Isabel Belloni Schmidt

Produção e germinação de sementes de "capim dourado", Syngonanthus nitens (Bong.) Ruhland (Eriocaulaceae): implicações para o manejo

A venda de artesanato feito com escapos de S. nitens e uma importante fonte de renda na regiao do Jalapao, TO. Conhecer a epoca de producao e dispersao das sementes, bem como seu potencial germinativo, e essencial para propor formas de manejo que garantam a sustentabilidade economica e ecologica deste extrativismo. Com o intuito de caracterizar a epoca de producao de sementes foram coletados capitulos entre agosto e dezembro/2003. Foram realizados experimentos de germinacao em câmara a 22-30 oC, sob foto e termoperiodo de 12 horas, e tambem em condicoes de escuro. Caracterizou-se tambem a germinacao em condicoes de hipoxia (imersao em agua) e acidez (pH 4 e 5). A producao de sementes iniciou-se em setembro e a maior parte da dispersao ocorreu entre outubro e novembro. A germinacao das sementes coletadas entre setembro e outubro foi de 92 ± 7% (media ± DP), sementes coletadas a partir de novembro tiveram germinacao significativamente menor. A acidez e a hipoxia nao afetaram negativamente a germinacao em relacao ao controle. As sementes sao fotoblasticas positivas e mantem a germinacao apos congelamento a -20 oC. A colheita de escapos apos a frutificacao (a partir do final de setembro) e a dispersao manual das sementes pelos proprios extrativistas no momento da colheita sao estrategias importantes para o manejo da especie e nao prejudicam a atividade artesanal que esta focada nos escapos e nao nas flores, como ocorre para outras sempre-vivas.

Ethnobotany and Harvesting Impacts on Candombá (Vellozia aff. sincorana), A Multiple Use Shrub Species Endemic to Northeast Brazil1

Ethnobotany and Harvesting Impacts on Candombá ( Vellozia aff. sincorana ), A Multiple Use Shrub Species Endemic to Northeast BrazilThis study assessed the relationship between knowledge, use, and harvesting impacts on Vellozia aff. sincorana L.B.Sm. & Ayensu (Velloziaceae) populations. The species has a dracaenoid habit and is endemic to the Chapada Diamantina National Park (NPDC), state of Bahia, in northeastern Brazil. We interviewed 37 key informants from local rural communities in the vicinity of the NPCD, who cited six types of use for the species’ pseudostems, which were grouped into four categories: fuel, magical–religious, technology, and trade. Presently, the pseudostems are used mostly to light wood stoves (fuel). Men had greater knowledge about this species compared to women, which is probably due to the historical use of these plants in rudimentary mining activities in the past, which were performed almost exclusively by men. Informants did not identify preferred spots for harvesting, but they did report areas with a higher density of plants with the desired qualities—larger pseudostems. We also studied the population structures of V. aff. sincorana in six areas under contrasting harvest levels (low vs. high harvesting pressure). We found a significantly lower density of plants in high harvested areas compared to low harvested areas. In contrast, harvest did not significantly change the population distribution in size classes, indicating that recruitment is not impaired by harvesting. Although presently V. aff. sincorana harvesting is only performed in a non–commercial scale, harvesting of this strictly endemic species persists in local communities. Therefore, local ecological knowledge and practices should be taken into account to help conserve this and other species in the region, as it is the case for other protected areas and regions, especially in the tropics.Etnobotânica e Impactos da coleta do Candombá (Vellozia aff. sincorana), uma espécie de múltiplos usos endêmica do Nordeste do BrasilInvestigamos a relação entre conhecimento, uso e impactos do extrativismo em populações de Vellozia aff. sincorana L.B.Sm. & Ayensu (Velloziaceae). Esta espécie dracenóide é endêmica do Parque Nacional da Chapada Diamantina (PNCD), Bahia, Brasil. As entrevistas semiestruturadas foram realizadas com 37 informantes–chave de comunidades rurais que vivem no entorno do PNCD. Identificamos seis tipos de uso para a espécie, que foram agrupadas em quatro categorias: fogo, mágico–religioso, tecnologia e comércio. Atualmente os pseudocaules desta espécie são usados apenas para iniciar fogo em fogões a lenha. Os homens detiveram maior conhecimento sobre a espécie em comparação com as informantes do sexo feminino, o que é provavelmente devido ao uso histórico da espécie durante as atividades rudimentares de mineração, realizadas exclusivamente por homens. Não foram declarados pontos preferenciais para a colheita ainda em prática, embora haja procura por áreas com maior densidade de plantas com as qualidades desejadas (pseudocaules com maiores diâmetros). Adicionalmente, a estrutura populacional da espécie foi caracterizada em seis áreas com diferentes níveis de colheita (baixa vs. alta pressão de extrativismo). Encontramos densidades significativamente menores de plantas em áreas de alta pressão de colheita em comparação com áreas de baixa pressão de colheita. Em contraste, a colheita não alterou significativamente a distribuição dos indivíduos em classes de tamanho entre as populações, indicando que a colheita não prejudica o recrutamento de novos indivíduos. Apesar de, atualmente, a colheita de V. aff. sincorana ser realizada apenas em escala não–comercial, a atividade persiste e é mantida nas comunidades locais. Portanto, o conhecimento e as práticas ecológicas locais devem ser levados em conta para ajudar a conservar essa e outras espécies na região, assim como ocorre em outras regiões e áreas protegidas, especialmente em regiões tropicais.

