Superação de dormência de sementes como estratégia para restauração florestal de pastagem tropical

Given that land-use change is the main cause of global biodiversity decline, there is widespread interest in adopting land-use practices that maintain high levels of biodiversity, and in restoring degraded land that previously had high biodiversity value. In this study, we use ant taxonomic and functional diversity to examine the effects of different land uses (agriculture, pastoralism, silviculture and conservation) and restoration practices on Cerrado (Brazilian savanna) biodiversity. We also examine the extent to which ant diversity and composition can be explained by vegetation attributes that apply across the full land management spectrum. We surveyed vegetation attributes and ant communities in five replicate plots of each of 13 land-use and restoration treatments, including two types of native vegetation as reference sites: cerrado sensu stricto and cerradão. Several land-use and restoration treatments had comparable plot richness to that of the native reference habitats. Ant species and functional composition varied systematically among land-use treatments following a gradient from open habitats such as agricultural fields to forested sites. Tree basal area and grass cover were the strongest predictors of ant species richness. Losses in ant diversity were higher in land-use systems that transform vegetation structure. Among productive systems, therefore, uncleared pastures and old pine plantations had similar species composition to that occurring in cerrado sensu stricto. Restoration techniques currently applied to sites that were previously Cerrado have focused on returning tree cover, and have failed to restore ant communities typical of savanna. To improve restoration outcomes for Cerrado biodiversity, greater attention needs to be paid to the re-establishment and maintenance of the grass layer, which requires frequent fire. At the broader scale, conservation planning in agricultural landscapes, should recognize the value of landuse mosaics and the risks of homogenization.

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“…Innovative techniques have been tested, such as direct seeding (Pereira et al . ,b; Silva et al . ; Cava et al .…”

Section: Introductionmentioning

confidence: 99%

Biodiversity responses to land‐use and restoration in a global biodiversity hotspot: Ant communities in Brazilian Cerrado

2018

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“…Accordingly, control seeds took more time to germinate than that taken by scarified ones. In line with this result, numerous other studies have shown a positive effect of scarification treatment on germinability and MGT in other Mimosa species (Orozco-Almanza et al 2003;Silveira and Fernandes 2006;Chauhan and Johnson 2009;Rosa et al 2012;Pereira et al 2013). Timing of seed germination in the field determines the conditions that germinants will be exposed to immediately upon germination, and consequently, strongly influences the success of seedling establishment (Donohue 2005).…”

Section: Discussionmentioning

confidence: 75%

Environmental control of seed dormancy and germination of Mimosa calodendron (Fabaceae): implications for ecological restoration of a highly threatened environment

et al. 2015

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Rupestrian grasslands over ironstone outcrop, locally named canga, are montane ecosystems with restricted distribution known to harbor an unusually a large number of endemic plant species. These communities are highly threatened due to their high sensitivity to habitat conversions and extreme low resilience derived from anthropogenic pressure. Ecological restoration attempts on degraded rupestrian grassland areas have not yet been successful. Mimosa calodendron is an endemic canga shrub thought to play a facilitator role and, therefore, may enhance seedling recruitment in degraded areas. Since dormancy and slow germination are key factors of the biology of seeds and may hamper their use in ecological restoration, this study aimed to investigate the environmental control of seed dormancy and germination of M. calodendron seeds. We tested the effect of mechanical scarification, light and different incubation temperatures on seed germination. The effect of scarification on water uptake by seeds was also measured. M. calodendron seeds have physical dormancy and scarification was an effective treatment to promote high and rapid germination. Heat treatment also increased germination percentage of nonscarified seeds, but was less efficient than scarification. Once water uptake occurred, germination took place under a broad thermal gradient, regardless of light condition. Therefore, the germination profile of M. calodendron seems to be suitable for uncomplicated use in restoration projects, requiring only a pretreatment for dormancy release.

