Collembola as bioindicators of restoration in mined sand dunes of Northeastern Brazil

Abstract

Opencast mining causes severe environmental impacts by removing the vegetation cover and depleting the fauna. Reforestation methods using native species and diverse pre-and post-disturbance approaches aim to recover the original richness and diversity of species found before the impact. Bioindicators are powerful tools to evaluate the restoration of the original environmental conditions in disturbed areas. We used species richness, endemism and diversity measurements of Collembola to compare successional stages in reforested sites of different ages compared with a control undisturbed area. Richness and abundance of Collembola were subjected to correlation analysis with age of plots and vegetational variables. Areas that were reforested for up to 16 years supported a much lower Collembola species richness than undisturbed areas. Both the age of reforestation plots and vegetation variables (number of trees, diameter of crowns, depth of leaf litter and tree species richness) were positively and significantly correlated to collembolan abundance and richness. The results showed that the diversity of the 16-year-old plot was significantly higher than that of younger areas, but significantly less diverse than that of the control area. Endemic species were more sensitive to disturbance than non-endemics. Thus, species richness and diversity of soil Collembola can be only partially restored with appropriate reforestation methods, and although it takes many years, to some extent even endemic species can be gradually restored. Nevertheless, the maintenance of undisturbed diversity reservoirs linked by ecological corridors to reforested plots is imperative, as only undisturbed areas can support most of the endemic species able to re-colonize reforested sites.

Influência dos processos de recuperação do solo após mineração de carvão sobre a mesofauna edáfica em Lauro Müller, Santa Catarina, Brasil

“…A mineração a céu aberto provoca sérios impactos ambientais através da remoção do solo e da cobertura vegetal, além da diminuição das comunidades de organismos do solo (ZEPPELINI et al, 2009). Os processos de mineração tendem a alterar radicalmente os solos, bem como o ambiente onde ocorrem e o seu entorno (ALBUQUERQUE et al, 2011).…”

Feeding habits, sexual dimorphism and size at maturity of the lizard Cnemidophorus ocellifer (Spix, 1825) (Teiidae) in a reforested restinga habitat in northeastern Brazil

“…Additionally, Lee and Wood (1971) observed that sandy soils generally provide poor stability for underground tunnels and nests built by termites, and these insects tend to inhabit soils with higher clay contents. Another strong indication of the low habitatquality of these reforested restinga areas was reported by Zeppelini et al (2008), who observed that there was a very reduced diversity of collembolan species in areas that had been reforested only two, four, or eight years earlier (although diversity was seen to be greater in areas recuperating for sixteen years). The sixteen year-old areas, nonetheless, still demonstrated collembolan diversity that was significantly reduced in comparison to control areas (preserved restinga).…”

“…During mining, all of the vegetation is removed and the underlying sand is processed to extract heavy minerals such as ilmenite, zirconite and rutile. A post-mining restoration plan was initiated in 1988 and comprises five stages: (a) re-establishment of the dune topography, (b) top soil recomposition (20-30 cm), (c) fertilisation, (d) planting and sowing grass, and (e) control of pests and exotic species (Rosado, 2001;Zeppelini et al, 2008). There are also remnant areas of intact restinga forest on the mining property whose floristic composition was previ-ously studied by Oliveira-Filho and Carvalho (1993) and Rosado (2001).…”

“…The mean annual rainfall in 2006 was 1,246 mm (Zeppelini et al, 2008), with the most rainfall occurring between the months of April to July; the driest month was December. The average annual temperature is 26.0 °C and the monthly averages range from 23.7 °C in April to 27.2 °C in November (Rosado, 2001).…”

Colêmbolos e fungos micorrízicos arbusculares como indicadores de degradação em fragmentos florestais de encosta

“…Para os colêmbolos, o número de indivíduos e de espécies está relacionado com variáveis de vegetação e com todos os fatores que afetam a disponibilidade de matéria orgânica (Zeppelini et al, 2009), já que a formação da associação micorrízica depende de fatores ambientais, fisiologia do hospedeiro, microrganismos do solo, quantidade e composição de fungos micorrízicos (Smith & Read, 2008). Assim, foram encontradas correlações significativas dessas comunidades com a fertilidade, a granulometria do solo, a vegetação e outros fatores (Tabela 4).…”