Influence of different tree species on autotrophic and heterotrophic
soil respiration in a mined area under reclamation
Planting trees is one of the most effective activities in recovering
soil organic carbon (SOC) stocks of degraded areas, but we still lack
information on how different tree species can influence soil
respiration, one of the main sources of dioxide carbon (CO2) to the
atmosphere. This study aimed to explore the influence of different
forest species on the autotrophic and heterotrophic components of the
total soil respiration in a bauxite mining area under reclamation. We
analysed the soil CO2 efflux under five treatments: i) monoculture of
clonal Eucalyptus; ii) monoculture of Anadenanthera peregrina (L.); iii)
a mixed plantation of 16 native forest species (Nat); iv) a mined area
without vegetation cover; and v) a natural forest cover. This design
allowed exploring the soil CO2 dynamics in a gradient of recovery, from
a degraded area to natural vegetation. Additionally, we measured soil
temperature, moisture and soil characteristics. Soil CO2 efflux
increased with increasing forest species cover in the rainy months.
There was no significant change in CO2 efflux among the tree species.
Heterotrophic soil respiration contributed to 64% of total soil CO2
efflux and was associated with litter decomposition. Amongst the abiotic
variables, increases in soil moisture had the most influence on CO2
efflux. Therefore, these results help to understand the factors that
underpin the loss of SOC and can orient management practices to improve
soil organic matter and restore soil quality in degraded areas.