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“…Assim, foi observado um expressivo declínio quanto ao percentual de sobrevivência em relação à emergência, situação essa também constatada por Lacerda & Figueiredo (2009), porém sem nenhuma plântula sobrevivente aos 6 meses de estudo. Ferreira et al (2009) Quanto ao declínio nos percentuais de sobrevivência encontrados no presente estudo, tal condição pode ser explicada pela indução da germinação, principalmente pelo uso da superação da dormência, que possibilitou o aumento da emergência de plântulas, porém em um ambiente onde as condições ambientais, ao longo do tempo, não favoreceram a sobrevivência das plantas jovens, resultando em menor número de plantas jovens ao final do estudo (Pereira et al, 2013). Tal condição pode ser explicada no corrente trabalho pelos fortes eventos pluviométricos que afetaram a sobrevivência das plântulas emergidas, ocasionando aumento da mortalidade dos indivíduos.…”

Section: Discussionunclassified

Estabelecimento de Espécies Florestais Nativas Via Semeadura Direta no Rio Piauitinga - Sergipe

et al. 2017

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RESUMOA técnica de semeadura direta vem se destacando nos projetos de recuperação florestal pela redução de custos na implantação e tem sido cada vez mais utilizada. Este trabalho foi realizado com o objetivo de avaliar a emergência, sobrevivência e estabelecimento de espécies florestais nativas, por meio de sementes em áreas de mata ciliar no Rio Piauitinga, município de Lagarto, SE. As espécies utilizadas foram Libidibia ferrea var. leiostachya (Benth.) L. P. Queiroz, Cassia grandis L. f., Cecropia pachystachya Trec., Enterolobium contortisiliquum (Vell.) Morong e Guazuma ulmifolia Lam. O experimento em campo foi implantado em Delineamento em Blocos Casualizados (DBC) com quatro repetições, em esquema fatorial, testando-se as cinco espécies com e sem tratamento para superação de dormência. A semeadura direta mostrou-se uma técnica viável para a área de estudo apenas para as espécies L. ferrea var. leiostachya, E. contortisiliquum e Cassia grandis, utilizando-se sementes com e sem dormência.Palavras-chave: degradação ambiental, dormência, sementes florestais. Establishment of Native Species Through Direct Seeding inPiauitinga River -Sergipe ABSTRACTThe direct seeding technique stands out for forest restoration projects due to savings in deployment costs and has been increasingly used. This work was carried out with the objective of assessing emergence, survival and establishment of native forest species, by means of seeds, in riparian areas of Piauitinga River, in the municipality of Lagarto-SE. The species used were Libidibia ferrea var. leiostachya (Benth.) L.P.Queiroz., Cassia grandis L.F., Cecropia pachystachya Trec., Enterolobium contortisiliquum (Vell.) Morong and Guazuma ulmifolia Lam. The field work was performed in a randomized block design (RBD) with four replications in factorial scheme, testing five species with and without treatment for overcoming of dormancy. It was observed that direct sowing is a viable technique for the area of study only for the species L. ferrea var. leiostachya, E. contortisiliquum and Cassia grandis, using seeds with and without dormancy.

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Superação de dormência de sementes como estratégia para restauração florestal de pastagem tropical

Abstract: Resumo -O objetivo deste trabalho foi avaliar a influência de tratamentos de superação da dormência de sementes sobre a taxa e o tempo de emergência de espécies arbóreas de Fabaceae, e sobre seu estabelecimento, quando reintroduzidas em pastagem, no Cerrado.

Cited by 24 publications

References 19 publications

Biodiversity responses to land‐use and restoration in a global biodiversity hotspot: Ant communities in Brazilian Cerrado

Biodiversity responses to land‐use and restoration in a global biodiversity hotspot: Ant communities in Brazilian Cerrado

Environmental control of seed dormancy and germination of Mimosa calodendron (Fabaceae): implications for ecological restoration of a highly threatened environment

Estabelecimento de Espécies Florestais Nativas Via Semeadura Direta no Rio Piauitinga - Sergipe

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