Impacts of Land-use Change on Carbon Stocks and Dynamics in Central-southern South American Biomes: Cerrado, Atlantic Forest and Southern Grasslands - Soil Carbon: Science, Management and Policy for Multiple Benefits - page 251

oxidation and denitrification) in the Cerra-
do and related those to physical and chem-
ical soil attributes. A significantly higher
impact was caused by preharvest burning,
and a high correlation was found between
the microbial metagenomic data and attri-
butes such as soil bulk density and water-
filled pore spaces.

carbon and nitrogen stocks, Maquère et al .
(2008) found that significant SCSs increased
with Eucalyptus spp. under short-rotation
management (approximately 25%), while
SCSs in the continuous forest plantation in-
creased by 15%, both compared with soils
under native vegetation.
The impacts of Eucalyptus spp. on
SCSs varies according to land-use history,
previous crop management, local climate
and spatial variability of soil attributes. The
available data show that good silvicultural
management practices (reduced tillage, resi-
due maintenance over the soil and espe-
cially consortia with nitrogen-fixing tree
species) improve the C sequestration rates
under Eucalyptus spp. afforestation (Baliei-
ro et al ., 2002, 2008; Forrester et al ., 2006;
Chaer and Totola, 2007; Coelho et al ., 2007;
Laclau et al ., 2008). The positive effect of
including legume trees in the eucalyptus
management system was demonstrated by
Balieiro et al . (2008), who showed that 5 years
after the afforestation of pasture fields in a
sandy soil of the Atlantic Forest biome, a
mixed plantation of Eucalyptus grandis and
Pseudosamanea guachapele (a legume tree
native to Central America) resulted in an in-
crease of 6.6 Mg C ha - 1 in the soil C stocks
(0-40 cm), in comparison with single plant-
ations of E. grandis . However, no differences
in C stocks were observed between soils
under pasture (24.24 Mg C ha -1 ) and mixed
plantation (23.83 Mg C ha -1 ). On the other
hand, a study developed by Voigtlaender et al .
(2012) with mixed and pure plantations of
Acacia mangium and E. grandis in the Cerrado
environment demonstrated that mixed plant-
ations largely increased the turnover rate of
nitrogen (N) in the topsoil (124 kg N ha - 1
year - 1 for mixed versus 64 kg N ha - 1 year - 1 for
pure eucalyptus stands), despite a 44% re-
duction in soil C stocks. They conclude that
introducing A. mangium trees might im-
prove mineral N availability in soils where
commercial eucalyptus plantations have
been managed for a long time.
The introduction of nitrogen-fixing trees
has also been used as a strategy of land rec-
lamation in Brazil. Significant levels (0-60 cm:
88.1 Mg C ha -1 ) and rates (1.73 Mg C ha - 1 year -1 )
of soil C storage have been shown to

Forest Plantations and Impacts on
Carbon Stocks and Dynamics

Eucalyptus and pine forests are the most
important sources of wood, cellulose and
charcoal for industry worldwide; thus, af-
forestation with these species is expand-
ing significantly all over the world. Plant-
ed forests account for an estimated 7% of
the total forest area of the world (FAO,
2010). Between 1980 and 2005, global an-
nual industrial wood production increased
from 1450 to 1710 million m 3 year - 1 , while
that for energy production increased from
1530 to 1840 million m 3 year - 1 (FAO, 2008).
In Brazil, Eucalyptus and Pinus spp. for-
ests occupied about 6.51 Mha in 2011,
with 75% covered by eucalyptus alone
(ABRAF, 2012).
In the Cerrados, especially in degraded
pastures, several authors observed a posi-
tive effect of Eucalyptus spp. afforestation
on soil organic carbon stocks. For example,
during the aggrading period, Lima et al .
(2006) observed carbon fixation rates of up
to 0.57 Mg C ha - 1 year - 1 . These values are
similar to those found in Cerrado oxisol
soils (0-20 cm) under annual no-till crops
(Sá et al ., 2001; Bayer et al ., 2006; Cerri et al .,
2007). Higher rates of carbon sequestration
were found by Corazza et al . (1999) in soils
under eucalyptus plantations (1.22 Mg C ha - 1
year -1 ), as well as under no-till systems
(1.43 Mg C ha - 1 year -1 ) in Cerrado sites of
the Distrito Federal, in Brazil.
Forest stand management can influence
SCSs significantly. Studying the impacts of
different land uses (savannah, pasture and
Eucalyptus spp. plantations) and manage-
ment ( 60 years under short rotation versus
60 years under continuous growth) on soil