Banca de DEFESA: ANDRES OLAYA MONTES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: ANDRES OLAYA MONTES
DATA: 30/06/2026
HORA: 14:00
LOCAL: Online
TÍTULO:

PALAVRAS-CHAVES:

Soil multifunctionality, Ecosystem services, Land-use change, Agroforestry, Biochar, Tropical soils, Ecological restoration, Colombian Amazon, Andean coffee systems, Nature-based solutions.

PÁGINAS: 130
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Ciência do Solo
ESPECIALIDADE: Fertilidade do Solo e Adubação
RESUMO:

Land-use change in tropical regions has acted as one of the main drivers of functional soil reconfiguration, frequently resulting in structural degradation, nutrient depletion, and the loss of vertical ecological connectivity. Within this context, the first study assessed the multifunctionality of soil ecosystem services (SES) along a land-use gradient in the Colombian Amazon, comprising Primary Forest (FOR), Traditional Pasture (PAS), and Cocoa-based Agroforestry Systems (AFS). The second study extended this restorative approach to Andean coffee systems, evaluating coffee-wood-derived biochar as a regenerative amendment under factorial designs. Together, both studies offer a complementary understanding of soil restoration across tropical lowland and montane landscapes. Along the Amazonian gradient, 22 physical, chemical, and biological indicators were integrated into seven ecosystem services assessed down to a depth of 100 cm. Forest-to-pasture conversion induced systemic functional collapse, characterized by compaction, reduced microbial biomass, nutrient depletion, and diminished deep-soil carbon stabilization. Although pastures maintained surface erosion control and some climate regulation in the 0–10 cm layer, these services declined sharply below 30 cm, revealing a shallow and transient functionality.
In contrast, cocoa-based agroforestry systems acted as a functional bridge between conservation and production. At cumulative depths of 0–50 and 0–100 cm, the AFS significantly increased fertility, acidity buffering, and climate regulation, in some cases surpassing the forest in chemical services. This pattern suggests a “fertility pump” effect associated with root complementarity and diversified organic matter inputs. Despite the superiority of the forest in structural stability and hydrological regulation, agroforestry re-established vertical connectivity and strengthened biogeochemical synergies.
In the Andean coffee system, strongly acidic and structurally limited soils were subjected to two factorial experiments using biologically activated biochar (2.5, 5.0, and 10.0 t ha⁻¹), combining reduced fertilization and application methods. Biochar application raised the cation exchange capacity, reduced exchangeable acidity, improved aggregate stability, and increased functional porosity. Moreover, under a 25% reduction in fertilization, biochar-amended plots exhibited higher productivity, indicating an increase in nutrient-use efficiency. Carbon stabilization in mineral-associated fractions and the increase in microbial biomass evidenced biological reactivation.
Convergently, both studies demonstrate that the restoration of multifunctionality depends on the integration of structural and biogeochemical processes throughout the soil profile. Agroforestry re-establishes deep connectivity in extensive systems, whereas biochar strengthens chemical regulation and structural resilience in intensive systems.
Thus, tree diversification and biomass recycling constitute Nature-based Solutions capable of restoring soil natural capital and sustaining agricultural productivity and ecosystem services in tropical landscapes.

MEMBROS DA BANCA:
Externo à Instituição - RAFAEL DA SILVA TEIXEIRA - UFV (Suplente)
Interno - MARCO AURELIO CARBONE CARNEIRO (Membro)
Presidente - LEONIDAS CARRIJO AZEVEDO MELO (Membro)
Externo à Instituição - LEIDIVAN ALMEIDA FRAZÃO - UFMG (Membro)
Externo à Instituição - GERMÁN ANDRÉS ESTRADA BONILLA - ESALQ (Membro)
Externo à Instituição - FAUSTO ANDRÉS ORTIZ-MOREA - UDLA (Suplente)
Interno - CARLOS ALBERTO SILVA (Membro)