas (TORCHELSEN; CADENAZZI; OVERBECK, 2018) e em savanas na américa do Norte (ABELLA; SCHETTER; WALTERS, 2017; CATLING; KOSTIUK, 2010) podem incentivar a prática e possibilitar a diminuição dos gastos da restauração pela venda da madeira (FERRACIN et al, 2013;PIIROINEN;VALTONEN;ROININEN, 2016). Entretanto, o corte das árvores plantadas pode favorecer a formação de um ambiente de menor riqueza e/ou com proliferação de gramíneas invasoras, com necessidade de intervenções adicionais JÚNIOR et al, 2015;KASEL et al, 2015;.…”