AGRICULTURAL EXTENSION IN AGROFORESTRY ANDEMPOWERMENT OF RURAL COMMUNITIES, INSOUTHEASTERN BRAZIL

N° ISBN - 978-2-7380-1284-5International audienceThis paper aims to promote the dissemination of agroforestry systems in southeastern Brazil, through techniques of innovative extension in order to stimulate small family farmer in the transition from traditional agriculture towards agroecology, based on agroforestry systems that insure the increase of product diversity and income, associated to ecological sustainability. The project is based on participatory methodologies, such as diagnosis, reflection, discussion and training of social pacts. The project is being developed in rural settlements around the National Forest of Ipanema in Iperó/SP, Brazil. . Of the total of 150 families, about 40 participated in the project. Six young people were selected from the community to act as multiplier monitors. Exchange visits allowed them to share real experiences with rural farmers and to observe community organization and production in agroforestry. From a participatory diagnosis, farmers cited the species they would like to plant. Since only exotic species were cited in the diagnosis, the project prepared an illustrative material with native species. Planning workshops were held where farmers laid down the species and combinations that they would like to deploy. Thereafter, the demonstration units were deployed in the monitors' areas with exotic agricultural species and native species of medium and long cycle. It is believed that the project objectives have been achieved because, currently, several new voluntary initiatives to diversify production and deploy agroforestry are seen

Axial sampling height outperforms site as predictor of wood trait variation

Covariation amongst wood traits along the stem axis is important to maintain hydraulic integrity ensuring sufficient sap flow to the canopy. Here, we test how wood traits (co)vary along the trunk and whether two seasonally dry Brazilian habitats (cerrado and caatinga) influence this variation in two co-occurring species, Tocoyena formosa (Rubiaceae) and Tabebuia aurea (Bignoniaceae). The samples were collected at five heights along the main trunk of three individuals per species in both sites. We used light, scanning and transmission electron microscopy to observe the wood traits. Out of 13 wood traits, nine show relationships with sampling height: eight traits predict height in T. formosa and five in T. aurea. Contrastingly, only three traits show differences between sites and only for T. formosa. The intratrunk wood variation is reflected by the hydraulically weighted vessel diameter showing a curvilinear relationship, disagreeing with the prediction of a continuous vessel widening from tip to base. In both species, the largest vessels are linked to the thinnest intervessel pit membranes. Wood density increases basipetally for both species, being site-dependent and correlated with vessel traits in T. formosa, and site-independent and determined by fiber wall thickness in T. aurea. Furthermore, the functional role of rays was found to be different for each species, and may be related to the marked difference in ray composition. In conclusion, both species show a unique adaptation to deal with height-related constraints using species-specific co-variation amongst wood traits, while site does not contribute much to the wood variation402191S3CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNo206433/2014-02015/14954-1We thank CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil [Proc. No206433/2014-0)] for granting L. C. Dória, and Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil (FAPESP, Proc. 2015/14954-1) for the financial support to C.R. Marcati. We also thank Liliane C. Pereira, R. Langelaan, and W. Star for technical assistance in the laboratory. We acknowledge José Roberto Lima, Maria do Ceo Rodrigues Pessoa Barros, and Aparecido Bessa Ramon for the support during the field collection. We also thank Prof. Dr. Pieter Baas and an anonymous reviewer for their valuable comment

Site and plant community parameters drive the effect of vegetation on litterfall and nutrient inputs in restored tropical forests

Background and aimsRestoring healthy ecosystem depends on recovering not only biodiversity, but also ecosystem processes and functionality. We investigated the effects of tree community parameters and site abiotic conditions on nutrient cycling in restored forests.MethodsWe assessed litter production and nutrient inputs in five 16-year old restored forests established using different restoration methods and species combinations, i.e. unplanted control (natural regeneration), direct seeding, agroforestry, mixed commercial species plantation (commercial mix), and high-diversity plantation, replicated at two sites that differed in soil fertility. We used adjacent seasonal semideciduous forest remnants as references.ResultsRestoration treatments with intermediate and high species richness had higher litter and nutrient inputs and did not differ from the reference forest. In the more fertile site, litter and nutrient inputs increased across different treatments with increasing stand density, whereas in the low fertility site, litter and nutrient inputs in the different treatments increased with increasing tree species richness and the proportion of putative nitrogen-fixing tree species.ConclusionsRestoration treatments, even those with low species richness, but with a relatively high proportion of trees with nitrogen-fixing capability might be effective in restoring nutrient cycles in lower fertility soils, whereas in the more fertile soils it is possible to increase nutrient inputs by establishing restoration treatments at high stem densities. Our results suggest that the magnitude of relationships among plant community parameters and nutrient cycling depends strongly on site conditions