Influence of Edge Effect on the Dynamics of the Tree Community and on the Carbon Stock of Aboveground Biomass in a Dense Ombrophilous Forest
Name: ALAN CALDEIRA DE OLIVEIRA
Publication date: 27/02/2026
Examining board:
Name |
Role |
|---|---|
| HENRIQUE MACHADO DIAS | Presidente |
| JEHOVA LOURENÇO JÚNIOR | Examinador Externo |
| VICTOR BRAGA RODRIGUES DUARTE | Examinador Externo |
Summary: Lowland tropical forests play a critical role in maintaining the global ecological balance through carbon sequestration and storage in biomass. However, the fragmentation of these ecosystems creates interfaces with anthropic matrices and intensifies edge effects, driving microclimatic and biotic alterations that influence the composition, structure, and dynamics of the remaining vegetation. Against this backdrop, this study aimed to evaluate tree community demographic dynamics and structural variations to understand forest resilience to anthropic disturbances, as well as to quantify the potential of aboveground biomass carbon storage in a patch of tableland forest. The research was conducted at the Córrego Grande Biological Reserve (RBCG), located in northern Espírito Santo State, Brazil. Monitoring encompassed 36 permanent plots (0.9 ha in total) distributed along transition edges adjacent to eucalyptus silviculture, an unpaved road, and within the core area of the conservation unit, spanning a seven-year interval (2017–2024). The study measured, tagged, and identified all individuals with a diameter at breast height (DBH, 1.30 m) 2.5 cm. The research also recalculated phytosociological parameters and evaluated the diversity and horizontal structure of the vegetation. The work analyzed plant community dynamics through demographic rates, and the diameter distribution allowed for observing changes in the horizontal structure over time. The study also estimated aboveground biomass and carbon stocks using Brown’s (1997) allometric equation for moist tropical forests and the carbon fraction conversion factor proposed by Martin et al. (2018). Indicator species were identified for each environment, and a redundancy analysis was performed to verify the association between environmental variables and community structure. The results indicated the record of 2,632 individuals distributed across 367 morphotypes, with diversity remaining high (H' = 4.87 to 4.93) and stability in Pielou’s evenness (J' = 0.84). Demographic variations occurred as a function of the surrounding matrices: the road edge acted as a vector of instability with the highest annual mortality (2.63%), while the core area recorded higher recruitment (3.60%). The eucalyptus edge exhibited greater demographic stability and a net gain in aboveground biomass. The average carbon stock in the RBCG was 111.06 Mg C ha-1, showing a marked spatial heterogeneity where the increment at the edges did not compensate for the biomass reduction in the core area, which resulted from the treefall of large-statured individuals. The plant community is undergoing demographic rejuvenation, with a massive influx of young individuals occupying structural gaps. The study concludes that the integrity of the plant community depends on integrated landscape management and the use of forested matrices as buffer zones. The preservation of large-statured individuals and the continuous monitoring of aboveground biomass fluxes are crucial to ensuring the functionality of the remnant against climate change.
Keywords: forest fragmentation; demographic rates; ecosystem services; ecological resilience; tabuleiro forest.