Allelopathy of a native shrub can help control invasive grasses at sites under ecological restoration in the Neotropical savanna

ABSTRACT Background: African C4 grasses threatens newly restored areas in Neotropical savannas. Allelopathy exhibited by some native species may contribute to ecological restoration. Aims: To establish the potential use of Lepidaploa aurea (Asteraceae) in ecological restoration of invaded savannas, we evaluated its allelopathic effects on two invasive grasses, a native grass, and two native trees (one savanna and one riparian forest species). Methods: We tested the allelopathic effects of the leaves and roots of L. aurea in a growth chamber, a greenhouse, and in field experiments. Results: Leaf extracts reduced the growth of all other species in the growth chamber experiment. Root extracts reduced growth in one invasive grass and promoted root growth in the savanna tree. The invasive grass and riparian forest tree were negatively affected when planted in soil where L. aurea had grown, whereas the savanna tree showed increased growth. Lepidaploa aurea litter reduced growth in one invasive grass species and increased root biomass accumulation in the native grass species. Conclusions: Lepidaploa aurea negatively affected the growth of invasive grasses, through plant extracts, litter and through soil. These patterns could explain its ability to colonise abandoned pasturelands and its high success of establishing in restoration areas.

Community-based native seed production for restoration in Brazil - the role of science and policy

Large-scale restoration programmes in the tropics require large volumes of high quality, genetically diverse and locally adapted seeds from a large number of species. However, scarcity of native seeds is a critical restriction to achieve restoration targets. In this paper, we analyse three successful community-based networks that supply native seeds and seedlings for Brazilian Amazon and Cerrado restoration projects. In addition, we propose directions to promote local participation, legal, technical and commercialisation issues for up-scaling the market of native seeds for restoration with high quality and social justice. We argue that effective community-based restoration arrangements should follow some principles: (i) seed production must be based on real market demand; (ii) non-governmental and governmental organisations have a key role in supporting local organisation, legal requirements and selling processes; (iii) local ecological knowledge and labour should be valued, enabling local communities to promote large-scale seed production; (iv) applied research can help develop appropriate techniques and solve technical issues. The case studies from Brazil and principles presented here can be useful for the up-scaling restoration ecology efforts in many other parts of the world and especially in tropical countries where improving rural community income is a strategy for biodiversity conservation and restoration.

New perspectives in fire management in South American savannas: The importance of intercultural governance

Wildfires continue to cause damage to property, livelihoods and environments around the world. Acknowledging that dealing with wildfires has to go beyond fire-fighting, governments in countries with fire-prone ecosystems have begun to recognize the multiple perspectives of landscape burning and the need to engage with local communities and their practices. In this perspective, we outline the experiences of Brazil and Venezuela, two countries where fire management has been highly contested, but where there have been recent advances in fire management approaches. Success of these new initiatives have been measured by the reduction in wildfire extent through prescribed burning, and the opening of a dialogue on fire management between government agencies and local communities. Yet, it is clear that further developments in community participation need to take place in order to avoid the appropriation of local knowledge systems by institutions, and to better reflect more equitable fire governance.

Evidence of phytotoxicity in a fast-growing shrub useful for savanna restoration in Central Brazil

Finding fast-growing native species able to interfere in invasive grass species’ growth is essential to restore savannas and grasslands, where native tree growth is rather limited. We tested the phytotoxicity of Lepidaploa aurea (Mart. ex DC.) H.Rob. (Asteraceae), a native shrub from the Brazilian savanna that apparently inhibits the growth of invasive grasses in degraded areas and in areas under restoration process. We performed experiments in Petri dishes and soil conditions using four receiver species: three eudicots: Lactuca sativa L., Raphanus sativus L., Solanum lycopersicum L. and a monocot: Sorghum bicolor L. Moench. These are model species commonly used in phytotoxic studies for their known germination rates and high sensitivity to allelochemicals. We tested the effects of aqueous extracts of L. aurea’s leaves and roots, in four concentrations (10, 5, 2.5, 1.25%) and a control (distilled water). We performed tests in natural versus sterilized soils to identify the influence of soil microbiota in L. aurea’s phytotoxicity. We found phytotoxic effects in all tested conditions. Leaf extracts had more accentuated negative effects on target plants than did root extracts. The growth of receiver plants’ root was more affected than shoot growth. Lepidaploa aurea can be an important ally for the restoration of degraded areas savannas and grasslands. Studies considering species that co-occur with L. aurea in conserved and disturbed are as are necessary to confirm this allelopathic potential.