Effect of the distribution pattern, density, and diversity of native trees in silvopastoral system in the Amazon biome

• Grant number: 24/07657-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date until: September 01, 2024
• End date until: August 31, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Adibe Luiz Abdalla
• Grantee: Vagner Ovani da Silva
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 21/10573-4 - Center for Carbon Research in Tropical Agriculture (CCARBON), AP.CEPID

Abstract

Silvopastoral Systems (SPS) represent a sustainable approach that integrates ruminants, grasses, shrubs, and trees to mimic forest ecosystems, thereby enhancing carbon capture, ecosystem services, and animal welfare, while promoting sustainable meat/milk production. Additionally, incorporating trees/shrubs into grass-based systems offers nutritional benefits, reduces costs, and manipulates rumen fermentation to decrease CH4 emissions, contributing to sustainable ruminant production by reducing dependency on chemical fertilizers. Numerous benefits have been documented regarding the adoption of SPS for rehabilitating degraded pastures in Brazil, with a significant use of exotic species in the arboreal component. Considering Brazil's vast biological diversity, marked by the presence of six biomes recognized for their exceptional ecological resilience, including in low-fertility soils, the introduction of native species emerges as a promising perspective for SPS. The fundamental purpose of this study is to thoroughly evaluate the benefits and challenges associated with integrating native tree species into SPS implemented through natural regeneration processes in the Amazon biome, focusing on three key variables: distribution pattern (dispersed or aggregated), density (with four gradients of tree cover), and tree diversity. The research will be conducted on a rural property located in the municipality of Nova Guarita, Mato Grosso state, comprising 120 plots dedicated to SPS for beef cattle production. The study will be subdivided into two distinct phases. In the initial phase, the plots will be meticulously categorized according to the distribution pattern and tree density, employing georeferenced images obtained through drones. Subsequently, 60 plots will be selected for botanical identification of all present trees. The second phase will entail a comprehensive assessment of the soil's chemical, physical, and biological attributes, carbon sequestration, along with measurements of CO2, CH4, and N2O emissions, analysis of forage biomass production and morphological composition, evaluation of forage nutritive value and arboreal resources with forage potential, determination of the proportion of consumption of C3 and C4 photosynthetic cycle plants, and estimation of dry matter consumption and CH4 emissions by grazing animals. It is expected that this investigation will provide a detailed understanding of the benefits and constraints associated with distribution, density, and tree diversity patterns concerning forage, soil, and animal-related parameters, aiming to establish precise guidelines for implementing SPS involving native tree species. Through these actions, significant contributions are aimed towards advancing technological knowledge to promote the development and dissemination of native tree use in SPS within the Brazilian context.