Carbon stock and uptake in the high-elevation tropical montane forests of the threatened Atlantic Forest hotspot: Ecosystem function and effects of elevation variation

• Published in: The Science of the total environment Vol. 882; p. 163503
• Main Authors: Souza, Cléber R., Mariano, Ravi Fernandes, Maia, Vinícius Andrade, Pompeu, Patrícia Vieira, Santos, Rubens Manoel dos, Fontes, Marco Aurélio Leite
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-07-2023
• Subjects: Altitudinal quotes; Biomass; Carbon; Carbon Sequestration; Carbon storage; Cloud tropical forests; Ecosystem; Evergreen forests; Forests; Soil; Trees; Tropical Climate; Wood; Evergreen forests; Cloud tropical forests; Carbon storage; Altitudinal quotes
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.163503

Tropical montane forests (TMF) of the threatened Atlantic Forest hotspot play an important role in providing essential ecosystem services associated with hydrological regime and biodiversity conservation. However, important ecological patterns such as those related to the woody carbon biogeochemical cycle are not yet known for these forests, especially those located at high elevations (> 1500 m. a.s.l.). Herein, we used a dataset of 60 plots (2.4 ha) of old-growth TMF sampled along a high-elevation gradient (1500–2100 m a.s.l.) and monitored in two inventories (2011 and 2016) to better understand the patterns of carbon stock and uptake of these high-elevation forests and the related environmental (soil) and elevation controls. We found differences in the carbon stock along different elevation levels (120.36–170.4C.ton.ha−1) and a carbon accumulation trend over the period along the entire gradient. Thus, forest carbon gain (3.82–5.14 ton.ha.year−1) was greater than the carbon loss (2.1–3.4 ton.ha.year−1) and resulted in a positive productivity net. In other words, the TMF acted as a carbon sink, removing carbon from the atmosphere and storing it in woody tissues. Soil variables also exert significant influences on carbon stock and uptake (significative effects of phosphorus on carbon stock and of cation exchange capacity on carbon loss), driving such patterns in isolation or in interaction with elevation. Considering the high conservation degree of the TMF monitored, our results may be indicative of a similar trend in other similar forests, but which have gone through disturbances in the more recent past. These TMF fragments have a wide occurrence in the Atlantic Forest hotspot and may also be acting or will soon act as carbon sinks in improved conservation scenarios. Thus, these forests can play an essential role in conserving ecosystem services in the region and in mitigating climate changes.
[Display omitted]
•We explore patterns of carbon processes of montane forests in Atlantic Forest hotspot.•High-elevation forests in the region are acting as carbon sinks.•Elevation and soil have important effects on patterns of carbon stock and uptake.•This ecological trend can be extended to other less conserved fragments of the region.•Montane forests can play an essential role in the conservation of ecosystem services.